persephone/Persephone/Services/Extensions/AlbumArtService+Filesystem.swift

//
//  AlbumArtService+Filesystem.swift
//  Persephone
//
//  Created by Daniel Barber on 2019/3/17.
//  Copyright © 2019 Dan Barber. All rights reserved.
//

import Cocoa

extension AlbumArtService {
  func getArtworkFromFilesystem(
    for album: AlbumItem,
    callback: @escaping (_ image: NSImage) -> Void
  ) {
    var tryImage: NSImage?

    let coverArtFilenames = [
      "folder.jpg",
      "cover.jpg",
      "\(album.artist) - \(album.title).jpg"
    ]

    let callback = { (_ albumURI: String?) in
      guard let albumURI = albumURI
        else { return }

      let musicDir = self.preferences.expandedMpdLibraryDir
      let fullAlbumURI = "\(musicDir)/\(albumURI)"

      for coverArtFilename in coverArtFilenames {
        let coverArtURI = "\(fullAlbumURI)/\(coverArtFilename)"

        tryImage = self.tryImage(coverArtURI)

        if let image = tryImage {
          self.cacheArtwork(
            for: album,
            data: image.jpegData(compressionQuality: self.cachedArtworkQuality)
          )
          callback(image)
          break
        }
      }

      if tryImage == nil && self.preferences.fetchMissingArtworkFromInternet {
        self.getRemoteArtwork(for: album, callback: callback)
      }
    }

    AppDelegate.mpdClient.getAlbumURI(
      for: album.album,
      callback: callback
    )
  }

  func tryImage(_ filePath: String) -> NSImage? {
    guard FileManager.default.fileExists(atPath: filePath),
      let data = FileManager.default.contents(atPath: filePath),
      let image = NSImage(data: data)
      else { return nil }

    let imageThumb = image.toFitBox(
      size: NSSize(width: self.cachedArtworkSize, height: self.cachedArtworkSize)
    )

    return imageThumb
  }
}