package app.myzel394.alibi.services

import android.content.Context
import android.content.pm.ServiceInfo
import android.media.AudioDeviceCallback
import android.media.AudioDeviceInfo
import android.media.AudioManager
import android.media.MediaRecorder
import android.media.MediaRecorder.OnErrorListener
import android.os.Build
import android.os.Handler
import android.os.Looper
import androidx.core.app.ServiceCompat
import app.myzel394.alibi.NotificationHelper
import app.myzel394.alibi.db.RecordingInformation
import app.myzel394.alibi.enums.RecorderState
import app.myzel394.alibi.helpers.AudioBatchesFolder
import app.myzel394.alibi.helpers.BatchesFolder
import app.myzel394.alibi.ui.SUPPORTS_SCOPED_STORAGE
import app.myzel394.alibi.ui.utils.MicrophoneInfo
import java.lang.IllegalStateException

class AudioRecorderService :
    IntervalRecorderService<RecordingInformation, AudioBatchesFolder>() {
    override var batchesFolder = AudioBatchesFolder.viaInternalFolder(this)

    private val handler = Handler(Looper.getMainLooper())

    var amplitudes = mutableListOf<Int>()
        private set
    var amplitudesAmount = 1000

    var selectedMicrophone: MicrophoneInfo? = null

    var recorder: MediaRecorder? = null
        private set

    // Callbacks
    var onSelectedMicrophoneChange: (MicrophoneInfo?) -> Unit = {}
    var onMicrophoneDisconnected: () -> Unit = {}
    var onMicrophoneReconnected: () -> Unit = {}
    var onAmplitudeChange: ((List<Int>) -> Unit)? = null

    override fun startNewCycle() {
        super.startNewCycle()

        val newRecorder = createRecorder().also {
            it.prepare()
        }

        resetRecorder()
        startAudioDevice()

        try {
            recorder = newRecorder
            newRecorder.start()
        } catch (error: RuntimeException) {
            onError()
        }
    }

    override fun start() {
        super.start()

        createAmplitudesTimer()
        registerMicrophoneListener()
    }

    override fun pause() {
        super.pause()

        resetRecorder()
    }

    override suspend fun stop() {
        resetRecorder()
        unregisterMicrophoneListener()

        super.stop()
    }

    override fun resume() {
        super.resume()
        createAmplitudesTimer()
    }

    override fun startForegroundService() {
        ServiceCompat.startForeground(
            this,
            NotificationHelper.RECORDER_CHANNEL_NOTIFICATION_ID,
            getNotificationHelper().buildStartingNotification(),
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
                ServiceInfo.FOREGROUND_SERVICE_TYPE_MICROPHONE
            } else {
                0
            },
        )
    }

    // ==== Amplitude related ====
    private fun getAmplitudeAmount(): Int = amplitudesAmount

    private fun getAmplitude(): Int {
        return try {
            recorder!!.maxAmplitude
        } catch (error: IllegalStateException) {
            0
        } catch (error: RuntimeException) {
            0
        }
    }

    private fun updateAmplitude() {
        if (state !== RecorderState.RECORDING) {
            return
        }

        amplitudes.add(getAmplitude())
        onAmplitudeChange?.invoke(amplitudes)

        // Delete old amplitudes
        if (amplitudes.size > getAmplitudeAmount()) {
            // Should be more efficient than dropping the elements, getting a new list
            // clearing old list and adding new elements to it
            repeat(amplitudes.size - getAmplitudeAmount()) {
                amplitudes.removeAt(0)
            }
        }

        handler.postDelayed(::updateAmplitude, 100)
    }

    private fun createAmplitudesTimer() {
        handler.postDelayed(::updateAmplitude, 100)
    }

    // ==== Audio device related ====

    /// Tell Android to use the correct bluetooth microphone, if any selected
    private fun startAudioDevice() {
        if (selectedMicrophone == null) {
            return
        }

        val audioManger = getSystemService(AUDIO_SERVICE)!! as AudioManager

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            audioManger.setCommunicationDevice(selectedMicrophone!!.deviceInfo)
        } else {
            audioManger.startBluetoothSco()
        }
    }

    private fun clearAudioDevice() {
        val audioManger = getSystemService(AUDIO_SERVICE)!! as AudioManager

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            audioManger.clearCommunicationDevice()
        } else {
            audioManger.stopBluetoothSco()
        }
    }

    private fun getNameForMediaFile() =
        "${batchesFolder.mediaPrefix}$counter.${settings.audioRecorderSettings.fileExtension}"

