Add dynamic dock menu with "Now Playing" section

Inspired pretty heavily by iTunes.

Cartfile

@@ -2,3 +2,5 @@ github "SwiftyJSON/SwiftyJSON" ~> 4.0
 github "PromiseKit/Foundation" ~> 3.0
 github "nhurden/MediaKeyTap"
 github "krzyzanowskim/CryptoSwift"
+github "ReSwift/ReSwift" "mjarvis/swift-5.0"
+github "tonyarnold/Differ"

Cartfile.resolved

@@ -1,5 +1,7 @@
 github "PromiseKit/Foundation" "3.3.2"
-github "SwiftyJSON/SwiftyJSON" "4.2.0"
+github "ReSwift/ReSwift" "bc5943ad9493fc7fbad5200f690be538db8e86fb"
+github "SwiftyJSON/SwiftyJSON" "4.3.0"
 github "krzyzanowskim/CryptoSwift" "1.0.0"
 github "mxcl/PromiseKit" "6.8.4"
 github "nhurden/MediaKeyTap" "2.2.1"
+github "tonyarnold/Differ" "1.4.2"

Persephone.xcodeproj/project.pbxproj

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@@ -31,38 +28,28 @@
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 		E4F6B467221E233200ACF42A /* AlbumDataSource.swift in Sources */ = {isa = PBXBuildFile; fileRef = E4F6B466221E233200ACF42A /* AlbumDataSource.swift */; };
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@@ -132,6 +141,24 @@
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 		E408D3BD220E03EE0006D9BE /* RawRepresentable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RawRepresentable.swift; sourceTree = "<group>"; };
 		E408D3C1220E134F0006D9BE /* AlbumViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumViewController.swift; sourceTree = "<group>"; };
 		E408D3C9220E341D0006D9BE /* AlbumViewItem.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = AlbumViewItem.xib; sourceTree = "<group>"; };
-		E40F41F2221EDE27004B6CB8 /* Preferences.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Preferences.swift; sourceTree = "<group>"; };
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 		E419E2862249B96600216A8C /* Song.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Song.swift; sourceTree = "<group>"; };
 		E41B22BF21FB6BBA00D544F6 /* libmpdclient.2.dylib */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = libmpdclient.2.dylib; path = libmpdclient/output/libmpdclient.2.dylib; sourceTree = "<group>"; };
@@ -201,9 +227,9 @@
 		E41E5306223C019100173814 /* MPDClient+Status.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MPDClient+Status.swift"; sourceTree = "<group>"; };
 		E41E5308223C020400173814 /* MPDClient+Command.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MPDClient+Command.swift"; sourceTree = "<group>"; };
 		E41E530A223C033700173814 /* MPDClient+Album.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MPDClient+Album.swift"; sourceTree = "<group>"; };
-		E41E530D223EF4CF00173814 /* AlbumArtService+Caching.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AlbumArtService+Caching.swift"; sourceTree = "<group>"; };
+		E41E530D223EF4CF00173814 /* CoverArtService+Caching.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CoverArtService+Caching.swift"; sourceTree = "<group>"; };
-		E41E530F223EF6CE00173814 /* AlbumArtService+Remote.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AlbumArtService+Remote.swift"; sourceTree = "<group>"; };
+		E41E530F223EF6CE00173814 /* CoverArtService+Remote.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CoverArtService+Remote.swift"; sourceTree = "<group>"; };
-		E41E5311223EF74A00173814 /* AlbumArtService+Filesystem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AlbumArtService+Filesystem.swift"; sourceTree = "<group>"; };
+		E41E5311223EF74A00173814 /* CoverArtService+Filesystem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CoverArtService+Filesystem.swift"; sourceTree = "<group>"; };
 		E41EA46B221636AF0068EF46 /* GeneralPrefsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GeneralPrefsViewController.swift; sourceTree = "<group>"; };
 		E421ACA1221F73B8008B2449 /* MediaKeyTap.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = MediaKeyTap.framework; path = Carthage/Build/Mac/MediaKeyTap.framework; sourceTree = "<group>"; };
 		E42410B52241B956005ED6DF /* MPDClient+Database.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "MPDClient+Database.swift"; sourceTree = "<group>"; };
@@ -212,12 +238,13 @@
 		E435E3E1221CD4E200184CFC /* NSFont.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NSFont.swift; sourceTree = "<group>"; };
 		E435E3E3221CD75D00184CFC /* NSImage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NSImage.swift; sourceTree = "<group>"; };
 		E439109722640213002982E9 /* SongNotifierService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SongNotifierService.swift; sourceTree = "<group>"; };
+		E4405191227644340090CD6F /* MPDServerController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDServerController.swift; sourceTree = "<group>"; };
 		E450AD7D222620A10091BED3 /* Album.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Album.swift; sourceTree = "<group>"; };
 		E450AD8522262AE60091BED3 /* SwiftyJSON.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SwiftyJSON.framework; path = Carthage/Build/Mac/SwiftyJSON.framework; sourceTree = "<group>"; };
 		E450AD8C22262C590091BED3 /* PromiseKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PromiseKit.framework; path = Carthage/Build/Mac/PromiseKit.framework; sourceTree = "<group>"; };
 		E450AD8E22262C620091BED3 /* PromiseKit.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = PromiseKit.framework.dSYM; path = Carthage/Build/Mac/PromiseKit.framework.dSYM; sourceTree = "<group>"; };
 		E450AD9022262C780091BED3 /* SwiftyJSON.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = SwiftyJSON.framework.dSYM; path = Carthage/Build/Mac/SwiftyJSON.framework.dSYM; sourceTree = "<group>"; };
-		E450AD9422262DF10091BED3 /* AlbumArtQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumArtQueue.swift; sourceTree = "<group>"; };
+		E450AD9422262DF10091BED3 /* CoverArtQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoverArtQueue.swift; sourceTree = "<group>"; };
 		E450AD96222633920091BED3 /* Alamofire.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = Alamofire.framework.dSYM; path = Carthage/Build/Mac/Alamofire.framework.dSYM; sourceTree = "<group>"; };
 		E450AD97222633920091BED3 /* Alamofire.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Alamofire.framework; path = Carthage/Build/Mac/Alamofire.framework; sourceTree = "<group>"; };
 		E450AD9E2229B9BC0091BED3 /* PersephoneBridgingHeader.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = PersephoneBridgingHeader.h; sourceTree = "<group>"; };
@@ -239,9 +266,29 @@
 		E47E2FE42220AA0700F747E6 /* AlbumViewLayout.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AlbumViewLayout.swift; sourceTree = "<group>"; };
 		E4928E0A2218D62A001D4BEA /* CGColor.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CGColor.swift; sourceTree = "<group>"; };
 		E4A642D922090CBE00067D21 /* MPDStatus.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDStatus.swift; sourceTree = "<group>"; };
-		E4A83BEE2221F8CF0098FED6 /* AlbumArtPrefsController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumArtPrefsController.swift; sourceTree = "<group>"; };
+		E4A83BEE2221F8CF0098FED6 /* CoverArtPrefsController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoverArtPrefsController.swift; sourceTree = "<group>"; };
 		E4A83BF02221FAA00098FED6 /* PreferencesViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesViewController.swift; sourceTree = "<group>"; };
-		E4A83BF3222207D50098FED6 /* AlbumArtService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumArtService.swift; sourceTree = "<group>"; };
+		E4A83BF3222207D50098FED6 /* CoverArtService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoverArtService.swift; sourceTree = "<group>"; };
+		E4B11B52226928F20075461B /* AppState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppState.swift; sourceTree = "<group>"; };
+		E4B11B572269296C0075461B /* ReSwift.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = ReSwift.framework; path = Carthage/Build/Mac/ReSwift.framework; sourceTree = "<group>"; };
+		E4B11B582269296C0075461B /* ReSwift.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = ReSwift.framework.dSYM; path = Carthage/Build/Mac/ReSwift.framework.dSYM; sourceTree = "<group>"; };
+		E4B11B60226A4BFF0075461B /* PlayerReducer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlayerReducer.swift; sourceTree = "<group>"; };
+		E4B11B62226A4C510075461B /* AppReducer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppReducer.swift; sourceTree = "<group>"; };
+		E4B11B65226A4F830075461B /* PlayerState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlayerState.swift; sourceTree = "<group>"; };
+		E4B11B67226A4FA00075461B /* QueueState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueState.swift; sourceTree = "<group>"; };
+		E4B11B69226A4FBC0075461B /* AlbumListState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumListState.swift; sourceTree = "<group>"; };
+		E4B11B72226A6C770075461B /* TrackTimer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TrackTimer.swift; sourceTree = "<group>"; };
+		E4B11B74226CC4D30075461B /* QueueReducer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueReducer.swift; sourceTree = "<group>"; };
+		E4B11B78226D346B0075461B /* AlbumListReducer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumListReducer.swift; sourceTree = "<group>"; };
+		E4B11B7C2274E36D0075461B /* Differ.framework.dSYM */ = {isa = PBXFileReference; lastKnownFileType = wrapper.dsym; name = Differ.framework.dSYM; path = Carthage/Build/Mac/Differ.framework.dSYM; sourceTree = "<group>"; };
+		E4B11B7D2274E36D0075461B /* Differ.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Differ.framework; path = Carthage/Build/Mac/Differ.framework; sourceTree = "<group>"; };
+		E4B11BA82274EDE30075461B /* Loading.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Loading.swift; sourceTree = "<group>"; };
+		E4B11BAF2274F71A0075461B /* EnumEquatable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EnumEquatable.swift; sourceTree = "<group>"; };
+		E4B11BB52275374B0075461B /* UserNotificationsController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UserNotificationsController.swift; sourceTree = "<group>"; };
+		E4B11BB7227538FA0075461B /* CurrentCoverArtView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CurrentCoverArtView.swift; sourceTree = "<group>"; };
+		E4B11BBD2275EDAA0075461B /* PlayerActions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PlayerActions.swift; sourceTree = "<group>"; };
+		E4B11BBF2275EE150075461B /* QueueActions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueActions.swift; sourceTree = "<group>"; };
+		E4B11BC12275EE410075461B /* AlbumListActions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumListActions.swift; sourceTree = "<group>"; };
 		E4C8B53B22342005009A20F3 /* PreferencesWindowController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesWindowController.swift; sourceTree = "<group>"; };
 		E4C8B53D22349002009A20F3 /* MPDIdle.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDIdle.swift; sourceTree = "<group>"; };
 		E4E8CC8F2204EC7F0024217A /* Delegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Delegate.swift; sourceTree = "<group>"; };
@@ -253,6 +300,10 @@
 		E4F6B45F221E119B00ACF42A /* QueueDataSource.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueDataSource.swift; sourceTree = "<group>"; };
 		E4F6B462221E125900ACF42A /* QueueItem.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = QueueItem.swift; sourceTree = "<group>"; };
 		E4F6B466221E233200ACF42A /* AlbumDataSource.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlbumDataSource.swift; sourceTree = "<group>"; };
+		E4FF718D2276010E00D4C412 /* PreferencesState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesState.swift; sourceTree = "<group>"; };
+		E4FF718F227601B400D4C412 /* PreferencesReducer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesReducer.swift; sourceTree = "<group>"; };
+		E4FF71912276029000D4C412 /* PreferencesActions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesActions.swift; sourceTree = "<group>"; };
+		E4FF71932276043A00D4C412 /* MPDServer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MPDServer.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -260,13 +311,14 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				E45E4FE122516953004B537F /* CryptoSwift.framework in Frameworks */,
+				E4B11BA72274E4500075461B /* libmpdclient.2.dylib in Frameworks */,
-				E41B22C021FB6BBA00D544F6 /* libmpdclient.2.dylib in Frameworks */,
+				E4B11B9A2274E43B0075461B /* CryptoSwift.framework in Frameworks */,
-				E421ACA3221F73C4008B2449 /* MediaKeyTap.framework in Frameworks */,
+				E4B11B962274E43B0075461B /* Differ.framework in Frameworks */,
-				E450AD8622262AE60091BED3 /* SwiftyJSON.framework in Frameworks */,
