class ImportSongs{
	constructor(...args){
		this.init(...args)
	}
	init(limited, otherFiles, noPlugins, pluginAmount){
		this.limited = limited
		this.tjaFiles = []
		this.osuFiles = []
		this.assetFiles = {}
		this.pluginFiles = []
		this.otherFiles = otherFiles || {}
		this.noPlugins = noPlugins
		this.pluginAmount = pluginAmount
		this.songs = []
		this.stylesheet = []
		this.plugins = []
		this.songTitle = this.otherFiles.songTitle || {}
		this.uraRegex = /\s*[\(（]裏[\)）]$/
		this.courseTypes = {
			"easy": 0,
			"normal": 1,
			"hard": 2,
			"oni": 3,
			"ura": 4
		}
		this.categoryAliases = {}
		assets.categories.forEach(cat => {
			this.categoryAliases[cat.title.toLowerCase()] = cat.id
			if(cat.aliases){
				cat.aliases.forEach(alias => {
					this.categoryAliases[alias.toLowerCase()] = cat.id
				})
			}
			if(cat.title_lang){
				for(var i in cat.title_lang){
					this.categoryAliases[cat.title_lang[i].toLowerCase()] = cat.id
				}
			}
		})
		this.assetSelectors = {}
		for(var selector in assets.cssBackground){
			var filename = assets.cssBackground[selector]
			var index = filename.lastIndexOf(".")
			if(index !== -1){
				filename = filename.slice(0, index)
			}
			this.assetSelectors[filename] = selector
		}
		this.comboVoices = ["v_combo_50"].concat(Array.from(Array(50), (d, i) => "v_combo_" + ((i + 1) * 100)))
	}
	load(files){
		var extensionRegex = /\.[^\/]+$/
		files.sort((a, b) => {
			var path1 = a.path.replace(extensionRegex, "")
			var path2 = b.path.replace(extensionRegex, "")
			return path1 > path2 ? 1 : -1
		})
		
		var metaFiles = []
		for(var i = 0; i < files.length; i++){
			var file = files[i]
			var name = file.name.toLowerCase()
			var path = file.path.toLowerCase()
			if(name.endsWith(".tja") || name.endsWith(".tjf")){
				this.tjaFiles.push({
					file: file,
					index: i
				})
			}else if(name.endsWith(".osu")){
				this.osuFiles.push({
					file: file,
					index: i
				})
			}else if(!this.limited && (name === "genre.ini" || name === "box.def") || name === "songtitle.txt"){
				var level = (file.path.match(/\//g) || []).length
				metaFiles.push({
					file: file,
					level: (level * 2) + (name === "genre.ini" ? 1 : 0)
				})
			}else if(!this.limited && (path.indexOf("/taiko-web assets/") !== -1 || path.indexOf("taiko-web assets/") === 0)){
				if(!(name in this.assetFiles)){
					this.assetFiles[name] = file
				}
			}else if(name.endsWith(".taikoweb.js")){
				this.pluginFiles.push({
					file: file,
					index: i
				})
			}else{
				this.otherFiles[path] = file
			}
		}
		
		if(!this.noPlugins && this.pluginFiles.length){
			var pluginPromises = []
			this.pluginFiles.forEach(fileObj => {
				pluginPromises.push(this.addPlugin(fileObj).catch(e => console.warn(e)))
			})
			return Promise.all(pluginPromises).then(() => {
				var startPromises = []
				var pluginAmount = 0
				if(this.plugins.length && confirm(strings.plugins.warning.replace("%s",
					strings.plugins.plugin[strings.plural.select(this.plugins.length)].replace("%s",
						this.plugins.length.toString()
					)
				))){
					this.plugins.forEach(obj => {
						var plugin = plugins.add(obj.data, {
							name: obj.name,
							raw: true
						})
						if(plugin){
							pluginAmount++
							plugin.imported = true
							startPromises.push(plugin.start())
						}
					})
				}
				return Promise.all(startPromises).then(() => {
					var importSongs = new ImportSongs(this.limited, this.otherFiles, true, pluginAmount)
					return importSongs.load(files)
				})
			})
		}
		
		var metaPromises = []
		metaFiles.forEach(fileObj => {
			metaPromises.push(this.addMeta(fileObj))
		})
		
		return Promise.all(metaPromises).then(() => {
			var songPromises = []
			
