/**
 * Request组件, modern版, 支持IE9+,chrome,FF
 * @authors yutent (yutent@doui.cc)
 * @date    2016-11-27 13:08:40
 *
 */

"use strict";
define(function(){
    var _request = function(url, protocol){
            this.transport = true
            protocol = (protocol + '').trim().toUpperCase()
            this.xhr = Xhr()
            this.opt = {
                url: (url + '').trim(),
                type: protocol || 'GET',
                form: '',
                data: {},
                headers: {},
                timeoutID: 0,
                uuid: Math.random().toString(16).substr(2)
            }
        },
    _requestp = _request.prototype,
    toS = Object.prototype.toString,
    win = window,
    doc = win.document,
    encode = encodeURIComponent,
    decode = decodeURIComponent,
    noop = function(e, res){
        if(e)
            throw new Error(e + '')
    };

    // -----------------------------
    
    // 本地协议判断正则
    var rlocalProtocol = /^(?:about|app|app-storage|.+-extension|file|res|widget):$/ 
    var isLocal = false
    try{
        isLocal = rlocalProtocol.test(location.protocol)
    }catch(e){}


    var rheaders = /^(.*?):[ \t]*([^\r\n]*)\r?$/mg

    // ----------------- 一些兼容性预处理 --------------------

    win.Xhr = function(){
        return new XMLHttpRequest()
    }
    // var supportCors = 'withCredentials' in Xhr()

    // ------------------- 几个解释方法 -----------------------

    var Format = function(){
            this.tagHooks = new function(){
                this.option = doc.createElement('select')
                this.thead = doc.createElement('table')
                this.td = doc.createElement('tr')
                this.area = doc.createElement('map')
                this.tr = doc.createElement('tbody')
                this.col = doc.createElement('colgroup')
                this.legend = doc.createElement('fieldset')
                this._default = doc.createElement('div')
                this.g = doc.createElementNS('http://www.w3.org/2000/svg', 'svg')

                this.optgroup = this.option
                this.tbody = this.tfoot = this.colgroup = this.caption = this.thead
                this.th = this.td
            };
            var _this = this
            'circle,defs,ellipse,image,line,path,polygon,polyline,rect,symbol,text,use'.replace(/,/g, function(m){
                _this.tagHooks[m] = _this.tagHooks.g //处理svg
            })

            this.rtagName = /<([\w:]+)/
            this.rxhtml = /<(?!area|br|col|embed|hr|img|input|link|meta|param)(([\w:]+)[^>]*)\/>/ig
            this.scriptTypes = {
                    'text/javascript': 1,
                    'text/ecmascript': 1,
                    'application/ecmascript': 1,
                    'application/javascript': 1
                }
            this.rhtml = /<|&#?\w+;/
        }

    function serialize(p, obj, q){
        var k
        if(Array.isArray(obj)){
            obj.forEach(function(it, i){
                k = p ? (p + '[' + (Array.isArray(it) ? i : '') + ']') : i
                if(typeof it === 'object'){
                    serialize(k, it, q)
                }else{
                    q(k, it)
                }
            })
        }else{
            for(var i in obj){
                k = p ? (p + '[' + i + ']') : i
                if(typeof obj[i] === 'object'){
                    serialize(k, obj[i], q)
                }else{
                    q(k, obj[i])
                }
            }
        }
        
    }

    Format.prototype = {
        parseJS: function(code){
            code = (code + '').trim()
            if(code){
                if(code.indexOf('use strict') === 1){
                    var script = doc.createElement('script')
                    script.text = code
                    doc.head
                        .appendChild(script)
                        .parentNode
                        .removeChild(script)
                }else{
                    eval(code)
                }
            }
        },
        parseXML: function(data, xml, tmp){
            try{
                tmp = new DOMParser();
                xml = tmp.parseFromString(data, 'text/xml');
            }catch(e){
                xml = void 0;
            }

            if(!xml ||
                !xml.documentElement ||
                xml.getElementsByTagName('parsererror').length){
                    console.error('Invalid XML: ' + data)
            }
            return xml
        },
        parseHTML: function (html){
            var fragment = (doc.createDocumentFragment()).cloneNode(false)

            if(typeof html !== 'string')
                return fragment

            if(!this.rhtml.test(html)){
                fragment.appendChild(document.createTextNode(html))
                return fragment
            }

            html = html.replace(this.rxhtml, '<$1></$2>').trim()
            var tag = (this.rtagName.exec(html) || ['', ''])[1].toLowerCase()
            var wrap = this.tagHooks[tag] || this.tagHooks._default
            var firstChild = null

