/*
MIT License
Copyright (c) 2008 Jean-Denis Caron
jean-denis@paralines.net

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

function xmlDOM(str){
    //Code for IE.
    if (window.ActiveXObject)
    {
        var doc=new ActiveXObject("Microsoft.XMLDOM");
        doc.async="false";
        doc.loadXML(str);
    }
    // Code for the other browsers.
    else
    {
        var parser=new DOMParser();
        var doc=parser.parseFromString(str,"text/xml");
    }

    return doc
}

function loadPage(url){
// Write a function that return the next structure
// with the URLs replaced in the load nodes.

    window.url = url;

    // Start the loading indicator for
    // the user.
    document.getElementById('loading').style.top = document.body.scrollTop;
    document.getElementById('loading').style.visibility = 'visible';

    urlSplit_array = url.split('&');
    window.nextUrlList_array = [];
    window.pageName = '';
    for(var i=0;i<urlSplit_array.length;i++){
        if(urlSplit_array[i].split('=')[0] == 'page'){
            // Load the page defined by the variable 'page'
            // in the URL.
            window.pageName = urlSplit_array[i].split('=')[1];
            window.nextTemplate_xml = eval('page.'+window.pageName+'()');
        }
    }
    if(window.pageName == ''){
        window.nextTemplate_xml = page.index();
    }

    // Retrieve all the URLs of a template and put them in
    // an associative array.
    processTemplateStructure(window.nextTemplate_xml, 'next');
    loadBlocks();
}

function loadBlocks(){
    window.urlsToLoad_array = [];
    for(var i=0;i<window.nextUrlList_array.length;i++){
        if(window.actualUrlList_array[window.nextUrlList_array[i][1]] == null || !isNaN(window.nextUrlList_array[i][1]) || window.nextUrlList_array[i][2] == '1'){
            // Set a list of URLs in an array. And start
            // the loading asynchronously with an AJAX request.
            // The array contains the URL to load and the index
            // position in the other array (nextUrlList_array).
            if(!isNaN(window.nextUrlList_array[i][1])){
                window.nextUrlList_array[i][1] = urlMerge(window.urlList_array[window.nextUrlList_array[i][1]], window.url);
            }else if(window.nextUrlList_array[i][2] == '1'){
                window.nextUrlList_array[i][1] = urlMerge(window.nextUrlList_array[i][1], window.url);
            }
            window.urlsToLoad_array[window.urlsToLoad_array.length] = [i, window.nextUrlList_array[i][1]];
        }else{
            // Get the content of the blocks which
            // are already loaded in the page and
            // save it in the array which will be used
            // to show in next page.
            window.nextUrlList_array[i][1] = document.getElementById(window.actualUrlList_array[window.nextUrlList_array[i][1]]).innerHTML;
        }
    }
    // Send the AJAX requests. This is done after
    // getting the whole list to avoid a bug that
    // appeared with the asynchronous queries and
    // JS that run at the same time.
    window.numberOfLoadedUrls = 0;
    urlIsLoaded = '';
    for(var i=0;i<window.urlsToLoad_array.length;i++){
        if(urlIsLoaded.indexOf(window.urlsToLoad_array[i][1].toString() + ';') == -1){
            new Ajax.Request(window.urlsToLoad_array[i][1], { method: 'get', onComplete: loadUrlInArray, requestHeaders: ['If-Modified-Since', 'Thu, 1 Jan 1970 00:00:00 GMT']});
            urlIsLoaded = urlIsLoaded + window.urlsToLoad_array[i][1].toString() + ';';
        }
    }
}

function urlMerge(urlFromTemplate, requestedUrl){
        return urlFromTemplate + '?' + requestedUrl;
}

function returnStructure(template){
    // Return the structure depending of
    // it's type. Used by the 2 classes
    // that define the pages of the
    // site : page, template.
    structure_xml = xmlDOM(template);
    if(structure_xml.firstChild.firstChild.nodeName == 'template'){
        window.urlList_array = [];
        // Fill an array with the dynamic urls to load if there
        // are urls in the child node.
        if(structure_xml.firstChild.childNodes.length > 1){
            for(var i=0;i<structure_xml.firstChild.childNodes[1].childNodes.length;i++){
                // Put the URLs to load in an array.
                window.urlList_array[structure_xml.firstChild.childNodes[1].childNodes[i].nodeName.replace('_', '')] = structure_xml.firstChild.childNodes[1].childNodes[i].firstChild.nodeValue;
            }
        }
        // Return the structure.
        return eval('window.template.'+structure_xml.firstChild.firstChild.firstChild.nodeValue+'()');
    }else{
        return structure_xml;
    }
}

function loadUrlInArray(response){

    for(var i=0;i<window.urlsToLoad_array.length;i++){
        if(window.urlsToLoad_array[i][1] == response.url){
            // Put the HTML result in the array
            // that holds the information for the
            // next page.
            window.nextUrlList_array[window.urlsToLoad_array[i][0]][1] = response.responseText;
            window.numberOfLoadedUrls++;
        }
    }

    // All the blocks has been loaded and it's now
    // time to change the content displayed to the user.
    if(window.numberOfLoadedUrls == window.urlsToLoad_array.length){
        compare2Structures(window.actualTemplate_xml.firstChild.firstChild, window.nextTemplate_xml.firstChild.firstChild);

        // Set the template and the url list as actual
        // since they have been loaded to the page.
        window.actualUrlList_array = [];
        window.actualTemplate_xml = window.nextTemplate_xml;
        processTemplateStructure(eval('page.'+window.pageName+'()'), 'actual');