+				E4B11BA02274E43B0075461B /* SwiftyJSON.framework in Frameworks */,
-				E45E4FE0225168DA004B537F /* CryptoSwift.framework in Frameworks */,
+				E4B11B9E2274E43B0075461B /* PromiseKit.framework in Frameworks */,
-				E450ADA32229E7E00091BED3 /* PMKFoundation.framework in Frameworks */,
+				E4B11B9C2274E43B0075461B /* PMKFoundation.framework in Frameworks */,
-				E450AD9222262C970091BED3 /* PromiseKit.framework in Frameworks */,
+				E4B11BA22274E43B0075461B /* MediaKeyTap.framework in Frameworks */,
+				E4B11B982274E43B0075461B /* ReSwift.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -316,6 +368,7 @@
 		E407861A2110CE6E006887B1 /* Persephone */ = {
 			isa = PBXGroup;
 			children = (
+				E4B11BAE2274F7030075461B /* Protocols */,
 				E407861B2110CE6E006887B1 /* AppDelegate.swift */,
 				E407861F2110CE70006887B1 /* Assets.xcassets */,
 				E4D1B597220BA3A20026F233 /* Controllers */,
@@ -332,6 +385,7 @@
 				E4A83BEC2221F5DD0098FED6 /* Preferences */,
 				E4D1B598220BA3C90026F233 /* Resources */,
 				E4A83BF2222207BE0098FED6 /* Services */,
+				E4B11B64226A4F460075461B /* State */,
 				E408D3C3220E138B0006D9BE /* Views */,
 			);
 			path = Persephone;
@@ -390,6 +444,7 @@
 			children = (
 				E47E2FD62220720300F747E6 /* AlbumItemView.swift */,
 				E47E2FD222205D2500F747E6 /* MainWindow.swift */,
+				E4B11BB7227538FA0075461B /* CurrentCoverArtView.swift */,
 			);
 			path = Views;
 			sourceTree = "<group>";
@@ -397,6 +452,10 @@
 		E41B22BE21FB6B3300D544F6 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
+				E4B11B7D2274E36D0075461B /* Differ.framework */,
+				E4B11B7C2274E36D0075461B /* Differ.framework.dSYM */,
+				E4B11B572269296C0075461B /* ReSwift.framework */,
+				E4B11B582269296C0075461B /* ReSwift.framework.dSYM */,
 				E45E4FDE225168DA004B537F /* CryptoSwift.framework */,
 				E45E4FDD225168DA004B537F /* CryptoSwift.framework.dSYM */,
 				E450ADA02229E7C90091BED3 /* PMKFoundation.framework */,
@@ -468,9 +527,9 @@
 		E41E530C223EF4BA00173814 /* Extensions */ = {
 			isa = PBXGroup;
 			children = (
-				E41E530D223EF4CF00173814 /* AlbumArtService+Caching.swift */,
+				E41E530D223EF4CF00173814 /* CoverArtService+Caching.swift */,
-				E41E5311223EF74A00173814 /* AlbumArtService+Filesystem.swift */,
+				E41E5311223EF74A00173814 /* CoverArtService+Filesystem.swift */,
-				E41E530F223EF6CE00173814 /* AlbumArtService+Remote.swift */,
+				E41E530F223EF6CE00173814 /* CoverArtService+Remote.swift */,
 			);
 			path = Extensions;
 			sourceTree = "<group>";
@@ -478,7 +537,7 @@
 		E450AD8922262B420091BED3 /* Operations */ = {
 			isa = PBXGroup;
 			children = (
-				E450AD9422262DF10091BED3 /* AlbumArtQueue.swift */,
+				E450AD9422262DF10091BED3 /* CoverArtQueue.swift */,
 			);
 			path = Operations;
 			sourceTree = "<group>";
@@ -513,7 +572,7 @@
 		E4A83BED2221F5E60098FED6 /* Controllers */ = {
 			isa = PBXGroup;
 			children = (
-				E4A83BEE2221F8CF0098FED6 /* AlbumArtPrefsController.swift */,
+				E4A83BEE2221F8CF0098FED6 /* CoverArtPrefsController.swift */,
 				E41EA46B221636AF0068EF46 /* GeneralPrefsViewController.swift */,
 				E4A83BF02221FAA00098FED6 /* PreferencesViewController.swift */,
 				E4C8B53B22342005009A20F3 /* PreferencesWindowController.swift */,
@@ -524,13 +583,58 @@
 		E4A83BF2222207BE0098FED6 /* Services */ = {
 			isa = PBXGroup;
 			children = (
-				E4A83BF3222207D50098FED6 /* AlbumArtService.swift */,
+				E4A83BF3222207D50098FED6 /* CoverArtService.swift */,
 				E439109722640213002982E9 /* SongNotifierService.swift */,
 				E41E530C223EF4BA00173814 /* Extensions */,
 			);
 			path = Services;
 			sourceTree = "<group>";
 		};
+		E4B11B5F226A4BED0075461B /* Reducers */ = {
+			isa = PBXGroup;
+			children = (
+				E4B11B60226A4BFF0075461B /* PlayerReducer.swift */,
+				E4B11B62226A4C510075461B /* AppReducer.swift */,
+				E4B11B74226CC4D30075461B /* QueueReducer.swift */,
+				E4B11B78226D346B0075461B /* AlbumListReducer.swift */,
+				E4FF718F227601B400D4C412 /* PreferencesReducer.swift */,
+			);
+			path = Reducers;
+			sourceTree = "<group>";
+		};
+		E4B11B64226A4F460075461B /* State */ = {
+			isa = PBXGroup;
+			children = (
+				E4B11B6B226A5AF50075461B /* Actions */,
+				E4B11B5F226A4BED0075461B /* Reducers */,
+				E4B11B52226928F20075461B /* AppState.swift */,
+				E4B11B65226A4F830075461B /* PlayerState.swift */,
+				E4B11B67226A4FA00075461B /* QueueState.swift */,
+				E4B11B69226A4FBC0075461B /* AlbumListState.swift */,
+				E4FF718D2276010E00D4C412 /* PreferencesState.swift */,
+			);
+			path = State;
+			sourceTree = "<group>";
+		};
+		E4B11B6B226A5AF50075461B /* Actions */ = {
+			isa = PBXGroup;
+			children = (
+				E4B11BC12275EE410075461B /* AlbumListActions.swift */,
+				E4B11BBD2275EDAA0075461B /* PlayerActions.swift */,
+				E4B11BBF2275EE150075461B /* QueueActions.swift */,
+				E4FF71912276029000D4C412 /* PreferencesActions.swift */,
+			);
+			path = Actions;
+			sourceTree = "<group>";
+		};
+		E4B11BAE2274F7030075461B /* Protocols */ = {
+			isa = PBXGroup;
+			children = (
+				E4B11BAF2274F71A0075461B /* EnumEquatable.swift */,
+			);
+			path = Protocols;
+			sourceTree = "<group>";
+		};
 		E4D1B594220BA2490026F233 /* Models */ = {
 			isa = PBXGroup;
 			children = (
@@ -558,8 +662,10 @@
 				E408D3C1220E134F0006D9BE /* AlbumViewController.swift */,
 				E47E2FD4222071FD00F747E6 /* AlbumViewItem.swift */,
 				E47E2FD022205C4600F747E6 /* MainSplitViewController.swift */,
+				E4405191227644340090CD6F /* MPDServerController.swift */,
 				E4E8CC932206097F0024217A /* NotificationsController.swift */,
 				E4E8CC912204F4B80024217A /* QueueViewController.swift */,
+				E4B11BB52275374B0075461B /* UserNotificationsController.swift */,
 				E465049921E94DF500A70F4C /* WindowController.swift */,
 			);
 			path = Controllers;
@@ -587,10 +693,12 @@
 			isa = PBXGroup;
 			children = (
 				E450AD7D222620A10091BED3 /* Album.swift */,
-				E40F41F2221EDE27004B6CB8 /* Preferences.swift */,
+				E4B11BA82274EDE30075461B /* Loading.swift */,
+				E4FF71932276043A00D4C412 /* MPDServer.swift */,
 				E4F6B462221E125900ACF42A /* QueueItem.swift */,
 				E419E2862249B96600216A8C /* Song.swift */,
 				E47E2FDC2220A6D100F747E6 /* Time.swift */,
+				E4B11B72226A6C770075461B /* TrackTimer.swift */,
 			);
 			path = Models;
 			sourceTree = "<group>";
@@ -606,8 +714,8 @@
 				E40786152110CE6E006887B1 /* Frameworks */,
 				E40786162110CE6E006887B1 /* Resources */,
 				E42A98F122430936004D8180 /* ShellScript */,
-				E41B22C221FB6C3300D544F6 /* Embed Libraries */,
 				E421AC9B221F7319008B2449 /* CopyFiles */,
+				E4B11BA52274E43B0075461B /* Embed Frameworks */,
 			);
 			buildRules = (
 			);
@@ -724,6 +832,8 @@
 				E42A8F3C22176D6400A13ED9 /* README.md in Resources */,
 				E450AD8F22262C620091BED3 /* PromiseKit.framework.dSYM in Resources */,
 				E408D3CB220E341D0006D9BE /* AlbumViewItem.xib in Resources */,
+				E4B11B5A2269296C0075461B /* ReSwift.framework.dSYM in Resources */,
+				E4B11B7E2274E36D0075461B /* Differ.framework.dSYM in Resources */,
 				E40786232110CE70006887B1 /* Main.storyboard in Resources */,
 				E450ADA12229E7C90091BED3 /* PMKFoundation.framework.dSYM in Resources */,
 				E47E2FCC2220573500F747E6 /* MediaKeyTap.framework.dSYM in Resources */,
@@ -771,21 +881,27 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
-				E4A83BEF2221F8CF0098FED6 /* AlbumArtPrefsController.swift in Sources */,
+				E4A83BEF2221F8CF0098FED6 /* CoverArtPrefsController.swift in Sources */,
 				E4F6B467221E233200ACF42A /* AlbumDataSource.swift in Sources */,
+				E4B11BA92274EDE30075461B /* Loading.swift in Sources */,
 				E408D3C2220E134F0006D9BE /* AlbumViewController.swift in Sources */,
 				E40FE71B221B904300A4223F /* NSEvent.swift in Sources */,
+				E4B11BB62275374B0075461B /* UserNotificationsController.swift in Sources */,
+				E4B11B68226A4FA00075461B /* QueueState.swift in Sources */,
 				E4928E0B2218D62A001D4BEA /* CGColor.swift in Sources */,
+				E4405192227644340090CD6F /* MPDServerController.swift in Sources */,
 				E4C8B53E22349002009A20F3 /* MPDIdle.swift in Sources */,
 				E4F6B460221E119B00ACF42A /* QueueDataSource.swift in Sources */,
 				E4C8B53C22342005009A20F3 /* PreferencesWindowController.swift in Sources */,
+				E4B11B63226A4C510075461B /* AppReducer.swift in Sources */,
 				E41E5307223C019100173814 /* MPDClient+Status.swift in Sources */,
-				E41E5310223EF6CE00173814 /* AlbumArtService+Remote.swift in Sources */,
+				E41E5310223EF6CE00173814 /* CoverArtService+Remote.swift in Sources */,
 				E41E530B223C033700173814 /* MPDClient+Album.swift in Sources */,
 				E42410B62241B956005ED6DF /* MPDClient+Database.swift in Sources */,
 				E4A642DA22090CBE00067D21 /* MPDStatus.swift in Sources */,
+				E4B11BC02275EE150075461B /* QueueActions.swift in Sources */,
 				E47E2FD72220720300F747E6 /* AlbumItemView.swift in Sources */,
-				E450AD9522262DF10091BED3 /* AlbumArtQueue.swift in Sources */,
+				E450AD9522262DF10091BED3 /* CoverArtQueue.swift in Sources */,
 				E41E52FD223BF87300173814 /* MPDClient+Connection.swift in Sources */,
 				E450AD7E222620A10091BED3 /* Album.swift in Sources */,
 				E4E8CC942206097F0024217A /* NotificationsController.swift in Sources */,
@@ -793,33 +909,47 @@
 				E45962C62241A78500FC1A1E /* MPDCommand.swift in Sources */,
 				E408D3B9220DE98F0006D9BE /* NSUserInterfaceItemIdentifier.swift in Sources */,
 				E4EB2379220F10B8008C70C0 /* MPDPair.swift in Sources */,
+				E4FF7190227601B400D4C412 /* PreferencesReducer.swift in Sources */,
 				E4F6B463221E125900ACF42A /* QueueItem.swift in Sources */,
 				E4A83BF12221FAA00098FED6 /* PreferencesViewController.swift in Sources */,
+				E4B11BC22275EE410075461B /* AlbumListActions.swift in Sources */,
+				E4B11B61226A4C000075461B /* PlayerReducer.swift in Sources */,
+				E4FF71922276029000D4C412 /* PreferencesActions.swift in Sources */,
 				E465049A21E94DF500A70F4C /* WindowController.swift in Sources */,
 				E41B22C621FB932700D544F6 /* MPDClient.swift in Sources */,
-				E40F41F3221EDE27004B6CB8 /* Preferences.swift in Sources */,
 				E47E2FDD2220A6D100F747E6 /* Time.swift in Sources */,
 				E419E2872249B96600216A8C /* Song.swift in Sources */,
+				E4FF718E2276010E00D4C412 /* PreferencesState.swift in Sources */,
 				E439109822640213002982E9 /* SongNotifierService.swift in Sources */,
 				E407861C2110CE6E006887B1 /* AppDelegate.swift in Sources */,
+				E4B11B75226CC4D30075461B /* QueueReducer.swift in Sources */,
 				E41E5309223C020400173814 /* MPDClient+Command.swift in Sources */,
+				E4B11BB02274F71A0075461B /* EnumEquatable.swift in Sources */,
+				E4B11B73226A6C770075461B /* TrackTimer.swift in Sources */,
+				E4B11B79226D346B0075461B /* AlbumListReducer.swift in Sources */,
 				E47E2FE52220AA0700F747E6 /* AlbumViewLayout.swift in Sources */,
 				E41E52FF223BF95E00173814 /* MPDClient+Transport.swift in Sources */,
 				E47E2FD322205D2500F747E6 /* MainWindow.swift in Sources */,
 				E47E2FD122205C4600F747E6 /* MainSplitViewController.swift in Sources */,
+				E4B11BB8227538FA0075461B /* CurrentCoverArtView.swift in Sources */,
 				E4E8CC9A22075D370024217A /* MPDSong.swift in Sources */,
 				E41EA46C221636AF0068EF46 /* GeneralPrefsViewController.swift in Sources */,
 				E4E8CC902204EC7F0024217A /* Delegate.swift in Sources */,
-				E4A83BF4222207D50098FED6 /* AlbumArtService.swift in Sources */,
+				E4A83BF4222207D50098FED6 /* CoverArtService.swift in Sources */,
 				E47E2FD5222071FD00F747E6 /* AlbumViewItem.swift in Sources */,
 				E408D3BE220E03EE0006D9BE /* RawRepresentable.swift in Sources */,
-				E41E530E223EF4CF00173814 /* AlbumArtService+Caching.swift in Sources */,
+				E4B11B66226A4F830075461B /* PlayerState.swift in Sources */,
+				E4B11BBE2275EDAA0075461B /* PlayerActions.swift in Sources */,
+				E4FF71942276043A00D4C412 /* MPDServer.swift in Sources */,
+				E41E530E223EF4CF00173814 /* CoverArtService+Caching.swift in Sources */,
 				E4E8CC922204F4B80024217A /* QueueViewController.swift in Sources */,
-				E41E5312223EF74A00173814 /* AlbumArtService+Filesystem.swift in Sources */,
+				E41E5312223EF74A00173814 /* CoverArtService+Filesystem.swift in Sources */,
 				E41E5301223BF99300173814 /* MPDClient+Queue.swift in Sources */,
 				E4EB237B220F7CF1008C70C0 /* MPDAlbum.swift in Sources */,
 				E41E5303223BF9C300173814 /* MPDClient+Idle.swift in Sources */,
+				E4B11B53226928F20075461B /* AppState.swift in Sources */,
 				E435E3E4221CD75D00184CFC /* NSImage.swift in Sources */,
+				E4B11B6A226A4FBC0075461B /* AlbumListState.swift in Sources */,
 				E41E5305223BFB0700173814 /* MPDClient+Error.swift in Sources */,
 				E435E3E2221CD4E200184CFC /* NSFont.swift in Sources */,
 			);

