cloudstream/app/src/main/java/com/lagradost/cloudstream3/utils/VideoDownloadManager.kt

package com.lagradost.cloudstream3.utils

import android.app.Notification
import android.app.NotificationChannel
import android.app.NotificationManager
import android.app.PendingIntent
import android.content.*
import android.graphics.Bitmap
import android.net.Uri
import android.os.Build
import androidx.annotation.DrawableRes
import androidx.core.app.NotificationCompat
import androidx.core.app.NotificationManagerCompat
import androidx.core.net.toUri
import androidx.preference.PreferenceManager
import androidx.work.Data
import androidx.work.ExistingWorkPolicy
import androidx.work.OneTimeWorkRequest
import androidx.work.WorkManager
import com.bumptech.glide.load.model.GlideUrl
import com.fasterxml.jackson.annotation.JsonProperty
import com.lagradost.cloudstream3.APIHolder.getApiFromNameNull
import com.lagradost.cloudstream3.AcraApplication.Companion.removeKey
import com.lagradost.cloudstream3.AcraApplication.Companion.setKey
import com.lagradost.cloudstream3.BuildConfig
import com.lagradost.cloudstream3.MainActivity
import com.lagradost.cloudstream3.R
import com.lagradost.cloudstream3.TvType
import com.lagradost.cloudstream3.app
import com.lagradost.cloudstream3.mvvm.logError
import com.lagradost.cloudstream3.mvvm.normalSafeApiCall
import com.lagradost.cloudstream3.services.VideoDownloadService
import com.lagradost.cloudstream3.utils.Coroutines.ioSafe
import com.lagradost.cloudstream3.utils.Coroutines.main
import com.lagradost.cloudstream3.utils.DataStore.getKey
import com.lagradost.cloudstream3.utils.DataStore.removeKey
import com.lagradost.cloudstream3.utils.UIHelper.colorFromAttribute
import com.lagradost.safefile.MediaFileContentType
import com.lagradost.safefile.SafeFile
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlinx.coroutines.cancel
import kotlinx.coroutines.delay
import kotlinx.coroutines.isActive
import kotlinx.coroutines.launch
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
import kotlinx.coroutines.withContext
import okhttp3.internal.closeQuietly
import java.io.Closeable
import java.io.File
import java.io.IOException
import java.io.OutputStream
import java.net.URL
import java.util.*

const val DOWNLOAD_CHANNEL_ID = "cloudstream3.general"
const val DOWNLOAD_CHANNEL_NAME = "Downloads"
const val DOWNLOAD_CHANNEL_DESCRIPT = "The download notification channel"

object VideoDownloadManager {
    var maxConcurrentDownloads = 3
    var maxConcurrentConnections = 3
    private var currentDownloads = mutableListOf<Int>()

    private const val USER_AGENT =
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36"

    @get:DrawableRes
    val imgDone get() = R.drawable.rddone

    @get:DrawableRes
    val imgDownloading get() = R.drawable.rdload

    @get:DrawableRes
    val imgPaused get() = R.drawable.rdpause

    @get:DrawableRes
    val imgStopped get() = R.drawable.rderror

    @get:DrawableRes
    val imgError get() = R.drawable.rderror

    @get:DrawableRes
    val pressToPauseIcon get() = R.drawable.ic_baseline_pause_24

    @get:DrawableRes
    val pressToResumeIcon get() = R.drawable.ic_baseline_play_arrow_24

    @get:DrawableRes
    val pressToStopIcon get() = R.drawable.baseline_stop_24

    enum class DownloadType {
        IsPaused,
        IsDownloading,
        IsDone,
        IsFailed,
        IsStopped,
        IsPending
    }

    enum class DownloadActionType {
        Pause,
        Resume,
        Stop,
    }

    interface IDownloadableMinimum {
        val url: String
        val referer: String
        val headers: Map<String, String>
    }

    fun IDownloadableMinimum.getId(): Int {
        return url.hashCode()
    }

    data class DownloadEpisodeMetadata(
        @JsonProperty("id") val id: Int,
        @JsonProperty("mainName") val mainName: String,
        @JsonProperty("sourceApiName") val sourceApiName: String?,
        @JsonProperty("poster") val poster: String?,
        @JsonProperty("name") val name: String?,
        @JsonProperty("season") val season: Int?,
        @JsonProperty("episode") val episode: Int?,
        @JsonProperty("type") val type: TvType?,
    )

    data class DownloadItem(
        @JsonProperty("source") val source: String?,
        @JsonProperty("folder") val folder: String?,
        @JsonProperty("ep") val ep: DownloadEpisodeMetadata,
        @JsonProperty("links") val links: List<ExtractorLink>,
    )

    data class DownloadResumePackage(
        @JsonProperty("item") val item: DownloadItem,
        @JsonProperty("linkIndex") val linkIndex: Int?,
    )

    data class DownloadedFileInfo(
        @JsonProperty("totalBytes") val totalBytes: Long,
        @JsonProperty("relativePath") val relativePath: String,
        @JsonProperty("displayName") val displayName: String,
        @JsonProperty("extraInfo") val extraInfo: String? = null,
        @JsonProperty("basePath") val basePath: String? = null // null is for legacy downloads. See getDefaultPath()
    )

    data class DownloadedFileInfoResult(
        @JsonProperty("fileLength") val fileLength: Long,
        @JsonProperty("totalBytes") val totalBytes: Long,
        @JsonProperty("path") val path: Uri,
    )

    data class DownloadQueueResumePackage(
        @JsonProperty("index") val index: Int,
        @JsonProperty("pkg") val pkg: DownloadResumePackage,
    )

    data class DownloadStatus(
        /** if you should retry with the same args and hope for a better result */
        val retrySame: Boolean,
        /** if you should try the next mirror */
        val tryNext: Boolean,
        /** if the result is what the user intended */
        val success: Boolean,
    )

    /** Invalid input, just skip to the next one as the same args will give the same error */
    private val DOWNLOAD_INVALID_INPUT =
        DownloadStatus(retrySame = false, tryNext = true, success = false)

    /** no need to try any other mirror as we have downloaded the file */
    private val DOWNLOAD_SUCCESS =
        DownloadStatus(retrySame = false, tryNext = false, success = true)

    /** the user pressed stop, so no need to download anything else */
    private val DOWNLOAD_STOPPED =
        DownloadStatus(retrySame = false, tryNext = false, success = true)

    /** the process failed due to some reason, so we retry and also try the next mirror */
    private val DOWNLOAD_FAILED = DownloadStatus(retrySame = true, tryNext = true, success = false)

