/**
 * The background script to handle url redirection.
 */

var storage = null;
var downloading = false;
var downloadTimer = null;
// 存储MIS的IP
var misHost="121.15.171.92";
// 请求映射表项时兴趣包使用的前缀
var misPrefix="/mis/resolve";
// 兴趣包前缀序号
var misPrefixNum=0;
// 是否开启mis更新映射表
var misEnableState=true;

// 获取兴趣包前缀
function getInterestPrefix() {
    misPrefixNum++;
    browser.storage.local.set({'misPrefixNum':misPrefixNum});
    return misPrefix+'/'+misPrefixNum;
}

// 加载mis的IP
function loadMisHost() {
    browser.storage.local.get('misHostIP',function (result) {
        if($.isEmptyObject(result)){
            // alert("hostIP: null");
            browser.storage.local.set({'misHostIP':misHost});
        }else{
            // alert("hostIP: "+result.misHostIP);
            misHost=result.misHostIP;
        }
    });
    browser.storage.local.get('misPrefix',function (result) {
        if($.isEmptyObject(result)){
            // alert("misPrefix: null");
            browser.storage.local.set({'misPrefix':misPrefix});
        }else{
            // alert("misPrefix: "+result.misPrefix);
            misPrefix=result.misPrefix;
        }
    });
    browser.storage.local.get('misPrefixNum',function (result) {
        if($.isEmptyObject(result)){
            // alert("misPrefix: null");
            browser.storage.local.set({'misPrefixNum':misPrefixNum});
        }else{
            // alert("misPrefix: "+result.misPrefix);
            misPrefixNum=result.misPrefixNum;
        }
    });
    browser.storage.local.get('misEnableState',function (result) {
        if($.isEmptyObject(result)){
            // alert("misPrefix: null");
            browser.storage.local.set({'misEnableState':misEnableState});
        }else{
            // alert("misPrefix: "+result.misPrefix);
            misEnableState=result.misEnableState;
            // alert("48641");
        }
    });
}

/* Reload callback */
function reload(result) {
    storage = new Storage();
    if (result && result.storage) {
        storage.fromObject(result.storage);
        resetDownloadTimer();
    }
}

/* Auto reload */
browser.storage.onChanged.addListener(function (changes, area) {
    // if (area == "local") {
        load("storage", reload);
        loadMisHost();
    // }
});


/* The first time of loading storage */
load("storage", reload);
loadMisHost();
// alert("成功加载mis的IP: "+misHost+"; misPrefix: "+misPrefix);

function getJsonString(u_identifier){
    var jsonObj={
        "Type":"user-act",
        "Command":"Resolve",
        "QueryCode":2,
        "U_identifier":u_identifier
    };
    // return jsonObj;
    return JSON.stringify(jsonObj);
}


function onData(interest, data)
{
    // printLine("Got data packet with name " + data.getName().toUri());
    // printLine(data.getContent().buf().toString('binary'));
}

function onTimeout(interest)
{
    // printLine("Time out for interest " + interest.getName().toUri());
}

// 增加映射表项时，判断该表项是否重复
function addCustomRule(editingRule) {
    var flag=0;
    for (var i=0; i<storage.customRules.length; i++) {
        var rule = storage.customRules[i];
        if ((rule.origin === editingRule.origin)  && (rule.target === editingRule.target)) {
            flag=1;
        }
    }
    if(flag===0){
        storage.customRules.push(editingRule);
    }
}

function express(prefixUri) {
    // alert("成功加载mis的IP: "+misHost+"; misPrefix: "+misPrefix);
    var host = misHost;
    // Connect to the forwarder with a WebSocket.
    var face = new Face({host: host});

