window.onload = function(){
    createlist();
	InitPlayMode();
}

// Title Controller
class TitleStat{
    constructor( originTitle ){
        this.originTitle = originTitle;
    }

    GlobalInterval = null;
    OriginTitle = document.title;
    TargetTitle = "";
    SCROLL_SPEED = 1000;
    ActivateStat = false;

    getActivateStat() {
        return this.ActivateStat;
    }

    activate(){
        this.ActivateStat = true;
    }

    deactivate() {
        this.ActivateStat = false;
    }
    
    setTargetTitle( title ){
        this.TargetTitle = title;
    }

    setScrollSpeed( speed ){
        this.SCROLL_SPEED = speed;
    }

    setOriginTitle( title ){
        this.originTitle = title;
    }

    setTitleManual( title ){
        document.title = title;
    }

    startLoop(){
        this.activate();
        clearInterval(this.GlobalInterval);
        this.TempTitle = this.TargetTitle;
        if ( this.TempTitle.length < 10 ){
           this.noScrollTitle();
        } else {
            window.userdefines_title = {
                "TempTitle": this.TargetTitle + "    ",
            }
            this.GlobalInterval = setInterval(this.scorllTheTitle, this.SCROLL_SPEED);
        }   
    }

    stopLoop(){
        clearInterval(this.GlobalInterval);
    }

    reset(){
        this.stopLoop();
        delete window.userdefines_title;
        document.title = this.OriginTitle;
        this.deactivate();
    }

    noScrollTitle() {
        console.log("使用的是非滚动标题！");
        if( document.getElementById("Player").paused == false ){
            document.title = "[▶️] " + this.TempTitle;
        }else{
            document.title = "[⏸] " + this.TempTitle;
        }
    }

    scorllTheTitle() {
        // 此处的this指的是window对象
        if( document.getElementById("Player").paused == false ){
            document.title = "[▶️] " + this.userdefines_title.TempTitle.substring(0,20) + "...";
        }else{
            document.title = "[⏸] " + this.userdefines_title.TempTitle.substring(0,20) + "...";
        }
        
        this.userdefines_title.TempTitle = this.userdefines_title.TempTitle.substring(1) + this.userdefines_title.TempTitle.substring(0,1);
    }
}

// Player Controller
class PlayerControl {
	constructor() {
		this.playerObject = document.getElementById('Player');
		this.ListenerStatus = false;
	}
 
	setFunction() {
		this.FuncObj = this.playStatCheck;
	}
 
	enableListener(func) {
		this.playerObject.addEventListener('ended', func);
		this.ListenerStatus = true;
		console.log("启用播放器播放结束事件监听");
	}
 
	disableListener(func) {
		this.playerObject.removeEventListener('ended', func);
		this.ListenerStatus = false;
		console.log("停用播放器播放结束事件监听");
	}
 
	getListenerStatus() {
		return this.ListenerStatus;
	}
 
	startCheck() {
		if (this.ListenerStatus) {
			this.disableListener(this.FuncObj);
		}
		this.enableListener(this.FuncObj);
	}
 
	stopCheck() {
		if (this.ListenerStatus) {
			this.disableListener(this.FuncObj);
		} else {
			console.error("失败！");
		}
	}
 
	/* 默认函数 */
	playStatCheck() {
		console.log(this);
		// debug
		console.warn("当前模式：" + CyclePlayMode);
		// 是否单曲？
		if (CyclePlayMode == 2) {
			// 从头开始
			this.playerObject.play();
			console.log("洗脑的单曲循环！");
			return;
		}
 
		// 播放到列表尾部，检查播放状态是否为0（单次播放列表）
		if (nowPlay >= (list.size + 1)) {
			if (CyclePlayMode === 0) {
				if (this.ListenerStatus) {
					// 播放列表完毕就清除事件监听器
					this.disableListener(this.playStatCheck);
					console.log("播放完毕，已清除事件监听。");
					return;
				} else {
					// 事件监听器未打开
					console.error("关闭失败，事件监听器未启用。");
					return;
				}
			}
		}
		// Safe
		if (this.playerObject.ended === false) {
			console.log("安全模式| 歌曲未完播，安全执行函数");
			return;
		}
		// 切歌
		playnext();
	}
 }

// Title Control
let TitleControl = new TitleStat(document.title);
// Window OnBlur
window.onblur = () => {
    console.log("您已离开播放器！");
    TitleControl.setScrollSpeed(500);
    TitleControl.setTargetTitle(document.getElementById("nowplay").innerHTML);
    TitleControl.startLoop();
}