			this.tjaFiles.forEach(fileObj => {
				songPromises.push(this.addTja(fileObj).catch(e => console.warn(e)))
			})
			this.osuFiles.forEach(fileObj => {
				songPromises.push(this.addOsu(fileObj).catch(e => console.warn(e)))
			})
			songPromises.push(this.addAssets())
			return Promise.all(songPromises)
		}).then(this.loaded.bind(this))
	}
	
	addMeta(fileObj){
		var file = fileObj.file
		var level = fileObj.level
		var name = file.name.toLowerCase()
		return file.read(name === "songtitle.txt" ? undefined : "utf-8").then(data => {
			var data = data.replace(/\0/g, "").split("\n")
			var category
			if(name === "genre.ini"){
				var key
				for(var i = 0; i < data.length; i++){
					var line = data[i].trim().toLowerCase()
					if(line.startsWith("[") && line.endsWith("]")){
						key = line.slice(1, -1)
					}else if(key === "genre"){
						var equalsPos = line.indexOf("=")
						if(equalsPos !== -1 && line.slice(0, equalsPos).trim() === "genrename"){
							var value = line.slice(equalsPos + 1).trim()
							if(value.toLowerCase() in this.categoryAliases){
								category = value
							}else{
								category = data[i].trim().slice(equalsPos + 1).trim()
							}
							break
						}
					}
				}
			}else if(name === "box.def"){
				for(var i = 0; i < data.length; i++){
					var line = data[i].trim().toLowerCase()
					if(line.startsWith("#title:")){
						var value = line.slice(7).trim()
						if(value.toLowerCase() in this.categoryAliases){
							category = value
						}
					}else if(line.startsWith("#genre:")){
						var value = line.slice(7).trim()
						if(value.toLowerCase() in this.categoryAliases){
							category = value
						}else{
							category = data[i].trim().slice(7).trim()
						}
						break
					}
				}
			}else if(name === "songtitle.txt"){
				var lastTitle
				for(var i = 0; i < data.length; i++){
					var line = data[i].trim()
					if(line){
						var lang = line.slice(0, 2)
						if(line.charAt(2) !== " " || !(lang in allStrings)){
							this.songTitle[line] = {}
							lastTitle = line
						}else if(lastTitle){
							this.songTitle[lastTitle][lang] = line.slice(3).trim()
						}
					}
				}
			}
			if(category){
				var metaPath = file.path.toLowerCase().slice(0, file.name.length * -1)
				var filesLoop = fileObj => {
					var tjaPath = fileObj.file.path.toLowerCase().slice(0, fileObj.file.name.length * -1)
					if(tjaPath.startsWith(metaPath) && (!("categoryLevel" in fileObj) || fileObj.categoryLevel < level)){
						if(category.toLowerCase() in this.categoryAliases){
							fileObj.category_id = this.categoryAliases[category.toLowerCase()]
						}else{
							fileObj.category = category
						}
						fileObj.categoryLevel = level
					}
				}
				this.tjaFiles.forEach(filesLoop)
				this.osuFiles.forEach(filesLoop)
			}
		}).catch(e => {
			console.warn(e)
		})
	}
	
