/* 
 *   Copyright (C) 2014
 *   This file is part of WvS VPlan.
 *
 *   WvS VPlan is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Affero General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Affero General Public License for more details.
 *
 *   You should have received a copy of the GNU Affero General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

// Login-Popup beim Start
$('#loginpage').on('pagebeforeshow', function(){
    setTimeout(function(){
        $('#lnklogin').click();
    }, 500);
});

$('#loginpage').on('pageshow', function(){
    setTimeout(function(){
        trylogin();
    }, 2000);
});

// Ladebutton bei fehlender Verbindung
$('#loadbtn').click(function(){
    load();
});

// Page-Template für Vertretungsplan
var page_html = '\n\
<div data-role="page" class="page" id="page-vplan-{ID}" data-prefetch>\n\
    <div data-role="header">\n\
        <h1>WvS VPlan | Vertretungen</h1>\n\
    </div>\n\
    <div role="main" class="ui-content" id="pdf-{ID}" data-plan-url="">\n\
    </div>\n\
</div>\n\
';

function renderPage(div, pdf, pageNumber, callback){
    pdf.getPage(pageNumber).then(function(page){
        var scale = 2;
        var viewport = page.getViewport(scale);

        var pageDisplayWidth = viewport.width;
        var pageDisplayHeight = viewport.height;

        var pageDivHolder = document.createElement('div');
        pageDivHolder.className = 'pdfpage';

        var $canvas = $('<canvas></canvas>');
        var canvas = $canvas.get(0);
        canvas.className = 'pdfcanvas';
        var context = canvas.getContext('2d');
        canvas.width = pageDisplayWidth;
        canvas.height = pageDisplayHeight;

        pageDivHolder.appendChild(canvas);
        div.appendChild(pageDivHolder);

        var renderContext = {
            canvasContext: context,
            viewport: viewport
        };
        page.render(renderContext).promise.then(callback);
    });
}

function render_pdf(viewerstr){
    console.log('Rendere PDF: ' + $(viewerstr).attr('data-plan-url') + ' (' + viewerstr + ')');

    PDFJS.getDocument($(viewerstr).attr('data-plan-url')).then(function(pdf){
        var viewer = document.getElementById(viewerstr.replace(/#/, ''));
        var pageNumber = 1;
        renderPage(viewer, pdf, pageNumber++, function pageRenderingComplete(){
            if(pageNumber > pdf.numPages){
                return;
            }
            renderPage(viewer, pdf, pageNumber++, pageRenderingComplete);
        });
    });
}

function fail(text){
    $('#loginform').removeClass('ui-disabled');
    $('#loader').hide('slow');
    $('#error_noconn').show('fast');
    console.log('Fehler: ' + text.toString() + ' / ' + text.code);
}

function download_pdf(link, id){
    var filename = link.substring(link.lastIndexOf("/") + 1);

    window.requestFileSystem(
    LocalFileSystem.PERSISTENT, 0,
    function(fileSystem){
        fileSystem.root.getDirectory('WvSVPlan', {create: true, exclusive: false},
        function(dirEntry){
            dirEntry.getFile(filename, {create: false, exclusive: false},
            function(fileEntry){
                // Datei ist schon heruntergeladen
                var sPath = fileEntry.toURL();

                console.log('Datei vorhanden: ' + sPath);
                $('#pdf-' + id).attr('data-plan-url', sPath);

                if(location.href.indexOf('page-') == -1){
                    $.mobile.changePage('#page-vplan-' + id);
                }
            },
        function(err){
            // Datei existiert noch nicht
            dirEntry.getFile(filename, {create: true, exclusive: false},
            function(fileEntry){
                var sPath = fileEntry.toURL();

                console.log('Pfad: ' + sPath);

                var fileTransfer = new FileTransfer();

                fileTransfer.download(
                link,
                sPath,
                function(theFile){
                    console.log('Download fertig: ' + theFile.toURL());
                    $('#pdf-' + id).attr('data-plan-url', theFile.toURL());

                    if(location.href.indexOf('page-') == -1){
                        $.mobile.changePage('#page-vplan-' + id);
                    }
                },
                function(error){
                    console.log('Fehler: ' + error.source + ' - '+ error.target + ' - ' + error.code);
                    fail();
                });
                }, fail);
            });
        }, fail);
    });
}

function get_plan(link, id){
    var request = $.ajax({
        url: link
    });

    request.done(function gotplan(resulthtml){
        var pdf_re = new RegExp('(http://***REMOVED***\\.de/moodle/pluginfile\\.php/\\d+/mod_resource/content/\\d+.*?\\.pdf)');
        var pdflink = pdf_re.exec(resulthtml)[1];

        if(pdflink == null){
            return 0;
        }

        console.log('Plan gefunden: ' + pdflink);
        download_pdf(pdflink, id);

        return 1;
    });

    request.fail(fail);
}

function prepare_html(number){
    // Pages für Vertretungsplände erstellen und pageshow-Events festlegen
        
    for(j = 0; j < number; j++){
        new_html = page_html.replace(/{ID}/g, j);
        
