Added Spotify source support (#2)

* Added Spotify source support. Fixes #1

* Handle empty track being returned from itunes

4 files changed, 48 insertions, 2 deletions

diff --git a/Sources/configuration.swift b/Sources/configuration.swift
index 1db3695..05e2802 100644
--- a/Sources/configuration.swift
+++ b/Sources/configuration.swift
@@ -8,7 +8,7 @@ class Configuration {
     // Default options, will be automatically written to the global config if
     // not found.
     private var configuration: [String: Any] =  [
-        "enabled_sources": ["arguments", "itunes"]
+        "enabled_sources": ["arguments", "itunes", "spotify"]
     ]
 
     // The shared instance of the object
diff --git a/Sources/itunes_source.swift b/Sources/itunes_source.swift
index 449dd8a..6f4aef9 100644
--- a/Sources/itunes_source.swift
+++ b/Sources/itunes_source.swift
@@ -44,6 +44,10 @@ class ItunesSource: Source {
                     if let name = track.name {
                         if let artist = track.artist {
 
+                            // track properties are empty strings if itunes is closed
+                            if (!(name != "" && artist != "")) {
+                                return nil
+                            }
                             return Track(withName: name, andArtist: artist)
                         }
                     }
diff --git a/Sources/source_manager.swift b/Sources/source_manager.swift
index aaac696..e6c42da 100644
--- a/Sources/source_manager.swift
+++ b/Sources/source_manager.swift
@@ -4,7 +4,8 @@ class SourceManager {
     // List of sources enabled for the crurent platform
     private var availableSources: [String: Source] = [
         "arguments": ArgumentsSource(),
-        "itunes": ItunesSource()
+        "itunes": ItunesSource(),
+        "spotify": SpotifySource()
     ]
 
     // Iterate over the sources until we find a track or run out of sources
diff --git a/Sources/spotify_source.swift b/Sources/spotify_source.swift
new file mode 100644
index 0000000..2e56c8e
--- /dev/null
+++ b/Sources/spotify_source.swift
@@ -0,0 +1,41 @@
+import ScriptingBridge
+
+// Protocol to obtain the track from Spotify
+@objc protocol SpotifyTrack {
+    @objc optional var name: String {get}
+    @objc optional var artist: String {get}
+}
+
+// Protocol to interact with Spotify
+@objc protocol SpotifyApplication {
+    @objc optional var currentTrack: SpotifyTrack? {get}
+}
+
+extension SBApplication : SpotifyApplication {}
+
+// Source that reads track artist and name from current Spotify track
+class SpotifySource: Source {
+
+    // Calls the spotify API and returns the current track
+    var currentTrack: Track? {
+
+        if let spotify: SpotifyApplication = SBApplication(bundleIdentifier: "com.spotify.client") {
+
+            // Attempt to fetch the title from a song
+            if let currentTrack = spotify.currentTrack {
+                if let track = currentTrack {
+                    if let name = track.name {
+                        if let artist = track.artist {
+
+                            return Track(withName: name, andArtist: artist)
+                        }
+                    }
+                }
+            }
+        }
+
+        return nil
+    }
+
+}
+