Redesigned ListenService

app/build.gradle

@@ -208,4 +208,7 @@ dependencies {
 
     //Jetpack Compose accompanists (https://github.com/google/accompanist)
     implementation "com.google.accompanist:accompanist-systemuicontroller:$accompanist_version"
+
+    // Util
+    implementation 'com.github.dariobrux:Timer:1.1.0'
 }

app/src/main/java/org/listenbrainz/android/model/ListenSubmitBody.kt

@@ -26,7 +26,7 @@ class ListenSubmitBody {
     }
 
     private fun Payload.setClientDetails(): Payload{
-        this.metadata.additionalInfo.submission_client = BuildConfig.APPLICATION_ID
+        this.metadata.additionalInfo.submission_client = "ListenBrainz Android"
         this.metadata.additionalInfo.submission_client_version = BuildConfig.VERSION_NAME
         return this
     }

app/src/main/java/org/listenbrainz/android/util/ListenHandler.kt

@@ -16,7 +16,7 @@ import retrofit2.Call
 import retrofit2.Response
 
 class ListenHandler : Handler(Looper.getMainLooper()) {
-    private val delay = 30000
+
     private val timestamp = "timestamp"
 
     override fun handleMessage(msg: Message) {
@@ -52,7 +52,7 @@ class ListenHandler : Handler(Looper.getMainLooper()) {
         data.putLong(this.timestamp, timestamp)
         message.what = timestamp.toInt()
         message.data = data
-        sendMessageDelayed(message, delay.toLong())
+        sendMessageDelayed(message, 0)
     }
 
     fun cancelListen(timestamp: Long) {

app/src/main/java/org/listenbrainz/android/util/ListenSessionListener.kt

@@ -4,6 +4,8 @@ import android.media.MediaMetadata
 import android.media.session.MediaController
 import android.media.session.MediaSessionManager.OnActiveSessionsChangedListener
 import android.media.session.PlaybackState
+import com.dariobrux.kotimer.Timer
+import com.dariobrux.kotimer.interfaces.OnTimerListener
 import org.listenbrainz.android.repository.AppPreferences
 import org.listenbrainz.android.util.Log.d
 import org.listenbrainz.android.util.Log.w
@@ -53,73 +55,125 @@ class ListenSessionListener(
         var artist: String? = null
         var title: String? = null
         var timestamp: Long = 0
+        var duration: Long = 0
+        val timer: Timer = Timer()
         var state: PlaybackState? = null
-        var submitted = true
+        var submitted = false
+
+        // FIXME:
+        //  1) First ever session song isn't recorded. This is because onMetadataChanged
+        //      isn't called by callback itself.
 
         override fun onMetadataChanged(metadata: MediaMetadata?) {
 
             if (metadata == null) return
 
+            // Stop timer and reset metadata.
+            resetMetadata()     // Do not perform this action in timer's onTimerStop due to concurrency issues.
+            timer.stop()
+
             when {
                 state != null -> d("onMetadataChanged: Listen Metadata " + state!!.state)
                 else -> d("onMetadataChanged: Listen Metadata")
             }
 
-            artist = when {
-                !metadata.getString(MediaMetadata.METADATA_KEY_ARTIST).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_ARTIST)
-                !metadata.getString(MediaMetadata.METADATA_KEY_ALBUM_ARTIST).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_ALBUM_ARTIST)
-                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE)
-                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_DESCRIPTION).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_DESCRIPTION)
-                else -> null
-            }
-
-            title = when {
-                !metadata.getString(MediaMetadata.METADATA_KEY_TITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_TITLE)
-                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE)
-                else -> null
-            }
+            setArtist(metadata)
+            setTitle(metadata)
 
-            if (artist.isNullOrEmpty() || title.isNullOrEmpty()){
+            if (isMetadataFaulty()){
                 w("${if (artist == null) "Artist" else "Title"} is null, listen cancelled.")
                 return
             }
 
-            // If the difference between the timestamp of this listen and previously
-            // submitted listen is less that 1 second, listen should not be submitted.
-            if ( (System.currentTimeMillis() / 1000 - timestamp) >= 1000) {
-                submitted = false
-            }
+            setDurationAndCallbacks(metadata)
 