    var name = new Name(getInterestPrefix());
    var interest=new Interest(name);
    interest.setMustBeFresh(true);
    var jsonPrefix=getJsonString(prefixUri);
    interest.setApplicationParameters(new Blob(jsonPrefix));
    interest.setInterestLifetimeMilliseconds(2000);
    // alert("express Interest: "+jsonPrefix);
    // printLine("Express interest " + interest.getName().toUri());
    // printLine("The json string is "+interest.getApplicationParameters().toString());
    face.expressInterest(interest, function(interest,data){
        var targetJsonString=data.getContent().buf().toString('binary');
        // alert("targetJsonString: "+targetJsonString);
        var targetJson=JSON.parse(targetJsonString);
        // 将targetJson解析成targetUri
        var StatusCode=targetJson.StatusCode;
        var targetUri=targetJson.Message;
        if((StatusCode===200)&&(targetUri!=="")) {
            var editingRule = new Rule();
            editingRule.enable = true;
            editingRule.description = "initial based on MIS";
            editingRule.origin = prefixUri;
            editingRule.target = targetUri;
            editingRule.exclude = "";
            editingRule.example = "";
            editingRule.process = "";
            editingRule.methods = [];
            editingRule.types = [];
            // storage.customRules.push(editingRule);
            addCustomRule(editingRule);
            /* save */
            save({"storage": storage});
            load("storage", reload);
        }else{
            // mis没有该前缀对应的映射
        }
        // alert("really begin 4");
    }, onTimeout);
}

/* ini storage based on the MIS System */
// function iniStorageBasedMIS() {
//     // alert("really begin");
//     var prefixUri="/mis/baidu";
//     express(prefixUri);
// }

// alert("begin reset");
// iniStorageBasedMIS();

/* Download online rules */
function downloadOnlineURLs() {
    /* Still downloading */
    if (!storage.onlineURLs || storage.onlineURLs.length <=0 || downloading) {
        return;
    }
    downloading = true;
    var toDownload = [];    // URLs that need to be downloaded
    for (var i = 0; i < storage.onlineURLs.length; i++) {
        var onlineURL = storage.onlineURLs[i];
        if (onlineURL.auto && onlineURL.enable && onlineURL.url !== "") {
            toDownload.push(onlineURL.url);
        }
    }
    if (toDownload.length === 0) {
        sendMessage("downloaded");
    }
    var downloadErrors = [];
    var parseErrors = [];
    for (var i = 0; i<toDownload.length; i++) {
        download(toDownload[i], function (url, content) {
            toDownload.remove(url);
            if (content) {
                try {
                    var json;
                    // content may be a string or json object
                    if (typeof content === "string") {
                         json = JSON.parse(content);
                    } else {
                        json = content;
                    }
                    json.url = url;
                    json.enable = true;
                    json.downloadAt = new Date();
                    /* To compact with gooreplacer */
                    /* version < 1.0, version >= 1.0 doesn't change */
                    if (!json.version || json.version < "1.0") {
                        var rules = [];
                        for (var key in json.rules) {
                            var rule = json.rules[key];
                            rules.push({
                                origin: key,
                                target: rule.dstURL,
                                enable: rule.enable === undefined ? true : rule.enable,
                                kind: rule.kind
                            });
                        }
                        json.rules = rules;
                    }
                    /* replace the onlineURL */
                    for (var j = 0; j < storage.onlineURLs.length; j++){
                        if (storage.onlineURLs[j].url == url){
                            storage.onlineURLs[j] = new OnlineURL();
                            storage.onlineURLs[j].fromObject(json);
                            break;
                        }
                    }
                } catch (err) {
                    parseErrors.push(url);
                    console.error(err);
                }
            }
            else {
                downloadErrors.push(url);
            }
            if (toDownload.length <= 0) {
                downloading = false;
                sendMessage("downloaded");
                if (downloadErrors.length > 0) {
                    sendMessage("downloadError", downloadErrors);
                }
                if (parseErrors.length > 0) {
                    sendMessage("parseError", parseErrors);
                }
                storage.updatedAt = (new Date()).toISOString();
                save({"storage": storage});
            }
        });
    }
}