            //使用innerHTML生成的script节点不会触发请求与执行text属性
            wrap.innerHTML = html
            var script = wrap.getElementsByTagName('script')
            if(script.length){
                for(var i = 0, el; el = script[i++];){
                    if(this.scriptTypes[el.type]){
                        var tmp = (doc.createElement("script")).cloneNode(false)
                        el.attributes.forEach(function(attr){
                            tmp.setAttribute(attr.name, attr.value)
                        })
                        tmp.text = el.text
                        el.parentNode.replaceChild(tmp, el)
                    }
                }
            }

            while(firstChild = wrap.firstChild){
                fragment.appendChild(firstChild)
            }

            return fragment
        },
        param: function(obj){
            if(!obj || typeof obj === 'string' || typeof obj === 'number')
                return obj

            var arr = []
            var q = function(k, v){
                    if(/native code/.test(v))
                        return

                    v = (typeof v === 'function') ? v() : v
                    v = (toS.call(v) !== '[object File]') ? encode(v) : v

                    arr.push(encode(k) + '=' + v)
                }
            
            if(typeof obj === 'object')
                serialize('', obj, q)
            
            return arr.join('&')
        },
        parseForm: function(form){
            var data = {}
            for(var i = 0,field; field = form.elements[i++];){

                switch(field.type){
                    case 'select-one':
                    case 'select-multiple':
                        if(field.name.length && !field.disabled){
                            for(var j = 0, opt;opt = field.options[j++];){
                                if(opt.selected){
                                    data[field.name] = opt.value || opt.text
                                }
                            }
                        }
                        break;
                    case 'file':
                        if(field.name.length && !field.disabled){
                            data[field.name] = field.files[0]
                        }
                        break;
                    case undefined:
                    case 'submit':
                    case 'reset':
                    case 'button':
                        break; //按钮啥的, 直接忽略
                    case 'radio':
                    case 'checkbox':
                        // 只处理选中的
                        if(!field.checked)
                            break;
                    default:
                        if(field.name.length && !field.disabled){
                            data[field.name] = field.value
                        }
                        
                }
                
            }
            return data
        },
        merge: function(a, b){
            if(typeof a !== 'object' || typeof b !== 'object')
                throw new TypeError('argument must be an object')

            if(Object.assign)
                return Object.assign(a, b)

            for(var i in b){
                a[i] = b[i]
            }
            return a
        }
    }


    var F = new Format()


    // ---------------------------------------------------------
    // -------------------- request 模块开始 --------------------
    // ---------------------------------------------------------


    var requestConvert = {
            text: function(val){
                return val
            },
            xml: function(val, xml){
                return xml !== undefined ? xml : F.parseXML(val)
            },
            html: function(val){
                return F.parseHTML(val)
            },
            json: function(val){
                return JSON.parse(val)
            },
            script: function(val){
                return F.parseJS(val)
            },
            jsonp: function(name){
                var json = request.cache[name]
                delete request.cache[name];
                return json
            }
        }
    var requestExtend = {
            formData: function(){
                
                if(this.opt.form){
                    var data = F.parseForm(this.opt.form)
                    F.merge(this.opt.data, data)
                }

                var form = new FormData()
                for(var i in this.opt.data){
                    var el = this.opt.data[i]
                    if(Array.isArray(el)){
                        el.forEach(function(it){
                            form.append(i + '[]', it)
                        })
                    }else{
                        form.append(i, this.opt.data[i])
                    }
                }
                return form
                
            },
            jsonp: function(jsonpcallback){
                win[jsonpcallback] = function(val){
                    delete win[jsonpcallback]
                    request.cache[jsonpcallback] = val
                }
            },
            dispatch: function(self){
                

                if(!this.transport)
                    return

                var _this = this,
                    result = {
                        response: {
                            url: this.opt.url,
                            headers: {'content-type': ''}
                        },
                        request: {
                            url: this.opt.url,
                            headers: _this.opt.headers
                        },
                        status: self === null ? 504 : 200,
                        statusText: self === null ? 'Connected timeout' : 'ok',
                        text: '',
                        body: '',
                        error: null
                    };

                //状态为4,既已成功, 则清除超时
                clearTimeout(_this.opt.timeoutID);

                if(typeof this.transport === 'object'
                    && this.opt.type === 'JSONP'){

                    //移除script
                    // this.transport.parentNode.removeChild(this.transport);

                    //超时返回
                    if(self !== null){
                        var exec = !this.transport.readyState
                            || this.transport.readyState === 'loaded'
                            || this.transport.readyState === 'complete';

                        if(exec){
                            result.body = requestConvert.jsonp(this.opt.data.callback)
                            result.text = JSON.stringify(result.body)
                        }
                    }

                    this.callback(result.error, result)

                }else{

                    //成功的回调
                    var isSucc = self ? ((self.status >= 200 && self.status < 300) || self.status === 304) : false,
                        headers = self && self.getAllResponseHeaders().split('\n') || [];
                        
