package net.torvald.terrarum.modulebasegame

import com.badlogic.gdx.Gdx
import com.badlogic.gdx.utils.GdxRuntimeException
import com.jme3.math.FastMath
import net.torvald.terrarum.*
import net.torvald.terrarum.App.printdbg
import net.torvald.terrarum.audio.AudioMixer
import net.torvald.terrarum.audio.MusicContainer
import net.torvald.terrarum.gameworld.WorldTime.Companion.DAY_LENGTH
import java.io.File

class TerrarumMusicGovernor : MusicGovernor() {
    private val STATE_INIT = 0
    private val STATE_FIREPLAY = 1
    private val STATE_PLAYING = 2
    private val STATE_INTERMISSION = 3


    init {
        musicState = STATE_INTERMISSION
    }

    private var songs: List<MusicContainer> = emptyList()
    var playlistName = ""; private set
    /** canonicalPath with path separators converted to forward slash */
    var playlistSource = "" ; private set
    private var musicBin: ArrayList<MusicContainer> = ArrayList()
    private var shuffled = true
    private var diskJockeyingMode = "intermittent" // intermittent, continuous

    private fun registerSongsFromDir(musicDir: String, fileToName: ((String) -> String)?) {
        val musicDir = musicDir.replace('\\', '/')
        playlistSource = musicDir
        printdbg(this, "registerSongsFromDir $musicDir")

        val fileToName = if (fileToName == null) {
            { name: String -> name.substringBeforeLast('.').replace('_', ' ').split(" ").map { it.capitalize() }.joinToString(" ") }
        }
        else fileToName

        playlistName = musicDir.substringAfterLast('/')

        songs = File(musicDir).listFiles()?.sortedBy { it.name }?.mapNotNull {
            printdbg(this, "Music: ${it.absolutePath}")
            try {
                MusicContainer(
                    fileToName(it.name),
                    it
                ).also { muscon ->

                    printdbg(this, "MusicTitle: ${muscon.name}")

                    muscon.songFinishedHook =  {
                        if (it == App.audioMixer.musicTrack.currentTrack?.gdxMusic) {
                            stopMusic(this, true, getRandomMusicInterval())
                        }
                    }
                }
            }
            catch (e: GdxRuntimeException) {
                e.printStackTrace()
                null
            }
        } ?: emptyList() // TODO test code
    }

    private fun restockMusicBin() {
        musicBin = ArrayList(if (shuffled) songs.shuffled() else songs.slice(songs.indices))
    }

    /**
     * @param musicDir where the music files are. Absolute path.
     * @param shuffled if the tracks are to be shuffled
     * @param diskJockeyingMode `intermittent` to give random gap between tracks, `continuous` for continuous playback
     */
    fun queueDirectory(musicDir: String, shuffled: Boolean, diskJockeyingMode: String, fileToName: ((String) -> String)? = null) {
        if (musicState != STATE_INIT && musicState != STATE_INTERMISSION) {
            App.audioMixer.requestFadeOut(App.audioMixer.fadeBus, AudioMixer.DEFAULT_FADEOUT_LEN) // explicit call for fade-out when the game instance quits
            stopMusic0(App.audioMixer.musicTrack.currentTrack)
        }

        songs.forEach { it.gdxMusic.tryDispose() }
        registerSongsFromDir(musicDir, fileToName)

        this.shuffled = shuffled
        this.diskJockeyingMode = diskJockeyingMode

        restockMusicBin()
    }

    /**
     * Adds a song to the head of the internal playlist (`musicBin`)
     */
    fun queueMusicToPlayNext(music: MusicContainer) {
        musicBin.add(0, music)
    }

    /**
     * Unshifts an internal playlist (`musicBin`). The `music` argument must be the song that exists on the `songs`.
     */
    fun unshiftPlaylist(music: MusicContainer) {
        val indexAtMusicBin = songs.indexOf(music)
        if (indexAtMusicBin < 0) throw IllegalArgumentException("The music does not exist on the internal songs list ($music)")

        // rewrite musicBin
        val newMusicBin = if (shuffled) songs.shuffled().toTypedArray().also {
            // if shuffled,
            // 1. create a shuffled version of songlist
            // 2. swap two songs such that the songs[indexAtMusicBin] comes first
            val swapTo = it.indexOf(songs[indexAtMusicBin])
            val tmp = it[swapTo]
            it[swapTo] = it[0]
            it[0] = tmp
        }
        else Array(songs.size - indexAtMusicBin) { offset ->
            val k = offset + indexAtMusicBin
            songs[k]
        }

        musicBin = ArrayList(newMusicBin.toList())
    }

    fun queueIndexFromPlaylist(indexAtMusicBin: Int) {
        if (indexAtMusicBin !in songs.indices) throw IndexOutOfBoundsException("The index is outside of the internal songs list ($indexAtMusicBin/${songs.size})")