    /** bad config, skip all mirrors as every call to download will have the same bad config */
    private val DOWNLOAD_BAD_CONFIG =
        DownloadStatus(retrySame = false, tryNext = false, success = false)

    private const val KEY_RESUME_PACKAGES = "download_resume"
    const val KEY_DOWNLOAD_INFO = "download_info"
    private const val KEY_RESUME_QUEUE_PACKAGES = "download_q_resume"

    val downloadStatus = HashMap<Int, DownloadType>()
    val downloadStatusEvent = Event<Pair<Int, DownloadType>>()
    val downloadDeleteEvent = Event<Int>()
    val downloadEvent = Event<Pair<Int, DownloadActionType>>()
    val downloadProgressEvent = Event<Triple<Int, Long, Long>>()
    val downloadQueue = LinkedList<DownloadResumePackage>()

    private var hasCreatedNotChanel = false
    private fun Context.createNotificationChannel() {
        hasCreatedNotChanel = true
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val name = DOWNLOAD_CHANNEL_NAME //getString(R.string.channel_name)
            val descriptionText = DOWNLOAD_CHANNEL_DESCRIPT//getString(R.string.channel_description)
            val importance = NotificationManager.IMPORTANCE_DEFAULT
            val channel = NotificationChannel(DOWNLOAD_CHANNEL_ID, name, importance).apply {
                description = descriptionText
            }
            // Register the channel with the system
            val notificationManager: NotificationManager =
                this.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
            notificationManager.createNotificationChannel(channel)
        }
    }

    ///** Will return IsDone if not found or error */
    //fun getDownloadState(id: Int): DownloadType {
    //    return try {
    //        downloadStatus[id] ?: DownloadType.IsDone
    //    } catch (e: Exception) {
    //        logError(e)
    //        DownloadType.IsDone
    //    }
    //}

    private val cachedBitmaps = hashMapOf<String, Bitmap>()
    fun Context.getImageBitmapFromUrl(url: String, headers: Map<String, String>? = null): Bitmap? {
        try {
            if (cachedBitmaps.containsKey(url)) {
                return cachedBitmaps[url]
            }

            val bitmap = GlideApp.with(this)
                .asBitmap()
                .load(GlideUrl(url) { headers ?: emptyMap() })
                .into(720, 720)
                .get()

            if (bitmap != null) {
                cachedBitmaps[url] = bitmap
            }
            return bitmap
        } catch (e: Exception) {
            logError(e)
            return null
        }
    }

    /**
     * @param hlsProgress will together with hlsTotal display another notification if used, to lessen the confusion about estimated size.
     * */
    private suspend fun createNotification(
        context: Context,
        source: String?,
        linkName: String?,
        ep: DownloadEpisodeMetadata,
        state: DownloadType,
        progress: Long,
        total: Long,
        notificationCallback: (Int, Notification) -> Unit,
        hlsProgress: Long? = null,
        hlsTotal: Long? = null,
        bytesPerSecond: Long
    ): Notification? {
        try {
            if (total <= 0) return null// crash, invalid data

//        main { // DON'T WANT TO SLOW IT DOWN
            val builder = NotificationCompat.Builder(context, DOWNLOAD_CHANNEL_ID)
                .setAutoCancel(true)
                .setColorized(true)
                .setOnlyAlertOnce(true)
                .setShowWhen(false)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                .setColor(context.colorFromAttribute(R.attr.colorPrimary))
                .setContentTitle(ep.mainName)
                .setSmallIcon(
                    when (state) {
                        DownloadType.IsDone -> imgDone
                        DownloadType.IsDownloading -> imgDownloading
                        DownloadType.IsPaused -> imgPaused
                        DownloadType.IsFailed -> imgError
                        DownloadType.IsStopped -> imgStopped
                        DownloadType.IsPending -> imgDownloading
                    }
                )

            if (ep.sourceApiName != null) {
                builder.setSubText(ep.sourceApiName)
            }

            if (source != null) {
                val intent = Intent(context, MainActivity::class.java).apply {
                    data = source.toUri()
                    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
                }
                val pendingIntent: PendingIntent =
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_IMMUTABLE)
                    } else {
                        PendingIntent.getActivity(context, 0, intent, 0)
                    }
                builder.setContentIntent(pendingIntent)
            }

            if (state == DownloadType.IsDownloading || state == DownloadType.IsPaused) {
                builder.setProgress((total / 1000).toInt(), (progress / 1000).toInt(), false)
            } else if (state == DownloadType.IsPending) {
                builder.setProgress(0, 0, true)
            }

            val rowTwoExtra = if (ep.name != null) " - ${ep.name}\n" else ""
            val rowTwo = if (ep.season != null && ep.episode != null) {
                "${context.getString(R.string.season_short)}${ep.season}:${context.getString(R.string.episode_short)}${ep.episode}" + rowTwoExtra
            } else if (ep.episode != null) {
                "${context.getString(R.string.episode)} ${ep.episode}" + rowTwoExtra
            } else {
                (ep.name ?: "") + ""
            }
            val downloadFormat = context.getString(R.string.download_format)

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                if (ep.poster != null) {
                    val poster = withContext(Dispatchers.IO) {
                        context.getImageBitmapFromUrl(ep.poster)
                    }
                    if (poster != null)
                        builder.setLargeIcon(poster)
                }

                val progressPercentage: Long
                val progressMbString: String
                val totalMbString: String
                val suffix: String

                val mbFormat = "%.1f MB"

                if (hlsProgress != null && hlsTotal != null) {
                    progressPercentage = hlsProgress.toLong() * 100 / hlsTotal
                    progressMbString = hlsProgress.toString()
                    totalMbString = hlsTotal.toString()
                    suffix = " - $mbFormat".format(progress / 1000000f)
                } else {
                    progressPercentage = progress * 100 / total
                    progressMbString = mbFormat.format(progress / 1000000f)
                    totalMbString = mbFormat.format(total / 1000000f)
                    suffix = ""
                }

                val mbPerSecondString =
                    if (state == DownloadType.IsDownloading) {
                        " ($mbFormat/s)".format(bytesPerSecond.toFloat() / 1000000f)
                    } else ""

                val bigText =
                    when (state) {
                        DownloadType.IsDownloading, DownloadType.IsPaused -> {
                            (if (linkName == null) "" else "$linkName\n") + "$rowTwo\n$progressPercentage % ($progressMbString/$totalMbString)$suffix$mbPerSecondString"
                        }

                        DownloadType.IsPending -> {
                            (if (linkName == null) "" else "$linkName\n") + rowTwo
                        }

                        DownloadType.IsFailed -> {
                            downloadFormat.format(
                                context.getString(R.string.download_failed),
                                rowTwo
                            )
                        }

                        DownloadType.IsDone -> {
                            downloadFormat.format(context.getString(R.string.download_done), rowTwo)
                        }

                        DownloadType.IsStopped -> {
                            downloadFormat.format(
                                context.getString(R.string.download_canceled),
                                rowTwo
                            )
                        }
                    }

                val bodyStyle = NotificationCompat.BigTextStyle()
                bodyStyle.bigText(bigText)
                builder.setStyle(bodyStyle)
            } else {
                val txt =
                    when (state) {
                        DownloadType.IsDownloading, DownloadType.IsPaused, DownloadType.IsPending -> {
                            rowTwo
                        }

                        DownloadType.IsFailed -> {
                            downloadFormat.format(
                                context.getString(R.string.download_failed),
                                rowTwo
                            )
                        }

                        DownloadType.IsDone -> {
                            downloadFormat.format(context.getString(R.string.download_done), rowTwo)
                        }