                    //处理返回的Header
                    headers.forEach(function(it, i){
                        it = it.trim()
                        if(it){
                            it = it.split(':')
                            result.response.headers[it.shift().toLowerCase()] = it.join(':').trim()
                        }

                    });

                    
                    if(isSucc){
                        result.status = self.status
                        if(result.status === 204){
                            result.statusText = 'no content'
                        }else if(result.status === 304){
                            result.statusText = 'not modified'
                        }
                    }else{
                        result.status = self === null ? 504 : (self.status || 500)
                        result.statusText = self === null ? 'Connected timeout' : (self.statusText || 'Internal Server Error')
                        result.error = F.merge(new Error(result.statusText), {status: result.status})
                    }

                    try{
                        //处理返回的数据
                        var dataType = result.response.headers['content-type'].match(/json|xml|script|html/i) || ['text']
                        
                        dataType = dataType[0].toLowerCase()
                        result.text = self && (self.responseText || self.responseXML) || ''
                        result.body = requestConvert[dataType](result.text, self && self.responseXML)
                    }catch(err){
                        result.error = err
                        result.statusText = 'parse error'
                    }

                    _this.callback(result.error, result)
                    


                }
                delete _this.transport;
                delete _this.opt
                delete _this.xhr
                
                
            }
        }

    // 设置表单类型, 支持2种, form/json
    _requestp.type = function(t){
        if(this.opt.formType === 'form-data')
            return this

        this.opt.formType = t || 'form'
        if(t === 'form' || this.opt.type === 'GET')
            this.set('content-type', 'application/x-www-form-urlencoded; charset=UTF-8')
        else
            this.set('content-type', 'application/json; charset=UTF-8')

        return this
    }

    //设置头信息
    _requestp.set = function(k, val){
        if(!this.transport)
            return

        if(typeof k === 'object'){
            for(var i in k){
                i = i.toLowerCase()
                this.opt.headers[i] = k[i]
            }

        }else if(typeof k === 'string'){
            if(arguments.length < 2)
                throw new Error('2 arguments required')

            // 全转小写,避免重复写入
            k = k.toLowerCase()

            if(val === undefined)
                delete this.opt.headers[k]
            else
                this.opt.headers[k] = val
        }else{
            throw new Error('arguments must be string/object, but [' + (typeof k) + '] given')
        }
        return this
    }

    //设置请求参数
    _requestp.send = function(k, val){

        if(!this.transport)
            return

        // 1. send方法可以多次调用, 但必须保证格式一致
        // 2. 2次圴提交纯字符串也会抛出异常
        if(typeof k === 'object'){
            if(this.opt.data && (typeof this.opt.data === 'string'))
                throw new Error('param can not be string and object at the same time')
            if(!this.opt.data)
                this.opt.data = {}

            F.merge(this.opt.data, k)
        }else{
            if(typeof k === 'string'){
                if(arguments.length === 1){
                    if(this.opt.data)
                        throw new Error('invalid param in function send')

                    this.opt.data = k
                }else{
                    if(this.opt.data && (typeof this.opt.data === 'string'))
                        throw new Error('param can not be string and object at the same time')

                    if(!this.opt.data)
                        this.opt.data = {}

                    this.opt.data[k] = val
                }
                
            }else{
                throw new Error('argument of send must be string/object, but [' + (typeof k) + '] given')
            }
            
        }

        return this
    }

    //该方法用于 form-data类型的post请求的参数设置
    _requestp.field = function(k, val){

        if(!this.transport)
            return

        // 此类型优先级最高
        this.opt.formType = 'form-data'
        if(!this.opt.data || (this.opt.data && typeof this.opt.data !== 'object'))
            this.opt.data = {}

        if(arguments.length === 1 && typeof k === 'object'){
            F.merge(this.opt.data, k)
        }else if(arguments.length === 2){
            this.opt.data[k] = val
        }else{
            throw new TypeError('argument must be an object, but ' + (typeof k) + ' given')
        }
        return this
    }


    //设置缓存
    _requestp.cache = function(t){
        if(!this.transport)
            return

        if(this.opt.type === 'GET')
            this.opt.cache = !!t

        return this
    }


    //取消网络请求
    _requestp.abort = function(){
        delete this.transport
        if(!this.opt.form)
            this.xhr.abort()

        return this
    }

    //超时设置, 单位毫秒
    _requestp.timeout = function(time){
        if(typeof time !== 'number' || time < 1)
            return this

        this.opt.timeout = time
        return this
    }


    _requestp.form = function(form){
        if(typeof form === 'object' && form.nodeName === 'FORM'){
            this.opt.type = 'POST'
            this.opt.form = form
        }
        
        return this
    }


    var originAnchor = doc.createElement('a');
    originAnchor.href = location.href;
    _requestp.end = function(callback){
        var _this = this;
        // 回调已执行, 或已取消, 则直接返回, 防止重复执行
        if(!this.transport)
            return

        if(!this.opt.url)
            throw new Error('Invalid  request url')

