var config={

    //不想访问的东西，节约流量

    "404":[

        "http://qidian.qpic.cn/qdbimg"

    ],

    //奇数为需要下载的，偶数为不需要下载的

    needLoad:[

        //匹配需要下载的

        [

            "/*.js",

            "/*.css",

            "/*.png"

        ],

        //匹配不需要下载的

        [

            "/a.js"

        ]

    ],

    //修改文件保存的地方,默认按照url来的

    saveFiles:[

        //防止太深文件夹

        ["(//*/*/*/*/*/)**/","$1"],

        //过滤无效文件夹字符

        [/(\/\w*)\?+(\w*\/)/gi,"$1$2"]

    ],

    //代理的端口号

    port:100

}

function regDir(str){

    var reg=str

    if(typeof reg=="string"){

        reg=reg.replace(/[\[\]\\\^\:\.\?\+]/g,function(m){

            return "\\"+m;

        })

        reg=reg.replace(/\*\*|\*/g,function(m){

            if(m=="**"){

                return "[\\w\\W]*";

            }else{

                return "[^\\\/]*";

            }

        })

        reg=new RegExp(reg,"gi")

    }

    return reg

}

String.prototype.Test=function(regStr){

    var reg=regDir(regStr)

    return reg.test(this)

}

String.prototype.Replace=function(regStr,fn){

    var reg=regDir(regStr)

    return this.replace(reg,fn);

}

var fs=require("fs")

function mkdir(filepath){

    var path=require("path")

    if(!fs.existsSync(path.dirname(filepath))){

        mkdir(path.dirname(filepath))

    }

    if(!fs.existsSync(filepath)){

        fs.mkdirSync(filepath)

    }

}

function eachHeader (obj, fn) {

    if (Array.isArray(obj.rawHeaders)) {

        // ideal scenario... >= node v0.11.x

        // every even entry is a "key", every odd entry is a "value"

        var key = null;

        obj.rawHeaders.forEach(function (v) {

            if (key === null) {

                key = v;

            } else {

                fn(key, v);

                key = null;

            }

        });

    } else {

        // otherwise we can *only* proxy the header names as lowercase'd

        var headers = obj.headers;

        if (!headers) return;

        Object.keys(headers).forEach(function (key) {

            var value = headers[key];

            if (Array.isArray(value)) {

                // set-cookie

                value.forEach(function (val) {

                    fn(key, val);

                });

            } else {

                fn(key, value);

            }

        });

    }

}

var hopByHopHeaders = [

    'Connection',

    'Keep-Alive',

    'Proxy-Authenticate',

    'Proxy-Authorization',

    'TE',

    'Trailers',

    'Transfer-Encoding',

    'Upgrade'

];

// create a case-insensitive RegExp to match "hop by hop" headers

var isHopByHop = new RegExp('^(' + hopByHopHeaders.join('|') + ')$', 'i');

//伪造http

function parse (req, server) {

    var parsed = require("url").parse(req.url);

    var socket = req.socket;

    parsed.uri=parsed.href;

    parsed.gzip=true;

    // proxy the request HTTP method

    parsed.method = req.method;

    // setup outbound proxy request HTTP headers

    var headers = {};

    var hasXForwardedFor = false;

    parsed.headers = headers;

    eachHeader(req, function (key, value) {

        var keyLower = key.toLowerCase();

        if (!hasXForwardedFor && 'x-forwarded-for' === keyLower) {

            // append to existing "X-Forwarded-For" header

            // http://en.wikipedia.org/wiki/X-Forwarded-For

            hasXForwardedFor = true;

            value += ', ' + socket.remoteAddress;

        }

        if (isHopByHop.test(key)) {

        } else {

            var v = headers[key];

            if (Array.isArray(v)) {

                v.push(value);

            } else if (null != v) {

                headers[key] = [ v, value ];

            } else {

                headers[key] = value;

            }

        }

    });

    if (!hasXForwardedFor) {

        headers['X-Forwarded-For'] = socket.remoteAddress;

    }

    if (null == parsed.port) {

        // default the port number if not specified, for >= node v0.11.6...

        // https://github.com/joyent/node/issues/6199

        parsed.port = 80;

    }

    return parsed

}

function getPath(url){

    var filename=url.Replace("(**)?*","$1").Replace("http://(**/*)","$1")

    var dirname=filename.Replace("(**)/*","$1")

    mkdir("www/"+dirname)

    return "www/"+filename

}

var api={

    parse:parse,

    mkdir:mkdir,

    getPath:getPath

}

/************************************/

var http = require('http');

var fs=require("fs")

var request = require('request');

var server = http.createServer();

server.listen(config.port||100, function () {

    var port = server.address().port;

    console.log('HTTP(s) proxy server listening on port %d', port);

});

server.on('request', function (req, res) {

    var url=req.url

    var arr404=config["404"]

    var is404=false

    arr404.forEach(function(v,k){

        if(url.Test(v)){

            is404=true

        }

    })

    if(is404){

        res.end()

        return

    }

    var parsed=api.parse(req,this)

    //是否下载

    var isLoaded=false;

    //是否下载的列表

    var regArr=config.needLoad

    var back=false

    regArr.forEach(function(v,k){

        back=!back

        v.forEach(function(v2,k2){

            if(url.Test(v2)){

                isLoaded=back

            }

        })

    })

    //修改保存文件路径

    /*

     * 匹配规则

     * 修改后 */

    var saveFiles=config.saveFiles

//    isLoaded=false

    if(isLoaded){

        saveFiles.forEach(function(v,k){

            url=url.Replace(v[0],v[1])

        })

        console.log(url)

        var path=api.getPath(url)

        console.log(path)

        //下载

        var reque=request(parsed,function(err,resp,body){

            if(err){

                return

            }

            if(path.Test("/*.css")){

                res.writeHead(200,{

                    "content-type":"text/css"

                })

            }

            fs.createReadStream(path).pipe(res)

        })

        reque.pipe(fs.createWriteStream(path))

        reque.on("error",function(){

            console.error(url)

        })

    }else{

        //不下载

        var reque=request(parsed)

        reque.pipe(res)

        reque.on("error",function(){

            console.error(url)

        })

    }

})