                        DownloadType.IsStopped -> {
                            downloadFormat.format(
                                context.getString(R.string.download_canceled),
                                rowTwo
                            )
                        }
                    }

                builder.setContentText(txt)
            }

            if ((state == DownloadType.IsDownloading || state == DownloadType.IsPaused) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                val actionTypes: MutableList<DownloadActionType> = ArrayList()
                // INIT
                if (state == DownloadType.IsDownloading) {
                    actionTypes.add(DownloadActionType.Pause)
                    actionTypes.add(DownloadActionType.Stop)
                }

                if (state == DownloadType.IsPaused) {
                    actionTypes.add(DownloadActionType.Resume)
                    actionTypes.add(DownloadActionType.Stop)
                }

                // ADD ACTIONS
                for ((index, i) in actionTypes.withIndex()) {
                    val actionResultIntent = Intent(context, VideoDownloadService::class.java)

                    actionResultIntent.putExtra(
                        "type", when (i) {
                            DownloadActionType.Resume -> "resume"
                            DownloadActionType.Pause -> "pause"
                            DownloadActionType.Stop -> "stop"
                        }
                    )

                    actionResultIntent.putExtra("id", ep.id)

                    val pending: PendingIntent = PendingIntent.getService(
                        // BECAUSE episodes lying near will have the same id +1, index will give the same requested as the previous episode, *100000 fixes this
                        context, (4337 + index * 1000000 + ep.id),
                        actionResultIntent,
                        PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
                    )

                    builder.addAction(
                        NotificationCompat.Action(
                            when (i) {
                                DownloadActionType.Resume -> pressToResumeIcon
                                DownloadActionType.Pause -> pressToPauseIcon
                                DownloadActionType.Stop -> pressToStopIcon
                            }, when (i) {
                                DownloadActionType.Resume -> context.getString(R.string.resume)
                                DownloadActionType.Pause -> context.getString(R.string.pause)
                                DownloadActionType.Stop -> context.getString(R.string.cancel)
                            }, pending
                        )
                    )
                }
            }

            if (!hasCreatedNotChanel) {
                context.createNotificationChannel()
            }

            val notification = builder.build()
            notificationCallback(ep.id, notification)
            with(NotificationManagerCompat.from(context)) {
                // notificationId is a unique int for each notification that you must define
                notify(ep.id, notification)
            }
            return notification
        } catch (e: Exception) {
            logError(e)
            return null
        }
    }

    private const val reservedChars = "|\\?*<\":>+[]/\'"
    fun sanitizeFilename(name: String, removeSpaces: Boolean = false): String {
        var tempName = name
        for (c in reservedChars) {
            tempName = tempName.replace(c, ' ')
        }
        if (removeSpaces) tempName = tempName.replace(" ", "")
        return tempName.replace("  ", " ").trim(' ')
    }

    /**
     * Used for getting video player subs.
     * @return List of pairs for the files in this format: <Name, Uri>
     * */
    fun getFolder(
        context: Context,
        relativePath: String,
        basePath: String?
    ): List<Pair<String, Uri>>? {
        val base = basePathToFile(context, basePath)
        val folder = base?.gotoDirectory(relativePath, false) ?: return null
        if (folder.isDirectory() != false) return null

        return folder.listFiles()
            ?.mapNotNull { (it.name() ?: "") to (it.uri() ?: return@mapNotNull null) }
    }


    data class CreateNotificationMetadata(
        val type: DownloadType,
        val bytesDownloaded: Long,
        val bytesTotal: Long,
        val hlsProgress: Long? = null,
        val hlsTotal: Long? = null,
        val bytesPerSecond: Long
    )

    data class StreamData(
        private val fileLength: Long,
        val file: SafeFile,
        //val fileStream: OutputStream,
    ) {
        @Throws(IOException::class)
        fun open(): OutputStream {
            return file.openOutputStreamOrThrow(resume)
        }

        @Throws(IOException::class)
        fun openNew(): OutputStream {
            return file.openOutputStreamOrThrow(false)
        }

        fun delete(): Boolean {
            return file.delete()
        }

        val resume: Boolean get() = fileLength > 0L
        val startAt: Long get() = if (resume) fileLength else 0L
        val exists: Boolean get() = file.exists() == true
    }


    @Throws(IOException::class)
    fun setupStream(
        context: Context,
        name: String,
        folder: String?,
        extension: String,
        tryResume: Boolean,
    ): StreamData {
        return setupStream(
            context.getBasePath().first ?: getDefaultDir(context) ?: throw IOException("Bad config"),
            name,
            folder,
            extension,
            tryResume
        )
    }

    /**
     * Sets up the appropriate file and creates a data stream from the file.
     * Used for initializing downloads.
     * */
    @Throws(IOException::class)
    fun setupStream(
        baseFile: SafeFile,
        name: String,
        folder: String?,
        extension: String,
        tryResume: Boolean,
    ): StreamData {
        val displayName = getDisplayName(name, extension)

        val subDir = baseFile.gotoDirectoryOrThrow(folder)
        val foundFile = subDir.findFile(displayName)

        val (file, fileLength) = if (foundFile == null || foundFile.exists() != true) {
            subDir.createFileOrThrow(displayName) to 0L
        } else {
            if (tryResume) {
                foundFile to foundFile.lengthOrThrow()
            } else {
                foundFile.deleteOrThrow()
                subDir.createFileOrThrow(displayName) to 0L
            }
        }

        return StreamData(fileLength, file)
    }

    /** This class handles the notifications, as well as the relevant key */
    data class DownloadMetaData(
        private val id: Int?,
        var bytesDownloaded: Long = 0,
        var bytesWritten: Long = 0,

        var totalBytes: Long? = null,

        // notification metadata
        private var lastUpdatedMs: Long = 0,
        private var lastDownloadedBytes: Long = 0,
        private val createNotificationCallback: (CreateNotificationMetadata) -> Unit,

        private var internalType: DownloadType = DownloadType.IsPending,

        // how many segments that we have downloaded
        var hlsProgress: Int = 0,
        // how many segments that exist
        var hlsTotal: Int? = null,
        // this is how many segments that has been written to the file
        // will always be <= hlsProgress as we may keep some in a buffer
        var hlsWrittenProgress: Int = 0,

        // this is used for copy with metadata on how much we have downloaded for setKey
        private var downloadFileInfoTemplate: DownloadedFileInfo? = null
    ) : Closeable {
        fun setResumeLength(length: Long) {
            bytesDownloaded = length
            bytesWritten = length
            lastDownloadedBytes = length
        }

        val approxTotalBytes: Long
            get() = totalBytes ?: hlsTotal?.let { total ->
                (bytesDownloaded * (total / hlsProgress.toFloat())).toLong()
            } ?: bytesDownloaded

        private val isHLS get() = hlsTotal != null

        private var stopListener: (() -> Unit)? = null

        /** on cancel button pressed or failed invoke this once and only once */
        fun setOnStop(callback: (() -> Unit)) {
            stopListener = callback
        }

        fun removeStopListener() {
            stopListener = null
        }

        private val downloadEventListener = { event: Pair<Int, DownloadActionType> ->
            if (event.first == id) {
                when (event.second) {
                    DownloadActionType.Pause -> {
                        type = DownloadType.IsPaused
                    }

                    DownloadActionType.Stop -> {
                        type = DownloadType.IsStopped
                        removeKey(KEY_RESUME_PACKAGES, event.first.toString())
                        saveQueue()
                        stopListener?.invoke()
                        stopListener = null
                    }