	addTja(fileObj){
		var file = fileObj.file
		var index = fileObj.index
		var category = fileObj.category
		var category_id = fileObj.category_id
		if(!this.limited){
			var filePromise = file.read("sjis") // utf-8にしたい
		}else{
			var filePromise = Promise.resolve()
		}
		return filePromise.then(dataRaw => {
			var data = dataRaw ? dataRaw.replace(/\0/g, "").split("\n") : []
			var tja = new ParseTja(data, "oni", 0, 0, true)
			var songObj = {
				id: index + 1,
				order: index + 1,
				title: file.name.slice(0, file.name.lastIndexOf(".")),
				type: "tja",
				chart: file,
				courses: {},
				music: "muted",
				custom: true
			}
			if(this.limited){
				songObj.unloaded = true
			}
			var coursesAdded = false
			var titleLang = {}
			var titleLangAdded = false
			var subtitleLangAdded = false
			var subtitleLang = {}
			var dir = file.path.toLowerCase()
			dir = dir.slice(0, dir.lastIndexOf("/") + 1)
			for(var diff in tja.metadata){
				var meta = tja.metadata[diff]
				songObj.title = meta.title || file.name.slice(0, file.name.lastIndexOf("."))
				var subtitle = meta.subtitle || ""
				if(subtitle.startsWith("--") || subtitle.startsWith("++")){
					subtitle = subtitle.slice(2).trim()
				}
				songObj.subtitle = subtitle
				songObj.preview = meta.demostart || 0
				songObj.courses[diff] = {
					stars: meta.level || 0,
					branch: !!meta.branch
				}
				coursesAdded = true
				if(meta.wave){
					songObj.music = this.otherFiles[dir + meta.wave.toLowerCase()] || songObj.music
				}
				if(meta.genre){
					if(meta.genre.toLowerCase() in this.categoryAliases){
						songObj.category_id = this.categoryAliases[meta.genre.toLowerCase()]
					}else{
						songObj.category = meta.genre
					}
				}
				if(meta.taikowebskin){
					songObj.song_skin = this.getSkin(dir, meta.taikowebskin)
				}
				if(meta.maker){
					var maker = meta.maker
					var url = null
					var gt = maker.lastIndexOf(">")
					if(gt === maker.length - 1){
						var lt = maker.lastIndexOf("<")
						if(lt !== -1 && lt !== gt - 2){
							url = maker.slice(lt + 1, gt).trim()
							if(url.startsWith("http://") || url.startsWith("https://")){
								maker = maker.slice(0, lt)
							}else{
								url = null
							}
						}
					}
					songObj.maker = {
						name: maker,
						url: url,
						id: 1
					}
				}
				if(meta.lyrics){
					var lyricsFile = this.normPath(this.joinPath(dir, meta.lyrics))
					if(lyricsFile in this.otherFiles){
						songObj.lyrics = true
						songObj.lyricsFile = this.otherFiles[lyricsFile]
					}
				}else if(meta.inlineLyrics){
					songObj.lyrics = true
				}
				for(var id in allStrings){
					var songTitle = songObj.title
					var ura = ""
					if(songTitle){
						var uraPos = songTitle.search(this.uraRegex)
						if(uraPos !== -1){
							ura = songTitle.slice(uraPos)
							songTitle = songTitle.slice(0, uraPos)
						}
					}
					if(meta["title" + id]){
						titleLang[id] = meta["title" + id]
						titleLangAdded = true
					}else if(songTitle in this.songTitle && this.songTitle[songTitle][id]){
						titleLang[id] = this.songTitle[songTitle][id] + ura
						titleLangAdded = true
					}
					if(meta["subtitle" + id]){
						subtitleLang[id] = meta["subtitle" + id]
						subtitleLangAdded = true
					}
				}
			}
			if(titleLangAdded){
				songObj.title_lang = titleLang
			}
			if(subtitleLangAdded){
				songObj.subtitle_lang = subtitleLang
			}
			if(!songObj.category_id && !songObj.category){
				if(!category && category_id === undefined){
					songObj.category_id = this.getCategory(file, [songTitle || songObj.title, file.name.slice(0, file.name.lastIndexOf("."))])
				}else if(category){
					songObj.category = category
					songObj.orginalCategory = category
				}else{
					songObj.category_id = category_id
				}
			}
			if(coursesAdded || songObj.unloaded){
				this.songs[index] = songObj
			}
			if(!this.limited){
				var hash = md5.base64(dataRaw).slice(0, -2)
				songObj.hash = hash
				scoreStorage.songTitles[songObj.title] = hash
				var score = scoreStorage.get(hash, false, true)
				if(score){
					score.title = songObj.title
				}
			}
		})
	}
	
