/**
 * JsHttpRequest: JavaScript "AJAX" data loader
 *
 * @license LGPL
 * @author Dmitry Koterov, http://en.dklab.ru/lib/JsHttpRequest/
 * @version 5.x $Id$
 */
function JsHttpRequest() {
    var t = this;
    t.onreadystatechange = null;
    t.readyState         = 0;
    t.responseText       = null;
    t.responseXML        = null;
    t.status             = 200;
    t.statusText         = "OK";
    t.responseJS         = null;
    t.caching            = false;
    t.loader             = null;
    t.session_name       = "PHPSESSID";
    t._ldObj              = null;
    t._reqHeaders        = [];
    t._openArgs          = null;
    t._errors = {
        inv_form_el:        'Invalid FORM element detected: name=%, tag=%',
        must_be_single_el:  'If used, <form> must be a single HTML element in the list.',
        js_invalid:         'JavaScript code generated by backend is invalid!\n%',
        url_too_long:       'Cannot use so long query with GET request (URL is larger than % bytes)',
        unk_loader:         'Unknown loader: %',
        no_loaders:         'No loaders registered at all, please check JsHttpRequest.LOADERS array',
        no_loader_matched:  'Cannot find a loader which may process the request. Notices are:\n%'
    }
    t.abort = function() { with (this) {
        if (_ldObj && _ldObj.abort) _ldObj.abort();
        _cleanup();
        if (readyState == 0) {
            return;
        }
        if (readyState == 1 && !_ldObj) {
            readyState = 0;
            return;
        }
        _changeReadyState(4, true);
    }}
    t.open = function(method, url, asyncFlag, username, password) { with (this) {
        if (url.match(/^((\w+)\.)?(GET|POST)\s+(.*)/i)) {
            this.loader = RegExp.$2? RegExp.$2 : null;
            method = RegExp.$3;
            url = RegExp.$4; 
        }
        try {
            if (
                document.location.search.match(new RegExp('[&?]' + session_name + '=([^&?]*)'))
                || document.cookie.match(new RegExp('(?:;|^)\\s*' + session_name + '=([^;]*)'))
            ) {
                url += (url.indexOf('?') >= 0? '&' : '?') + session_name + "=" + this.escape(RegExp.$1);
            }
        } catch (e) {}
        _openArgs = {
            method:     (method || '').toUpperCase(),
            url:        url,
            asyncFlag:  asyncFlag,
            username:   username != null? username : '',
            password:   password != null? password : ''
        }
        _ldObj = null;
        _changeReadyState(1, true);
        return true;
    }}
    t.send = function(content) {
        if (!this.readyState) {
            return;
        }
        this._changeReadyState(1, true);
        this._ldObj = null;
        var queryText = [];
        var queryElem = [];
        if (!this._hash2query(content, null, queryText, queryElem)) return;
        var hash = null;
        if (this.caching && !queryElem.length) {
            hash = this._openArgs.username + ':' + this._openArgs.password + '@' + this._openArgs.url + '|' + queryText + "#" + this._openArgs.method;
            var cache = JsHttpRequest.CACHE[hash];
            if (cache) {
                this._dataReady(cache[0], cache[1]);
                return false;
            }
        }
        var loader = (this.loader || '').toLowerCase();
        if (loader && !JsHttpRequest.LOADERS[loader]) return this._error('unk_loader', loader);
        var errors = [];
        var lds = JsHttpRequest.LOADERS;
        for (var tryLoader in lds) {
            var ldr = lds[tryLoader].loader;
            if (!ldr) continue;
            if (loader && tryLoader != loader) continue;
            var ldObj = new ldr(this);
            JsHttpRequest.extend(ldObj, this._openArgs);
            JsHttpRequest.extend(ldObj, {
                queryText:  queryText.join('&'),
                queryElem:  queryElem,
                id:         (new Date().getTime()) + "" + JsHttpRequest.COUNT++,
                hash:       hash,
                span:       null