                    DownloadActionType.Resume -> {
                        type = DownloadType.IsDownloading
                    }
                }
            }
        }

        private fun updateFileInfo() {
            if (id == null) return
            downloadFileInfoTemplate?.let { template ->
                setKey(
                    KEY_DOWNLOAD_INFO,
                    id.toString(),
                    template.copy(
                        totalBytes = approxTotalBytes,
                        extraInfo = if (isHLS) hlsWrittenProgress.toString() else null
                    )
                )
            }
        }

        fun setDownloadFileInfoTemplate(template: DownloadedFileInfo) {
            downloadFileInfoTemplate = template
            updateFileInfo()
        }

        init {
            if (id != null) {
                downloadEvent += downloadEventListener
            }
        }

        override fun close() {
            // as we may need to resume hls downloads, we save the current written index
            if (isHLS || totalBytes == null) {
                updateFileInfo()
            }
            if (id != null) {
                downloadEvent -= downloadEventListener
                downloadStatus -= id
            }
            stopListener = null
        }

        var type
            get() = internalType
            set(value) {
                internalType = value
                notify()
            }

        fun onDelete() {
            bytesDownloaded = 0
            hlsWrittenProgress = 0
            hlsProgress = 0
            if (id != null)
                downloadDeleteEvent(id)

            //internalType = DownloadType.IsStopped
            notify()
        }

        companion object {
            const val UPDATE_RATE_MS: Long = 1000L
        }

        @JvmName("DownloadMetaDataNotify")
        private fun notify() {
            // max 10 sec between notifications, min 0.1s, this is to stop div by zero
            val dt = (System.currentTimeMillis() - lastUpdatedMs).coerceIn(100, 10000)

            val bytesPerSecond =
                ((bytesDownloaded - lastDownloadedBytes) * 1000L) / dt

            lastDownloadedBytes = bytesDownloaded
            lastUpdatedMs = System.currentTimeMillis()
            try {
                val bytes = approxTotalBytes

                // notification creation
                if (isHLS) {
                    createNotificationCallback(
                        CreateNotificationMetadata(
                            internalType,
                            bytesDownloaded,
                            bytes,
                            hlsTotal = hlsTotal?.toLong(),
                            hlsProgress = hlsProgress.toLong(),
                            bytesPerSecond = bytesPerSecond
                        )
                    )
                } else {
                    createNotificationCallback(
                        CreateNotificationMetadata(
                            internalType,
                            bytesDownloaded,
                            bytes,
                            bytesPerSecond = bytesPerSecond
                        )
                    )
                }

                // as hls has an approx file size we want to update this metadata
                if (isHLS) {
                    updateFileInfo()
                }

                if (internalType == DownloadType.IsStopped || internalType == DownloadType.IsFailed) {
                    stopListener?.invoke()
                    stopListener = null
                }

                // push all events, this *should* not crash, TODO MUTEX?
                if (id != null) {
                    downloadStatus[id] = type
                    downloadProgressEvent(Triple(id, bytesDownloaded, bytes))
                    downloadStatusEvent(id to type)
                }
            } catch (t: Throwable) {
                logError(t)
                if (BuildConfig.DEBUG) {
                    throw t
                }
            }
        }

        private fun checkNotification() {
            if (lastUpdatedMs + UPDATE_RATE_MS > System.currentTimeMillis()) return
            notify()
        }


        /** adds the length and pushes a notification if necessary */
        fun addBytes(length: Long) {
            bytesDownloaded += length
            // we don't want to update the notification after it is paused,
            // download progress may not stop directly when we "pause" it
            if (type == DownloadType.IsDownloading) checkNotification()
        }

        fun addBytesWritten(length: Long) {
            bytesWritten += length
        }

        /** adds the length + hsl progress and pushes a notification if necessary */
        fun addSegment(length: Long) {
            hlsProgress += 1
            addBytes(length)
        }

        fun setWrittenSegment(segmentIndex: Int) {
            hlsWrittenProgress = segmentIndex + 1
            // in case of abort we need to save every written progress
            updateFileInfo()
        }
    }

    /** bytes have the size end-start where the byte range is [start,end)
     * note that ByteArray is a pointer and therefore cant be stored without cloning it */
    data class LazyStreamDownloadResponse(
        val bytes: ByteArray,
        val startByte: Long,
        val endByte: Long,
    ) {
        val size get() = endByte - startByte

        override fun toString(): String {
            return "$startByte->$endByte"
        }

        override fun equals(other: Any?): Boolean {
            if (other !is LazyStreamDownloadResponse) return false
            return other.startByte == startByte && other.endByte == endByte
        }

        override fun hashCode(): Int {
            return Objects.hash(startByte, endByte)
        }
    }

    data class LazyStreamDownloadData(
        private val url: String,
        private val headers: Map<String, String>,
        private val referer: String,
        /** This specifies where chunck i starts and ends,
         * bytes=${chuckStartByte[ i ]}-${chuckStartByte[ i+1 ] -1}
         * where out of bounds => bytes=${chuckStartByte[ i ]}- */
        private val chuckStartByte: LongArray,
        val totalLength: Long?,
        val downloadLength: Long?,
        val chuckSize: Long,
        val bufferSize: Int,
    ) {
        val size get() = chuckStartByte.size

        /** returns what byte it has downloaded,
         * so start at 10 and download 4 bytes = return 14
         *
         * the range is [startByte, endByte) to be able to do [a, b) [b, c) ect
         *
         * [a, null) will return inclusive to eof = [a, eof]
         *
         * throws an error if initial get request fails, can be specified as return startByte
         * */
        @Throws
        private suspend fun resolve(
            startByte: Long,
            endByte: Long?,
            callback: (suspend CoroutineScope.(LazyStreamDownloadResponse) -> Unit)
        ): Long = withContext(Dispatchers.IO) {
            var currentByte: Long = startByte
            val stopAt = endByte ?: Long.MAX_VALUE
            if (currentByte >= stopAt) return@withContext currentByte

            val request = app.get(
                url,
                headers = headers + mapOf(
                    // range header is inclusive so [startByte, endByte-1] = [startByte, endByte)
                    // if nothing at end the server will continue until eof
                    "Range" to "bytes=$startByte-" // ${endByte?.minus(1)?.toString() ?: "" }
                ),
                referer = referer,
                verify = false
            )
            val requestStream = request.body.byteStream()

            val buffer = ByteArray(bufferSize)
            var read: Int

            try {
                while (requestStream.read(buffer, 0, bufferSize).also { read = it } >= 0) {
                    val start = currentByte
                    currentByte += read.toLong()