        F.merge(this, requestExtend)

        this.callback = callback || noop

        // 1. url规范化
        this.opt.url = this.opt.url.replace(/#.*$/, '').replace(/^\/\//, location.protocol + '//')


        // 2. 处理跨域
        if(typeof this.opt.crossDomain !== 'boolean'){
            var anchor = doc.createElement('a')
            try{
                anchor.href = this.opt.url
                // IE7及以下浏览器 '1'[0]的结果是 undefined
                // IE7下需要获取绝对路径
                var absUrl = !'1'[0] ? anchor.getAttribute('href', 4) : anchor.href
                anchor.href = absUrl
                anchor.async = true
                this.opt.crossDomain = (originAnchor.protocol !== anchor.protocol) || (originAnchor.host !== anchor.host)
            }catch(e){
                this.opt.crossDomain = true
            }
        }

        // 2.1 进一步处理跨域配置
        if(this.opt.type === 'JSONP'){
            //如果没有跨域，自动转回xhr GET
            if(!this.opt.crossDomain){
                this.opt.type = 'GET';
            }else{
                this.opt.data['callback'] = this.opt.data['callback'] || ('jsonp' + request.cid++);
                this.jsonp(this.opt.data['callback']); //创建临时处理方法
            }
        }
        // 2.2 如果不是跨域请求，则自动加上一条header信息，用以标识这是ajax请求
        if(!this.opt.crossDomain){
            this.set('X-Requested-With', 'XMLHttpRequest')
        }


        // 3. data转字符串
        this.opt.param = F.param(this.opt.data)


        // 4. 设置Content-Type类型, 默认x-www-form-urlencoded
        if(!this.opt.formType)
            this.type('form')

        // 5.处理GET请求
        this.opt.hasContent = this.opt.type === 'POST' //是否为post请求
        if(!this.opt.hasContent){
            
            //GET请求直接把参数拼接到url上
            if(this.opt.param){
                this.opt.url += (/\?/.test(this.opt.url) ? '&' : '?') + this.opt.param
            }
            //加随机值,避免缓存
            if(this.opt.cache === false)
                this.opt.url += (/\?/.test(this.opt.url) ? '&' : '?') + '_=' + Math.random()
        }else{
            if(this.opt.formType === 'form-data'){
                delete this.opt.headers['content-type']
                this.opt.param = this.formData()

            }else if(this.opt.formType !== 'form'){
                this.opt.param = JSON.stringify(this.opt.data)
            } 
        }

        //jsonp
        if(this.opt.type === 'JSONP'){

            this.transport = doc.createElement('script')
            this.transport.onerror = this.transport.onload = function(){
                _this.dispatch(_this.transport)
            }
            this.transport.src = this.opt.url
            doc.head.insertBefore(this.transport, doc.head.firstChild)

            //6. 超时处理
            if(this.opt.timeout && this.opt.timeout > 0){
                this.opt.timeoutID = setTimeout(function(){
                    _this.transport.onerror = _this.transport.onload = null
                    _this.dispatch(null)
                }, this.opt.timeout)
            }
        }else{

            this.xhr.onreadystatechange = function(ev){

                if(_this.opt.timeout && _this.opt.timeout > 0){
                    _this.opt['time' + this.readyState] = ev.timeStamp
                    if(this.readyState === 4){
                        _this.opt.isTimeout = _this.opt.time4 - _this.opt.time1 > _this.opt.timeout
                    }
                }

                if(this.readyState !== 4){
                    return
                }
                
                _this.dispatch(_this.opt.isTimeout ? null : _this.xhr)

            }
            
            
            // 6. 初始化xhr提交
            this.xhr.open(this.opt.type, this.opt.url, true)

            // 7. 设置头信息
            for(var i in this.opt.headers){
                if(this.opt.headers[i])
                    this.xhr.setRequestHeader(i, this.opt.headers[i])
            }

            // 8. 发起网络请求
            _this.xhr.send(_this.opt.param)

            //超时处理
            if(this.opt.timeout && this.opt.timeout > 0){
                this.xhr.timeout = this.opt.timeout;
            }
        }
        
    }












    // ---------------------- end ------------------------


    if(!win.request){
        win.request = {
            get: function(url){
                if(!url)
                    throw new Error('argument url is required')

                return new _request(url, 'GET')
            },
            post: function(url){
                if(!url)
                    throw new Error('argument url is required')

                return new _request(url, 'POST')
            },
            jsonp: function(url){
                if(!url)
                    throw new Error('argument url is required')

                return new _request(url, 'JSONP')
            },
            cache: {},
            cid: 0,
            version: '1.0.0',
            release: 'request ES5 version/1.0.0'
        }
    }

    return request
})