/* Reset download timer to download online urls */
/* Setup a listener if alarm api supported */
if (browser.alarms) {
    browser.alarms.onAlarm.addListener(function (alarm) {
        if (alarm.name == "download") {
            downloadOnlineURLs();
        }
    })
}

/* Reset the download timer */
function resetDownloadTimer() {
    var interval = 900;     // Default 15min
    if (storage.updateInterval) {
        interval = parseInt(storage.updateInterval);
    }
    /* If the browser support alarms api */
    if (browser.alarms) {
        browser.alarms.create("download", {
            periodInMinutes: Math.ceil(interval / 60)
        });
    }
    else {
        /* With setInterval */
        if (downloadTimer != null) {
            clearInterval(downloadTimer);
        }
        interval = interval * 1000;     // In milli-seconds
        downloadTimer = setInterval(function () {
            if (storage.enable) {
                downloadOnlineURLs();
            }
        }, interval);
    }
}

/* Handle runtime messages */
browser.runtime.onMessage.addListener(function (message, sender, sendResponse) {
    if (message.method == "download" && !downloading) {
        downloadOnlineURLs();
    }
    else if (message.method == "isDownloading") {
        sendResponse(downloading);
    }
    else {
        console.error("Unknown method");
    }
});

function redirect(details) {
    if (storage.enable && details.url) {
        var newURL = storage.redirect(details.url, details.method, details.type);
        if (newURL){
            return {
                redirectUrl: newURL
            }
        }
    }
    return {};
}

var _redirect_promise_supported = false;

// 判断某个字符串是否是一个搜索url
function isSearchUrl(urlString){
    var searchLibs=[
        // 百度
        "https://www.baidu.com",
        "http://www.baidu.com",
        // 谷歌
        "https://www.google.com",
        "http://www.google.com",
        // 搜狗
        "https://www.sogou.com",
        "http://www.sogou.com",
        // 360
        "https://www.so.com",
        "http://www.so.com",
        // bing
        "https://cn.bing.com",
        "http://cn.bing.com"
    ];
    var flag=0;
    for(var i=0;i<searchLibs.length;i++){
        if(urlString.indexOf(searchLibs[i])>=0){
            flag=1;
            break;
        }
    }
    var haveSearchString=getPositiveNum(urlString.indexOf("?wd="))
        +getPositiveNum(urlString.indexOf("&wd="))
        +getPositiveNum(urlString.indexOf("?q="))
        +getPositiveNum(urlString.indexOf("&q="))
        +getPositiveNum(urlString.indexOf("?query="))
        +getPositiveNum(urlString.indexOf("&query="));
    if((flag>0)&&(haveSearchString>0)){
        // alert("it is a searchUrl: "+urlString);
        return true;
    }else{
        return false;
    }
}

// 对小于0的数取0
function getPositiveNum(num) {
    if(num>0){
        return num;
    }else{
        return 0;
    }
}