                    // this stops overflow
                    if (currentByte >= stopAt) {
                        callback(LazyStreamDownloadResponse(buffer, start, stopAt))
                        break
                    } else {
                        callback(LazyStreamDownloadResponse(buffer, start, currentByte))
                    }
                }
            } catch (e: CancellationException) {
                throw e
            } catch (t: Throwable) {
                logError(t)
            } finally {
                requestStream.closeQuietly()
            }

            return@withContext currentByte
        }

        /** retries the resolve n times and returns true if successful */
        suspend fun resolveSafe(
            index: Int,
            retries: Int = 3,
            callback: (suspend CoroutineScope.(LazyStreamDownloadResponse) -> Unit)
        ): Boolean {
            var start = chuckStartByte.getOrNull(index) ?: return false
            val end = chuckStartByte.getOrNull(index + 1)

            for (i in 0 until retries) {
                try {
                    // in case
                    start = resolve(start, end, callback)
                    // no end defined, so we don't care exactly where it ended
                    if (end == null) return true
                    // we have download more or exactly what we needed
                    if (start >= end) return true
                } catch (e: IllegalStateException) {
                    return false
                } catch (e: CancellationException) {
                    return false
                } catch (t: Throwable) {
                    continue
                }
            }
            return false
        }

    }

    @Throws
    suspend fun streamLazy(
        url: String,
        headers: Map<String, String>,
        referer: String,
        startByte: Long,
        /** how many bytes every connection should be, by default it is 10 MiB */
        chuckSize: Long = (1 shl 20) * 10,
        /** maximum bytes in the buffer that responds */
        bufferSize: Int = DEFAULT_BUFFER_SIZE
    ): LazyStreamDownloadData {
        // we don't want to make a separate connection for every 1kb
        require(chuckSize > 1000)

        var contentLength =
            app.head(url = url, headers = headers, referer = referer, verify = false).size
        if (contentLength != null && contentLength <= 0) contentLength = null

        var downloadLength: Long? = null
        var totalLength: Long? = null

        val ranges = if (contentLength == null) {
            // is the equivalent of [startByte..EOF] as we don't know the size we can only do one
            // connection
            LongArray(1) { startByte }
        } else {
            downloadLength = contentLength - startByte
            totalLength = contentLength
            // div with ceiling as
            // this makes the last part "unknown ending" and it will break at EOF
            // so eg startByte = 0, downloadLength = 13, chuckSize = 10
            // = LongArray(2) { 0, 10 } = [0,10) + [10..EOF]
            LongArray(((downloadLength + chuckSize - 1) / chuckSize).toInt()) { idx ->
                startByte + idx * chuckSize
            }
        }

        return LazyStreamDownloadData(
            url = url,
            headers = headers,
            referer = referer,
            chuckStartByte = ranges,
            downloadLength = downloadLength,
            totalLength = totalLength,
            chuckSize = chuckSize,
            bufferSize = bufferSize
        )
    }

    /** Helper function to make sure duplicate attributes don't get overriden or inserted without lowercase cmp
     * example: map("a" to 1) appendAndDontOverride map("A" to 2, "a" to 3, "c" to 4) = map("a" to 1, "c" to 4)
     * */
    private fun <V> Map<String, V>.appendAndDontOverride(rhs: Map<String, V>): Map<String, V> {
        val out = this.toMutableMap()
        val current = this.keys.map { it.lowercase() }
        for ((key, value) in rhs) {
            if (current.contains(key.lowercase())) continue
            out[key] = value
        }
        return out
    }

    private fun List<Job>.cancel() {
        forEach { job ->
            try {
                job.cancel()
            } catch (t: Throwable) {
                logError(t)
            }
        }
    }

    private suspend fun List<Job>.join() {
        forEach { job ->
            try {
                job.join()
            } catch (t: Throwable) {
                logError(t)
            }
        }
    }

    suspend fun downloadThing(
        context: Context,
        link: IDownloadableMinimum,
        name: String,
        folder: String,
        extension: String,
        tryResume: Boolean,
        parentId: Int?,
        createNotificationCallback: (CreateNotificationMetadata) -> Unit,
        parallelConnections: Int = 3
    ): DownloadStatus = withContext(Dispatchers.IO) {
        // we cant download torrents with this implementation, aria2c might be used in the future
        if (link.url.startsWith("magnet") || link.url.endsWith(".torrent") || parallelConnections < 1) {
            return@withContext DOWNLOAD_INVALID_INPUT
        }

        var fileStream: OutputStream? = null
        //var requestStream: InputStream? = null
        val metadata = DownloadMetaData(
            totalBytes = 0,
            bytesDownloaded = 0,
            createNotificationCallback = createNotificationCallback,
            id = parentId,
        )
        try {
            // get the file path
            val (baseFile, basePath) = context.getBasePath()
            val displayName = getDisplayName(name, extension)
            if (baseFile == null) return@withContext DOWNLOAD_BAD_CONFIG

            // set up the download file
            val stream = setupStream(baseFile, name, folder, extension, tryResume)

            fileStream = stream.open()

            metadata.setResumeLength(stream.startAt)
            metadata.type = DownloadType.IsPending

            val items = streamLazy(
                url = link.url.replace(" ", "%20"),
                referer = link.referer,
                startByte = stream.startAt,
                headers = link.headers.appendAndDontOverride(
                    mapOf(
                        "Accept-Encoding" to "identity",
                        "accept" to "*/*",
                        "user-agent" to USER_AGENT,
                        "sec-ch-ua" to "\"Chromium\";v=\"91\", \" Not;A Brand\";v=\"99\"",
                        "sec-fetch-mode" to "navigate",
                        "sec-fetch-dest" to "video",
                        "sec-fetch-user" to "?1",
                        "sec-ch-ua-mobile" to "?0",
                    )
                )
            )

            metadata.totalBytes = items.totalLength
            metadata.type = DownloadType.IsDownloading
            metadata.setDownloadFileInfoTemplate(
                DownloadedFileInfo(
                    totalBytes = metadata.approxTotalBytes,
                    relativePath = folder,
                    displayName = displayName,
                    basePath = basePath
                )
            )

            val currentMutex = Mutex()
            val current = (0 until items.size).iterator()

            val fileMutex = Mutex()
            // start to data
            val pendingData: HashMap<Long, LazyStreamDownloadResponse> =
                hashMapOf()

            val fileChecker = launch(Dispatchers.IO) {
                while (isActive) {
                    if (stream.exists) {
                        delay(5000)
                        continue
                    }
                    fileMutex.withLock {
                        metadata.type = DownloadType.IsStopped
                    }
                    break
                }
            }

            val jobs = (0 until parallelConnections).map {
                launch(Dispatchers.IO) {

                    // @downloadexplanation
                    // this may seem a bit complex but it more or less acts as a queue system
                    // imagine we do the downloading [0,3] and it response in the order 0,2,3,1
                    // file: [_,_,_,_] queue: [_,_,_,_] Initial condition
                    // file: [X,_,_,_] queue: [_,_,_,_] + added 0 directly to file
                    // file: [X,_,_,_] queue: [_,_,X,_] + added 2 to queue
                    // file: [X,_,_,_] queue: [_,_,X,X] + added 3 to queue
                    // file: [X,X,_,_] queue: [_,_,X,X] + added 1 directly to file
                    // file: [X,X,X,X] queue: [_,_,_,_] write the queue and remove from it

                    // note that this is a bit more complex compared to hsl as ever segment
                    // will return several bytearrays, and is therefore chained by the byte
                    // so every request has a front and back byte instead of an index
                    // this *requires* that no gap exist due because of resolve
                    val callback: (suspend CoroutineScope.(LazyStreamDownloadResponse) -> Unit) =
                        callback@{ response ->
                            if (!isActive) return@callback
                            fileMutex.withLock {
                                // wait until not paused
                                while (metadata.type == DownloadType.IsPaused) delay(100)
                                // if stopped then throw
                                if (metadata.type == DownloadType.IsStopped || metadata.type == DownloadType.IsFailed) {
                                    this.cancel()
                                    return@callback
                                }

