LibreTube/app/src/main/java/com/github/libretube/util/NowPlayingNotification.kt

package com.github.libretube.util

import android.R.attr.data
import android.annotation.SuppressLint
import android.app.NotificationManager
import android.app.PendingIntent
import android.content.Context
import android.content.Intent
import android.content.res.Resources
import android.graphics.Bitmap
import android.graphics.BitmapFactory
import android.graphics.drawable.BitmapDrawable
import android.os.Build
import android.os.Bundle
import android.support.v4.media.MediaDescriptionCompat
import android.support.v4.media.MediaMetadataCompat
import android.support.v4.media.session.MediaSessionCompat
import coil.request.ImageRequest
import com.github.libretube.R
import com.github.libretube.api.obj.Streams
import com.github.libretube.constants.BACKGROUND_CHANNEL_ID
import com.github.libretube.constants.IntentData
import com.github.libretube.constants.PLAYER_NOTIFICATION_ID
import com.github.libretube.ui.activities.MainActivity
import com.google.android.exoplayer2.ExoPlayer
import com.google.android.exoplayer2.Player
import com.google.android.exoplayer2.ext.mediasession.MediaSessionConnector
import com.google.android.exoplayer2.ext.mediasession.TimelineQueueNavigator
import com.google.android.exoplayer2.ui.PlayerNotificationManager

class NowPlayingNotification(
    private val context: Context,
    private val player: ExoPlayer,
    private val isBackgroundPlayerNotification: Boolean
) {
    private var videoId: String? = null
    private var streams: Streams? = null

    /**
     * The [MediaSessionCompat] for the [streams].
     */
    private lateinit var mediaSession: MediaSessionCompat

    /**
     * The [MediaSessionConnector] to connect with the [mediaSession] and implement it with the [player].
     */
    private lateinit var mediaSessionConnector: MediaSessionConnector

    /**
     * The [PlayerNotificationManager] to load the [mediaSession] content on it.
     */
    private var playerNotification: PlayerNotificationManager? = null

    /**
     * The [DescriptionAdapter] is used to show title, uploaderName and thumbnail of the video in the notification
     * Basic example [here](https://github.com/AnthonyMarkD/AudioPlayerSampleTest)
     */
    inner class DescriptionAdapter :
        PlayerNotificationManager.MediaDescriptionAdapter {
        /**
         * sets the title of the notification
         */
        override fun getCurrentContentTitle(player: Player): CharSequence {
            return streams?.title!!
        }

        /**
         * overrides the action when clicking the notification
         */
        @SuppressLint("UnspecifiedImmutableFlag")
        override fun createCurrentContentIntent(player: Player): PendingIntent? {
            // starts a new MainActivity Intent when the player notification is clicked
            // it doesn't start a completely new MainActivity because the MainActivity's launchMode
            // is set to "singleTop" in the AndroidManifest (important!!!)
            //  that's the only way to launch back into the previous activity (e.g. the player view
            val intent = Intent(context, MainActivity::class.java).apply {
                if (isBackgroundPlayerNotification) {
                    putExtra(IntentData.videoId, videoId)
                    addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
                }
            }
            return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                PendingIntent.getActivity(
                    context,
                    0,
                    intent,
                    PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
                )
            } else {
                PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT)
            }
        }

        /**
         * the description of the notification (below the title)
         */
        override fun getCurrentContentText(player: Player): CharSequence? {
            return streams?.uploader
        }

        /**
         * return the icon/thumbnail of the video
         */
        override fun getCurrentLargeIcon(
            player: Player,
            callback: PlayerNotificationManager.BitmapCallback
        ): Bitmap? {
            var bitmap: Bitmap? = null
            var resizedBitmap: Bitmap? = null

            val request = ImageRequest.Builder(context)
                .data(streams?.thumbnailUrl)
                .target { result ->
                    bitmap = (result as BitmapDrawable).bitmap
                    resizedBitmap = Bitmap.createScaledBitmap(
                        bitmap!!,
                        bitmap!!.width,
                        bitmap!!.width,
                        false
                    )
                }
                .build()

            ImageHelper.imageLoader.enqueue(request)

            // returns the scaled bitmap if it got fetched successfully
            return if (Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU) resizedBitmap else bitmap
        }
    }

    /**
     * Creates a [MediaSessionCompat] amd a [MediaSessionConnector] for the player
     */
    private fun createMediaSession() {
        if (this::mediaSession.isInitialized) return
        mediaSession = MediaSessionCompat(context, this.javaClass.name)
        mediaSession.isActive = true

        mediaSessionConnector = MediaSessionConnector(mediaSession)
        mediaSessionConnector.setQueueNavigator(object : TimelineQueueNavigator(mediaSession) {
            override fun getMediaDescription(
                player: Player,
                windowIndex: Int
            ): MediaDescriptionCompat {
                return MediaDescriptionCompat.Builder().apply {
                    setTitle(streams?.title!!)
                    setSubtitle(streams?.uploader)
                    val extras = Bundle()
                    val appIcon = BitmapFactory.decodeResource(
                        Resources.getSystem(),
                        R.drawable.ic_launcher_monochrome
                    )
                    extras.putParcelable(MediaMetadataCompat.METADATA_KEY_DISPLAY_ICON, appIcon)
                    extras.putString(MediaMetadataCompat.METADATA_KEY_TITLE, streams?.title!!)
                    extras.putString(MediaMetadataCompat.METADATA_KEY_ARTIST, streams?.uploader)
                    setIconBitmap(appIcon)
                    setExtras(extras)
                }.build()
            }
        })
        mediaSessionConnector.setPlayer(player)
    }

    /**
     * Updates or creates the [playerNotification]
     */
    fun updatePlayerNotification(
        videoId: String,
        streams: Streams
    ) {
        this.videoId = videoId
        this.streams = streams

        if (playerNotification == null) {
            createMediaSession()
            createNotification()
        }
    }

    /**
     * Initializes the [playerNotification] attached to the [player] and shows it.
     */
    private fun createNotification() {
        playerNotification = PlayerNotificationManager
            .Builder(context, PLAYER_NOTIFICATION_ID, BACKGROUND_CHANNEL_ID)
            // set the description of the notification
            .setMediaDescriptionAdapter(
                DescriptionAdapter()
            )
            .build()
        playerNotification?.apply {
            setPlayer(player)
            setUseNextAction(false)
            setUsePreviousAction(false)
            setUseStopAction(true)
            setColorized(true)
            setMediaSessionToken(mediaSession.sessionToken)
            setUseFastForwardActionInCompactView(true)
            setUseRewindActionInCompactView(true)
        }
    }

    /**
     * Destroy the [NowPlayingNotification]
     */
    fun destroySelfAndPlayer() {
        mediaSession.isActive = false
        mediaSession.release()
        mediaSessionConnector.setPlayer(null)
        playerNotification?.setPlayer(null)

        val notificationManager = context.getSystemService(
            Context.NOTIFICATION_SERVICE
        ) as NotificationManager
        notificationManager.cancel(PLAYER_NOTIFICATION_ID)

        player.stop()
        player.release()
    }
}