    // ==== Actual recording related ====
    private fun createRecorder(): MediaRecorder {
        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            MediaRecorder(this)
        } else {
            MediaRecorder()
        }.apply {
            val audioSettings = settings.audioRecorderSettings

            // Audio Source is kinda strange, here are my experimental findings using a Pixel 7 Pro
            // and Redmi Buds 3 Pro:
            // - MIC: Uses the bottom microphone of the phone (17)
            // - CAMCORDER: Uses the top microphone of the phone (2)
            // - VOICE_COMMUNICATION: Uses the bottom microphone of the phone (17)
            // - DEFAULT: Uses the bottom microphone of the phone (17)
            setAudioSource(MediaRecorder.AudioSource.MIC)

            when (batchesFolder.type) {
                BatchesFolder.BatchType.INTERNAL -> {
                    setOutputFile(
                        batchesFolder.asInternalGetFile(
                            counter,
                            audioSettings.fileExtension
                        ).absolutePath
                    )
                }

                BatchesFolder.BatchType.CUSTOM -> {
                    setOutputFile(
                        batchesFolder.asCustomGetFileDescriptor(
                            counter,
                            audioSettings.fileExtension
                        )
                    )
                }

                BatchesFolder.BatchType.MEDIA -> {
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                        setOutputFile(
                            batchesFolder.asMediaGetScopedStorageFileDescriptor(
                                getNameForMediaFile(),
                                "audio/${audioSettings.fileExtension}"
                            )
                        )
                    } else {
                        val name = getNameForMediaFile()
                        val file = batchesFolder.asMediaGetLegacyFile(name)

                        setOutputFile(file.absolutePath)
                    }
                }
            }

            setOutputFormat(audioSettings.getOutputFormat())

            setAudioEncoder(audioSettings.getEncoder())
            setAudioEncodingBitRate(audioSettings.bitRate)
            setAudioSamplingRate(audioSettings.getSamplingRate())
            setOnErrorListener(OnErrorListener { _, _, _ ->
                onError()
            })
        }
    }

    // ==== Microphone related ====
    private fun resetRecorder() {
        runCatching {
            recorder?.apply {
                stop()
                reset()
                release()
            }
            clearAudioDevice()
            batchesFolder.cleanup()
        }
    }

    fun changeMicrophone(microphone: MicrophoneInfo?) {
        selectedMicrophone = microphone
        onSelectedMicrophoneChange(microphone)

        if (state == RecorderState.RECORDING) {
            startNewCycle()
        }
    }

    private val audioDeviceCallback = object : AudioDeviceCallback() {
        override fun onAudioDevicesAdded(addedDevices: Array<out AudioDeviceInfo>?) {
            super.onAudioDevicesAdded(addedDevices)

            if (selectedMicrophone == null) {
                return
            }

            // We can't compare the ID, as it seems to be changing on each reconnect
            val newDevice = addedDevices?.find {
                it.productName == selectedMicrophone!!.deviceInfo.productName &&
                        it.isSink == selectedMicrophone!!.deviceInfo.isSink &&
                        it.type == selectedMicrophone!!.deviceInfo.type && (
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
                            it.address == selectedMicrophone!!.deviceInfo.address
                        } else true
                        )
            }
            if (newDevice != null) {
                changeMicrophone(MicrophoneInfo.fromDeviceInfo(newDevice))

                onMicrophoneReconnected()
            }
        }

        override fun onAudioDevicesRemoved(removedDevices: Array<out AudioDeviceInfo>?) {
            super.onAudioDevicesRemoved(removedDevices)

            if (selectedMicrophone == null) {
                return
            }

            if (removedDevices?.find { it.id == selectedMicrophone!!.deviceInfo.id } != null) {
                onMicrophoneDisconnected()
            }
        }
    }

    private fun registerMicrophoneListener() {
        val audioManager = getSystemService(Context.AUDIO_SERVICE)!! as AudioManager

        audioManager.registerAudioDeviceCallback(
            audioDeviceCallback,
            Handler(Looper.getMainLooper())
        )
    }

    private fun unregisterMicrophoneListener() {
        val audioManager = getSystemService(Context.AUDIO_SERVICE)!! as AudioManager

        audioManager.unregisterAudioDeviceCallback(audioDeviceCallback)
    }

    // ==== Settings ====
    override fun getRecordingInformation() = RecordingInformation(
        folderPath = batchesFolder.exportFolderForSettings(),
        recordingStart = recordingStart,
        maxDuration = settings.maxDuration,
        fileExtension = settings.audioRecorderSettings.fileExtension,
        intervalDuration = settings.intervalDuration,
        type = RecordingInformation.Type.AUDIO,
    )
}