                                val responseSize = response.size
                                metadata.addBytes(response.size)

                                if (response.startByte == metadata.bytesWritten) {
                                    // if we are first in the queue then write it directly
                                    fileStream.write(
                                        response.bytes,
                                        0,
                                        responseSize.toInt()
                                    )
                                    metadata.addBytesWritten(responseSize)
                                } else {
                                    // otherwise append to queue, we need to clone the bytes as they will be overridden otherwise
                                    pendingData[response.startByte] =
                                        response.copy(bytes = response.bytes.clone())
                                }

                                while (true) {
                                    // remove the current queue start, so no possibility of
                                    // while(true) { continue } in case size = 0, and removed extra
                                    // garbage
                                    val pending = pendingData.remove(metadata.bytesWritten) ?: break

                                    val size = pending.size

                                    fileStream.write(
                                        pending.bytes,
                                        0,
                                        size.toInt()
                                    )
                                    metadata.addBytesWritten(size)
                                }
                            }
                        }

                    // this will take up the first available job and resolve
                    while (true) {
                        if (!isActive) return@launch
                        fileMutex.withLock {
                            if (metadata.type == DownloadType.IsStopped
                                || metadata.type == DownloadType.IsFailed
                            ) return@launch
                        }

                        // mutex just in case, we never want this to fail due to multithreading
                        val index = currentMutex.withLock {
                            if (!current.hasNext()) return@launch
                            current.nextInt()
                        }

                        // in case something has gone wrong set to failed if the fail is not caused by
                        // user cancellation
                        if (!items.resolveSafe(index, callback = callback)) {
                            fileMutex.withLock {
                                if (metadata.type != DownloadType.IsStopped) {
                                    metadata.type = DownloadType.IsFailed
                                }
                            }
                            return@launch
                        }
                    }
                }
            }

            // fast stop as the jobs may be in a slow request
            metadata.setOnStop {
                jobs.cancel()
            }

            jobs.join()
            fileChecker.cancel()

            // jobs are finished so we don't want to stop them anymore
            metadata.removeStopListener()
            if (!stream.exists) metadata.type = DownloadType.IsStopped

            if (metadata.type == DownloadType.IsFailed) {
                return@withContext DOWNLOAD_FAILED
            }

            if (metadata.type == DownloadType.IsStopped) {
                // we need to close before delete
                fileStream.closeQuietly()
                metadata.onDelete()
                stream.delete()
                return@withContext DOWNLOAD_STOPPED
            }

            metadata.type = DownloadType.IsDone
            return@withContext DOWNLOAD_SUCCESS
        } catch (e: IOException) {
            // some sort of IO error, this should not happened
            // we just rethrow it
            logError(e)
            throw e
        } catch (t: Throwable) {
            // some sort of network error, will error

            // note that when failing we don't want to delete the file,
            // only user interaction has that power
            metadata.type = DownloadType.IsFailed
            return@withContext DOWNLOAD_FAILED
        } finally {
            fileStream?.closeQuietly()
            //requestStream?.closeQuietly()
            metadata.close()
        }
    }

    private suspend fun downloadHLS(
        context: Context,
        link: ExtractorLink,
        name: String,
        folder: String,
        parentId: Int?,
        startIndex: Int?,
        createNotificationCallback: (CreateNotificationMetadata) -> Unit,
        parallelConnections: Int = 3
    ): DownloadStatus = withContext(Dispatchers.IO) {
        if (parallelConnections < 1) return@withContext DOWNLOAD_INVALID_INPUT

        val metadata = DownloadMetaData(
            createNotificationCallback = createNotificationCallback,
            id = parentId
        )
        var fileStream: OutputStream? = null
        try {
            val extension = "mp4"

            // the start .ts index
            var startAt = startIndex ?: 0

            // set up the file data
            val (baseFile, basePath) = context.getBasePath()
            if (baseFile == null) return@withContext DOWNLOAD_BAD_CONFIG

            val displayName = getDisplayName(name, extension)
            val stream =
                setupStream(baseFile, name, folder, extension, startAt > 0)
            if (!stream.resume) startAt = 0
            fileStream = stream.open()

            // push the metadata
            metadata.setResumeLength(stream.startAt)
            metadata.hlsProgress = startAt
            metadata.type = DownloadType.IsPending
            metadata.setDownloadFileInfoTemplate(
                DownloadedFileInfo(
                    totalBytes = 0,
                    relativePath = folder,
                    displayName = displayName,
                    basePath = basePath
                )
            )

            // do the initial get request to fetch the segments
            val m3u8 = M3u8Helper.M3u8Stream(
                link.url, link.quality, link.headers.appendAndDontOverride(
                    mapOf(
                        "Accept-Encoding" to "identity",
                        "accept" to "*/*",
                        "user-agent" to USER_AGENT,
                    ) + if (link.referer.isNotBlank()) mapOf("referer" to link.referer) else emptyMap()
                )
            )
            val items = M3u8Helper2.hslLazy(listOf(m3u8))

            metadata.hlsTotal = items.size
            metadata.type = DownloadType.IsDownloading

            val currentMutex = Mutex()
            val current = (startAt until items.size).iterator()

            val fileMutex = Mutex()
            val pendingData: HashMap<Int, ByteArray> = hashMapOf()

            val fileChecker = launch(Dispatchers.IO) {
                while (isActive) {
                    if (stream.exists) {
                        delay(5000)
                        continue
                    }
                    fileMutex.withLock {
                        metadata.type = DownloadType.IsStopped
                    }
                    break
                }
            }

            // see @downloadexplanation for explanation of this download strategy,
            // this keeps all jobs working at all times,
            // does several connections in parallel instead of a regular for loop to improve
            // download speed
            val jobs = (0 until parallelConnections).map {
                launch(Dispatchers.IO) {
                    while (true) {
                        if (!isActive) return@launch
                        fileMutex.withLock {
                            if (metadata.type == DownloadType.IsStopped
                                || metadata.type == DownloadType.IsFailed
                            ) return@launch
                        }

                        // mutex just in case, we never want this to fail due to multithreading
                        val index = currentMutex.withLock {
                            if (!current.hasNext()) return@launch
                            current.nextInt()
                        }

                        // in case something has gone wrong set to failed if the fail is not caused by
                        // user cancellation
                        val bytes = items.resolveLinkSafe(index) ?: run {
                            fileMutex.withLock {
                                if (metadata.type != DownloadType.IsStopped) {
                                    metadata.type = DownloadType.IsFailed
                                }
                            }
                            return@launch
                        }

                        try {
                            fileMutex.lock()
                            // user pause
                            while (metadata.type == DownloadType.IsPaused) delay(100)
                            // if stopped then break to delete
                            if (metadata.type == DownloadType.IsStopped || metadata.type == DownloadType.IsFailed || !isActive) return@launch

                            val segmentLength = bytes.size.toLong()
                            // send notification, no matter the actual write order
                            metadata.addSegment(segmentLength)

