teapod/app/src/main/java/org/mosad/teapod/activity/player/PlayerActivity.kt

package org.mosad.teapod.activity.player

import android.animation.Animator
import android.animation.AnimatorListenerAdapter
import android.annotation.SuppressLint
import android.app.PictureInPictureParams
import android.content.Intent
import android.content.pm.PackageManager
import android.content.res.Configuration
import android.os.Build
import android.os.Bundle
import android.util.Log
import android.util.Rational
import android.view.GestureDetector
import android.view.MotionEvent
import android.view.View
import androidx.activity.viewModels
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.GestureDetectorCompat
import androidx.core.view.isVisible
import com.google.android.exoplayer2.ExoPlayer
import com.google.android.exoplayer2.Player
import com.google.android.exoplayer2.ui.StyledPlayerControlView
import com.google.android.exoplayer2.util.Util
import kotlinx.android.synthetic.main.activity_player.*
import kotlinx.android.synthetic.main.player_controls.*
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import org.mosad.teapod.R
import org.mosad.teapod.preferences.Preferences
import org.mosad.teapod.ui.components.EpisodesListPlayer
import org.mosad.teapod.ui.components.LanguageSettingsPlayer
import org.mosad.teapod.util.DataTypes
import org.mosad.teapod.util.hideBars
import org.mosad.teapod.util.isInPiPMode
import org.mosad.teapod.util.navToLauncherTask
import java.util.*
import java.util.concurrent.TimeUnit
import kotlin.concurrent.scheduleAtFixedRate

class PlayerActivity : AppCompatActivity() {

    private val model: PlayerViewModel by viewModels()

    private lateinit var controller: StyledPlayerControlView
    private lateinit var gestureDetector: GestureDetectorCompat
    private lateinit var timerUpdates: TimerTask

    private var wasInPiP = false
    private var playWhenReady = true
    private var currentWindow = 0
    private var playbackPosition: Long = 0
    private var remainingTime: Long = 0

    private val rwdTime: Long = 10000.unaryMinus()
    private val fwdTime: Long = 10000
    private val defaultShowTimeoutMs = 5000

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_player)
        hideBars() // Initial hide the bars

        savedInstanceState?.let {
            currentWindow = it.getInt(getString(R.string.state_resume_window))
            playbackPosition = it.getLong(getString(R.string.state_resume_position))
            playWhenReady = it.getBoolean(getString(R.string.state_is_playing))
        }

        model.loadMedia(
            intent.getIntExtra(getString(R.string.intent_media_id), 0),
            intent.getIntExtra(getString(R.string.intent_episode_id), 0)
        )
        model.currentEpisodeChangedListener.add { onMediaChanged() }
        gestureDetector = GestureDetectorCompat(this, PlayerGestureListener())

        controller = video_view.findViewById(R.id.exo_controller)
        controller.isAnimationEnabled = false // disable controls (time-bar) animation

        initExoPlayer() // call in onCreate, exoplayer lives in view model
        initGUI()
        initActions()
    }

    /**
     * once minimum is android 7.0 this can be simplified
     * only onStart and onStop should be needed then
     * see: https://developer.android.com/guide/topics/ui/picture-in-picture#continuing_playback
     */
    override fun onStart() {
        super.onStart()
        if (Util.SDK_INT > 23) {
            initPlayer()
            video_view?.onResume()
        }
    }

    override fun onResume() {
        super.onResume()
        if (isInPiPMode()) { return }

        if (Util.SDK_INT <= 23) {
            initPlayer()
            video_view?.onResume()
        }
    }

    override fun onPause() {
        super.onPause()
        if (isInPiPMode()) { return }

        if (Util.SDK_INT <= 23) {
            video_view?.onPause()
            releasePlayer()
        }
    }

    override fun onStop() {
        super.onStop()
        if (Util.SDK_INT > 23) {
            video_view?.onPause()
            releasePlayer()
        }

        // if the player was in pip, it's on a different task
        if (wasInPiP) { navToLauncherTask() }
    }

    override fun onSaveInstanceState(outState: Bundle) {
        outState.putInt(getString(R.string.state_resume_window), currentWindow)
        outState.putLong(getString(R.string.state_resume_position), playbackPosition)
        outState.putBoolean(getString(R.string.state_is_playing), playWhenReady)
        super.onSaveInstanceState(outState)
    }

    /**
     * used, when the player is in pip and the user selects a new media
     */
    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)

        // when the intent changed, lead the new media and play it
        intent?.let {
            model.loadMedia(
                it.getIntExtra(getString(R.string.intent_media_id), 0),
                it.getIntExtra(getString(R.string.intent_episode_id), 0)
            )
            model.playEpisode(model.currentEpisode, replace = true)
        }
    }

    /**
     * previous to android n, don't override
     */
    @RequiresApi(Build.VERSION_CODES.N)
    override fun onUserLeaveHint() {
        super.onUserLeaveHint()