            });
            var error = ldObj.load();
            if (!error) {
                this._ldObj = ldObj;
                JsHttpRequest.PENDING[ldObj.id] = this;
                return true;
            }
            if (!loader) {
                errors[errors.length] = '- ' + tryLoader.toUpperCase() + ': ' + this._l(error);
            } else {
                return this._error(error);
            }
        }
        return tryLoader? this._error('no_loader_matched', errors.join('\n')) : this._error('no_loaders');
    }
    t.getAllResponseHeaders = function() { with (this) {
        return _ldObj && _ldObj.getAllResponseHeaders? _ldObj.getAllResponseHeaders() : [];
    }}
    t.getResponseHeader = function(label) { with (this) {
        return _ldObj && _ldObj.getResponseHeader? _ldObj.getResponseHeader(label) : null;
    }}
    t.setRequestHeader = function(label, value) { with (this) {
        _reqHeaders[_reqHeaders.length] = [label, value];
    }}
    t._dataReady = function(text, js) { with (this) {
        if (caching && _ldObj) JsHttpRequest.CACHE[_ldObj.hash] = [text, js];
        responseText = responseXML = text;
        responseJS = js;
        if (js !== null) {
            status = 200;
            statusText = "OK";
        } else {
            status = 500;
            statusText = "Internal Server Error";
        }
        _changeReadyState(2);
        _changeReadyState(3);
        _changeReadyState(4);
        _cleanup();
    }}
    t._l = function(args) {
        var i = 0, p = 0, msg = this._errors[args[0]];
        while ((p = msg.indexOf('%', p)) >= 0) {
            var a = args[++i] + "";
            msg = msg.substring(0, p) + a + msg.substring(p + 1, msg.length);
            p += 1 + a.length;
        }
        return msg;
    }
    t._error = function(msg) {
        msg = this._l(typeof(msg) == 'string'? arguments : msg)
        msg = "JsHttpRequest: " + msg;
        if (!window.Error) {
            throw msg;
        } else if ((new Error(1, 'test')).description == "test") {
            throw new Error(1, msg);
        } else {
            throw new Error(msg);
        }
    }
    t._hash2query = function(content, prefix, queryText, queryElem) {
        if (prefix == null) prefix = "";
        if((''+typeof(content)).toLowerCase() == 'object') {
            var formAdded = false;
            if (content && content.parentNode && content.parentNode.appendChild && content.tagName && content.tagName.toUpperCase() == 'FORM') {
                content = { form: content };
            }
            for (var k in content) {
                var v = content[k];
                if (v instanceof Function) continue;
                var curPrefix = prefix? prefix + '[' + this.escape(k) + ']' : this.escape(k);
                var isFormElement = v && v.parentNode && v.parentNode.appendChild && v.tagName;
                if (isFormElement) {
                    var tn = v.tagName.toUpperCase();
                    if (tn == 'FORM') {
                        formAdded = true;
                    } else if (tn == 'INPUT' || tn == 'TEXTAREA' || tn == 'SELECT') {
                    } else {
                        return this._error('inv_form_el', (v.name||''), v.tagName);
                    }
                    queryElem[queryElem.length] = { name: curPrefix, e: v };
                } else if (v instanceof Object) {
                    this._hash2query(v, curPrefix, queryText, queryElem);
                } else {
                    if (v === null) continue;
                    if (v === true) v = 1; 
                    if (v === false) v = '';
                    queryText[queryText.length] = curPrefix + "=" + this.escape('' + v);
                }
                if (formAdded && queryElem.length > 1) {
                    return this._error('must_be_single_el');
                }
            }
        } else {
            queryText[queryText.length] = content;
        }
        return true;
    }
    t._cleanup = function() {