                            // directly write the bytes if you are first
                            if (metadata.hlsWrittenProgress == index) {
                                fileStream.write(bytes)

                                metadata.addBytesWritten(segmentLength)
                                metadata.setWrittenSegment(index)
                            } else {
                                // no need to clone as there will be no modification of this bytearray
                                pendingData[index] = bytes
                            }

                            // write the cached bytes submitted by other threads
                            while (true) {
                                val cache = pendingData.remove(metadata.hlsWrittenProgress) ?: break
                                val cacheLength = cache.size.toLong()

                                fileStream.write(cache)

                                metadata.addBytesWritten(cacheLength)
                                metadata.setWrittenSegment(metadata.hlsWrittenProgress)
                            }
                        } catch (t: Throwable) {
                            // this is in case of write fail
                            logError(t)
                            if (metadata.type != DownloadType.IsStopped) {
                                metadata.type = DownloadType.IsFailed
                            }
                        } finally {
                            try {
                                // may cause java.lang.IllegalStateException: Mutex is not locked because of cancelling
                                fileMutex.unlock()
                            } catch (t : Throwable) {
                                logError(t)
                            }
                        }
                    }
                }
            }

            // fast stop as the jobs may be in a slow request
            metadata.setOnStop {
                jobs.cancel()
            }

            jobs.join()
            fileChecker.cancel()

            metadata.removeStopListener()

            if (!stream.exists) metadata.type = DownloadType.IsStopped

            if (metadata.type == DownloadType.IsFailed) {
                return@withContext DOWNLOAD_FAILED
            }

            if (metadata.type == DownloadType.IsStopped) {
                // we need to close before delete
                fileStream.closeQuietly()
                metadata.onDelete()
                stream.delete()
                return@withContext DOWNLOAD_STOPPED
            }

            metadata.type = DownloadType.IsDone
            return@withContext DOWNLOAD_SUCCESS
        } catch (t: Throwable) {
            logError(t)
            metadata.type = DownloadType.IsFailed
            return@withContext DOWNLOAD_FAILED
        } finally {
            fileStream?.closeQuietly()
            metadata.close()
        }
    }

    private fun getDisplayName(name: String, extension: String): String {
        return "$name.$extension"
    }

    /**
     * Gets the default download path as an UniFile.
     * Vital for legacy downloads, be careful about changing anything here.
     *
     * As of writing UniFile is used for everything but download directory on scoped storage.
     * Special ContentResolver fuckery is needed for that as UniFile doesn't work.
     * */
    fun getDefaultDir(context: Context): SafeFile? {
        // See https://www.py4u.net/discuss/614761
        return SafeFile.fromMedia(
            context, MediaFileContentType.Downloads
        )
    }

    /**
     * Turns a string to an UniFile. Used for stored string paths such as settings.
     * Should only be used to get a download path.
     * */
    private fun basePathToFile(context: Context, path: String?): SafeFile? {
        return when {
            path.isNullOrBlank() -> getDefaultDir(context)
            path.startsWith("content://") -> SafeFile.fromUri(context, path.toUri())
            else -> SafeFile.fromFile(context, File(path))
        }
    }

    /**
     * Base path where downloaded things should be stored, changes depending on settings.
     * Returns the file and a string to be stored for future file retrieval.
     * UniFile.filePath is not sufficient for storage.
     * */
    fun Context.getBasePath(): Pair<SafeFile?, String?> {
        val settingsManager = PreferenceManager.getDefaultSharedPreferences(this)
        val basePathSetting = settingsManager.getString(getString(R.string.download_path_key), null)
        return basePathToFile(this, basePathSetting) to basePathSetting
    }

    fun getFileName(context: Context, metadata: DownloadEpisodeMetadata): String {
        return getFileName(context, metadata.name, metadata.episode, metadata.season)
    }

    private fun getFileName(
        context: Context,
        epName: String?,
        episode: Int?,
        season: Int?
    ): String {
        // kinda ugly ik
        return sanitizeFilename(
            if (epName == null) {
                if (season != null) {
                    "${context.getString(R.string.season)} $season ${context.getString(R.string.episode)} $episode"
                } else {
                    "${context.getString(R.string.episode)} $episode"
                }
            } else {
                if (episode != null) {
                    if (season != null) {
                        "${context.getString(R.string.season)} $season ${context.getString(R.string.episode)} $episode - $epName"
                    } else {
                        "${context.getString(R.string.episode)} $episode - $epName"
                    }
                } else {
                    epName
                }
            }
        )
    }

    private suspend fun downloadSingleEpisode(
        context: Context,
        source: String?,
        folder: String?,
        ep: DownloadEpisodeMetadata,
        link: ExtractorLink,
        notificationCallback: (Int, Notification) -> Unit,
        tryResume: Boolean = false,
    ): DownloadStatus {
        val name = getFileName(context, ep)

        // Make sure this is cancelled when download is done or cancelled.
        val extractorJob = ioSafe {
            if (link.extractorData != null) {
                getApiFromNameNull(link.source)?.extractorVerifierJob(link.extractorData)
            }
        }

        val callback: (CreateNotificationMetadata) -> Unit = { meta ->
            main {
                createNotification(
                    context,
                    source,
                    link.name,
                    ep,
                    meta.type,
                    meta.bytesDownloaded,
                    meta.bytesTotal,
                    notificationCallback,
                    meta.hlsProgress,
                    meta.hlsTotal,
                    meta.bytesPerSecond
                )
            }
        }

        try {
            if (link.isM3u8 || normalSafeApiCall { URL(link.url).path.endsWith(".m3u8") } == true) {
                val startIndex = if (tryResume) {
                    context.getKey<DownloadedFileInfo>(
                        KEY_DOWNLOAD_INFO,
                        ep.id.toString(),
                        null
                    )?.extraInfo?.toIntOrNull()
                } else null

                return downloadHLS(
                    context,
                    link,
                    name,
                    folder ?: "",
                    ep.id,
                    startIndex,
                    callback, parallelConnections = maxConcurrentConnections
                )
            } else {
                return downloadThing(
                    context,
                    link,
                    name,
                    folder ?: "",
                    "mp4",
                    tryResume,
                    ep.id,
                    callback, parallelConnections = maxConcurrentConnections
                )
            }
        } catch (t: Throwable) {
            return DOWNLOAD_FAILED
        } finally {
            extractorJob.cancel()
        }
    }

    suspend fun downloadCheck(
        context: Context, notificationCallback: (Int, Notification) -> Unit,
    ) {
        if (!(currentDownloads.size < maxConcurrentDownloads && downloadQueue.size > 0)) return

        val pkg = downloadQueue.removeFirst()
        val item = pkg.item
        val id = item.ep.id
        if (currentDownloads.contains(id)) { // IF IT IS ALREADY DOWNLOADING, RESUME IT
            downloadEvent.invoke(id to DownloadActionType.Resume)
            return
        }

        currentDownloads.add(id)
        try {
            for (index in (pkg.linkIndex ?: 0) until item.links.size) {
                val link = item.links[index]
                val resume = pkg.linkIndex == index

                setKey(
                    KEY_RESUME_PACKAGES,
                    id.toString(),
                    DownloadResumePackage(item, index)
                )

                var connectionResult =
                    downloadSingleEpisode(
                        context,
                        item.source,
                        item.folder,
                        item.ep,
                        link,
                        notificationCallback,
                        resume
                    )

                if (connectionResult.retrySame) {
                    connectionResult = downloadSingleEpisode(
                        context,
                        item.source,
                        item.folder,
                        item.ep,
                        link,
                        notificationCallback,
                        true
                    )
                }

                if (connectionResult.success) { // SUCCESS
                    removeKey(KEY_RESUME_PACKAGES, id.toString())
                    break
                } else if (!connectionResult.tryNext || index >= item.links.lastIndex) {
                    downloadStatusEvent.invoke(Pair(id, DownloadType.IsFailed))
                    break
                }
            }
        } catch (e: Exception) {
            logError(e)
        } finally {
            currentDownloads.remove(id)
            // Because otherwise notifications will not get caught by the work manager
            downloadCheckUsingWorker(context)
        }