        // rewrite musicBin
        val newMusicBin =  if (shuffled) songs.shuffled().toTypedArray().also {
            // if shuffled,
            // 1. create a shuffled version of songlist
            // 2. swap two songs such that the songs[indexAtMusicBin] comes first
            val swapTo = it.indexOf(songs[indexAtMusicBin])
            val tmp = it[swapTo]
            it[swapTo] = it[0]
            it[0] = tmp
        }
        else Array(songs.size - indexAtMusicBin) { offset ->
            val k = offset + indexAtMusicBin
            songs[k]
        }

        musicBin = ArrayList(newMusicBin.toList())
    }

    private val ambients: HashMap<String, HashSet<MusicContainer>> =
        HashMap(Terrarum.audioCodex.audio.filter { it.key.startsWith("ambient.") }.map { it.key to it.value.mapNotNull { fileHandle ->
            try {
                MusicContainer(
                    fileHandle.nameWithoutExtension().replace('_', ' ').split(" ").map { it.capitalize() }.joinToString(" "),
                    fileHandle.file(),
                    loop = true,
                )
            }
            catch (e: GdxRuntimeException) {
                e.printStackTrace()
                null
            }
        }.toHashSet() }.toMap())

    private val musicStartHooks = ArrayList<(MusicContainer) -> Unit>()
    private val musicStopHooks = ArrayList<(MusicContainer) -> Unit>()

    init {
        queueDirectory(App.customMusicDir, true, "intermittent")
    }


    fun addMusicStartHook(f: (MusicContainer) -> Unit) {
        musicStartHooks.add(f)
    }

    fun addMusicStopHook(f: (MusicContainer) -> Unit) {
        musicStopHooks.add(f)
    }

    init {
        songs.forEach {
            App.disposables.add(it.gdxMusic)
        }
        ambients.forEach { (k, v) ->
            printdbg(this, "Ambients: $k -> $v")

            v.forEach {
                App.disposables.add(it.gdxMusic)
            }
        }
    }


    private var warningPrinted = false



    protected var ambState = 0
    protected var ambFired = false

    fun getRandomMusicInterval() = 3.6f + Math.random().toFloat() * 1.2f // use shorter gap a la mixtape

    var stopCaller: Any? = null; private set
    var playCaller: Any? = null; private set
    var stopCallTime: Long? = null; private set

    private fun stopMusic0(song: MusicContainer?, callStopMusicHook: Boolean = true, customPauseLen: Float? = null) {
        musicState = if (customPauseLen == Float.POSITIVE_INFINITY) STATE_INIT else STATE_INTERMISSION
//        printdbg(this, "stopMusic1 customLen=$customPauseLen, stateNow: $musicState, called by")
//        printStackTrace(this)
        intermissionAkku = 0f
        intermissionLength = customPauseLen ?: getRandomMusicInterval()
        musicFired = false
        if (callStopMusicHook && musicStopHooks.isNotEmpty()) musicStopHooks.forEach {
            if (song != null) {
                it(song)
            }
        }
//        printdbg(this, "StopMusic Intermission: $intermissionLength seconds")
    }

    fun stopMusic(caller: Any?, callStopMusicHook: Boolean = true, pauseLen: Float = Float.POSITIVE_INFINITY) {
        val timeNow = System.currentTimeMillis()
        val trackThis = App.audioMixer.musicTrack.currentTrack

        if (caller is TerrarumMusicGovernor) {
            if (stopCaller == null) {
//                printdbg(this, "Caller: this, prev caller: $stopCaller, len: $pauseLen, obliging stop request")
                stopMusic0(trackThis, callStopMusicHook, pauseLen)
            }
            else {
//                printdbg(this, "Caller: this, prev caller: $stopCaller, len: $pauseLen, ignoring stop request")
            }
        }
        else {
//            printdbg(this, "Caller: $caller, prev caller: <doesn't matter>, len: $pauseLen, obliging stop request")
            stopMusic0(trackThis, callStopMusicHook, pauseLen)
        }

        stopCaller = caller?.javaClass?.canonicalName
        stopCallTime = System.currentTimeMillis()

//        printStackTrace(this)
    }

    fun startMusic(caller: Any?) {
        playCaller = caller
        startMusic0(pullNextMusicTrack())
    }

    private fun startMusic0(song: MusicContainer) {
        stopCaller = null
        stopCallTime = null