        $('#loginpage').after(new_html);

        if(j + 1 < number){
            $('#page-vplan-' + j).on('swipeleft', function(event){
                $.mobile.changePage('#page-vplan-' + (parseInt($('.ui-page-active').attr('id').match(/\d+/)[0]) + 1));
            });
        }

        if(j - 1 >= 0){
            $('#page-vplan-' + j).on('swiperight', function(event){
                $.mobile.changePage('#page-vplan-' + (parseInt($('.ui-page-active').attr('id').match(/\d+/)[0]) - 1));
            });
        }

        $('#page-vplan-' + j).on('pageshow', function(event){
            render_pdf($('.ui-page-active').attr('id').replace(/page-vplan/, '#pdf'));
        });
    }
}

function gotoverview(resulthtml){
    var plans_re = new RegExp('window\\.open\\(&#039;(http://***REMOVED***\\.de/moodle/mod/resource/view\\.php\\?id=\\d+)&amp;redirect=1&#039;\\)', 'g');

    var resultarr = resulthtml.match(plans_re);

    if(resultarr == null){
        $('#error_passwd').show('fast');
        $('#loginform').removeClass('ui-disabled');
        $('#loader').hide('slow');
        return 0;
    }

    var resultl = resultarr.length;

    prepare_html(resultl);
    
    j = 0;

    while((link = plans_re.exec(resulthtml)) !== null){
        console.log('suche Plan ' + link[1]);
        get_plan(link[1], j++);
    }

    console.log('Übersichts-Request erfolgreich');
    return 1;
}

function get_overview(link, onfail){
    var request = $.ajax({
        url: link
    });

    console.log('Hole Übersicht');

    request.done(gotoverview);
    request.fail(onfail);
}

function loggedin(resulthtml){
    var vertretungs_re = new RegExp('title="Vertretungsplan" href="(http://***REMOVED***\\.de/moodle/course/view\\.php\\?id=\\d+)"');
    var link = vertretungs_re.exec(resulthtml)[1];

    if(link == null){
        return 0;
    }

    window.localStorage.setItem('overviewlink', link);
    console.log('Eingeloggt');
    get_overview(link, fail);

    return 1;
}

function sendlogin(username, password){
    var params = 'username=' + username + '&password=' + password;

    $('#loginform').addClass('ui-disabled');
    $('#loader').show('fast');
    
    $('#error_noconn').hide('fast');
    $('#error_passwd').hide('fast');
    
    var request = $.ajax({
        type: 'POST',
        url: 'https://***REMOVED***/moodle/login/index.php',
        data: {username: username, password: password}
    });

    console.log('Logge ein');

    request.done(loggedin);
    request.fail(fail);
}

function getuserdata(){
    var username = encodeURIComponent($('#username').val());

    if(username == ''){
        username = window.localStorage.getItem('username');
    }else{
        window.localStorage.setItem('username', username);
    }

    var password = encodeURIComponent($('#password').val());
    if(password == ''){
        password = window.localStorage.getItem('password');
    }else{
        window.localStorage.setItem('password', password);
    }

    console.log('Benutzerdaten geladen');

    if(username !== 'undefined' && username != null && username != '' && password !== 'undefined' && password != null && password != ''){
        return [username, password];
    }else{
        return null;
    }
}

function login(){
    userdata = getuserdata();

    if(userdata != null){
        sendlogin(userdata[0], userdata[1]);
        return 1;
    }else{
        $('#loginform').removeClass('ui-disabled');
        $('#loader').hide('fast');
        return 0;
    }
}

// prüfen, ob ein Login notwendig ist oder ob die Session noch gültig ist

function trylogin(){
    var link = window.localStorage.getItem('overviewlink');

    $('#loginform').addClass('ui-disabled');
    $('#loader').show('fast');

    if(typeof link !== 'undefined' && link != null){
        console.log('Teste Login');
        console.log(link);

        get_overview(link, login);
    }else{
        login();
    }
}

function load(){
    window.requestFileSystem(
    LocalFileSystem.PERSISTENT, 0,
    function(fileSystem){
        fileSystem.root.getDirectory('WvSVPlan', {create: true, exclusive: false},
        function(dirEntry){
            var dirReader = dirEntry.createReader();

            dirReader.readEntries(
            function(entries){
                var actual = 0;
                var today = new Date();
                var fname_re = new RegExp('([^-]{4})-([^-]{2})-([^-]{2})(.*?)\.pdf'); // \d funktioniert nicht

                for(j = 0; j < entries.length; j++){
                    var name = entries[j].name;
                    console.log(name);
                    var results = name.match(fname_re);
                    var fdate = new Date(parseInt(results[1]), parseInt(results[2]), parseInt(results[3]));
                    
                    if(fdate >= today){
                        actual++;
                    }
                    console.log(actual);
                }

                console.log("Im Speicher: " + actual + " Pläne");

                if(actual > 0){
                    prepare_html(actual);

                    for(j = 0; j < entries.length; j++){
                        var results = entries[j].name.match(fname_re);
                        var fdate = new Date(results[1], results[2], results[3]);
                        
                        if(fdate >= today){
                            var sPath = entries[j].toURL();

                            console.log('lade Datei offline: ' + sPath);
                            $('#pdf-' + j).attr('data-plan-url', sPath);

                            if(location.href.indexOf('page-') == -1){
                                $.mobile.changePage('#page-vplan-' + j);
                            }

                        }
                    }
                }else{

                }
            }, fail);
        }, fail);
    });
}