Persephone/AppDelegate.swift

@@ -6,52 +6,90 @@
 //  Copyright © 2018 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
+import ReSwift
 import MediaKeyTap
 
 @NSApplicationMain
-class AppDelegate: NSObject, NSApplicationDelegate, MediaKeyTapDelegate {
+class AppDelegate: NSObject,
-  var preferences = Preferences()
+                   NSApplicationDelegate,
+                   MediaKeyTapDelegate {
   var mediaKeyTap: MediaKeyTap?
+  var userNotificationsController = UserNotificationsController()
+  var mpdServerController = MPDServerController()
 
   static let mpdClient = MPDClient(
     withDelegate: NotificationsController()
   )
 
-  func applicationDidFinishLaunching(_ aNotification: Notification) {
+  static let trackTimer = TrackTimer()
-    connect()
 
-    preferences.addObserver(self, forKeyPath: "mpdHost")
+  static let store = Store<AppState>(reducer: appReducer, state: nil)
-    preferences.addObserver(self, forKeyPath: "mpdPort")
+
+  func applicationDidFinishLaunching(_ aNotification: Notification) {
+    mpdServerController.connect()
 
     mediaKeyTap = MediaKeyTap(delegate: self)
     mediaKeyTap?.start()
 
-    NotificationCenter.default.addObserver(
+    AppDelegate.store.subscribe(self) {
-      self,
+      $0.select { $0.playerState }
-      selector: #selector(enableUpdateDatabaseMenuItem),
+    }
-      name: Notification.databaseUpdateFinished,
-      object: AppDelegate.mpdClient
-    )
   }
 
   func applicationWillTerminate(_ aNotification: Notification) {
-    disconnect()
+    mpdServerController.disconnect()
   }
 
-  override func observeValue(
+  func applicationDockMenu(_ sender: NSApplication) -> NSMenu? {
-    forKeyPath keyPath: String?,
+    let dockMenu = NSMenu()
-    of object: Any?,
+    dockMenu.autoenablesItems = false
-    change: [NSKeyValueChangeKey : Any]?,
+
-    context: UnsafeMutableRawPointer?
+    guard let state = AppDelegate.store.state.playerState.state else { return nil }
-  ) {
+
-    switch keyPath {
+    if let currentSong = AppDelegate.store.state.playerState.currentSong,
-    case "mpdHost", "mpdPort":
+      state.isOneOf([.playing, .paused]) {
-      disconnect()
+
-      connect()
+      let nowPlayingItem = NSMenuItem(title: "Now Playing", action: nil, keyEquivalent: "")
-    default:
+      let songItem = NSMenuItem(title: currentSong.title, action: nil, keyEquivalent: "")
-      break
+      let albumItem = NSMenuItem(
+        title: "\(currentSong.artist) — \(currentSong.album.title)",
+        action: nil,
+        keyEquivalent: ""
+      )
+
+      nowPlayingItem.isEnabled = false
+      songItem.indentationLevel = 1
+      songItem.isEnabled = false
+      albumItem.indentationLevel = 1
+      albumItem.isEnabled = false
+
+      dockMenu.addItem(nowPlayingItem)
+      dockMenu.addItem(songItem)
+      dockMenu.addItem(albumItem)
+      dockMenu.addItem(NSMenuItem.separator())
    }
+
+    let playPauseMenuItem = NSMenuItem(
+      title: state == .playing ? "Pause" : "Play",
+      action: #selector(playPauseMenuAction),
+      keyEquivalent: ""
+    )
+    let stopMenuItem = NSMenuItem(title: "Stop", action: #selector(stopMenuAction), keyEquivalent: "")
+    let nextTrackMenuItem = NSMenuItem(title: "Next", action: #selector(nextTrackMenuAction), keyEquivalent: "")
+    let prevTrackMenuItem = NSMenuItem(title: "Previous", action: #selector(prevTrackMenuAction), keyEquivalent: "")
+
+    playPauseMenuItem.isEnabled = state.isOneOf([.playing, .paused, .stopped])
+    stopMenuItem.isEnabled = state.isOneOf([.playing, .paused])
+    nextTrackMenuItem.isEnabled = state.isOneOf([.playing, .paused])
+    prevTrackMenuItem.isEnabled = state.isOneOf([.playing, .paused])
+
+    dockMenu.addItem(playPauseMenuItem)
+    dockMenu.addItem(stopMenuItem)
+    dockMenu.addItem(nextTrackMenuItem)
+    dockMenu.addItem(prevTrackMenuItem)
+
+    return dockMenu
   }
 
   func handle(mediaKey: MediaKey, event: KeyEvent) {
@@ -65,25 +103,50 @@ class AppDelegate: NSObject, NSApplicationDelegate, MediaKeyTapDelegate {
     }
   }
 
-  func connect() {
+//  func setDockTransportControlState(_ state: MPDClient.MPDStatus.State) {
-    AppDelegate.mpdClient.connect(
+//    playPauseMenuItem.isEnabled = state.isOneOf([.playing, .paused, .stopped])
-      host: preferences.mpdHostOrDefault,
+//    stopMenuItem.isEnabled = state.isOneOf([.playing, .paused])
-      port: preferences.mpdPortOrDefault
+//    nextTrackMenuItem.isEnabled = state.isOneOf([.playing, .paused])
-    )
+//    prevTrackMenuItem.isEnabled = state.isOneOf([.playing, .paused])
-  }
+//
-
+//    if state.isOneOf([.paused, .stopped, .unknown]) {
-  func disconnect() {
+//      playPauseMenuItem.title = "Play"
-    AppDelegate.mpdClient.disconnect()
+//    } else {
-  }
+//      playPauseMenuItem.title = "Pause"
-
+//    }
-  @IBAction func updateDatabase(_ sender: NSMenuItem) {
+//  }
-    sender.isEnabled = false
-    AppDelegate.mpdClient.updateDatabase()
-  }
 
   @objc func enableUpdateDatabaseMenuItem() {
     updateDatabaseMenuItem?.isEnabled = true
   }
 
+  @IBAction func updateDatabase(_ sender: NSMenuItem) {
+    AppDelegate.mpdClient.updateDatabase()
+  }
+
+  @IBAction func playPauseMenuAction(_ sender: NSMenuItem) {
+    AppDelegate.mpdClient.playPause()
+  }
+  @IBAction func stopMenuAction(_ sender: NSMenuItem) {
+    AppDelegate.mpdClient.stop()
+  }
+  @IBAction func nextTrackMenuAction(_ sender: NSMenuItem) {
+    AppDelegate.mpdClient.nextTrack()
+  }
+  @IBAction func prevTrackMenuAction(_ sender: Any) {
+    AppDelegate.mpdClient.prevTrack()
+  }
+
   @IBOutlet weak var updateDatabaseMenuItem: NSMenuItem!
 }
+
+extension AppDelegate: StoreSubscriber {
+  typealias StoreSubscriberStateType = PlayerState
+
+  func newState(state: PlayerState) {
+    updateDatabaseMenuItem.isEnabled = !state.databaseUpdating
+
+    guard let state = state.state else { return }
+    // setDockTransportControlState(state)
+  }
+}

Persephone/Controllers/AlbumViewController.swift

@@ -6,13 +6,13 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
+import ReSwift
+import Differ
 
 class AlbumViewController: NSViewController,
                            NSCollectionViewDelegate,
                            NSCollectionViewDelegateFlowLayout {
-  var preferences = Preferences()
-
   let paddingWidth: CGFloat = 40
   let gutterWidth: CGFloat = 20
 
@@ -21,26 +21,13 @@ class AlbumViewController: NSViewController,
   override func viewDidLoad() {
     super.viewDidLoad()
 
+    AppDelegate.store.subscribe(self) {
+      $0.select { $0.albumListState }
+    }
+
     albumScrollView.postsBoundsChangedNotifications = true
 
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(updateAlbums(_:)),
-      name: Notification.loadedAlbums,
-      object: AppDelegate.mpdClient
-    )
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(clearAlbums(_:)),
-      name: Notification.willDisconnect,
-      object: AppDelegate.mpdClient
-    )
-
     albumCollectionView.dataSource = dataSource
-
-    preferences.addObserver(self, forKeyPath: "mpdLibraryDir")
-    preferences.addObserver(self, forKeyPath: "fetchMissingArtworkFromInternet")
   }
 
   override func viewWillLayout() {
@@ -72,27 +59,25 @@ class AlbumViewController: NSViewController,
     case "mpdLibraryDir":
       albumCollectionView.reloadData()
     case "fetchMissingArtworkFromInternet":
-      dataSource.resetCoverArt()
+      AppDelegate.store.dispatch(ResetAlbumListCoverArtAction())
-      albumCollectionView.reloadData()
     default:
       break
     }
   }
 
