From 3b4b5f5b5cd81edb0ecd59a26253fb9fb1948da7 Mon Sep 17 00:00:00 2001
From: Daniel Barber <github@danbarber.me>
Date: Wed, 12 Feb 2020 21:10:26 -0500
Subject: [PATCH] Refactor cover art refresh using Promises

---
 Persephone/Services/CoverArtService.swift | 95 +++++++++++++++--------
 1 file changed, 61 insertions(+), 34 deletions(-)

diff --git a/Persephone/Services/CoverArtService.swift b/Persephone/Services/CoverArtService.swift
index d19a307..e890a70 100644
--- a/Persephone/Services/CoverArtService.swift
+++ b/Persephone/Services/CoverArtService.swift
@@ -7,50 +7,77 @@
 //
 
 import Foundation
+import PromiseKit
 import Kingfisher
 
 struct CoverArtService {
   let song: Song
+  let provider: MPDAlbumArtImageDataProvider
   
-  func refresh(callback: @escaping () -> Void?) {
-    let provider = MPDAlbumArtImageDataProvider(
+  init(song: Song) {
+    self.song = song
+
+    provider = MPDAlbumArtImageDataProvider(
       songUri: song.mpdSong.uriString,
       cacheKey: song.album.hash
     )
-    
-    _ = KingfisherManager.shared.retrieveImage(
-      with: .provider(provider),
-      options: [
-        .forceRefresh,
-        .memoryCacheExpiration(.never),
-        .processor(DownsamplingImageProcessor(size: .albumListCoverSize)),
-        .scaleFactor(2),
-      ]
-    ) { _ in
-      callback()
+  }
+  
+  func refreshAlbumListArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .albumListCoverSize)),
+          .scaleFactor(2),
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
     }
-    
-    _ = KingfisherManager.shared.retrieveImage(
-      with: .provider(provider),
-      options: [
-        .forceRefresh,
-        .memoryCacheExpiration(.never),
-        .processor(DownsamplingImageProcessor(size: .currentlyPlayingCoverSize)),
-        .scaleFactor(2),
-        .callbackQueue(.mainAsync)
-      ]
-    ) { _ in }
-
-    _ = KingfisherManager.shared.retrieveImage(
-      with: .provider(provider),
-      options: [
-        .forceRefresh,
-        .memoryCacheExpiration(.never),
-        .processor(DownsamplingImageProcessor(size: .queueSongCoverSize)),
-        .scaleFactor(2),
-      ]
-    ) { _ in
+  }
+  
+  func refreshCurrentlyPlayingArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .currentlyPlayingCoverSize)),
+          .scaleFactor(2),
+          .callbackQueue(.mainAsync)
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
+    }
+  }
+  
+  func refreshQueueSongArt() -> Promise<Any> {
+    return Promise<Any> { seal in
+      _ = KingfisherManager.shared.retrieveImage(
+        with: .provider(provider),
+        options: [
+          .forceRefresh,
+          .memoryCacheExpiration(.never),
+          .processor(DownsamplingImageProcessor(size: .queueSongCoverSize)),
+          .scaleFactor(2),
+        ]
+      ) { result in
+        seal.fulfill(result)
+      }
+    }
+  }
+  
+  func refresh(callback: @escaping () -> Void?) {
+    _ = firstly {
+      when(fulfilled: refreshAlbumListArt(), refreshQueueSongArt(), refreshCurrentlyPlayingArt())
+    }.done { _, _, _ in
       NotificationCenter.default.post(name: .didReloadAlbumArt, object: nil)
+      callback()
     }
   }
 }