-            timestamp = System.currentTimeMillis() / 1000
-            if (state != null && state!!.state == PlaybackState.STATE_PLAYING && !submitted) {
-                handler.submitListen(artist, title, timestamp)
-                submitted = true
-            }
         }
-        // FIXME : Listens are only submitted when song is paused once, then played and skipped.
-
+
         override fun onPlaybackStateChanged(state: PlaybackState?) {
             if (state == null) return
 
             this.state = state
             d("onPlaybackStateChanged: Listen PlaybackState " + state.state)
+
+            if (isDurationUndefined() || submitted) return
 
-            if (state.state == PlaybackState.STATE_PLAYING && !submitted) {
-
-                if (artist.isNullOrEmpty() || title.isNullOrEmpty()) return
-
-                handler.submitListen(artist, title, timestamp)
-                submitted = true
+            if (state.state == PlaybackState.STATE_PLAYING){
+                timer.start()
+                // d("Timer started")
             }
 
-            if (state.state == PlaybackState.STATE_PAUSED ||
-                    state.state == PlaybackState.STATE_STOPPED) {
-                handler.cancelListen(timestamp)
-                d("Listen Cancelled.")
-                artist = ""
-                title = ""
-                timestamp = 0
+            if (state.state == PlaybackState.STATE_PAUSED){
+                timer.pause()
+                // d("Timer paused")
             }
+
         }
+
+        // UTILITY FUNCTIONS
+
+        private fun setTitle(metadata: MediaMetadata) {
+            title = when {
+                !metadata.getString(MediaMetadata.METADATA_KEY_TITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_TITLE)
+                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_TITLE)
+                else -> null
+            }
+        }
+
+        private fun setArtist(metadata: MediaMetadata) {
+            artist = when {
+                !metadata.getString(MediaMetadata.METADATA_KEY_ARTIST).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_ARTIST)
+                !metadata.getString(MediaMetadata.METADATA_KEY_ALBUM_ARTIST).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_ALBUM_ARTIST)
+                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_SUBTITLE)
+                !metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_DESCRIPTION).isNullOrEmpty() -> metadata.getString(MediaMetadata.METADATA_KEY_DISPLAY_DESCRIPTION)
+                else -> null
+            }
+        }
+
+        private fun isMetadataFaulty() : Boolean
+            = artist.isNullOrEmpty() || title.isNullOrEmpty()
+
+        /** Run [artist] and [title] value-check before invoking this function.*/
+        private fun setDurationAndCallbacks(metadata: MediaMetadata) {
+            duration = roundDuration(duration = metadata.getLong(MediaMetadata.METADATA_KEY_DURATION) / 2L)
+                .coerceAtMost(240000)   // Since maximum time required to validate a listen as submittable listen is 4 minutes.
+            timestamp = System.currentTimeMillis() / 1000
+
+            // d(duration.toString())
+            timer.setDuration(duration)
+
+            // Setting listener
+            timer.setOnTimerListener(listener = object : OnTimerListener {
+                override fun onTimerEnded() {
+                    handler.submitListen(artist, title, timestamp)
+                    submitted = true
+                }
+
+                override fun onTimerPaused(remainingMillis: Long) {
+                    d("${remainingMillis / 1000} seconds left to submit listen.")
+                }
+                override fun onTimerRun(milliseconds: Long) {}
+                override fun onTimerStarted() {}
+                override fun onTimerStopped() {}
+
+            }, callbacksOnMainThread = true)
+            d("Listener Set")
+        }
+
+        private fun isDurationUndefined() : Boolean
+            = duration <= 0
+
+        private fun resetMetadata() {
+            d("Metadata Reset")
+            artist = null
+            title = null
+            timestamp = 0
+            duration = 0
+            submitted = false
+        }
+
+        private fun roundDuration(duration: Long): Long {
+            return (duration / 1000) * 1000
+        }
+
     }
 }

app/src/main/java/org/listenbrainz/android/util/cacheService.kt

@@ -1,7 +1,10 @@
+
 import android.content.Context
 import com.google.gson.Gson
 import com.google.gson.JsonSyntaxException
-import java.io.*
+import java.io.File
+import java.io.FileWriter
+import java.io.IOException
 
 class CacheService<T>(private val context: Context, private val key: String,private val maxSize:Int=10000) {
     fun saveData(value: T, dataType: Class<T>) {
@@ -18,7 +21,7 @@ class CacheService<T>(private val context: Context, private val key: String,priv
             if (!data.contains(value)) {
                 if (file.length() >= maxSize) {
                     val newData = data.toMutableList()
-                    newData.removeAt(0)
+                    if (newData.size > 0) newData.removeAt(0)
                     newData.add(value)
                     var tostore=gson.toJson(newData)
                     val fileWriter = FileWriter(file, false)