// 传入一个搜索uri，获取其中的搜索数值
function getSearchContent(uriString) {
    if(!isSearchUrl(uriString)){
        return "";
    }
    var content="";
    if(uriString.indexOf("//www.baidu.com")>=0){
    // &wd=   [end] 或 &wd=   &
        var startIndex=getPositiveNum(uriString.indexOf("?wd="))
            +getPositiveNum(uriString.indexOf("&wd="))+4;
        var lastString=uriString.substring(startIndex);
        var endIndex=lastString.indexOf('&');
        if(endIndex>=0){
            content=lastString.substring(0,endIndex);
        }else{
            content=lastString;
        }
    }else if(uriString.indexOf("//www.google.com")>=0){
    //    ?q=   &
        var startIndex=getPositiveNum(uriString.indexOf("?q="))
            +getPositiveNum(uriString.indexOf("&q="))+3;
        var lastString=uriString.substring(startIndex);
        var endIndex=lastString.indexOf('&');
        if(endIndex>=0){
            content=lastString.substring(0,endIndex);
        }else{
            content=lastString;
        }
    }else if(uriString.indexOf("//www.sogou.com")>=0){
    // &query=   [end]
        var startIndex=getPositiveNum(uriString.indexOf("?query="))
            +getPositiveNum(uriString.indexOf("&query="))+7;
        var lastString=uriString.substring(startIndex);
        var endIndex=lastString.indexOf('&');
        if(endIndex>=0){
            content=lastString.substring(0,endIndex);
        }else{
            content=lastString;
        }
    }else if(uriString.indexOf("//www.so.com")>=0){
        // &q=   [end]
        var startIndex=getPositiveNum(uriString.indexOf("?q="))
            +getPositiveNum(uriString.indexOf("&q="))+3;
        var lastString=uriString.substring(startIndex);
        var endIndex=lastString.indexOf('&');
        if(endIndex>=0){
            content=lastString.substring(0,endIndex);
        }else{
            content=lastString;
        }
    }else if(uriString.indexOf("//cn.bing.com")>=0){
        //  ？q=   &
        var startIndex=getPositiveNum(uriString.indexOf("?q="))
            +getPositiveNum(uriString.indexOf("&q="))+3;
        var lastString=uriString.substring(startIndex);
        var endIndex=lastString.indexOf('&');
        if(endIndex>=0){
            content=lastString.substring(0,endIndex);
        }else{
            content=lastString;
        }
    }else{}
    return content.replace(/%2F/g,'/');
}

// 判断某个字符串是否包含映射表中的表项
function isIncludedRules(urlString) {
    var flag=0;
    for (var i=0; i<storage.customRules.length; i++) {
        var rule = storage.customRules[i];
        var afterDecodeOrigin=rule.origin.replace('/','%2F');
        if ((urlString.indexOf(rule.origin)>=0)||(urlString.indexOf(afterDecodeOrigin)>=0)) {
            flag=1;
            break;
        }
    }
    if(flag===0){
        // alert("it do not includes rules");
        return false;
    }else{
        // alert("it includes rules");
        // console.log("it includes rules");
        return true;
    }
}

// 模糊判断一个string是否是一个合法前缀
function isRightfulPrefix(urlString){
    if(urlString===''){
        return false;
    }
    if(urlString.indexOf('.')>=0){
        return false;
    }
    if((urlString.indexOf('/')!==0)&&(urlString.indexOf('%2F')!==0)){
        // alert("没/");
        return false;
    }
    return true;
}

// 判断某个字符串是否是映射表的一个前缀表项
// 判断某个字符串是否包含映射表中的表项
function isRulesPrefix(urlString) {
    // alert("要判断的urlString: "+urlString);
    // 先进行模糊判断
    // if(urlString===''){
    //     return false;
    // }
    // if(urlString.indexOf('.')>=0){
    //     return false;
    // }
    // if((urlString.indexOf('/')!==0)&&(urlString.indexOf('%2F')!==0)){
    //     // alert("没/");
    //     return false;
    // }
    if(!isRightfulPrefix(urlString)){
        return false;
    }
    // 再遍历本地映射表
    var flag=0;
    for (var i=0; i<storage.customRules.length; i++) {
        var rule = storage.customRules[i];
        var afterDecodeOrigin=rule.origin.replace('/','%2F');
        if ((urlString===rule.origin)||(urlString===afterDecodeOrigin)) {
            flag=1;
            break;
        }
    }
    if(flag===0){
        // alert("it do not includes rules");
        return false;
    }else{
        // alert("it includes rules");
        // console.log("it includes rules");
        return true;
    }
}

// 判断某个字符串是在搜索映射表表项
function isSearchForRules(urlString) {
    if(isSearchUrl(urlString)&&isIncludedRules(urlString)){
        // console.log("it is searching for rules!!!");
        return true;
    }else{
        return false;
    }
}

// 获取url中包括的rule.origin
function getIncludedRules(urlString) {
    var flag=0;
    var originString="";
    for (var i=0; i<storage.customRules.length; i++) {
        var rule = storage.customRules[i];
        var afterDecodeOrigin=rule.origin.replace('/','%2F');
        if ((urlString.indexOf(rule.origin)>=0)||(urlString.indexOf(afterDecodeOrigin)>=0)) {
            flag=1;
            originString=rule.origin;
            break;
        }
    }
    return originString;
}