        var ldObj = this._ldObj;
        if (!ldObj) return;
        JsHttpRequest.PENDING[ldObj.id] = false;
        var span = ldObj.span;
        if (!span) return;
        ldObj.span = null;
        var closure = function() {
            span.parentNode.removeChild(span);
        }
        JsHttpRequest.setTimeout(closure, 50);
    }
    t._changeReadyState = function(s, reset) { with (this) {
        if (reset) {
            status = statusText = responseJS = null;
            responseText = '';
        }
        readyState = s;
        if (onreadystatechange) onreadystatechange();
    }}
    t.escape = function(s) {
        return escape(s).replace(new RegExp('\\+','g'), '%2B');
    }
}
JsHttpRequest.COUNT = 0;
JsHttpRequest.MAX_URL_LEN = 2000;
JsHttpRequest.CACHE = {};
JsHttpRequest.PENDING = {};
JsHttpRequest.LOADERS = {};
JsHttpRequest._dummy = function() {};
JsHttpRequest.TIMEOUTS = { s: window.setTimeout, c: window.clearTimeout };
JsHttpRequest.setTimeout = function(func, dt) {
    window.JsHttpRequest_tmp = JsHttpRequest.TIMEOUTS.s; 
    if (typeof(func) == "string") {
        id = window.JsHttpRequest_tmp(func, dt);
    } else {
        var id = null;
        var mediator = function() {
            func();
            delete JsHttpRequest.TIMEOUTS[id];
        }
        id = window.JsHttpRequest_tmp(mediator, dt);
        JsHttpRequest.TIMEOUTS[id] = mediator;
    }
    window.JsHttpRequest_tmp = null;
    return id;
}
JsHttpRequest.clearTimeout = function(id) {
    window.JsHttpRequest_tmp = JsHttpRequest.TIMEOUTS.c;
    delete JsHttpRequest.TIMEOUTS[id];
    var r = window.JsHttpRequest_tmp(id);
    window.JsHttpRequest_tmp = null;
    return r;
}
JsHttpRequest.query = function(url, content, onready, nocache) {
    var req = new this();
    req.caching = !nocache;
    req.onreadystatechange = function() {
        if (req.readyState == 4) {
            onready(req.responseJS, req.responseText);
        }
    }
    req.open(null, url, true);
    req.send(content);
}
JsHttpRequest.dataReady = function(d) {
    var th = this.PENDING[d.id];
    delete this.PENDING[d.id];
    if (th) {
        th._dataReady(d.text, d.js);
    } else if (th !== false) {
        throw "dataReady(): unknown pending id: " + d.id;
    }
}
JsHttpRequest.extend = function(dest, src) {
    for (var k in src) dest[k] = src[k];
}
JsHttpRequest.LOADERS.xml = { loader: function(req) {
    JsHttpRequest.extend(req._errors, {
        xml_no:          'Cannot use XMLHttpRequest or ActiveX loader: not supported',
        xml_no_diffdom:  'Cannot use XMLHttpRequest to load data from different domain %',
        xml_no_headers:  'Cannot use XMLHttpRequest loader or ActiveX loader, POST method: headers setting is not supported, needed to work with encodings correctly',
        xml_no_form_upl: 'Cannot use XMLHttpRequest loader: direct form elements using and uploading are not implemented'
    });
    
    this.load = function() {
        if (this.queryElem.length) return ['xml_no_form_upl'];
        if (this.url.match(new RegExp('^([a-z]+://[^\\/]+)(.*)', 'i'))) {
            if (RegExp.$1.toLowerCase() != document.location.protocol + '//' + document.location.hostname.toLowerCase()) {
                return ['xml_no_diffdom', RegExp.$1];
            }
        }
        var xr = null;
        if (window.XMLHttpRequest) {
            try { xr = new XMLHttpRequest() } catch(e) {}
        } else if (window.ActiveXObject) {
            try { xr = new ActiveXObject("Microsoft.XMLHTTP") } catch(e) {}
            if (!xr) try { xr = new ActiveXObject("Msxml2.XMLHTTP") } catch (e) {}
        }
        if (!xr) return ['xml_no'];
        var canSetHeaders = window.ActiveXObject || xr.setRequestHeader;
        if (!this.method) this.method = canSetHeaders && this.queryText.length? 'POST' : 'GET';
        if (this.method == 'GET') {
            if (this.queryText) this.url += (this.url.indexOf('?') >= 0? '&' : '?') + this.queryText;
            this.queryText = '';