        App.audioMixer.startMusic(song)
//        printdbg(this, "startMusic Now playing: ${song.name}, called by:")
//        printStackTrace(this)
//        INGAME.sendNotification("Now Playing $EMDASH ${song.name}")
        if (musicStartHooks.isNotEmpty()) musicStartHooks.forEach { it(song) }
        musicState = STATE_PLAYING
        intermissionLength = 42.42424f
    }

    // MixerTrackProcessor will call this function externally to make gapless playback work
    fun pullNextMusicTrack(callNextMusicHook: Boolean = false): MusicContainer {
//        printStackTrace(this)

        // prevent same song to play twice in row (for the most time)
        if (musicBin.isEmpty()) {
            restockMusicBin()
        }
        return musicBin.removeAt(0).also { mus ->
            if (callNextMusicHook && musicStartHooks.isNotEmpty()) musicStartHooks.forEach { it(mus) }
        }
    }

    private fun stopAmbient() {
//        if (::currentAmbientTrack.isInitialized)
//            App.audioMixer.ambientTrack.nextTrack = currentAmbientTrack
    }

    private fun startAmbient1(song: MusicContainer) {
        App.audioMixer.startAmb1(song)
        printdbg(this, "startAmbient1 Now playing: $song")
        ambState = STATE_PLAYING
    }
    private fun startAmbient2(song: MusicContainer) {
        App.audioMixer.startAmb2(song)
        printdbg(this, "startAmbient2 Now playing: $song")
        ambState = STATE_PLAYING
    }

    private fun queueAmbientForce1(song: MusicContainer) {
        App.audioMixer.ambientTrack1.let {
            it.nextTrack = song
            it.stop()
        }
        printdbg(this, "startAmbient1 Now playing: $song")
        ambState = STATE_PLAYING
    }
    private fun queueAmbientForce2(song: MusicContainer) {
        App.audioMixer.ambientTrack2.let {
            it.nextTrack = song
            it.stop()
        }
        printdbg(this, "startAmbient2 Now playing: $song")
        ambState = STATE_PLAYING
    }

    var firstTime = true

    override fun update(ingame: IngameInstance, delta: Float) {
        val timeNow = System.currentTimeMillis()
        val callerRecordExpired = (timeNow - (stopCallTime ?: 0L) > 1000)

        if (callerRecordExpired && stopCaller != null) {
            stopCaller = null
            stopCallTime = null
        }

        // start the song queueing if there is one to play
        if (firstTime) {
            firstTime = false
            if (songs.isNotEmpty()) musicState = STATE_INTERMISSION
            if (ambients.isNotEmpty()) ambState = STATE_INTERMISSION
        }


        when (musicState) {
            STATE_FIREPLAY -> {
                if (!musicFired) {
                    musicFired = true
                    startMusic0(pullNextMusicTrack())
                }
            }
            STATE_PLAYING -> {
                // stopMusic() will be called when the music finishes; it's on the setOnCompletionListener
            }
            STATE_INTERMISSION -> {
                intermissionAkku += delta

                if (intermissionAkku >= intermissionLength && songs.isNotEmpty()) {
                    intermissionAkku = 0f
                    musicState = STATE_FIREPLAY
                }
            }
        }

        val season = ingame.world.worldTime.ecologicalSeason
        val isAM = (ingame.world.worldTime.todaySeconds < DAY_LENGTH / 2) // 0 until DAY_LENGTH (86400)
        val solarElevDeg = ingame.world.worldTime.solarElevationDeg
        val isSunUp = (solarElevDeg >= 0)
        val seasonName = when (season) {
            in 0f..2f -> "autumn"
            in 2f..3f -> "summer"
            in 3f..5f -> "autumn"
            else -> "winter"
        }

        when (ambState) {
            STATE_FIREPLAY -> {
                if (!ambFired) {
                    ambFired = true

                    // ambient track 1: diurnal/nocturnal
                    // ambient track 2: crepuscular/matutinal
                    val track1 = if (isSunUp)
                        ambients["ambient.season.diurnal_$seasonName"]!!.random() // mad respect to Klankbeeld
                    else
                        ambients["ambient.season.nocturnal"]!!.random() // as it turns out ambient recordings of a wild place AT NIGHT is quite rare

                    val track2 = if (isAM)
                        ambients["ambient.season.matutinal"]!!.random()
                    else
                        ambients["ambient.season.crepuscular"]!!.random()

                    startAmbient1(track1)
                    startAmbient2(track2)
                }
            }
            STATE_PLAYING -> {
                // mix ambient tracks