// Window OnFocus
window.onfocus = () => {
    // document.title = originTitle;
    console.log("您已回到播放器！");
    TitleControl.reset();
}

// 搜索音乐
function getsongs(){
    document.getElementById("reslist").innerHTML = "";
    var search = document.getElementById("search-song");
    var reslist = document.getElementById("reslist");
    var urls = `http://150.158.7.169:3000/search?keywords=${search.value}`
    var xhr = new XMLHttpRequest();
    xhr.open("GET", urls);
    xhr.send();
    xhr.onreadystatechange = function(){
        if(xhr.readyState == 4 && xhr.status == 200){
           var obj = JSON.parse(xhr.responseText);
           console.log(obj);
           var list = obj.result.songs;
           for(var i = 0; i < list.length; i++){
               artiststr = getArtist(list[i]);
               console.log({"songid":list[i].id, "songname":list[i].name, "artist":artiststr});
               if(list[i].fee == 0 || list[i].fee == 8){
                    reslist.innerHTML += `<li id="listitem"><a href="javascript:void(0)" onclick="javascript:playmusic(${list[i].id}, '${list[i].name}', '${artiststr}')">${list[i].name} - ${getArtist(list[i])}</a>` + 
                    `<span class="">` + 
					`<button type="button" id="playbtn" onclick="javascript:addlist(${list[i].id}, '${list[i].name}', '${artiststr}')">加入播放列表</button>` + 
					`</span></li>`;
               }else{
                    reslist.innerHTML += `<li id="listitem">${list[i].name} - ${getArtist(list[i])}`+
                    `<span class="">` + 
                    `<button type="button" id="disablebtn" onclick="javascript:jumpTo163CM(${list[i].id})">跳转到网易云</button>` + 
                    `</span></li>`;
               }
           }
        }else{
			console.warn("WARNNING：API服务器响应失败");
        }
    }
    document.getElementById("keyword").innerHTML = search.value;
}

// 获取艺术家
function getArtist(obj){
    var artiststr = "";
    var artistd = obj.artists;
    for(var i = 0; i < artistd.length; i++){
        if(i != artistd.length - 1){
            artiststr += artistd[i].name + "/";
        }else{
            artiststr += artistd[i].name;
        }
    }
    return artiststr;
}

// 播放音乐
function playmusic(playid, songname, artist){
    document.getElementById("nowplay").innerHTML = `${songname} - ${artist}`
    url = `https://music.163.com/song/media/outer/url?id=${playid}.mp3`;
    document.getElementById("Player").setAttribute('src',url);
    // 选中后自动播放
    document.getElementById("Player").play();
    // 插入到历史记录
    inserthistory(playid, songname, artist);
}

// 列表
function List(){
	this.items = [];
	List.prototype.insertRear = (element) => {
		this.items.push(element);
	}
	
	List.prototype.deleteItem = (loc) => {
		if(loc == undefined) {
			return false;
		}
		
		this.items.splice(loc, 1);
		return true;
	}
	
	List.prototype.isEmpty = () => {
		return this.items.length == 0;
	}
	
	List.prototype.clear = () => {
		this.items = [];
	}
	
	List.prototype.size = () => {
		return this.items.length;
	}
	
	List.prototype.getElem = (loc) => {
		if(loc < 0 || loc == undefined){
			return undefined;
		}
		
		if(this.isEmpty()){
			return false;
		}
		
		return this.items[loc];
	}

    // CodeGeeX Written
    List.prototype.locate = (items) => {
        for(var i = 0; i < this.items.length; i++){
            if(items == this.items[i]){
                return i;
            } else {
                return undefined;
            }
        }
    }
	
	List.prototype.getLength = () => {
		return this.items.length;
	}
}

// 创建播放列表
function createlist(){
    // 构造队列
    // list = new Queue();
	list = new List();
	nowPlay = 0;
}

// 添加到播放列表
function addlist(songid, songname, artist){
	for (var i = 0; i < list.getLength(); i++) {
		if(list.getElem(i).songid == songid){
			console.log(`${songname} - ${artist} 已存在于播放列表`);
			return;
		}
	}
    list.insertRear({"songid":songid, "songname":songname, "artist":artist});
	console.log(`${songname} - ${artist} 已被加入播放列表`);
}

// 播放下一首
function playnext(){
    if(list.isEmpty()){
        console.log("音乐列表已经播放完毕了哦，快加入新的音乐吧~");
        alert("音乐列表已经播放完毕了哦，快加入新的音乐吧~");
        return;
    }
	if(nowPlay >= (list.size() - 1)){
		nowPlay = 0;
	}else{
		nowPlay += 1;
    }
	var next = list.getElem(nowPlay);
	playmusic(next.songid, next.songname, next.artist);
	// 标题控制
    if ( TitleControl.getActivateStat() == true ) {
        TitleControl.reset();
        TitleControl.setTitleManual("Loading...");
        TitleControl.setTargetTitle(next.songname + " - " + next.artist);
        TitleControl.startLoop();
    }
}