-  @objc func updateAlbums(_ notification: Notification) {
-    guard let albums = notification.userInfo?[Notification.albumsKey] as? [MPDClient.MPDAlbum]
-      else { return }
-
-    dataSource.albums = albums.map { Album(mpdAlbum: $0) }
-    albumCollectionView.reloadData()
-  }
-
-  @objc func clearAlbums(_ notification: Notification) {
-    dataSource.albums = []
-
-    albumCollectionView.reloadData()
-  }
-
   @IBOutlet var albumScrollView: NSScrollView!
   @IBOutlet var albumCollectionView: NSCollectionView!
 }
+
+extension AlbumViewController: StoreSubscriber {
+  typealias StoreSubscriberStateType = AlbumListState
+
+  func newState(state: StoreSubscriberStateType) {
+    let oldAlbums = dataSource.albums
+    dataSource.albums = state.albums
+    albumCollectionView.animateItemChanges(
+      oldData: oldAlbums,
+      newData: dataSource.albums
+    )
+  }
+}

Persephone/Controllers/AlbumViewItem.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class AlbumViewItem: NSCollectionViewItem {
   var observer: NSKeyValueObservation?
@@ -32,9 +32,10 @@ class AlbumViewItem: NSCollectionViewItem {
     albumTitle.stringValue = album.title
     albumArtist.stringValue = album.artist
 
-    if let coverArt = album.coverArt {
+    switch album.coverArt {
-      albumCoverView.image = coverArt
+    case .loaded(let coverArt):
-    } else {
+      albumCoverView.image = coverArt ?? .defaultCoverArt
+    default:
       albumCoverView.image = .defaultCoverArt
     }
   }

Persephone/Controllers/MPDServerController.swift

@@ -0,0 +1,38 @@
+//
+//  MPDServerController.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import ReSwift
+
+class MPDServerController {
+  init() {
+    AppDelegate.store.subscribe(self) {
+      $0.select { $0.preferencesState.mpdServer }
+    }
+  }
+
+  func connect() {
+    AppDelegate.mpdClient.connect(
+      host: AppDelegate.store.state.preferencesState.mpdServer.hostOrDefault,
+      port: AppDelegate.store.state.preferencesState.mpdServer.portOrDefault
+    )
+  }
+
+  func disconnect() {
+    AppDelegate.mpdClient.disconnect()
+  }
+}
+
+extension MPDServerController: StoreSubscriber {
+  typealias StoreSubscriberStateType = MPDServer
+
+  func newState(state: MPDServer) {
+    disconnect()
+    connect()
+  }
+}

Persephone/Controllers/MainSplitViewController.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class MainSplitViewController: NSSplitViewController {
   override func keyDown(with event: NSEvent) {

Persephone/Controllers/NotificationsController.swift

@@ -1,5 +1,5 @@
 //
-//  MPDClientNotificationHandler.swift
+//  NotificationsController.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/2/02.
@@ -16,53 +16,46 @@ class NotificationsController: MPDClientDelegate {
   }
 
   func willDisconnect(mpdClient: MPDClient) {
+    DispatchQueue.main.async {
+      AppDelegate.store.dispatch(UpdateAlbumListAction(albums: []))
+    }
     sendNotification(name: Notification.willDisconnect)
   }
 
-  func didUpdateState(mpdClient: MPDClient, state: MPDClient.MPDStatus.State) {
+  func didUpdateStatus(mpdClient: MPDClient, status: MPDClient.MPDStatus) {
-    sendNotification(
+    DispatchQueue.main.async {
-      name: Notification.stateChanged,
+      AppDelegate.store.dispatch(UpdateStatusAction(status: status))
-      userInfo: [Notification.stateKey: state]
-    )
     }
-
-  func didUpdateTime(mpdClient: MPDClient, total: UInt, elapsedMs: UInt) {
-    sendNotification(
-      name: Notification.timeChanged,
-      userInfo: [
-        Notification.totalTimeKey: total,
-        Notification.elapsedTimeMsKey: elapsedMs
-      ]
-    )
   }
 
   func willStartDatabaseUpdate(mpdClient: MPDClient) {
-    sendNotification(name: Notification.databaseUpdateStarted)
+    DispatchQueue.main.async {
+      AppDelegate.store.dispatch(StartedDatabaseUpdateAction())
+    }
   }
 
   func didFinishDatabaseUpdate(mpdClient: MPDClient) {
-    sendNotification(name: Notification.databaseUpdateFinished)
+    DispatchQueue.main.async {
+      AppDelegate.store.dispatch(FinishedDatabaseUpdateAction())
+    }
   }
 
   func didUpdateQueue(mpdClient: MPDClient, queue: [MPDClient.MPDSong]) {
-    sendNotification(
+    DispatchQueue.main.async {
-      name: Notification.queueChanged,
+      AppDelegate.store.dispatch(UpdateQueueAction(queue: queue))
-      userInfo: [Notification.queueKey: queue]
+    }
-    )
   }
 
   func didUpdateQueuePos(mpdClient: MPDClient, song: Int) {
-    sendNotification(
+    DispatchQueue.main.async {
-      name: Notification.queuePosChanged,
+      AppDelegate.store.dispatch(UpdateQueuePosAction(queuePos: song))
-      userInfo: [Notification.queuePosKey: song]
+    }
-    )
   }
 
   func didLoadAlbums(mpdClient: MPDClient, albums: [MPDClient.MPDAlbum]) {
-    sendNotification(
+    DispatchQueue.main.async {
-      name: Notification.loadedAlbums,
+      AppDelegate.store.dispatch(UpdateAlbumListAction(albums: albums))
-      userInfo: [Notification.albumsKey: albums]
+    }
-    )
   }
 
   private func sendNotification(name: Notification.Name, userInfo: [AnyHashable : Any] = [:]) {

Persephone/Controllers/QueueViewController.swift

@@ -6,20 +6,22 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
-import PromiseKit
+import ReSwift
 
 class QueueViewController: NSViewController,
                            NSOutlineViewDelegate {
   var dataSource = QueueDataSource()
 
   @IBOutlet var queueView: NSOutlineView!
-  @IBOutlet var queueAlbumArtImage: NSImageView!
+  @IBOutlet var queueCoverArtImage: NSImageView!
 
   override func viewDidLoad() {
     super.viewDidLoad()
 
-    setupNotificationObservers()
+    AppDelegate.store.subscribe(self) {
+      $0.select { $0.queueState }
+    }
 
     queueView.dataSource = dataSource
     queueView.columnAutoresizingStyle = .sequentialColumnAutoresizingStyle
@@ -42,60 +44,6 @@ class QueueViewController: NSViewController,
     }
   }
 
-  @objc func stateChanged(_ notification: Notification) {
-    guard let state = notification.userInfo?[Notification.stateKey] as? MPDClient.MPDStatus.State
-      else { return }
-
-    dataSource.setQueueIcon(state)
-  }
-
-  func notifyTrack() {
-    guard let currentSong = dataSource.currentSong,
-      let status = AppDelegate.mpdClient.status,
-      status.state == .playing
-    else { return }
-
-    SongNotifierService(song: currentSong, image: queueAlbumArtImage.image)
-      .deliver()
-  }
-
-  @objc func queueChanged(_ notification: Notification) {
-    guard let queue = notification.userInfo?[Notification.queueKey] as? [MPDClient.MPDSong]
-      else { return }
-
-    dataSource.updateQueue(queue)
-    queueView.reloadData()
-  }
-
-  @objc func queuePosChanged(_ notification: Notification) {
-    guard let queuePos = notification.userInfo?[Notification.queuePosKey] as? Int
-      else { return }
-
-    dataSource.setQueuePos(queuePos)
-    queueView.reloadData()
-    updateAlbumArt()
-  }
-
-  func updateAlbumArt() {
-    if let playingQueueItem = dataSource.queue.first(where: { $0.isPlaying }) {
-      let albumArtService = AlbumArtService(song: playingQueueItem.song)
-
-      albumArtService.fetchBigAlbumArt()
-        .done() {
-          if let image = $0 {
-            self.queueAlbumArtImage.image = image
-          } else {
-            self.queueAlbumArtImage.image = NSImage.defaultCoverArt
-          }
-
-          self.notifyTrack()
-        }
-        .cauterize()
-    } else {
-      queueAlbumArtImage.image = NSImage.defaultCoverArt
-    }
-  }
-
   func outlineView(
     _ outlineView: NSOutlineView,
     selectionIndexesForProposedSelection proposedSelectionIndexes: IndexSet
@@ -168,27 +116,14 @@ func cellForSongTitle(_ outlineView: NSOutlineView, with queueItem: QueueItem) -
 
     return cellView
   }
+}
 
-  func setupNotificationObservers() {
+extension QueueViewController: StoreSubscriber {
-    NotificationCenter.default.addObserver(
+  typealias StoreSubscriberStateType = QueueState
-      self,
-      selector: #selector(stateChanged(_:)),
-      name: Notification.stateChanged,
-      object: AppDelegate.mpdClient
-    )
 
-    NotificationCenter.default.addObserver(
+  func newState(state: StoreSubscriberStateType) {
-      self,
+    dataSource.queue = state.queue
-      selector: #selector(queueChanged(_:)),
+    dataSource.setQueueIcon(state)
-      name: Notification.queueChanged,
+    queueView.reloadData()
-      object: AppDelegate.mpdClient
-    )
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(queuePosChanged(_:)),
-      name: Notification.queuePosChanged,
-      object: AppDelegate.mpdClient
-    )
   }
 }

Persephone/Controllers/UserNotificationsController.swift

@@ -0,0 +1,42 @@
+//
+//  UserNotificationsController.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/27.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import ReSwift
+
+class UserNotificationsController {
+  init() {
+    AppDelegate.store.subscribe(self) {
+      $0.select { $0.playerState.currentSong }
+    }
+  }
+
+  func notifyTrack(_ state: Song?) {
+    guard let currentSong = state,
+      let status = AppDelegate.mpdClient.status,
+      status.state == .playing
+      else { return }
+
+    let coverArtService = CoverArtService(song: currentSong)
+
+    coverArtService.fetchBigCoverArt()
+      .done() {
+        SongNotifierService(song: currentSong, image: $0)
+          .deliver()
+      }
+      .cauterize()
+  }
+}
+
+extension UserNotificationsController: StoreSubscriber {
+  typealias StoreSubscriberStateType = Song?
+
+  func newState(state: Song?) {
+    notifyTrack(state)
+  }
+}

Persephone/Controllers/WindowController.swift

@@ -6,7 +6,8 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
+import ReSwift
 
 class WindowController: NSWindowController {
   enum TransportAction: Int {
@@ -14,41 +15,16 @@ class WindowController: NSWindowController {
   }
 
   var state: MPDClient.MPDStatus.State?
-  var totalTime: UInt?
-  var elapsedTimeMs: UInt?
   var trackTimer: Timer?
 
   override func windowDidLoad() {
     super.windowDidLoad()
     window?.titleVisibility = .hidden
+    window?.isExcludedFromWindowsMenu = true
 
-    NotificationCenter.default.addObserver(
+    AppDelegate.store.subscribe(self) {
-      self,
+      $0.select { $0.playerState }
-      selector: #selector(stateChanged(_:)),
+    }
-      name: Notification.stateChanged,
-      object: AppDelegate.mpdClient
-    )
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(timeChanged(_:)),
-      name: Notification.timeChanged,
-      object: AppDelegate.mpdClient
-    )
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(startDatabaseUpdatingIndicator),
-      name: Notification.databaseUpdateStarted,
-      object: AppDelegate.mpdClient
-    )
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(stopDatabaseUpdatingIndicator),
-      name: Notification.databaseUpdateFinished,
-      object: AppDelegate.mpdClient
-    )
 
     trackProgress.font = .timerFont
     trackRemaining.font = .timerFont
@@ -63,17 +39,8 @@ class WindowController: NSWindowController {
     }
   }
 
-  @objc func stateChanged(_ notification: Notification) {
+  func setTransportControlState(_ state: PlayerState) {
-    guard let state = notification.userInfo?[Notification.stateKey] as? MPDClient.MPDStatus.State
+    guard let state = state.state else { return }
-      else { return }
-
-    self.state = state
-
-    setTransportControlState()
-  }
-
-  func setTransportControlState() {
-    guard let state = state else { return }
 
     transportControls.setEnabled(state.isOneOf([.playing, .paused]), forSegment: 0)
     transportControls.setEnabled(state.isOneOf([.playing, .paused, .stopped]), forSegment: 1)
@@ -87,74 +54,37 @@ class WindowController: NSWindowController {
     }
   }
 
-  @objc func timeChanged(_ notification: Notification) {
+  func setTrackProgressControls(_ playerState: PlayerState) {
-    guard let totalTime = notification.userInfo?[Notification.totalTimeKey] as? UInt,
+    guard let state = playerState.state,
-      let elapsedTimeMs = notification.userInfo?[Notification.elapsedTimeMsKey] as? UInt
+      let totalTime = playerState.totalTime,
+      let elapsedTimeMs = playerState.elapsedTimeMs
       else { return }
 