        // start pip mode, if supported
        if (packageManager.hasSystemFeature(PackageManager.FEATURE_PICTURE_IN_PICTURE)) {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
                @Suppress("deprecation")
                enterPictureInPictureMode()
            } else {
                val width = model.player.videoFormat?.width ?: 0
                val height = model.player.videoFormat?.height ?: 0
                val params = PictureInPictureParams.Builder()
                    .setAspectRatio(Rational(width, height))
                    .build()
                enterPictureInPictureMode(params)
            }

            wasInPiP = isInPiPMode()
        }
    }

    override fun onPictureInPictureModeChanged(
        isInPictureInPictureMode: Boolean,
        newConfig: Configuration?
    ) {
        super.onPictureInPictureModeChanged(isInPictureInPictureMode, newConfig)

        // Hide the full-screen UI (controls, etc.) while in picture-in-picture mode.
        if (isInPictureInPictureMode) {
            controller.hideImmediately()
        }
    }

    private fun initPlayer() {
        if (model.media.id < 0) {
            Log.e(javaClass.name, "No media was set.")
            this.finish()
        }

        initVideoView()
        initTimeUpdates()

        // if the player is ready or buffering we can simply play the file again, else do nothing
        if ((model.player.playbackState == ExoPlayer.STATE_READY || model.player.playbackState == ExoPlayer.STATE_BUFFERING)
        ) {
            model.player.play()
        }
    }

    /**
     * set play when ready and listeners
     */
    private fun initExoPlayer() {
        model.player.playWhenReady = playWhenReady
        model.player.addListener(object : Player.EventListener {
            override fun onPlaybackStateChanged(state: Int) {
                super.onPlaybackStateChanged(state)

                loading.visibility = when (state) {
                    ExoPlayer.STATE_READY -> View.GONE
                    ExoPlayer.STATE_BUFFERING -> View.VISIBLE
                    else -> View.GONE
                }

                exo_play_pause.visibility = when (loading.visibility) {
                    View.GONE -> View.VISIBLE
                    View.VISIBLE -> View.INVISIBLE
                    else -> View.VISIBLE
                }

                if (state == ExoPlayer.STATE_ENDED && model.nextEpisode != null && Preferences.autoplay) {
                    playNextEpisode()
                }
            }
        })

        // start playing the current episode, after all needed player components have been initialized
        model.playEpisode(model.currentEpisode, true, playbackPosition)
    }

    @SuppressLint("ClickableViewAccessibility")
    private fun initVideoView() {
        video_view.player = model.player

        // when the player controls get hidden, hide the bars too
        video_view.setControllerVisibilityListener {
            when (it) {
                View.GONE -> hideBars()
                View.VISIBLE -> updateControls()
            }
        }

        video_view.setOnTouchListener { _, event ->
            gestureDetector.onTouchEvent(event)
            true
        }
    }

    private fun initActions() {
        exo_close_player.setOnClickListener {
            this.finish()
        }
        rwd_10.setOnButtonClickListener { rewind() }
        ffwd_10.setOnButtonClickListener { fastForward() }
        button_next_ep.setOnClickListener { playNextEpisode() }
        button_language.setOnClickListener { showLanguageSettings() }
        button_episodes.setOnClickListener { showEpisodesList() }
        button_next_ep_c.setOnClickListener { playNextEpisode() }
    }

    private fun initGUI() {
        if (model.media.type == DataTypes.MediaType.MOVIE) {
            button_episodes.visibility = View.GONE
        }
    }

    private fun initTimeUpdates() {
        if (this::timerUpdates.isInitialized) {
            timerUpdates.cancel()
        }

        timerUpdates = Timer().scheduleAtFixedRate(0, 500) {
            GlobalScope.launch {
                var btnNextEpIsVisible: Boolean
                var controlsVisible: Boolean

                withContext(Dispatchers.Main) {
                    if (model.player.duration > 0) {
                        remainingTime = model.player.duration - model.player.currentPosition
                        remainingTime = if (remainingTime < 0) 0 else remainingTime
                    }
                    btnNextEpIsVisible = button_next_ep.isVisible
                    controlsVisible = controller.isVisible
                }

                if (remainingTime in 1..20000) {
                    // if the next ep button is not visible, make it visible. Don't show in pip mode
                    if (!btnNextEpIsVisible && model.nextEpisode != null && Preferences.autoplay && !isInPiPMode()) {
                        withContext(Dispatchers.Main) { showButtonNextEp() }
                    }
                } else if (btnNextEpIsVisible) {
                    withContext(Dispatchers.Main) { hideButtonNextEp() }
                }

                // if controls are visible, update them
                if (controlsVisible) {
                    withContext(Dispatchers.Main) { updateControls() }
                }
            }
        }
    }

    private fun releasePlayer() {
        playbackPosition = model.player.currentPosition
        currentWindow = model.player.currentWindowIndex
        playWhenReady = model.player.playWhenReady
        model.player.pause()
        timerUpdates.cancel()
    }