// 剪切不包含.这个字符的URI的http头
function cutHttpHead(uri) {
    // 判断是http:还是https:
    var startIndex=0;
    if(uri.indexOf("https:")>=0){
       startIndex=8;
    }else if(uri.indexOf("http:")>=0){
        startIndex=7;
    }
    // 判断uri中是否含有.这个字符
    if(uri.indexOf('.')>=0){
        return "";
    }else{
        var uritmp=uri.substr(startIndex);
        if(uritmp.indexOf(0)==='/'){
            return uritmp;
        }else{
            return '/'+uritmp;
        }
    }
}

// 根据传入的uri获取前缀，从而更新本地映射表
function updateStorageBasedUri(uri) {
    // alert("begin upgrate");
    var uriCut=cutHttpHead(uri);
    // alert("uricut: "+uriCut);
    if(uriCut===""){
    }else{
        express(uriCut);
    }
}

// 根据传入的前缀，更新本地映射表
function updateStorageBasedPrefix(prefix) {
    express(prefix);
}

/* Handle redirect */
function handleRedirect(details) {
    // 判断url是否是一个搜索url，并根据搜索内容，判断是否直接命中本地映射表
    var searchContent=getSearchContent(details.url);
    // alert("sc: "+searchContent);
    // 判断url去掉头部之后是否直接命中本地映射表
    var cutHeadString=cutHttpHead(details.url);
    // 如果该搜索内容或网址命中了缓存中的映射表前缀，则重定向
    if(isRulesPrefix(searchContent)||isRulesPrefix(cutHeadString)){
        // alert("sc: "+searchContent+" isRules: "+isRulesPrefix(searchContent));
        // alert("cut: "+cutHeadString+" isRules: "+isRulesPrefix(cutHeadString));
        var prefixTemp="";
        if(searchContent!==""){
            prefixTemp=searchContent;
        }else{
            prefixTemp=cutHeadString;
        }
        details.url = "http://" + prefixTemp;
        // alert("detail-url: "+details.url);
        if (_redirect_promise_supported) {
            var promise = new Promise(function (resolve, reject) {
                var blockingResponse = redirect(details);
                return resolve(blockingResponse);
            });
            return promise;
        } else {
            // alert("redirect: "+details.url);
            return redirect(details);
        }
    }
    // 如果没有命中缓存映射表，但是它是一个检索内容的网址，
    // 则根据该内容更新本地缓存之后，进行重定向
    if(searchContent!==""){
        // alert("检索内容了呢："+searchContent);
        if ((misEnableState === true)&&isRightfulPrefix(searchContent)) {
            // 如果检索内容模糊判断是一个前缀，且mis同步是开着的
            // alert("成功加载mis的IP: "+misHost+"; misPrefix: "+misPrefix);
            var host = misHost;
            // Connect to the forwarder with a WebSocket.
            var face = new Face({host: host});