-    self.totalTime = totalTime
+    trackProgressBar.isEnabled = state.isOneOf([.playing, .paused])
-    self.elapsedTimeMs = elapsedTimeMs
-
-    setTrackProgressControls()
-  }
-
-  func setTrackProgressControls() {
-    guard let totalTime = totalTime,
-      let elapsedTimeMs = elapsedTimeMs
-      else { return }
-
-    trackProgressBar.isEnabled = [.playing, .paused].contains(state)
     trackProgressBar.maxValue = Double(totalTime * 1000)
-
-    if state == .playing {
-      trackTimer?.invalidate()
-
-      trackTimer = Timer.scheduledTimer(
-        timeInterval: 0.25,
-        target: self,
-        selector: #selector(updateProgress(_:)),
-        userInfo: [
-          "startTime": CACurrentMediaTime(),
-          "startElapsed": Double(elapsedTimeMs) / 1000
-        ],
-        repeats: true
-      )
-    } else {
-      trackTimer?.invalidate()
-
     trackProgressBar.integerValue = Int(elapsedTimeMs)
-      setTimeElapsed()
+
-      setTimeRemaining()
+    setTimeElapsed(elapsedTimeMs)
+    setTimeRemaining(elapsedTimeMs, totalTime * 1000)
+  }
+
+  func setDatabaseUpdatingIndicator(_ playerState: PlayerState) {
+    if playerState.databaseUpdating {
+      startDatabaseUpdatingIndicator()
+    } else {
+      stopDatabaseUpdatingIndicator()
     }
   }
 
-  @objc func updateProgress(_ timer: Timer) {
+  func startDatabaseUpdatingIndicator() {
-    let currentTime = CACurrentMediaTime()
-
-    guard let userInfo = timer.userInfo as? Dictionary<String, Any>,
-      let startTime = userInfo["startTime"] as? Double,
-      let startElapsed = userInfo["startElapsed"] as? Double
-      else { return }
-
-    let timeDiff = currentTime - startTime
-    let newElapsedTimeMs = (startElapsed + timeDiff) * 1000
-
-    self.elapsedTimeMs = UInt(newElapsedTimeMs)
-    trackProgressBar.integerValue = Int(newElapsedTimeMs)
-
-    setTimeElapsed()
-    setTimeRemaining()
-  }
-
-  @objc func startDatabaseUpdatingIndicator() {
     databaseUpdatingIndicator.startAnimation(self)
   }
 
-  @objc func stopDatabaseUpdatingIndicator() {
+  func stopDatabaseUpdatingIndicator() {
     databaseUpdatingIndicator.stopAnimation(self)
   }
 
-  func setTimeElapsed() {
+  func setTimeElapsed(_ elapsedTimeMs: UInt?) {
     guard let elapsedTimeMs = elapsedTimeMs else { return }
 
     let time = Time(timeInSeconds: Int(elapsedTimeMs) / 1000)
@@ -162,30 +92,30 @@ class WindowController: NSWindowController {
     trackProgress.stringValue = time.formattedTime
   }
 
-  func setTimeRemaining() {
+  func setTimeRemaining(_ elapsedTimeMs: UInt?, _ totalTime: UInt?) {
     guard let elapsedTimeMs = elapsedTimeMs,
       let totalTime = totalTime
       else { return }
 
-    let time = Time(timeInSeconds: -(Int(totalTime) - Int(elapsedTimeMs) / 1000))
+    let time = Time(
+      timeInSeconds: -(Int(totalTime) - Int(elapsedTimeMs)) / 1000
+    )
 
     trackRemaining.stringValue = time.formattedTime
   }
 
   // TODO: Refactor this using a gesture recognizer
   @IBAction func changeTrackProgress(_ sender: NSSlider) {
-    guard let event = NSApplication.shared.currentEvent else {
+    guard let event = NSApplication.shared.currentEvent
-      return
+      else { return }
-    }
 
     switch event.type {
     case .leftMouseDown:
       trackTimer?.invalidate()
     case .leftMouseDragged:
-      self.elapsedTimeMs = UInt(sender.integerValue)
+      AppDelegate.store.dispatch(
-
+        UpdateElapsedTimeAction(elapsedTimeMs: UInt(sender.integerValue))
-      setTimeElapsed()
+      )
-      setTimeRemaining()
     case .leftMouseUp:
       let seekTime = Float(sender.integerValue) / 1000
 
@@ -218,3 +148,17 @@ class WindowController: NSWindowController {
   @IBOutlet var trackRemaining: NSTextField!
   @IBOutlet var databaseUpdatingIndicator: NSProgressIndicator!
 }
+
+extension WindowController: StoreSubscriber {
+  typealias StoreSubscriberStateType = PlayerState
+
+  func newState(state: StoreSubscriberStateType) {
+    self.state = state.state
+
+    DispatchQueue.main.async {
+      self.setTransportControlState(state)
+      self.setTrackProgressControls(state)
+      self.setDatabaseUpdatingIndicator(state)
+    }
+  }
+}

Persephone/DataSources/AlbumDataSource.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import PromiseKit
 
 class AlbumDataSource: NSObject, NSCollectionViewDataSource {
@@ -16,14 +16,6 @@ class AlbumDataSource: NSObject, NSCollectionViewDataSource {
     return albums.count
   }
 
-  func resetCoverArt() {
-    albums = albums.map {
-      var album = $0
-      album.coverArtFetched = false
-      return album
-    }
-  }
-
   func collectionView(_ collectionView: NSCollectionView, itemForRepresentedObjectAt indexPath: IndexPath) -> NSCollectionViewItem {
     let item = collectionView.makeItem(withIdentifier: .albumViewItem, for: indexPath)
     guard let albumViewItem = item as? AlbumViewItem else { return item }
@@ -31,23 +23,23 @@ class AlbumDataSource: NSObject, NSCollectionViewDataSource {
     albumViewItem.view.wantsLayer = true
     albumViewItem.setAlbum(albums[indexPath.item])
 
-    if albums[indexPath.item].coverArt == nil &&
+    switch albums[indexPath.item].coverArt {
-      !albums[indexPath.item].coverArtFetched {
+    case .notLoaded:
-
       AppDelegate.mpdClient.getAlbumFirstSong(for: albums[indexPath.item].mpdAlbum) {
         guard let song = $0 else { return }
 
-        AlbumArtService(song: Song(mpdSong: song))
+        CoverArtService(song: Song(mpdSong: song))
-          .fetchAlbumArt()
+          .fetchCoverArt()
           .done { image in
-            self.albums[indexPath.item].coverArt = image
-            self.albums[indexPath.item].coverArtFetched = true
-
             DispatchQueue.main.async {
-              collectionView.reloadItems(at: [indexPath])
+              AppDelegate.store.dispatch(
+                UpdateCoverArtAction(coverArt: image, albumIndex: indexPath.item)
+              )
             }
           }
       }
+    default:
+       break
     }
 
     return albumViewItem

Persephone/DataSources/QueueDataSource.swift

@@ -6,49 +6,17 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class QueueDataSource: NSObject, NSOutlineViewDataSource {
   var queue: [QueueItem] = []
-  var queuePos: Int = -1
-  var currentSong: Song?
-
   var queueIcon: NSImage? = nil
 
-  func updateQueue(_ queue: [MPDClient.MPDSong]) {
+  func setQueueIcon(_ state: QueueState) {
-    queuePos = -1
+    switch state.state {
-    
+    case .playing?:
-    self.queue = queue.enumerated().map { index, mpdSong in
-      let song = Song(mpdSong: mpdSong)
-      return QueueItem(
-        song: song,
-        queuePos: index,
-        isPlaying: index == queuePos
-      )
-    }
-  }
-
-  func setQueuePos(_ queuePos: Int) {
-    let oldSongRowPos = self.queuePos
-    let newSongRowPos = queuePos
-    self.queuePos = queuePos
-
-    if oldSongRowPos >= 0 {
-      queue[oldSongRowPos].isPlaying = false
-    }
-    if newSongRowPos >= 0 {
-      queue[newSongRowPos].isPlaying = true
-      currentSong = queue[newSongRowPos].song
-    } else {
-      currentSong = nil
-    }
-  }
-
-  func setQueueIcon(_ state: MPDClient.MPDStatus.State) {
-    switch state {
-    case .playing:
       queueIcon = .playIcon
-    case .paused:
+    case .paused?:
       queueIcon = .pauseIcon
     default:
       queueIcon = nil

Persephone/Extensions/CGColor.swift

@@ -6,9 +6,9 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 extension CGColor {
-  static let albumBorderColorLight = NSColor.black.withAlphaComponent(0.1).cgColor
+  static let albumBorderColorLight = NSColor.black.withAlphaComponent(0.15).cgColor
-  static let albumBorderColorDark = NSColor.white.withAlphaComponent(0.1).cgColor
+  static let albumBorderColorDark = NSColor.white.withAlphaComponent(0.15).cgColor
 }

Persephone/Extensions/NSEvent.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 extension NSEvent {
   static let keyCodeSpace: UInt16 = 49

Persephone/Extensions/NSFont.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 extension NSFont {
   static let systemFontRegular = systemFont(ofSize: 13, weight: .regular)

Persephone/Extensions/NSImage.swift

@@ -6,13 +6,13 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 extension NSImage {
   static let playIcon = NSImage(named: "playButton")
   static let pauseIcon = NSImage(named: "pauseButton")
 
-  static let defaultCoverArt = NSImage(named: "blankAlbum")
+  static let defaultCoverArt = NSImage(named: "defaultCoverArt")
 
   func toFitBox(size: NSSize) -> NSImage {
     var newSize: NSSize = NSSize.zero

Persephone/Extensions/NSUserInterfaceItemIdentifier.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 extension NSUserInterfaceItemIdentifier {
   static let queueSongTitleColumn = NSUserInterfaceItemIdentifier("songTitleColumn")

Persephone/Info.plist

@@ -17,7 +17,7 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.11.2-alpha</string>
+	<string>0.12.0-pre-alpha</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
 	<key>LSApplicationCategoryType</key>

Persephone/Layouts/AlbumViewLayout.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class AlbumViewLayout: NSCollectionViewFlowLayout {
   let maxItemWidth: CGFloat = 180

Persephone/MPDClient/Extensions/MPDClient+Connection.swift

@@ -29,8 +29,7 @@ extension MPDClient {
       self.idle()
 
       self.delegate?.didConnect(mpdClient: self)
-      self.delegate?.didUpdateState(mpdClient: self, state: self.status!.state)
+      self.delegate?.didUpdateStatus(mpdClient: self, status: self.status!)
-      self.delegate?.didUpdateTime(mpdClient: self, total: self.status!.totalTime, elapsedMs: self.status!.elapsedTimeMs)
       self.delegate?.didUpdateQueue(mpdClient: self, queue: self.queue)
       self.delegate?.didUpdateQueuePos(mpdClient: self, song: self.status!.song)
     }

Persephone/MPDClient/Extensions/MPDClient+Idle.swift

@@ -43,9 +43,8 @@ extension MPDClient {
       self.fetchStatus()
 
       if let status = self.status {
+        self.delegate?.didUpdateStatus(mpdClient: self, status: status)
         self.delegate?.didUpdateQueuePos(mpdClient: self, song: status.song)
-        self.delegate?.didUpdateState(mpdClient: self, state: status.state)
-        self.delegate?.didUpdateTime(mpdClient: self, total: status.totalTime, elapsedMs: status.elapsedTimeMs)
       }
     }
     if mpdIdle.contains(.update) {

Persephone/MPDClient/Protocols/Delegate.swift

@@ -12,8 +12,7 @@ protocol MPDClientDelegate {
   func didConnect(mpdClient: MPDClient)
   func willDisconnect(mpdClient: MPDClient)
 
-  func didUpdateState(mpdClient: MPDClient, state: MPDClient.MPDStatus.State)
+  func didUpdateStatus(mpdClient: MPDClient, status: MPDClient.MPDStatus)
-  func didUpdateTime(mpdClient: MPDClient, total: UInt, elapsedMs: UInt)
 
   func willStartDatabaseUpdate(mpdClient: MPDClient)
   func didFinishDatabaseUpdate(mpdClient: MPDClient)