            if (this.url.length > JsHttpRequest.MAX_URL_LEN) return ['url_too_long', JsHttpRequest.MAX_URL_LEN];
        } else if (this.method == 'POST' && !canSetHeaders) {
            return ['xml_no_headers'];
        }
        this.url += (this.url.indexOf('?') >= 0? '&' : '?') + 'JsHttpRequest=' + (req.caching? '0' : this.id) + '-xml';        
        var id = this.id;
        xr.onreadystatechange = function() { 
            if (xr.readyState != 4) return;
            xr.onreadystatechange = JsHttpRequest._dummy;
            req.status = null;
            try { 
                req.status = xr.status;
                req.responseText = xr.responseText;
            } catch (e) {}
            if (!req.status) return;
            try {
                var rtext = req.responseText || '{ js: null, text: null }';
                eval('JsHttpRequest._tmp = function(id) { var d = ' + rtext + '; d.id = id; JsHttpRequest.dataReady(d); }');
            } catch (e) {
                return req._error('js_invalid', req.responseText)
            }
            JsHttpRequest._tmp(id);
            JsHttpRequest._tmp = null;
        };
        xr.open(this.method, this.url, true, this.username, this.password);
        if (canSetHeaders) {
            for (var i = 0; i < req._reqHeaders.length; i++) {
                xr.setRequestHeader(req._reqHeaders[i][0], req._reqHeaders[i][1]);
            }
            xr.setRequestHeader('Content-Type', 'application/octet-stream');
        }
        xr.send(this.queryText);
        this.span = null;
        this.xr = xr;
        return null;
    }
    this.getAllResponseHeaders = function() {
        return this.xr.getAllResponseHeaders();
    }
    this.getResponseHeader = function(label) {
        return this.xr.getResponseHeader(label);
    }

    this.abort = function() {
        this.xr.abort();
        this.xr = null;
    }
}}
JsHttpRequest.LOADERS.script = { loader: function(req) {
    JsHttpRequest.extend(req._errors, {
        script_only_get:   'Cannot use SCRIPT loader: it supports only GET method',
        script_no_form:    'Cannot use SCRIPT loader: direct form elements using and uploading are not implemented'
    })
    this.load = function() {
        if (this.queryText) this.url += (this.url.indexOf('?') >= 0? '&' : '?') + this.queryText;
        this.url += (this.url.indexOf('?') >= 0? '&' : '?') + 'JsHttpRequest=' + this.id + '-' + 'script';        
        this.queryText = '';
        if (!this.method) this.method = 'GET';
        if (this.method !== 'GET') return ['script_only_get'];
        if (this.queryElem.length) return ['script_no_form'];
        if (this.url.length > JsHttpRequest.MAX_URL_LEN) return ['url_too_long', JsHttpRequest.MAX_URL_LEN];
        var th = this, d = document, s = null, b = d.body;
        if (!window.opera) {
            this.span = s = d.createElement('SCRIPT');
            var closure = function() {
                s.language = 'JavaScript';
                if (s.setAttribute) s.setAttribute('src', th.url); else s.src = th.url;
                b.insertBefore(s, b.lastChild);
            }
        } else {
            this.span = s = d.createElement('SPAN');
            s.style.display = 'none';
            b.insertBefore(s, b.lastChild);
            s.innerHTML = 'Workaround for IE.<s'+'cript></' + 'script>';
            var closure = function() {
                s = s.getElementsByTagName('SCRIPT')[0];
                s.language = 'JavaScript';
                if (s.setAttribute) s.setAttribute('src', th.url); else s.src = th.url;
            }
        }
        JsHttpRequest.setTimeout(closure, 10);
        return null;
    }
}}
JsHttpRequest.LOADERS.form = { loader: function(req) {
    JsHttpRequest.extend(req._errors, {
        form_el_not_belong:  'Element "%" does not belong to any form!',
        form_el_belong_diff: 'Element "%" belongs to a different form. All elements must belong to the same form!',
        form_el_inv_enctype: 'Attribute "enctype" of the form must be "%" (for IE), "%" given.'