    /**
     * update the custom controls
     */
    private fun updateControls() {
        // update remaining time label
        val hours =  TimeUnit.MILLISECONDS.toHours(remainingTime) % 24
        val minutes = TimeUnit.MILLISECONDS.toMinutes(remainingTime) % 60
        val seconds = TimeUnit.MILLISECONDS.toSeconds(remainingTime) % 60

        // if remaining time is below 60 minutes, don't show hours
        exo_remaining.text = if (TimeUnit.MILLISECONDS.toMinutes(remainingTime) < 60) {
            getString(R.string.time_min_sec, minutes, seconds)
        } else {
            getString(R.string.time_hour_min_sec, hours, minutes, seconds)
        }
    }

    /**
     * update title text and next ep button visibility, set ignoreNextStateEnded
     */
    private fun onMediaChanged() {
        exo_text_title.text = model.getMediaTitle()

        // hide the next ep button, if there is none
        button_next_ep_c.visibility = if (model.nextEpisode == null) {
            View.GONE
        } else {
            View.VISIBLE
        }

        // hide the episodes button, if the media type changed
        button_episodes.visibility = if (model.media.type == DataTypes.MediaType.MOVIE) {
            View.GONE
        } else {
            View.VISIBLE
        }
    }

    /**
     * TODO set position of rewind/fast forward indicators programmatically
     */

    private fun rewind() {
        model.seekToOffset(rwdTime)

        // hide/show needed components
        exo_double_tap_indicator.visibility = View.VISIBLE
        ffwd_10_indicator.visibility = View.INVISIBLE
        rwd_10.visibility = View.INVISIBLE

        rwd_10_indicator.onAnimationEndCallback = {
            exo_double_tap_indicator.visibility = View.GONE
            ffwd_10_indicator.visibility = View.VISIBLE
            rwd_10.visibility = View.VISIBLE
        }

        // run animation
        rwd_10_indicator.runOnClickAnimation()
    }

    private fun fastForward() {
        model.seekToOffset(fwdTime)

        // hide/show needed components
        exo_double_tap_indicator.visibility = View.VISIBLE
        rwd_10_indicator.visibility = View.INVISIBLE
        ffwd_10.visibility = View.INVISIBLE

        ffwd_10_indicator.onAnimationEndCallback = {
            exo_double_tap_indicator.visibility = View.GONE
            rwd_10_indicator.visibility = View.VISIBLE
            ffwd_10.visibility = View.VISIBLE
        }

        // run animation
        ffwd_10_indicator.runOnClickAnimation()
    }

    private fun playNextEpisode() {
        model.playNextEpisode()
        hideButtonNextEp()
    }

    /**
     * show the next episode button
     * TODO improve the show animation
     */
    private fun showButtonNextEp() {
        button_next_ep.visibility = View.VISIBLE
        button_next_ep.alpha = 0.0f

        button_next_ep.animate()
            .alpha(1.0f)
            .setListener(null)
    }

    /**
     * hide the next episode button
     * TODO improve the hide animation
     */
    private fun hideButtonNextEp() {
        button_next_ep.animate()
            .alpha(0.0f)
            .setListener(object : AnimatorListenerAdapter() {
                override fun onAnimationEnd(animation: Animator?) {
                    super.onAnimationEnd(animation)
                    button_next_ep.visibility = View.GONE
                }
            })

    }

    private fun showEpisodesList() {
        val episodesList = EpisodesListPlayer(this, model = model).apply {
            onViewRemovedAction = { model.player.play() }
        }
        player_layout.addView(episodesList)
        pauseAndHideControls()
    }

    private fun showLanguageSettings() {
        val languageSettings = LanguageSettingsPlayer(this, model = model).apply {
            onViewRemovedAction = { model.player.play() }
        }
        player_layout.addView(languageSettings)
        pauseAndHideControls()
    }

    /**
     * pause playback and hide controls
     */
    private fun pauseAndHideControls() {
        model.player.pause() // showTimeoutMs is set to 0 when calling pause, but why
        controller.showTimeoutMs = defaultShowTimeoutMs // fix showTimeoutMs set to 0
        controller.hide()
    }

    inner class PlayerGestureListener : GestureDetector.SimpleOnGestureListener() {

        /**
         * on single tap hide or show the controls
         */
        override fun onSingleTapConfirmed(e: MotionEvent?): Boolean {
            if (!isInPiPMode()) {
                if (controller.isVisible) controller.hide() else  controller.show()
            }

            return true
        }

        /**
         * on double tap rewind or forward
         */
        override fun onDoubleTap(e: MotionEvent?): Boolean {
            val eventPosX = e?.x?.toInt() ?: 0
            val viewCenterX = video_view.measuredWidth / 2

            // if the event position is on the left side rewind, if it's on the right forward
            if (eventPosX < viewCenterX) rewind() else fastForward()

            return true
        }

        /**
         * not used
         */
        override fun onDoubleTapEvent(e: MotionEvent?): Boolean {
            return true
        }

        /**
         * on long press toggle pause/play
         */
        override fun onLongPress(e: MotionEvent?) {
            model.togglePausePlay()
        }

    }

}