package eu.kanade.tachiyomi.source

import android.content.Context
import eu.kanade.tachiyomi.R
import eu.kanade.tachiyomi.source.model.*
import eu.kanade.tachiyomi.util.ChapterRecognition
import eu.kanade.tachiyomi.util.DiskUtil
import eu.kanade.tachiyomi.util.EpubFile
import eu.kanade.tachiyomi.util.ImageUtil
import junrar.Archive
import junrar.rarfile.FileHeader
import net.greypanther.natsort.CaseInsensitiveSimpleNaturalComparator
import rx.Observable
import timber.log.Timber
import java.io.File
import java.io.FileInputStream
import java.io.InputStream
import java.util.Comparator
import java.util.Locale
import java.util.concurrent.TimeUnit
import java.util.zip.ZipEntry
import java.util.zip.ZipFile

class LocalSource(private val context: Context) : CatalogueSource {
    companion object {
        private val COVER_NAME = "cover.jpg"
        private val POPULAR_FILTERS = FilterList(OrderBy())
        private val LATEST_FILTERS = FilterList(OrderBy().apply { state = Filter.Sort.Selection(1, false) })
        private val LATEST_THRESHOLD = TimeUnit.MILLISECONDS.convert(7, TimeUnit.DAYS)
        val ID = 0L

        fun updateCover(context: Context, manga: SManga, input: InputStream): File? {
            val dir = getBaseDirectories(context).firstOrNull()
            if (dir == null) {
                input.close()
                return null
            }
            val cover = File("${dir.absolutePath}/${manga.url}", COVER_NAME)

            // It might not exist if using the external SD card
            cover.parentFile.mkdirs()
            input.use {
                cover.outputStream().use {
                    input.copyTo(it)
                }
            }
            return cover
        }

        private fun getBaseDirectories(context: Context): List<File> {
            val c = context.getString(R.string.app_name) + File.separator + "local"
            return DiskUtil.getExternalStorages(context).map { File(it.absolutePath, c) }
        }
    }

    override val id = ID
    override val name = context.getString(R.string.local_source)
    override val lang = ""
    override val supportsLatest = true

    override fun toString() = context.getString(R.string.local_source)

    override fun fetchPopularManga(page: Int) = fetchSearchManga(page, "", POPULAR_FILTERS)

    override fun fetchSearchManga(page: Int, query: String, filters: FilterList): Observable<MangasPage> {
        val baseDirs = getBaseDirectories(context)

        val time = if (filters === LATEST_FILTERS) System.currentTimeMillis() - LATEST_THRESHOLD else 0L
        var mangaDirs = baseDirs.mapNotNull { it.listFiles()?.toList() }
                .flatten()
                .filter { it.isDirectory && if (time == 0L) it.name.contains(query, ignoreCase = true) else it.lastModified() >= time }
                .distinctBy { it.name }

        val state = ((if (filters.isEmpty()) POPULAR_FILTERS else filters)[0] as OrderBy).state
        when (state?.index) {
            0 -> {
                if (state.ascending)
                    mangaDirs = mangaDirs.sortedBy { it.name.toLowerCase(Locale.ENGLISH) }
                else
                    mangaDirs = mangaDirs.sortedByDescending { it.name.toLowerCase(Locale.ENGLISH) }
            }
            1 -> {
                if (state.ascending)
                    mangaDirs = mangaDirs.sortedBy(File::lastModified)
                else
                    mangaDirs = mangaDirs.sortedByDescending(File::lastModified)
            }
        }

        val mangas = mangaDirs.map { mangaDir ->
            SManga.create().apply {
                title = mangaDir.name
                url = mangaDir.name

                // Try to find the cover
                for (dir in baseDirs) {
                    val cover = File("${dir.absolutePath}/$url", COVER_NAME)
                    if (cover.exists()) {
                        thumbnail_url = cover.absolutePath
                        break
                    }
                }