    })
    this.load = function() {
        var th = this;
        if (!th.method) th.method = 'POST';
        th.url += (th.url.indexOf('?') >= 0? '&' : '?') + 'JsHttpRequest=' + th.id + '-' + 'form';
        if (th.method == 'GET') {
            if (th.queryText) th.url += (th.url.indexOf('?') >= 0? '&' : '?') + th.queryText;
            if (th.url.length > JsHttpRequest.MAX_URL_LEN) return ['url_too_long', JsHttpRequest.MAX_URL_LEN];
            var p = th.url.split('?', 2);
            th.url = p[0];
            th.queryText = p[1] || '';
        }
        var form = null;
        var wholeFormSending = false;
        if (th.queryElem.length) {
            if (th.queryElem[0].e.tagName.toUpperCase() == 'FORM') {
                form = th.queryElem[0].e;
                wholeFormSending = true;
                th.queryElem = [];
            } else {
                form = th.queryElem[0].e.form;
                for (var i = 0; i < th.queryElem.length; i++) {
                    var e = th.queryElem[i].e;
                    if (!e.form) {
                        return ['form_el_not_belong', e.name];
                    }
                    if (e.form != form) {
                        return ['form_el_belong_diff', e.name];
                    }
                }
            }
            if (th.method == 'POST') {
                var need = "multipart/form-data";
                var given = (form.attributes.encType && form.attributes.encType.nodeValue) || (form.attributes.enctype && form.attributes.enctype.value) || form.enctype;
                if (given != need) {
                    return ['form_el_inv_enctype', need, given];
                }
            }
        }
        var d = form && (form.ownerDocument || form.document) || document;
        var ifname = 'jshr_i_' + th.id;
        var s = th.span = d.createElement('DIV');
        s.style.position = 'absolute';
        s.style.display = 'none';
        s.style.visibility = 'hidden';
        s.innerHTML = 
            (form? '' : '<form' + (th.method == 'POST'? ' enctype="multipart/form-data" method="post"' : '') + '></form>') +
            '<iframe name="' + ifname + '" id="' + ifname + '" style="width:0px; height:0px; overflow:hidden; border:none"></iframe>'
        if (!form) {
            form = th.span.firstChild;
        }
        d.body.insertBefore(s, d.body.lastChild);
        var setAttributes = function(e, attr) {
            var sv = [];
            var form = e;
            if (e.mergeAttributes) {
                var form = d.createElement('form');
                form.mergeAttributes(e, false);
            }
            for (var i = 0; i < attr.length; i++) {
                var k = attr[i][0], v = attr[i][1];
                sv[sv.length] = [k, form.getAttribute(k)];
                form.setAttribute(k, v);
            }
            if (e.mergeAttributes) {
                e.mergeAttributes(form, false);
            }
            return sv;
        }
        var closure = function() {
            top.JsHttpRequestGlobal = JsHttpRequest;
            var savedNames = [];
            if (!wholeFormSending) {
                for (var i = 0, n = form.elements.length; i < n; i++) {
                    savedNames[i] = form.elements[i].name;
                    form.elements[i].name = '';
                }
            }
            var qt = th.queryText.split('&');
            for (var i = qt.length - 1; i >= 0; i--) {
                var pair = qt[i].split('=', 2);
                var e = d.createElement('INPUT');
                e.type = 'hidden';
                e.name = unescape(pair[0]);
                e.value = pair[1] != null? unescape(pair[1]) : '';
                form.appendChild(e);
            }
            for (var i = 0; i < th.queryElem.length; i++) {
                th.queryElem[i].e.name = th.queryElem[i].name;
            }
            var sv = setAttributes(
                form, 
                [
                    ['action',   th.url],
                    ['method',   th.method],
                    ['onsubmit', null],
                    ['target',   ifname]
                ]
            );
            form.submit();
            setAttributes(form, sv);
            for (var i = 0; i < qt.length; i++) {
                form.lastChild.parentNode.removeChild(form.lastChild);
            }
            if (!wholeFormSending) {
                for (var i = 0, n = form.elements.length; i < n; i++) {
                    form.elements[i].name = savedNames[i];
                }
            }
        }
        JsHttpRequest.setTimeout(closure, 100);
        return null;
    }    
}}