// 播放上一首
function playlast() {
	if(list.isEmpty()){
	    console.log("音乐列表已经播放完毕了哦，快加入新的音乐吧~");
	    alert("音乐列表已经播放完毕了哦，快加入新的音乐吧~");
	    return;
	}
	if(nowPlay <= 0){
		nowPlay = list.size() - 1;
	}else{
		nowPlay -= 1;
	}
	var prior = list.getElem(nowPlay);
	playmusic(prior.songid, prior.songname, prior.artist);
	if ( TitleControl.getActivateStat() == true ) {
	    TitleControl.reset();
	    TitleControl.setTitleManual("Loading...");
	    TitleControl.setTargetTitle(prior.songname + " - " + prior.artist);
	    TitleControl.startLoop();
	}
}

function processCyclePlay(){
	switch ( CyclePlayMode ){
		case 0: 	// OFF
			if ( nowPlay >= (list.size() - 1) ) {
				
			} 
			break;
		case 1: 	// single cycle	
			document.getElementById("Player").play();
			break;
		case 2:		// list cycle
			if ( false ) {
				
			}
			break;
		default: break;
	}
}

// 播放列表
function playthelist(){
    if(list.isEmpty()){
        console.log("音乐列表没有歌曲哦，快加入新的音乐吧~");
        alert("音乐列表没有歌曲哦，快加入新的音乐吧~");
        return;
    }
    // var next = list.dequeue();
    var next = list.getElem(0);
	playmusic(next.songid, next.songname, next.artist);
}

// 获取播放列表
function getplaylist(){
    var reslist = document.getElementById("reslist");
    reslist.innerHTML = "";
    for(var i = 0; i < list.size(); i++){
        reslist.innerHTML += `<li>${list.items[i].songname} - ${list.items[i].artist}<span class="btn-series"><button type="button" id="delbtn" onclick="javascript:RemoveItemFromListByID(${i})">删除</button></span></li>`;
    }
    document.getElementById('keyword').innerHTML = "当前播放列表";
}

// 删除指定序号的音乐 -- Writtrn By Copilot
function RemoveItemFromListByID(uid){
    list.items.splice(uid, 1);
    getplaylist();
}

// 插入音乐到历史记录 -- Writtrn By Copilot
function inserthistory(songid, songname, artist){
    // 从本地获取历史记录
    var historyList = JSON.parse(localStorage.getItem("historyList"));
    // 判断是否有历史记录
    if(historyList == null){
        historyList = [];   // 创建一个空数组
    }
    var flag = false;       // 标记是否已经存在
    // 判断是否已经存在
    for(var i = 0; i < historyList.length; i++){
        // 如果已经存在，则更新播放时间
        if(historyList[i].songid == songid){
            flag = true;
            break;
        }
    }
    // 如果不存在，则插入
    if(!flag){
        historyList.push({"songid":songid, "songname":songname, "artist":artist});
    }
    // 存储到本地
    localStorage.setItem("historyList", JSON.stringify(historyList));
}

// 获取历史记录 -- Writtrn By Copilot
function gethistory(){
    var historyList = JSON.parse(localStorage.getItem("historyList"));
    if(historyList == null){
        historyList = [];
    }
    var reslist = document.getElementById("reslist");
    reslist.innerHTML = "";
    for(var i = 0; i < historyList.length; i++){
        reslist.innerHTML += `<li>${historyList[i].songname} - ${historyList[i].artist}` +
		`<span class="btn-series">` + 
		`<button type="button" id="delbtn" onclick="javascript:deleteHistory(${i})">删除</button>` + 
        `<button type="button" id="playbtn" onclick="javascript:addlist(${historyList[i].songid}, '${historyList[i].songname}', '${historyList[i].artist}')">加入播放列表</button></li>` + 
		`</span>`;
	}
    document.getElementById('keyword').innerHTML = "历史记录";
}

// 清空历史记录 -- Writtrn By Copilot
function removehistory(){
    localStorage.removeItem("historyList");
    gethistory();
}

// 当点击清空列表的时候进行一次确认，如果确认之后再进行删除操作。
function ClearList(){
    var Choose = confirm("确定清空歌单吗？(此操作不可逆！)")
    if(Choose == true){
        removehistory();
        console.log("The History List Has been cleared.");
        return true;
    }else{
        console.log("List Clear Canceled!");
        return false;
    }
}