	addOsu(fileObj){
		var file = fileObj.file
		var index = fileObj.index
		var category = fileObj.category
		var category_id = fileObj.category_id
		if(!this.limited){
			var filePromise = file.read()
		}else{
			var filePromise = Promise.resolve()
		}
		return filePromise.then(dataRaw => {
			var data = dataRaw ? dataRaw.replace(/\0/g, "").split("\n") : []
			var osu = new ParseOsu(data, "oni", 0, 0, true)
			var dir = file.path.toLowerCase()
			dir = dir.slice(0, dir.lastIndexOf("/") + 1)
			var songObj = {
				id: index + 1,
				order: index + 1,
				type: "osu",
				chart: file,
				subtitle: osu.metadata.ArtistUnicode || osu.metadata.Artist,
				subtitle_lang: {
					en: osu.metadata.Artist || osu.metadata.ArtistUnicode
				},
				preview: osu.generalInfo.PreviewTime ? osu.generalInfo.PreviewTime / 1000 : 0,
				courses: {},
				music: (osu.generalInfo.AudioFilename ? this.otherFiles[dir + osu.generalInfo.AudioFilename.toLowerCase()] : "") || "muted"
			}
			if(!this.limited){
				songObj.courses.oni = {
					stars: parseInt(osu.difficulty.overallDifficulty) || 0,
					branch: false
				}
			}else{
				songObj.unloaded = true
			}
			var filename = file.name.slice(0, file.name.lastIndexOf("."))
			var title = osu.metadata.TitleUnicode || osu.metadata.Title || file.name.slice(0, file.name.lastIndexOf("."))
			if(title){
				var suffix = ""
				var matches = filename.match(/\[.+?\]$/)
				if(matches){
					suffix = " " + matches[0]
				}
				songObj.title = title + suffix
				songObj.title_lang = {
					en: (osu.metadata.Title || osu.metadata.TitleUnicode || title) + suffix
				}
			}else{
				songObj.title = filename
			}
			this.songs[index] = songObj
			if(!category && category_id === undefined){
				songObj.category_id = this.getCategory(file, [osu.metadata.TitleUnicode, osu.metadata.Title, file.name.slice(0, file.name.lastIndexOf("."))])
			}else if(category){
				songObj.category = category
				songObj.orginalCategory = category
			}else{
				songObj.category_id = category_id
			}
			if(!this.limited){
				var hash = md5.base64(dataRaw).slice(0, -2)
				songObj.hash = hash
				scoreStorage.songTitles[songObj.title] = hash
				var score = scoreStorage.get(hash, false, true)
				if(score){
					score.title = songObj.title
				}
			}
		})
	}
	
	addAssets(){
		var promises = []
		for(let name in this.assetFiles){
			let id = this.getFilename(name)
			var file = this.assetFiles[name]
			var index = name.lastIndexOf(".")
			if(name === "vectors.json"){
				promises.push(file.read().then(response => {
					vectors = JSON.parse(response)
				}))
			}
			if(name.endsWith(".png") || name.endsWith(".gif")){
				let image = document.createElement("img")
				promises.push(pageEvents.load(image).then(() => {
					if(id in this.assetSelectors){
						var selector = this.assetSelectors[id]
						var gradient = ""
						if(selector === "#song-search"){
							gradient = loader.songSearchGradient
						}
						this.stylesheet.push(loader.cssRuleset({
							[selector]: {
								"background-image": gradient + "url(\"" + image.src + "\")"
							}
						}))
					}
				}))
				image.id = name
				promises.push(file.blob().then(blob => {
					image.src = URL.createObjectURL(blob)
				}))
				loader.assetsDiv.appendChild(image)
				var oldImage = assets.image[id]
				if(oldImage && oldImage.parentNode){
					URL.revokeObjectURL(oldImage.src)
					oldImage.parentNode.removeChild(oldImage)
				}
				assets.image[id] = image
			}
			if(assets.audioSfx.indexOf(name) !== -1){
				assets.sounds[id].clean()
				promises.push(this.loadSound(file, name, snd.sfxGain))
			}
			if(assets.audioMusic.indexOf(name) !== -1){
				assets.sounds[id].clean()
				promises.push(this.loadSound(file, name, snd.musicGain))
			}
			if(assets.audioSfxLR.indexOf(name) !== -1){
				assets.sounds[id + "_p1"].clean()
				assets.sounds[id + "_p2"].clean()
				promises.push(this.loadSound(file, name, snd.sfxGain).then(sound => {
					assets.sounds[id + "_p1"] = assets.sounds[id].copy(snd.sfxGainL)
					assets.sounds[id + "_p2"] = assets.sounds[id].copy(snd.sfxGainR)
				}))
			}
			if(assets.audioSfxLoud.indexOf(name) !== -1){
				assets.sounds[id].clean()
				promises.push(this.loadSound(file, name, snd.sfxLoudGain))
			}
			if(this.comboVoices.indexOf(id) !== -1){
				promises.push(snd.sfxGain.load(file).then(sound => {
					assets.sounds[id] = sound
					assets.sounds[id + "_p1"] = assets.sounds[id].copy(snd.sfxGainL)
					assets.sounds[id + "_p2"] = assets.sounds[id].copy(snd.sfxGainR)
				}))
			}
		}
		return Promise.all(promises)
	}
	loadSound(file, name, gain){
		var id = this.getFilename(name)
		return gain.load(file).then(sound => {
			assets.sounds[id] = sound
		})
	}
	getFilename(name){
		return name.slice(0, name.lastIndexOf("."))
	}
	