            var name = new Name(getInterestPrefix());
            var interest=new Interest(name);
            interest.setMustBeFresh(true);
            var jsonPrefix=getJsonString(searchContent);
            interest.setApplicationParameters(new Blob(jsonPrefix));
            interest.setInterestLifetimeMilliseconds(2000);
            // alert("express Interest");
            face.expressInterest(interest, function(interest,data){
                var targetJsonString=data.getContent().buf().toString('binary');
                // alert("targetJsonString: "+targetJsonString);
                var targetJson=JSON.parse(targetJsonString);
                // 将targetJson解析成targetUri
                var StatusCode=targetJson.StatusCode;
                var targetUri=targetJson.Message;
                // alert("code: "+StatusCode+", "+targetUri);
                if((StatusCode===200)&&(targetUri!=="")) {
                    var editingRule = new Rule();
                    editingRule.enable = true;
                    editingRule.description = "initial based on MIS";
                    editingRule.origin = searchContent;
                    editingRule.target = targetUri;
                    editingRule.exclude = "";
                    editingRule.example = "";
                    editingRule.process = "";
                    editingRule.methods = [];
                    editingRule.types = [];
                    // storage.customRules.push(editingRule);
                    addCustomRule(editingRule);
                    /* save */
                    save({"storage": storage});
                    load("storage", reload);
                    // alert("已经重新更新了本地映射表");
                    // 缓存映射表更新之后，执行重定向操作
                    details.url = "http://" + searchContent;
                }
                // alert("根据本地缓存要重定向了哦");
                if (_redirect_promise_supported) {
                    var promise = new Promise(function (resolve, reject) {
                        var blockingResponse = redirect(details);
                        return resolve(blockingResponse);
                    });
                    return promise;
                } else {
                    // alert("deurl: "+details.url);
                    return redirect(details);
                }
            }, function (interest) {
                // alert("time out...");
                // mis系统崩溃，没有给任何应答，直接执行重定向操作
                if (_redirect_promise_supported) {
                    var promise = new Promise(function (resolve, reject) {
                        var blockingResponse = redirect(details);
                        return resolve(blockingResponse);
                    });
                    return promise;
                } else {
                    return redirect(details);
                }
            });
        }else{
            // 直接尝试重定向
            if (_redirect_promise_supported) {
                var promise = new Promise(function (resolve, reject) {
                    var blockingResponse = redirect(details);
                    return resolve(blockingResponse);
                });
                return promise;
            } else {
                return redirect(details);
            }
        }
    }else{
        // 如果不是进行搜索，且本地没有命中映射表，则异步请求mis更新映射表
        if((misEnableState===true)&&isRightfulPrefix(cutHeadString)){
             updateStorageBasedUri(details.url);
        }
        // 并进行重定向
        if (_redirect_promise_supported) {
            var promise = new Promise(function (resolve, reject) {
                var blockingResponse = redirect(details);
                return resolve(blockingResponse);
            });
            return promise;
        } else {
            return redirect(details);
        }
    }
}

// /* Handle redirect */
// function handleRedirect(details) {
//     // alert("misEnableState: " + misEnableState);
//     // alert("detail-url: "+details.url);
//     if(isSearchUrl(details.url)){
//         if (misEnableState === true) {
//             updateStorageBasedUri(details.url);
//         }
//     }
//     // 判断是否是搜索映射表表项，如果是，直接跳转到映射界面
//     if(isSearchForRules(details.url)){
//         // alert("捕获到了一个前缀搜索: "+details.url);
//         details.url="http://"+getIncludedRules(details.url);
//         // alert("B-url: "+details.url);
//     }else{
//         if (misEnableState === true) {
//             updateStorageBasedUri(details.url);
//         }
//     }
//
//     if (_redirect_promise_supported) {
//         var promise = new Promise(function (resolve, reject) {
//             var blockingResponse = redirect(details);
//             return resolve(blockingResponse);
//         });
//         // alert("修改后的details.url-0: "+details.url);
//         // history.pushState({},"Wow Title","/my/awesome/url");
//         return promise;
//     } else {
//         // history.pushState({},"Wow Title","/my/awesome/url");
//         // alert("修改后的details.url-1: "+details.url);
//         return redirect(details);
//     }
// }

/* Since firefox 52, could return a promise to handles asynchronously */
if (browser.runtime.getBrowserInfo) {
    function checkRedirectPromise(info) {
        if (info.name == "Firefox") {
            if (parseInt(info.version.split('.')[0]) >= 52) {
                _redirect_promise_supported = true;
            }
        }
    }
    var gettingInfo = browser.runtime.getBrowserInfo();
    gettingInfo.then(checkRedirectPromise)
}

/* Add listener */
browser.webRequest.onBeforeRequest.addListener(
    handleRedirect,
    {urls: ["<all_urls>"]},
    ["blocking"]
);