Persephone/Models/Album.swift

@@ -6,13 +6,12 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import CryptoSwift
 
 struct Album {
   var mpdAlbum: MPDClient.MPDAlbum
-  var coverArt: NSImage?
+  var coverArt: Loading<NSImage?> = .notLoaded
-  var coverArtFetched: Bool = false
 
   init(mpdAlbum: MPDClient.MPDAlbum) {
     self.mpdAlbum = mpdAlbum
@@ -30,3 +29,11 @@ struct Album {
     return "\(title) - \(artist)".sha1()
   }
 }
+
+extension Album: Equatable {
+  static func == (lhs: Album, rhs: Album) -> Bool {
+    return (lhs.artist == rhs.artist) &&
+      (lhs.title == rhs.title) &&
+      (lhs.coverArt ~= rhs.coverArt)
+  }
+}

Persephone/Models/Loading.swift

@@ -0,0 +1,30 @@
+//
+//  Loading.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/27.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+
+enum Loading<T> {
+  case notLoaded
+  case loading
+  case loaded(T)
+  case error(Error)
+}
+
+extension Loading: EnumEquatable {
+  static func ~= (lhs: Loading<T>, rhs: Loading<T>) -> Bool {
+    switch (lhs, rhs) {
+    case (_, .notLoaded),
+         (.loading, .loading),
+         (.loaded, .loaded),
+         (.error, .error):
+      return true
+    default:
+      return false
+    }
+  }
+}

Persephone/Models/MPDServer.swift

@@ -0,0 +1,33 @@
+//
+//  MPDServer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+
+struct MPDServer {
+  let hostDefault = "127.0.0.1"
+  let portDefault = 6600
+
+  var host: String?
+
+  var hostOrDefault: String {
+    return host ?? hostDefault
+  }
+
+  var port: Int?
+
+  var portOrDefault: Int {
+    return port ?? portDefault
+  }
+}
+
+extension MPDServer: Equatable {
+  static func == (lhs: MPDServer, rhs: MPDServer) -> Bool {
+    return (lhs.host == rhs.host) &&
+      (lhs.port == rhs.port)
+  }
+}

Persephone/Models/Preferences.swift

@@ -1,77 +0,0 @@
-//
-//  Preferences.swift
-//  Persephone
-//
-//  Created by Daniel Barber on 2019/2/15.
-//  Copyright © 2019 Dan Barber. All rights reserved.
-//
-
-import Foundation
-
-struct Preferences {
-  let mpdHostDefault = "127.0.0.1"
-  let mpdPortDefault = 6600
-  let mpdLibraryDirDefault = "~/Music"
-
-  let preferences = UserDefaults.standard
-
-  var mpdHost: String? {
-    get {
-      return preferences.string(forKey: "mpdHost")
-    }
-    set {
-      preferences.set(newValue, forKey: "mpdHost")
-    }
-  }
-
-  var mpdHostOrDefault: String {
-    return mpdHost ?? mpdHostDefault
-  }
-
-  var mpdPort: Int? {
-    get {
-      return preferences.value(forKey: "mpdPort") as? Int
-    }
-    set {
-      if (newValue.map { $0 > 0 } ?? false) {
-        preferences.set(newValue, forKey: "mpdPort")
-      } else {
-        preferences.removeObject(forKey: "mpdPort")
-      }
-    }
-  }
-
-  var mpdPortOrDefault: Int {
-    return mpdPort ?? mpdPortDefault
-  }
-
-  var mpdLibraryDir: String? {
-    get {
-      return preferences.string(forKey: "mpdLibraryDir")
-    }
-    set {
-      preferences.set(newValue, forKey: "mpdLibraryDir")
-    }
-  }
-
-  var mpdLibraryDirOrDefault: String {
-    return mpdLibraryDir ?? mpdLibraryDirDefault
-  }
-
-  var expandedMpdLibraryDir: String {
-    return NSString(string: mpdLibraryDirOrDefault).expandingTildeInPath
-  }
-
-  var fetchMissingArtworkFromInternet: Bool {
-    get {
-      return preferences.bool(forKey: "fetchMissingArtworkFromInternet")
-    }
-    set {
-      preferences.set(newValue, forKey: "fetchMissingArtworkFromInternet")
-    }
-  }
-
-  func addObserver(_ observer: NSObject, forKeyPath keyPath: String) {
-    preferences.addObserver(observer, forKeyPath: keyPath, options: .new, context: nil)
-  }
-}

Persephone/Models/QueueItem.swift

@@ -13,3 +13,11 @@ struct QueueItem {
   var queuePos: Int
   var isPlaying: Bool
 }
+
+extension QueueItem: Equatable {
+  static func == (lhs: QueueItem, rhs: QueueItem) -> Bool {
+    return (lhs.song == rhs.song) &&
+      (lhs.queuePos == rhs.queuePos) &&
+      (lhs.isPlaying == rhs.isPlaying)
+  }
+}

Persephone/Models/Song.swift

@@ -23,3 +23,11 @@ struct Song {
     return Album(mpdAlbum: mpdSong.album)
   }
 }
+
+extension Song: Equatable {
+  static func == (lhs: Song, rhs: Song) -> Bool {
+    return (lhs.title == rhs.title) &&
+      (lhs.artist == rhs.artist) &&
+      (lhs.album == rhs.album)
+  }
+}

Persephone/Models/TrackTimer.swift

@@ -0,0 +1,52 @@
+//
+//  TrackTimer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+
+class TrackTimer: NSObject {
+  var timer: Timer?
+  var startTime: CFTimeInterval = CACurrentMediaTime()
+  var startElapsed: Double = 0
+
+  func start(elapsedTimeMs: UInt?) {
+    guard let elapsedTimeMs = elapsedTimeMs else { return }
+
+    startTime = CACurrentMediaTime()
+    startElapsed = Double(elapsedTimeMs) / 1000
+
+    DispatchQueue.main.async {
+      self.timer?.invalidate()
+
+      self.timer = Timer.scheduledTimer(
+        withTimeInterval: 0.25,
+        repeats: true
+      ) { _ in
+        let currentTime = CACurrentMediaTime()
+
+        let timeDiff = currentTime - self.startTime
+        let newElapsedTimeMs = UInt((self.startElapsed + timeDiff) * 1000)
+
+        AppDelegate.store.dispatch(
+          UpdateElapsedTimeAction(elapsedTimeMs: newElapsedTimeMs)
+        )
+      }
+    }
+  }
+
+  func stop(elapsedTimeMs: UInt?) {
+    guard let elapsedTimeMs = elapsedTimeMs else { return }
+
+    DispatchQueue.main.async {
+      self.timer?.invalidate()
+
+      AppDelegate.store.dispatch(
+        UpdateElapsedTimeAction(elapsedTimeMs: elapsedTimeMs)
+      )
+    }
+  }
+}

Persephone/Operations/CoverArtQueue.swift

@@ -1,17 +1,17 @@
 //
-//  AlbumArtOperationQueue.swift
+//  CoverArtQueue.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/2/26.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
-class AlbumArtQueue {
+class CoverArtQueue {
-  static let shared = AlbumArtQueue()
+  static let shared = CoverArtQueue()
 
-  let queue = DispatchQueue(label: "AlbumArtQueue")
+  let queue = DispatchQueue(label: "CoverArtQueue")
   var lastDispatchedTime = DispatchTime(uptimeNanoseconds: 0) - 1
 
   func addToQueue(workItem: DispatchWorkItem) {

Persephone/Preferences/Controllers/CoverArtPrefsController.swift

@@ -1,24 +1,22 @@
 //
-//  AlbumArtPrefsController.swift
+//  CoverArtPrefsController.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/2/23.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
-
-class AlbumArtPrefsController: NSViewController {
-  var preferences = Preferences()
 
+class CoverArtPrefsController: NSViewController {
   override func viewDidLoad() {
     super.viewDidLoad()
 
-    if let mpdLibraryDir = preferences.mpdLibraryDir {
+    if let mpdLibraryDir = AppDelegate.store.state.preferencesState.mpdLibraryDir {
       mpdLibraryDirField.stringValue = mpdLibraryDir
     }
 
-    if preferences.fetchMissingArtworkFromInternet {
+    if AppDelegate.store.state.preferencesState.fetchMissingArtworkFromInternet {
       fetchMissingArtworkFromInternet.state = .on
     } else {
       fetchMissingArtworkFromInternet.state = .off
@@ -36,17 +34,17 @@ class AlbumArtPrefsController: NSViewController {
   }
 
   @IBAction func updateMpdLibraryDir(_ sender: NSTextField) {
-    preferences.mpdLibraryDir = sender.stringValue
+    AppDelegate.store.dispatch(UpdateMPDLibraryDir(mpdLibraryDir: sender.stringValue))
   }
 
   @IBOutlet var mpdLibraryDirField: NSTextField!
 
   @IBAction func updateFetchMissingArtworkFromInternet(_ sender: NSButton) {
-    if sender.state == .on {
+    AppDelegate.store.dispatch(
-      preferences.fetchMissingArtworkFromInternet = true
+      UpdateFetchMissingArtworkFromInternet(
-    } else {
+        fetchMissingArtworkFromInternet: sender.state == .on
-      preferences.fetchMissingArtworkFromInternet = false
+      )
-    }
+    )
   }
 
   @IBOutlet var fetchMissingArtworkFromInternet: NSButton!

Persephone/Preferences/Controllers/GeneralPrefsViewController.swift

@@ -6,19 +6,19 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
+import ReSwift
 
 class GeneralPrefsViewController: NSViewController {
-  var preferences = Preferences()
-
   override func viewDidLoad() {
     super.viewDidLoad()
 
-    if let mpdHost = preferences.mpdHost {
+    if let mpdHost = AppDelegate.store.state.preferencesState.mpdServer.host {
       mpdHostField.stringValue = mpdHost
     }
 
-    if let mpdPort = preferences.mpdPort {
+    if let mpdPort = AppDelegate.store.state.preferencesState.mpdServer.port {
+      print(mpdPort)
       mpdPortField.stringValue = "\(mpdPort)"
     }
 
@@ -34,11 +34,11 @@ class GeneralPrefsViewController: NSViewController {
   }
 
   @IBAction func updateMpdHost(_ sender: NSTextField) {
-    preferences.mpdHost = sender.stringValue
+    AppDelegate.store.dispatch(UpdateServerHost(host: sender.stringValue))
   }
 
   @IBAction func updateMpdPort(_ sender: NSTextField) {
-    preferences.mpdPort = sender.integerValue
+    AppDelegate.store.dispatch(UpdateServerPort(port: sender.integerValue))
   }
 
   @IBOutlet var mpdHostField: NSTextField!

Persephone/Preferences/Controllers/PreferencesViewController.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class PreferencesViewController: NSTabViewController {
   private lazy var tabViewSizes: [String : NSSize] = [:]

Persephone/Preferences/Controllers/PreferencesWindowController.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class PreferencesWindowController: NSWindowController, NSWindowDelegate {
   override func windowDidLoad() {
@@ -14,6 +14,7 @@ class PreferencesWindowController: NSWindowController, NSWindowDelegate {
   }
 
   func windowShouldClose(_ sender: NSWindow) -> Bool {
+    AppDelegate.store.dispatch(SavePreferences())
     self.window?.orderOut(sender)
     return false
   }

Persephone/Protocols/EnumEquatable.swift

@@ -0,0 +1,11 @@
+//
+//  EnumEquatable.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/27.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+protocol EnumEquatable {
+  static func ~=(lhs: Self, rhs: Self) -> Bool
+}

Persephone/Resources/AlbumViewItem.xib

@@ -39,7 +39,7 @@
                 </textField>
                 <imageView identifier="albumArtwork" horizontalHuggingPriority="251" verticalHuggingPriority="251" horizontalCompressionResistancePriority="250" verticalCompressionResistancePriority="250" translatesAutoresizingMaskIntoConstraints="NO" id="Kfb-8f-ean">
                     <rect key="frame" x="0.0" y="39" width="128" height="128"/>
-                    <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" image="blankAlbum" id="FsA-JX-BFh"/>
+                    <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" image="defaultCoverArt" id="FsA-JX-BFh"/>
                 </imageView>
                 <button hidden="YES" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="n8W-do-HyG">
                     <rect key="frame" x="43" y="81" width="42" height="43"/>
@@ -79,7 +79,7 @@
         <collectionViewItem id="Qgu-aI-55A" customClass="AlbumViewItem" customModule="Persephone" customModuleProvider="target"/>
     </objects>
     <resources>
-        <image name="blankAlbum" width="128" height="128"/>
+        <image name="defaultCoverArt" width="128" height="128"/>
         <image name="playButtonLarge" width="22" height="22"/>
     </resources>
 </document>