	addPlugin(fileObj){
		var file = fileObj.file
		var filePromise = file.read()
		return filePromise.then(dataRaw => {
			var name = file.name.slice(0, file.name.lastIndexOf(".taikoweb.js"))
			this.plugins.push({
				name: name,
				data: dataRaw
			})
		})
	}
	
	getCategory(file, exclude){
		var path = file.path.toLowerCase().split("/")
		for(var i = path.length - 2; i >= 0; i--){
			var hasTitle = false
			for(var j in exclude){
				if(exclude[j] && path[i].indexOf(exclude[j].toLowerCase()) !== -1){
					hasTitle = true
					break
				}
			}
			if(!hasTitle){
				for(var cat in this.categoryAliases){
					if(path[i].indexOf(cat) !== -1){
						return this.categoryAliases[cat]
					}
				}
			}
		}
	}
	
	getSkin(dir, config){
		var configArray = config.toLowerCase().split(",")
		var configObj = {}
		for(var i in configArray){
			var string = configArray[i].trim()
			var space = string.indexOf(" ")
			if(space !== -1){
				configObj[string.slice(0, space).trim()] = string.slice(space + 1).trim()
			}
		}
		if(!configObj.dir){
			configObj.dir = ""
		}
		configObj.prefix = "custom "
		var skinnable = ["song", "stage", "don"]
		for(var i in skinnable){
			var skinName = skinnable[i]
			var skinValue = configObj[skinName]
			if(skinValue && skinValue !== "none"){
				var fileName = "bg_" + skinName + "_" + configObj.name
				var skinPath = this.joinPath(dir, configObj.dir, fileName)
				for(var j = 0; j < 2; j++){
					if(skinValue !== "static"){
						var suffix = (j === 0 ? "_a" : "_b") + ".png"
					}else{
						var suffix = ".png"
					}
					var skinFull = this.normPath(skinPath + suffix)
					if(skinFull in this.otherFiles){
						configObj[fileName + suffix] = this.otherFiles[skinFull]
					}else{
						configObj[skinName] = null
					}
					if(skinValue === "static"){
						break
					}
				}
			}
		}
		return configObj
	}
	
	loaded(){
		this.songs = this.songs.filter(song => typeof song !== "undefined")
		if(this.stylesheet.length){
			var style = document.createElement("style")
			style.appendChild(document.createTextNode(this.stylesheet.join("\n")))
			document.head.appendChild(style)
		}
		if(this.songs.length){
			if(this.limited){
				assets.otherFiles = this.otherFiles
				assets.otherFiles.songTitle = this.songTitle
			}
			return Promise.resolve(this.songs)
		}else{
			if(this.noPlugins && this.pluginAmount || Object.keys(this.assetFiles).length){
				return Promise.resolve()
			}else{
				return Promise.reject("nosongs")
			}
		}
		this.clean()
	}
	
	joinPath(){
		var resultPath = arguments[0]
		for(var i = 1; i < arguments.length; i++){
			var pPath = arguments[i]
			if(pPath && (pPath[0] === "/" || pPath[0] === "\\")){
				resultPath = pPath
			}else{
				var lastChar = resultPath.slice(-1)
				if(resultPath && (lastChar !== "/" || lastChar !== "\\")){
					resultPath = resultPath + "/"
				}
				resultPath = resultPath + pPath
			}
		}
		return resultPath
	}
	normPath(path){
		path = path.replace(/\\/g, "/").toLowerCase()
		while(path[0] === "/"){
			path = path.slice(1)
		}
		var comps = path.split("/")
		for(var i = 0; i < comps.length; i++){
			if(comps[i] === "." || comps[i] === ""){
				comps.splice(i, 1)
				i--
			}else if(i !== 0 && comps[i] === ".." && comps[i - 1] !== ".."){
				comps.splice(i - 1, 2)
				i -= 2
			}
		}
		return comps.join("/")
	}
	
	clean(){
		delete this.songs
		delete this.tjaFiles
		delete this.osuFiles
		delete this.assetFiles
		delete this.otherFiles
	}
}