                // queue up nocturnal
                if (!isSunUp && oldWorldSolarElev >= 0)
                    queueAmbientForce1(ambients["ambient.season.nocturnal"]!!.random()) // as it turns out ambient recordings of a wild place AT NIGHT is quite rare
                // queue up diurnal
                else if (isSunUp && oldWorldSolarElev < 0)
                    queueAmbientForce1(ambients["ambient.season.diurnal_$seasonName"]!!.random()) // mad respect to Klankbeeld

                // queue up crepuscular
                if (!isAM && oldWorldTime < DAY_LENGTH / 2)
                    queueAmbientForce2(ambients["ambient.season.crepuscular"]!!.random())
                else if (isAM && oldWorldTime >= DAY_LENGTH / 2)
                    queueAmbientForce2(ambients["ambient.season.matutinal"]!!.random())

                // play around the fader
                val track2vol = if (isAM)
                    when (solarElevDeg) {
                        in TRACK2_DAWN_ELEV_UP_MIN..TRACK2_DAWN_ELEV_UP_MAX ->
                            FastMath.interpolateLinear(
                                (solarElevDeg - TRACK2_DAWN_ELEV_UP_MIN) / (TRACK2_DAWN_ELEV_UP_MAX - TRACK2_DAWN_ELEV_UP_MIN),
                                1.0, 0.0
                            )
                        in TRACK2_DAWN_ELEV_DN_MAX..TRACK2_DAWN_ELEV_DN_MIN ->
                            FastMath.interpolateLinear(
                                (solarElevDeg - TRACK2_DAWN_ELEV_DN_MIN) / (TRACK2_DAWN_ELEV_DN_MAX - TRACK2_DAWN_ELEV_DN_MIN),
                                1.0, 0.0
                            )
                        in TRACK2_DAWN_ELEV_DN_MIN..TRACK2_DAWN_ELEV_UP_MIN -> 1.0
                        else -> 0.0
                    }
                else 
                    when (solarElevDeg) {
                        in TRACK2_DUSK_ELEV_UP_MIN..TRACK2_DUSK_ELEV_UP_MAX ->
                            FastMath.interpolateLinear(
                                (solarElevDeg - TRACK2_DUSK_ELEV_UP_MIN) / (TRACK2_DUSK_ELEV_UP_MAX - TRACK2_DUSK_ELEV_UP_MIN),
                                1.0, 0.0
                            )
                        in TRACK2_DUSK_ELEV_DN_MAX..TRACK2_DUSK_ELEV_DN_MIN ->
                            FastMath.interpolateLinear(
                                (solarElevDeg - TRACK2_DUSK_ELEV_DN_MIN) / (TRACK2_DUSK_ELEV_DN_MAX - TRACK2_DUSK_ELEV_DN_MIN),
                                1.0, 0.0
                            )
                        in TRACK2_DUSK_ELEV_DN_MIN..TRACK2_DUSK_ELEV_UP_MIN -> 1.0
                        else -> 0.0
                    }
                val track1vol = 1.0 - track2vol

                App.audioMixer.ambientTrack1.volume = track1vol
                App.audioMixer.ambientTrack2.volume = track2vol
            }
            STATE_INTERMISSION -> {
                ambState = STATE_FIREPLAY
            }
        }

        oldWorldSolarElev = solarElevDeg
        oldWorldTime = ingame.world.worldTime.todaySeconds
    }

    private var oldWorldSolarElev = Terrarum.ingame?.world?.worldTime?.solarElevationDeg ?: 0.0
    private var oldWorldTime = Terrarum.ingame?.world?.worldTime?.todaySeconds ?: 0

    private val TRACK2_DUSK_ELEV_UP_MAX = 15.0
    private val TRACK2_DUSK_ELEV_UP_MIN = 0.1
    private val TRACK2_DUSK_ELEV_DN_MIN = -0.1
    private val TRACK2_DUSK_ELEV_DN_MAX = -15.0

    private val TRACK2_DAWN_ELEV_UP_MAX = 20.0
    private val TRACK2_DAWN_ELEV_UP_MIN = 5.0
    private val TRACK2_DAWN_ELEV_DN_MIN = 5.0
    private val TRACK2_DAWN_ELEV_DN_MAX = -10.0

    override fun dispose() {
        App.audioMixer.requestFadeOut(App.audioMixer.fadeBus, AudioMixer.DEFAULT_FADEOUT_LEN) // explicit call for fade-out when the game instance quits
        stopMusic0(App.audioMixer.musicTrack.currentTrack)
        stopAmbient()
    }
}