        // return id
    }

    /* fun getDownloadFileInfoAndUpdateSettings(context: Context, id: Int): DownloadedFileInfoResult? {
         val res = getDownloadFileInfo(context, id)
         if (res == null) context.removeKey(KEY_DOWNLOAD_INFO, id.toString())
         return res
     }
 */
    fun getDownloadFileInfoAndUpdateSettings(context: Context, id: Int): DownloadedFileInfoResult? =
        getDownloadFileInfo(context, id, removeKeys = true)

    private fun DownloadedFileInfo.toFile(context: Context): SafeFile? {
        return basePathToFile(context, this.basePath)?.gotoDirectory(relativePath)
            ?.findFile(displayName)
    }

    private fun getDownloadFileInfo(
        context: Context,
        id: Int,
        removeKeys: Boolean = false
    ): DownloadedFileInfoResult? {
        try {
            val info =
                context.getKey<DownloadedFileInfo>(KEY_DOWNLOAD_INFO, id.toString()) ?: return null
            val file = info.toFile(context)

            // only delete the key if the file is not found
            if (file == null || !file.existsOrThrow()) {
                //if (removeKeys) context.removeKey(KEY_DOWNLOAD_INFO, id.toString()) // TODO READD
                return null
            }

            return DownloadedFileInfoResult(
                file.lengthOrThrow(),
                info.totalBytes,
                file.uriOrThrow()
            )
        } catch (e: Exception) {
            logError(e)
            return null
        }
    }

    fun deleteFileAndUpdateSettings(context: Context, id: Int): Boolean {
        val success = deleteFile(context, id)
        if (success) context.removeKey(KEY_DOWNLOAD_INFO, id.toString())
        return success
    }

    /*private fun deleteFile(
        context: Context,
        folder: SafeFile?,
        relativePath: String,
        displayName: String
    ): Boolean {
        val file = folder?.gotoDirectory(relativePath)?.findFile(displayName) ?: return false
        if (file.exists() == false) return true
        return try {
            file.delete()
        } catch (e: Exception) {
            logError(e)
            (context.contentResolver?.delete(file.uri() ?: return true, null, null)
                ?: return false) > 0
        }
    }*/

    private fun deleteFile(context: Context, id: Int): Boolean {
        val info =
            context.getKey<DownloadedFileInfo>(KEY_DOWNLOAD_INFO, id.toString()) ?: return false
        downloadEvent.invoke(id to DownloadActionType.Stop)
        downloadProgressEvent.invoke(Triple(id, 0, 0))
        downloadStatusEvent.invoke(id to DownloadType.IsStopped)
        downloadDeleteEvent.invoke(id)
        return info.toFile(context)?.delete() ?: false
    }

    fun getDownloadResumePackage(context: Context, id: Int): DownloadResumePackage? {
        return context.getKey(KEY_RESUME_PACKAGES, id.toString())
    }

    suspend fun downloadFromResume(
        context: Context,
        pkg: DownloadResumePackage,
        notificationCallback: (Int, Notification) -> Unit,
        setKey: Boolean = true
    ) {
        if (!currentDownloads.any { it == pkg.item.ep.id } && !downloadQueue.any { it.item.ep.id == pkg.item.ep.id }) {
            downloadQueue.addLast(pkg)
            downloadCheck(context, notificationCallback)
            if (setKey) saveQueue()
            //ret
        } else {
            downloadEvent(
                pkg.item.ep.id to DownloadActionType.Resume
            )
            //null
        }
    }

    private fun saveQueue() {
        try {
            val dQueue =
                downloadQueue.toList()
                    .mapIndexed { index, any -> DownloadQueueResumePackage(index, any) }
                    .toTypedArray()
            setKey(KEY_RESUME_QUEUE_PACKAGES, dQueue)
        } catch (t: Throwable) {
            logError(t)
        }
    }

    /*fun isMyServiceRunning(context: Context, serviceClass: Class<*>): Boolean {
        val manager = context.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager?
        for (service in manager!!.getRunningServices(Int.MAX_VALUE)) {
            if (serviceClass.name == service.service.className) {
                return true
            }
        }
        return false
    }*/

    suspend fun downloadEpisode(
        context: Context?,
        source: String?,
        folder: String?,
        ep: DownloadEpisodeMetadata,
        links: List<ExtractorLink>,
        notificationCallback: (Int, Notification) -> Unit,
    ) {
        if (context == null) return
        if (links.isEmpty()) return
        downloadFromResume(
            context,
            DownloadResumePackage(DownloadItem(source, folder, ep, links), null),
            notificationCallback
        )
    }

    /** Worker stuff */
    private fun startWork(context: Context, key: String) {
        val req = OneTimeWorkRequest.Builder(DownloadFileWorkManager::class.java)
            .setInputData(
                Data.Builder()
                    .putString("key", key)
                    .build()
            )
            .build()
        (WorkManager.getInstance(context)).enqueueUniqueWork(
            key,
            ExistingWorkPolicy.KEEP,
            req
        )
    }

    fun downloadCheckUsingWorker(
        context: Context,
    ) {
        startWork(context, DOWNLOAD_CHECK)
    }

    fun downloadFromResumeUsingWorker(
        context: Context,
        pkg: DownloadResumePackage,
    ) {
        val key = pkg.item.ep.id.toString()
        setKey(WORK_KEY_PACKAGE, key, pkg)
        startWork(context, key)
    }

    // Keys are needed to transfer the data to the worker reliably and without exceeding the data limit
    const val WORK_KEY_PACKAGE = "work_key_package"
    const val WORK_KEY_INFO = "work_key_info"

    fun downloadEpisodeUsingWorker(
        context: Context,
        source: String?,
        folder: String?,
        ep: DownloadEpisodeMetadata,
        links: List<ExtractorLink>,
    ) {
        val info = DownloadInfo(
            source, folder, ep, links
        )

        val key = info.ep.id.toString()
        setKey(WORK_KEY_INFO, key, info)
        startWork(context, key)
    }

    data class DownloadInfo(
        @JsonProperty("source") val source: String?,
        @JsonProperty("folder") val folder: String?,
        @JsonProperty("ep") val ep: DownloadEpisodeMetadata,
        @JsonProperty("links") val links: List<ExtractorLink>
    )
}