        // Hide the loading indicator.
        document.getElementById('loading').style.visibility = 'hidden';
    }
}

function processTemplateStructure(childs_xml, action){
    // Process the nodes "childs" of this node.
    for(var i=0;i<childs_xml.childNodes.length;i++){
        for(var j=0;j<childs_xml.childNodes[i].childNodes.length;j++){
            if(childs_xml.childNodes[i].childNodes[j].nodeName == 'childs'){
                processTemplateStructure(childs_xml.childNodes[i].childNodes[j], action);
            }

            if(childs_xml.childNodes[i].childNodes[j].nodeName == 'load' && action == 'actual'){
                window.actualUrlList_array[childs_xml.childNodes[i].childNodes[j].firstChild.nodeValue] = childs_xml.childNodes[i].nodeName;
            }else if(childs_xml.childNodes[i].childNodes[j].nodeName == 'load' && action == 'next'){
                window.nextUrlList_array[window.nextUrlList_array.length] = [childs_xml.childNodes[i].nodeName, childs_xml.childNodes[i].childNodes[j].firstChild.nodeValue, childs_xml.childNodes[i].childNodes[j+1].firstChild.nodeValue];
            }
        }
    }
}

function compare2Structures(actual_xml, next_xml){
    // Delete the HTML elements that are not in
    // the new template.
    if(Try.these(function() {return actual_xml.childNodes.length > next_xml.childNodes.length;})){
        // Get the actual name tag and replace the last
        // part with the blocks numbers to delete.
        nameTags_array = next_xml.childNodes[0].nodeName.split('_');

        // Delete the blocks.
        for(var k=0;k<(actual_xml.childNodes.length-next_xml.childNodes.length);k++){
            nameTags_array[nameTags_array.length-1] = (nameTags_array[nameTags_array.length-1].substr(0,1)) + (actual_xml.childNodes.length-(actual_xml.childNodes.length-next_xml.childNodes.length)+k);
            Element.remove($(nameTags_array.join('_')));
        }
    }

    // Clean the blocks from their previous content if
    // they have no childs anymore. 
    blockToClean_array = next_xml.childNodes[0].nodeName.split('_')
    blockToClean_array = blockToClean_array.slice(0,blockToClean_array.length-1);
    if(Try.these(function() {return actual_xml.childNodes[0].childNodes[0] == undefined;})){
        Try.these(function() {$(blockToClean_array.join('_')).innerHTML = '';});
    }

    // Process the nodes "childs" of this node.
    for(var i=0;i<next_xml.childNodes.length;i++){

        for(var j=0;j<next_xml.childNodes[i].childNodes.length;j++){
                // Verify if the actual structure has childs
                // at that stage of the loading of the new structure.
                // This is done with a "Try" to avoid errors and
                // crash the process.
                nextChildsStatus = Try.these(function() {return next_xml.childNodes[i].childNodes[j].nodeName == 'childs';});

                if(nextChildsStatus){
                    // Create the block if it doesn't exists.
                    if($(next_xml.childNodes[i].nodeName) == null){
                        if(next_xml.childNodes[i].nodeName.toString().search('_') != -1){
                            parentBlock = next_xml.childNodes[i].nodeName.slice(0, next_xml.childNodes[i].nodeName.lastIndexOf('_'));
                        }else{
                            parentBlock = 'page';
                        }
                        new Insertion.Bottom(parentBlock, '<div id="' + next_xml.childNodes[i].nodeName + '"></div>');
                    }

                    if(Try.these(function() {return actual_xml.childNodes[i].childNodes[j];}) == undefined){
                        actualTree_xml = '';
                    }else{
                        actualTree_xml = actual_xml.childNodes[i].childNodes[j];
                    }
                    compare2Structures(actualTree_xml, next_xml.childNodes[i].childNodes[j]);
                }else{
                    if(next_xml.childNodes[i].childNodes[j].nodeName == 'load'){
                        // This node has content to load.
                        for(var c=0;c<window.nextUrlList_array.length;c++){
                            if(window.nextUrlList_array[c][0] == next_xml.childNodes[i].nodeName){
                                var nextBlockContent = window.nextUrlList_array[c][1];
                            }
                        }

                        blockExists = true;
                        try{actual_xml.childNodes[i].childNodes[j].hasChildNodes();}catch(e){blockExists = false;}
                        if(blockExists){
                            // Replace the content of the already
                            // existing block if the value of the node
                            // is an URL.
                            if($(actual_xml.childNodes[i].nodeName).innerHTML != nextBlockContent){
                                $(next_xml.childNodes[i].nodeName).innerHTML = nextBlockContent;
                            }
                        }else{
                            // Build the block and insert the content
                            // at the end of the parent.
                            if(next_xml.childNodes[i].nodeName.split('_').length > 1){
                                // Split the div name and remove the last
                                // suffix of it so the content is inserted
                                // at the bottom of his parent.
                                divToInsertBottom = next_xml.childNodes[i].nodeName.split('_').slice(0, next_xml.childNodes[i].nodeName.split('_').length-1).join('_');
                            }else{
                                divToInsertBottom = 'page';
                            }
                            new Insertion.Bottom(divToInsertBottom, '<div id="' + next_xml.childNodes[i].nodeName + '">' + nextBlockContent + '</div>');
                        }
                    }
                }

                // Set the style of this block.
                if(next_xml.childNodes[i].childNodes[j].nodeName == 'style'){
                    Element.setStyle(next_xml.childNodes[i].nodeName, next_xml.childNodes[i].childNodes[j].firstChild.nodeValue);
                }
        }
    }
}