Persephone/Resources/Base.lproj/Main.storyboard

@@ -3,7 +3,6 @@
     <dependencies>
         <deployment identifier="macosx"/>
         <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="14490.70"/>
-        <capability name="System colors introduced in macOS 10.14" minToolsVersion="10.0"/>
         <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <scenes>
@@ -91,6 +90,8 @@
                                                 <action selector="performZoom:" target="Ady-hI-5gd" id="DIl-cC-cCs"/>
                                             </connections>
                                         </menuItem>
+                                        <menuItem isSeparatorItem="YES" id="QhP-iz-rRa"/>
+                                        <menuItem title="Persephone" state="on" keyEquivalent="0" id="1Sq-L7-znT"/>
                                         <menuItem isSeparatorItem="YES" id="eu3-7i-yIM"/>
                                         <menuItem title="Bring All to Front" id="LE2-aR-0XJ">
                                             <modifierMask key="keyEquivalentModifierMask"/>
@@ -127,13 +128,13 @@
                 <customObject id="YLy-65-1bz" customClass="NSFontManager"/>
                 <customObject id="Ady-hI-5gd" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="115" y="-366"/>
+            <point key="canvasLocation" x="81" y="-332"/>
         </scene>
         <!--Window Controller-->
         <scene sceneID="R2V-B0-nI4">
             <objects>
                 <windowController id="B8D-0N-5wS" customClass="WindowController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
-                    <window key="window" title="Window" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" animationBehavior="default" id="IQv-IB-iLA" customClass="MainWindow" customModule="Persephone" customModuleProvider="target">
+                    <window key="window" title="Persephone" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" animationBehavior="default" id="IQv-IB-iLA" customClass="MainWindow" customModule="Persephone" customModuleProvider="target">
                         <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
                         <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
                         <rect key="contentRect" x="207" y="570" width="960" height="560"/>
@@ -289,7 +290,7 @@
                 <tabViewController title="General" selectedTabViewItemIndex="0" tabStyle="toolbar" id="zhe-qh-Mal" customClass="PreferencesViewController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
                     <tabViewItems>
                         <tabViewItem label="General" identifier="generalPreferencesTab" image="NSPreferencesGeneral" id="kn0-fa-vM3"/>
-                        <tabViewItem label="Album Art" identifier="albumArtPreferencesTab" image="coverArtPreferencesIcon" id="4Lj-dz-bOK"/>
+                        <tabViewItem label="Cover Art" identifier="coverArtPreferencesTab" image="coverArtPreferencesIcon" id="4Lj-dz-bOK"/>
                     </tabViewItems>
                     <viewControllerTransitionOptions key="transitionOptions" allowUserInteraction="YES"/>
                     <tabView key="tabView" type="noTabsNoBorder" id="6dC-M0-oC5">
@@ -310,10 +311,10 @@
             </objects>
             <point key="canvasLocation" x="916" y="236"/>
         </scene>
-        <!--Album Art-->
+        <!--Cover Art-->
         <scene sceneID="pQx-0G-WVt">
             <objects>
-                <viewController title="Album Art" id="3C9-vU-zjZ" customClass="AlbumArtPrefsController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
+                <viewController title="Cover Art" id="3C9-vU-zjZ" userLabel="Cover Art" customClass="CoverArtPrefsController" customModule="Persephone" customModuleProvider="target" sceneMemberID="viewController">
                     <view key="view" id="PyK-v2-kus">
                         <rect key="frame" x="0.0" y="0.0" width="524" height="168"/>
                         <autoresizingMask key="autoresizingMask"/>
@@ -527,7 +528,7 @@
                                                                     </constraints>
                                                                     <textFieldCell key="cell" lineBreakMode="truncatingTail" sendsActionOnEndEditing="YES" title="QUEUE" id="Mqf-uh-ibl">
                                                                         <font key="font" metaFont="smallSystemBold"/>
-                                                                        <color key="textColor" name="controlAccentColor" catalog="System" colorSpace="catalog"/>
+                                                                        <color key="textColor" name="secondaryLabelColor" catalog="System" colorSpace="catalog"/>
                                                                         <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
                                                                     </textFieldCell>
                                                                 </textField>
@@ -635,9 +636,9 @@
                                 <rect key="frame" x="0.0" y="220" width="328" height="328"/>
                                 <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
                                 <subviews>
-                                    <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" horizontalCompressionResistancePriority="250" verticalCompressionResistancePriority="250" translatesAutoresizingMaskIntoConstraints="NO" id="Dw3-M5-tWY">
+                                    <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" horizontalCompressionResistancePriority="250" verticalCompressionResistancePriority="250" translatesAutoresizingMaskIntoConstraints="NO" id="Dw3-M5-tWY" customClass="CurrentCoverArtView" customModule="Persephone" customModuleProvider="target">
                                         <rect key="frame" x="0.0" y="0.0" width="328" height="328"/>
-                                        <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" image="blankAlbum" id="IoN-3N-TCb"/>
+                                        <imageCell key="cell" refusesFirstResponder="YES" alignment="left" imageScaling="proportionallyUpOrDown" image="defaultCoverArt" id="IoN-3N-TCb"/>
                                     </imageView>
                                 </subviews>
                                 <constraints>
@@ -658,7 +659,7 @@
                         </holdingPriorities>
                     </splitView>
                     <connections>
-                        <outlet property="queueAlbumArtImage" destination="Dw3-M5-tWY" id="3hQ-Gu-XqM"/>
+                        <outlet property="queueCoverArtImage" destination="Dw3-M5-tWY" id="3hQ-Gu-XqM"/>
                         <outlet property="queueView" destination="jEJ-jg-fll" id="cwo-E8-deo"/>
                     </connections>
                 </viewController>
@@ -720,8 +721,8 @@
     </scenes>
     <resources>
         <image name="NSPreferencesGeneral" width="32" height="32"/>
-        <image name="blankAlbum" width="128" height="128"/>
         <image name="coverArtPreferencesIcon" width="32" height="32"/>
+        <image name="defaultCoverArt" width="128" height="128"/>
         <image name="nextTrackButton" width="17" height="17"/>
         <image name="playButton" width="17" height="17"/>
         <image name="prevTrackButton" width="17" height="17"/>

Persephone/Services/CoverArtService.swift

@@ -1,16 +1,15 @@
 //
-//  AlbumArtService.swift
+//  CoverArtService.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/2/23.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import PromiseKit
 
-class AlbumArtService {
+class CoverArtService {
-  var preferences = Preferences()
   let song: Song
   let album: Album
 
@@ -20,14 +19,14 @@ class AlbumArtService {
   let bigArtworkSize = 600
 
   var session = URLSession(configuration: .default)
-  let artworkQueue = DispatchQueue(label: "albumArtQueue", qos: .utility)
+  let coverArtQueue = DispatchQueue(label: "coverArtQueue", qos: .utility)
 
   init(song: Song) {
     self.song = song
     self.album = song.album
   }
 
-  func fetchBigAlbumArt() -> Promise<NSImage?> {
+  func fetchBigCoverArt() -> Promise<NSImage?> {
     return firstly {
       self.getArtworkFromFilesystem()
     }.then { (image: NSImage?) -> Promise<NSImage?> in
@@ -37,14 +36,14 @@ class AlbumArtService {
     }
   }
 
-  func fetchAlbumArt() -> Guarantee<NSImage?> {
+  func fetchCoverArt() -> Guarantee<NSImage?> {
     return firstly {
       self.getCachedArtwork()
     }.then { (artwork: NSImage?) -> Promise<NSImage?> in
       artwork.map(Promise.value) ?? self.getArtworkFromFilesystem()
     }.then { (artwork: NSImage?) -> Promise<NSImage?> in
       artwork.map(Promise.value) ?? self.getRemoteArtwork()
-    }.compactMap(on: artworkQueue) {
+    }.compactMap(on: coverArtQueue) {
       return self.sizeAndCacheImage($0).map(Optional.some)
     }.recover { _ in
       return .value(nil)

Persephone/Services/Extensions/CoverArtService+Caching.swift

@@ -1,22 +1,22 @@
 //
-//  AlbumArtService+Caching.swift
+//  CoverArtService+Caching.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/3/17.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import PromiseKit
 
-extension AlbumArtService {
+extension CoverArtService {
   static let cacheDir = try! FileManager.default.url(for: .cachesDirectory, in: .userDomainMask, appropriateFor: nil, create: true).appendingPathComponent(Bundle.main.bundleIdentifier!)
 
   func getCachedArtwork() -> Promise<NSImage?> {
     return Promise { seal in
-      artworkQueue.async {
+      coverArtQueue.async {
         if self.isArtworkCached() {
-          let cacheFilePath = AlbumArtService.cacheDir.appendingPathComponent(self.album.hash).path
+          let cacheFilePath = CoverArtService.cacheDir.appendingPathComponent(self.album.hash).path
           let data = FileManager.default.contents(atPath: cacheFilePath)
           let image = NSImage(data: data ?? Data()) ?? NSImage.defaultCoverArt
 
@@ -29,7 +29,7 @@ extension AlbumArtService {
   }
 
   func cacheArtwork(data: Data?) {
-    artworkQueue.async {
+    coverArtQueue.async {
       guard let bundleIdentifier = Bundle.main.bundleIdentifier,
         let cacheDir = try? FileManager.default.url(for: .cachesDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
           .appendingPathComponent(bundleIdentifier)
@@ -44,7 +44,7 @@ extension AlbumArtService {
   }
 
   func isArtworkCached() -> Bool {
-    let cacheFilePath = AlbumArtService.cacheDir.appendingPathComponent(album.hash).path
+    let cacheFilePath = CoverArtService.cacheDir.appendingPathComponent(album.hash).path
 
     return FileManager.default.fileExists(atPath: cacheFilePath)
   }

Persephone/Services/Extensions/CoverArtService+Filesystem.swift

@@ -1,15 +1,15 @@
 //
-//  AlbumArtService+Filesystem.swift
+//  CoverArtService+Filesystem.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/3/17.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import PromiseKit
 
-extension AlbumArtService {
+extension CoverArtService {
   var coverArtFilenames: [String] {
     return [
       "folder.jpg",
@@ -19,12 +19,12 @@ extension AlbumArtService {
   }
 
   var musicDir: String {
-    return self.preferences.expandedMpdLibraryDir
+    return AppDelegate.store.state.preferencesState.expandedMpdLibraryDir
   }
 
   func getArtworkFromFilesystem() -> Promise<NSImage?> {
     return Promise { seal in
-      artworkQueue.async {
+      coverArtQueue.async {
         guard let artworkPath = self.fileSystemArtworkFilePath()
           else { seal.fulfill(nil); return }
 
@@ -48,7 +48,7 @@ extension AlbumArtService {
   }
 
   func fileSystemArtworkFilePath() -> String? {
-    let musicDir = self.preferences.expandedMpdLibraryDir
+    let musicDir = AppDelegate.store.state.preferencesState.expandedMpdLibraryDir
 
     return self.coverArtFilenames
       .lazy

Persephone/Services/Extensions/CoverArtService+Remote.swift

@@ -1,17 +1,17 @@
 //
-//  AlbumArtService+Remote.swift
+//  CoverArtService+Remote.swift
 //  Persephone
 //
 //  Created by Daniel Barber on 2019/3/17.
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 import SwiftyJSON
 import PromiseKit
 import PMKFoundation
 
-extension AlbumArtService {
+extension CoverArtService {
   enum RemoteArtworkError: Error {
     case noArtworkAvailable
     case notConfigured
@@ -19,13 +19,13 @@ extension AlbumArtService {
 
   func getRemoteArtwork() -> Promise<NSImage?> {
     return Promise { seal in
-      if preferences.fetchMissingArtworkFromInternet {
+      if AppDelegate.store.state.preferencesState .fetchMissingArtworkFromInternet {
-        artworkQueue.async {
+        coverArtQueue.async {
-          let albumArtWorkItem = DispatchWorkItem {
+          let coverArtWorkItem = DispatchWorkItem {
             self.getArtworkFromMusicBrainz().map(Optional.some).pipe(to: seal.resolve)
           }
 
-          AlbumArtQueue.shared.addToQueue(workItem: albumArtWorkItem)
+          CoverArtQueue.shared.addToQueue(workItem: coverArtWorkItem)
         }
       } else {
         throw RemoteArtworkError.notConfigured

Persephone/Services/SongNotifierService.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 struct SongNotifierService {
   let song: Song

Persephone/State/Actions/AlbumListActions.swift

@@ -0,0 +1,21 @@
+//
+//  AlbumListActions.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+struct ResetAlbumListCoverArtAction: Action {}
+
+struct UpdateCoverArtAction: Action {
+  var coverArt: NSImage?
+  var albumIndex: Int
+}
+
+struct UpdateAlbumListAction: Action {
+  var albums: [MPDClient.MPDAlbum]
+}