// 添加所有歌曲到播放列表
function addAllHistorytoPlayList(){
    var historyList = JSON.parse(localStorage.getItem("historyList"));
    if(historyList == null){
        historyList = [];
    }
    var reslist = document.getElementById("reslist");
    reslist.innerHTML = "";
    for(var i = 0; i < historyList.length; i++){
        addlist(historyList[i].songid, historyList[i].songname, historyList[i].artist);
        console.log(`${historyList[i].songname} - ${historyList[i].artist} is add to list.`);
    }
    alert("已把历史记录插入到了播放列表");
    // Planning to Code...
}

// 清空播放列表
function ClearthePlaylist(){
    if(!list.isEmpty()){
        list.clear();
        console.log("List Cleared!");
    }else{
        console.log("List is empty, not need to clear.")
    }
}

// 将历史记录转换为云列表可接受形式
function convertHist2CloudList(origin){
	// var temp = JSON.parse(origin);
	var result = []
	for (var i = 0; i < origin.length; i++) {
		result.push({
			"name"	: origin[i].songname,
			"id"	: origin[i].songid,
			"author": origin[i].artist
		});
	}
	return result;
}

// 删除历史记录
function deleteHistory( count ) {
	// get HistoryList from LocalStorage
	var historyList = JSON.parse( localStorage.getItem( "historyList" ) );
	// is null?
    if( historyList == null ){
        // failed
    }
    
	// if count is smaller than List length, throw error
	if ( count  > historyList.length ){
		console.log( "本次删除无效！\nThis deletion is invaild." );
		return;
	}
	
	// console log output
	console.log(`${historyList[count].songname} - ${historyList[count].artist} (位于 ${count}) 已从历史记录删除.`)
	
    // find the item and delete it.
    historyList.splice( count, 1 );
	
	// Refresh the page
	var reslist = document.getElementById( "reslist" );
	reslist.innerHTML = "";
	for( var i = 0; i < historyList.length; i++ ){
	    reslist.innerHTML += `<li>${historyList[i].songname} - ${historyList[i].artist}` +
	    `<span class="btn-series">` + 
	    `<button type="button" id="delbtn" onclick="javascript:deleteHistory(${i})">删除</button>` + 
	    `<button type="button" id="playbtn" onclick="javascript:addlist(${historyList[i].songid}, '${historyList[i].songname}', '${historyList[i].artist}')">加入播放列表</button>` + 
	    `</span></li>`;
	}
	document.getElementById( 'keyword' ).innerHTML = "历史记录";
	
	// put the HistoryList back into the LocalStorage
	localStorage.setItem( "historyList", JSON.stringify( historyList ) );
}

// 无版权音乐跳转到网易云
function jumpTo163CM( songid ) {
	console.log("因为没钱，所以放不了，要不你自己去官网开会员听？");
	if ( confirm( "因为没钱，所以放不了，要不你自己去官网开会员听？" ) ){
		window.open( 'https://music.163.com/#/song?id=' + songid );
		console.log("感谢你的理解！^_^");
	} else {
		console.log("好吧，那我也没有办法了，总之是放不了。\(sad")
	}
}

// 初始化播放模式
function InitPlayMode() {
	// About PlatMode
	RandomMode = 0;
	CyclePlayMode = 0;
	PlayerController = new  PlayerControl();
}

// 更改随机播放模式按钮
function changeRandButton() {
	switch( RandomMode ) {
		case 0  : document.getElementById('random-stat').innerHTML = "关";   break;
		case 1  : document.getElementById('random-stat').innerHTML = "开";   break;
		default : document.getElementById('random-stat').innerHTML = "null"; break;
	}
}

// 更改随机播放模式
function changeRandomMode() {
	RandomMode = (RandomMode + 1) % 2;
	changeRandButton();
}

// 更改循环播放模式按钮
function changeCycleButton() {
	switch( CyclePlayMode ) {
		case 0  : document.getElementById('cycle-stat').innerHTML = "关";   break;
		case 1  : document.getElementById('cycle-stat').innerHTML = "列表"; break;
		case 2  : document.getElementById('cycle-stat').innerHTML = "单曲"; break;
		default : document.getElementById('cycle-stat').innerHTML = "null"; break;
	}
}

// 更改循环播放模式
function changeCyeleMode() {
	CyclePlayMode = (CyclePlayMode + 1) % 3;
	console.log(`当前的播放模式：${document.getElementById('cycle-stat').innerHTML}, ${CyclePlayMode}`)
	changeCycleButton();
}