                // Copy the cover from the first chapter found.
                if (thumbnail_url == null) {
                    val chapters = fetchChapterList(this).toBlocking().first()
                    if (chapters.isNotEmpty()) {
                        try {
                            val dest = updateCover(chapters.last(), this)
                            thumbnail_url = dest?.absolutePath
                        } catch (e: Exception) {
                            Timber.e(e)
                        }
                    }
                }

                initialized = true
            }
        }
        return Observable.just(MangasPage(mangas, false))
    }

    override fun fetchLatestUpdates(page: Int) = fetchSearchManga(page, "", LATEST_FILTERS)

    override fun fetchMangaDetails(manga: SManga) = Observable.just(manga)

    override fun fetchChapterList(manga: SManga): Observable<List<SChapter>> {
        val comparator = CaseInsensitiveSimpleNaturalComparator.getInstance<String>()
        val chapters = getBaseDirectories(context)
                .mapNotNull { File(it, manga.url).listFiles()?.toList() }
                .flatten()
                .filter { it.isDirectory || isSupportedFile(it.extension) }
                .map { chapterFile ->
                    SChapter.create().apply {
                        url = "${manga.url}/${chapterFile.name}"
                        val chapName = if (chapterFile.isDirectory) {
                            chapterFile.name
                        } else {
                            chapterFile.nameWithoutExtension
                        }
                        val chapNameCut = chapName.replace(manga.title, "", true).trim(' ', '-', '_')
                        name = if (chapNameCut.isEmpty()) chapName else chapNameCut
                        date_upload = chapterFile.lastModified()
                        ChapterRecognition.parseChapterNumber(this, manga)
                    }
                }
                .sortedWith(Comparator { c1, c2 ->
                    val c = c2.chapter_number.compareTo(c1.chapter_number)
                    if (c == 0) comparator.compare(c2.name, c1.name) else c
                })

        return Observable.just(chapters)
    }

    override fun fetchPageList(chapter: SChapter): Observable<List<Page>> {
        return Observable.error(Exception("Unused"))
    }

    private fun isSupportedFile(extension: String): Boolean {
        return extension.toLowerCase() in setOf("zip", "rar", "cbr", "cbz", "epub")
    }

    fun getFormat(chapter: SChapter): Format {
        val baseDirs = getBaseDirectories(context)

        for (dir in baseDirs) {
            val chapFile = File(dir, chapter.url)
            if (!chapFile.exists()) continue

            return getFormat(chapFile)
        }
        throw Exception("Chapter not found")
    }

    private fun getFormat(file: File): Format {
        val extension = file.extension
        return if (file.isDirectory) {
            Format.Directory(file)
        } else if (extension.equals("zip", true) || extension.equals("cbz", true)) {
            Format.Zip(file)
        } else if (extension.equals("rar", true) || extension.equals("cbr", true)) {
            Format.Rar(file)
        } else if (extension.equals("epub", true)) {
            Format.Epub(file)
        } else {
            throw Exception("Invalid chapter format")
        }
    }

    private fun updateCover(chapter: SChapter, manga: SManga): File? {
        val format = getFormat(chapter)
        val comparator = CaseInsensitiveSimpleNaturalComparator.getInstance<String>()
        return when (format) {
            is Format.Directory -> {
                val entry = format.file.listFiles()
                    .sortedWith(Comparator<File> { f1, f2 -> comparator.compare(f1.name, f2.name) })
                    .find { !it.isDirectory && ImageUtil.isImage(it.name, { FileInputStream(it) }) }

                entry?.let { updateCover(context, manga, it.inputStream())}
            }
            is Format.Zip -> {
                ZipFile(format.file).use { zip ->
                    val entry = zip.entries().toList()
                        .sortedWith(Comparator<ZipEntry> { f1, f2 -> comparator.compare(f1.name, f2.name) })
                        .find { !it.isDirectory && ImageUtil.isImage(it.name, { zip.getInputStream(it) }) }

                    entry?.let { updateCover(context, manga, zip.getInputStream(it) )}
                }
            }
            is Format.Rar -> {
                Archive(format.file).use { archive ->
                    val entry = archive.fileHeaders
                        .sortedWith(Comparator<FileHeader> { f1, f2 -> comparator.compare(f1.fileNameString, f2.fileNameString) })
                        .find { !it.isDirectory && ImageUtil.isImage(it.fileNameString, { archive.getInputStream(it) }) }

                    entry?.let { updateCover(context, manga, archive.getInputStream(it) )}
                }
            }
            is Format.Epub -> {
                EpubFile(format.file).use { epub ->
                    val entry = epub.getImagesFromPages()
                        .firstOrNull()
                        ?.let { epub.getEntry(it) }

                    entry?.let { updateCover(context, manga, epub.getInputStream(it)) }
                }
            }
        }
    }

    private class OrderBy : Filter.Sort("Order by", arrayOf("Title", "Date"), Filter.Sort.Selection(0, true))

    override fun getFilterList() = FilterList(OrderBy())

    sealed class Format {
        data class Directory(val file: File) : Format()
        data class Zip(val file: File) : Format()
        data class Rar(val file: File): Format()
        data class Epub(val file: File) : Format()
    }

}