Persephone/State/Actions/PlayerActions.swift

@@ -0,0 +1,30 @@
+//
+//  PlayerActions.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+struct UpdateCurrentCoverArtAction: Action {
+  var coverArt: NSImage?
+}
+
+struct UpdateCurrentSongAction: Action {
+  var currentSong: Song
+}
+
+struct UpdateElapsedTimeAction: Action {
+  var elapsedTimeMs: UInt = 0
+}
+
+struct UpdateStatusAction: Action {
+  var status: MPDClient.MPDStatus
+}
+
+struct StartedDatabaseUpdateAction: Action {}
+
+struct FinishedDatabaseUpdateAction: Action {}

Persephone/State/Actions/PreferencesActions.swift

@@ -0,0 +1,27 @@
+//
+//  PreferencesActions.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+struct UpdateServerHost: Action {
+  var host: String?
+}
+
+struct UpdateServerPort: Action {
+  var port: Int?
+}
+
+struct UpdateMPDLibraryDir: Action {
+  var mpdLibraryDir: String?
+}
+
+struct UpdateFetchMissingArtworkFromInternet: Action {
+  var fetchMissingArtworkFromInternet: Bool
+}
+
+struct SavePreferences: Action {}

Persephone/State/Actions/QueueActions.swift

@@ -0,0 +1,21 @@
+//
+//  QueueActions.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+struct UpdateQueueAction: Action {
+  var queue: [MPDClient.MPDSong]
+}
+
+struct UpdateQueuePosAction: Action {
+  var queuePos: Int
+}
+
+struct UpdateQueuePlayerStateAction: Action {
+  var state: MPDClient.MPDStatus.State?
+}

Persephone/State/AlbumListState.swift

@@ -0,0 +1,19 @@
+//
+//  AlbumListState.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+struct AlbumListState: StateType {
+  var albums: [Album] = []
+}
+
+extension AlbumListState: Equatable {
+  static func == (lhs: AlbumListState, rhs: AlbumListState) -> Bool {
+    return lhs.albums == rhs.albums
+  }
+}

Persephone/State/AppState.swift

@@ -0,0 +1,16 @@
+//
+//  AppState.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/18.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+struct AppState: StateType {
+  var playerState = PlayerState()
+  var queueState = QueueState()
+  var albumListState = AlbumListState()
+  var preferencesState = PreferencesState()
+}

Persephone/State/PlayerState.swift

@@ -0,0 +1,32 @@
+//
+//  PlayerState.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+struct PlayerState: StateType {
+  var status: MPDClient.MPDStatus?
+  var currentSong: Song?
+  var currentArtwork: NSImage?
+
+  var state: MPDClient.MPDStatus.State?
+
+  var totalTime: UInt?
+  var elapsedTimeMs: UInt?
+
+  var databaseUpdating: Bool = false
+}
+
+extension PlayerState: Equatable {
+  static func == (lhs: PlayerState, rhs: PlayerState) -> Bool {
+    return (lhs.state == rhs.state) &&
+      (lhs.totalTime == rhs.totalTime) &&
+      (lhs.elapsedTimeMs == rhs.elapsedTimeMs) &&
+      (lhs.databaseUpdating == rhs.databaseUpdating)
+  }
+}

Persephone/State/PreferencesState.swift

@@ -0,0 +1,51 @@
+//
+//  PreferencesState.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import ReSwift
+
+struct PreferencesState: StateType {
+  let preferences = UserDefaults.standard
+
+  var mpdServer: MPDServer
+  let mpdLibraryDirDefault = "~/Music"
+
+  var mpdLibraryDir: String?
+
+  var mpdLibraryDirOrDefault: String {
+    return mpdLibraryDir ?? mpdLibraryDirDefault
+  }
+
+  var expandedMpdLibraryDir: String {
+    return NSString(string: mpdLibraryDirOrDefault).expandingTildeInPath
+  }
+
+  var fetchMissingArtworkFromInternet: Bool
+
+  init() {
+    self.mpdServer = MPDServer(
+      host: preferences.string(forKey: "mpdHost"),
+      port: preferences.value(forKey: "mpdPort") as? Int
+    )
+    self.mpdLibraryDir = preferences.string(forKey: "mpdLibraryDir")
+    self.fetchMissingArtworkFromInternet = preferences.bool(
+      forKey: "fetchMissingArtworkFromInternet"
+    )
+  }
+
+  func save() {
+    preferences.set(mpdServer.host, forKey: "mpdHost")
+    if (mpdServer.port.map { $0 > 0 } ?? false) {
+      preferences.set(mpdServer.port, forKey: "mpdPort")
+    } else {
+      preferences.removeObject(forKey: "mpdPort")
+    }
+    preferences.set(mpdLibraryDir, forKey: "mpdLibraryDir")
+    preferences.set(fetchMissingArtworkFromInternet, forKey: "fetchMissingArtworkFromInternet")
+  }
+}

Persephone/State/QueueState.swift

@@ -0,0 +1,24 @@
+//
+//  QueueState.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+struct QueueState: StateType {
+  var queue: [QueueItem] = []
+  var queuePos: Int = -1
+
+  var state: MPDClient.MPDStatus.State?
+}
+
+extension QueueState: Equatable {
+  static func == (lhs: QueueState, rhs: QueueState) -> Bool {
+    return (lhs.queue == rhs.queue) &&
+      (lhs.queuePos == rhs.queuePos) &&
+      (lhs.state == rhs.state)
+  }
+}

Persephone/State/Reducers/AlbumListReducer.swift

@@ -0,0 +1,41 @@
+//
+//  AlbumListReducer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/21.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+func albumListReducer(action: Action, state: AlbumListState?) -> AlbumListState {
+  var state = state ?? AlbumListState()
+
+  switch action {
+  case let action as UpdateAlbumListAction:
+    state.albums = action.albums.map { Album(mpdAlbum: $0) }
+
+  case let action as UpdateCoverArtAction:
+    state.albums[action.albumIndex].coverArt = .loaded(action.coverArt)
+
+  case is ResetAlbumListCoverArtAction:
+    state.albums = AppDelegate.store.state.albumListState.albums.map {
+      var album = $0
+      switch album.coverArt {
+      case .loaded(let coverArt):
+        if coverArt == nil {
+          album.coverArt = .notLoaded
+        }
+      default:
+        album.coverArt = .notLoaded
+      }
+      return album
+    }
+
+  default:
+    break
+
+  }
+
+  return state
+}

Persephone/State/Reducers/AppReducer.swift

@@ -0,0 +1,18 @@
+//
+//  AppReducer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import ReSwift
+
+func appReducer(action: Action, state: AppState?) -> AppState {
+  return AppState(
+    playerState: playerReducer(action: action, state: state?.playerState),
+    queueState: queueReducer(action: action, state: state?.queueState),
+    albumListState: albumListReducer(action: action, state: state?.albumListState),
+    preferencesState: preferencesReducer(action: action, state: state?.preferencesState)
+  )
+}

Persephone/State/Reducers/PlayerReducer.swift

@@ -0,0 +1,74 @@
+//
+//  PlayerReducer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/19.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+func playerReducer(action: Action, state: PlayerState?) -> PlayerState {
+  var state = state ?? PlayerState()
+
+  switch action {
+  case let action as UpdateStatusAction:
+    state.status = action.status
+    state.state = action.status.state
+    state.totalTime = action.status.totalTime
+    state.elapsedTimeMs = action.status.elapsedTimeMs
+
+    if state.state == .playing {
+      AppDelegate.trackTimer.start(elapsedTimeMs: state.elapsedTimeMs)
+    } else {
+      AppDelegate.trackTimer.stop(elapsedTimeMs: state.elapsedTimeMs)
+    }
+
+    DispatchQueue.main.async {
+      AppDelegate.store.dispatch(
+        UpdateQueuePlayerStateAction(state: state.state)
+      )
+    }
+
+  case let action as UpdateCurrentSongAction:
+    state.currentSong = action.currentSong
+
+    if let currentSong = state.currentSong {
+      let coverArtService = CoverArtService(song: currentSong)
+
+      coverArtService.fetchBigCoverArt()
+        .done() { image in
+          DispatchQueue.main.async {
+            if let image = image {
+              AppDelegate.store.dispatch(UpdateCurrentCoverArtAction(coverArt: image))
+            } else {
+              AppDelegate.store.dispatch(UpdateCurrentCoverArtAction(coverArt: .defaultCoverArt))
+            }
+          }
+        }
+        .cauterize()
+    } else {
+      DispatchQueue.main.async {
+        AppDelegate.store.dispatch(UpdateCurrentCoverArtAction(coverArt: .defaultCoverArt))
+      }
+    }
+
+  case let action as UpdateCurrentCoverArtAction:
+    state.currentArtwork = action.coverArt
+
+  case let action as UpdateElapsedTimeAction:
+    state.elapsedTimeMs = action.elapsedTimeMs
+
+  case is StartedDatabaseUpdateAction:
+    state.databaseUpdating = true
+
+  case is FinishedDatabaseUpdateAction:
+    state.databaseUpdating = false
+
+  default:
+    break
+  }
+
+  return state
+}

Persephone/State/Reducers/PreferencesReducer.swift

@@ -0,0 +1,34 @@
+//
+//  PreferencesReducer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/28.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import Foundation
+import ReSwift
+
+func preferencesReducer(action: Action, state: PreferencesState?) -> PreferencesState {
+
+  var state = state ?? PreferencesState()
+
+  switch action {
+  case let action as UpdateServerHost:
+    state.mpdServer.host = action.host
+
+  case let action as UpdateServerPort:
+    state.mpdServer.port = action.port
+
+  case let action as UpdateMPDLibraryDir:
+    state.mpdLibraryDir = action.mpdLibraryDir
+
+  case is SavePreferences:
+    state.save()
+
+  default:
+    break
+  }
+
+  return state
+}

Persephone/State/Reducers/QueueReducer.swift

@@ -0,0 +1,55 @@
+//
+//  QueueReducer.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/21.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+func queueReducer(action: Action, state: QueueState?) -> QueueState {
+  var state = state ?? QueueState()
+
+  switch action {
+  case let action as UpdateQueueAction:
+    state.queuePos = -1
+
+    state.queue = action.queue.enumerated().map { index, mpdSong in
+      let song = Song(mpdSong: mpdSong)
+
+      return QueueItem(
+        song: song,
+        queuePos: index,
+        isPlaying: index == state.queuePos
+      )
+    }
+
+  case let action as UpdateQueuePosAction:
+    let oldSongRowPos = state.queuePos
+    let newSongRowPos = action.queuePos
+    state.queuePos = action.queuePos
+
+    if oldSongRowPos >= 0 {
+      state.queue[oldSongRowPos].isPlaying = false
+    }
+    if newSongRowPos >= 0 {
+      state.queue[newSongRowPos].isPlaying = true
+    }
+
+    DispatchQueue.main.async {
+      AppDelegate.store.dispatch(
+        UpdateCurrentSongAction(currentSong: state.queue[newSongRowPos].song)
+      )
+    }
+
+  case let action as UpdateQueuePlayerStateAction:
+    state.state = action.state
+    
+  default:
+    break
+  }
+
+  return state
+}

Persephone/Views/AlbumItemView.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class AlbumItemView: NSView {
   var trackingArea: NSTrackingArea?

Persephone/Views/CurrentCoverArtView.swift

@@ -0,0 +1,32 @@
+//
+//  CurrentCoverArtView.swift
+//  Persephone
+//
+//  Created by Daniel Barber on 2019/4/27.
+//  Copyright © 2019 Dan Barber. All rights reserved.
+//
+
+import AppKit
+import ReSwift
+
+class CurrentCoverArtView: NSImageView {
+  required init?(coder: NSCoder) {
+    super.init(coder: coder)
+
+    AppDelegate.store.subscribe(self) {
+      $0.select { $0.playerState.currentArtwork }
+    }
+  }
+}
+
+extension CurrentCoverArtView: StoreSubscriber {
+  typealias StoreSubscriberStateType = NSImage?
+
+  func newState(state: NSImage?) {
+    if let coverArt = state {
+      image = coverArt
+    } else {
+      image = .defaultCoverArt
+    }
+  }
+}

Persephone/Views/MainWindow.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Dan Barber. All rights reserved.
 //
 
-import Cocoa
+import AppKit
 
 class MainWindow: NSWindow {
   override func keyDown(with event: NSEvent) {