/**
 * @license
 * Copyright (C) 2012-2013 KO GmbH <copyright@kogmbh.com>
 *
 * @licstart
 * The JavaScript code in this page is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Affero General Public License
 * (GNU AGPL) as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.  The code is distributed
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU AGPL for more details.
 *
 * As additional permission under GNU AGPL version 3 section 7, you
 * may distribute non-source (e.g., minimized or compacted) forms of
 * that code without the copy of the GNU GPL normally required by
 * section 4, provided you include this license notice and a URL
 * through which recipients can access the Corresponding Source.
 *
 * As a special exception to the AGPL, any HTML file which merely makes function
 * calls to this code, and for that purpose includes it by reference shall be
 * deemed a separate work for copyright law purposes. In addition, the copyright
 * holders of this code give you permission to combine this code with free
 * software libraries that are released under the GNU LGPL. You may copy and
 * distribute such a system following the terms of the GNU AGPL for this code
 * and the LGPL for the libraries. If you modify this code, you may extend this
 * exception to your version of the code, but you are not obligated to do so.
 * If you do not wish to do so, delete this exception statement from your
 * version.
 *
 * This license applies to this entire compilation.
 * @licend
 * @source: http://www.webodf.org/
 * @source: http://gitorious.org/webodf/webodf/
 */

/*global define,require */

define("webodf/editor/widgets/paragraphStyles",
       ["webodf/editor/EditorSession"],

   function (EditorSession) {
    "use strict";
    /**
     * @constructor
     */
    var ParagraphStyles = function (callback) {
        var self = this,
            editorSession,
            select,
            translator = document.translator,
            defaultStyleUIId = ":default";

        this.widget = function () {
            return select;
        };

        /*
         * In this widget, we name the default style
         * (which is referred to as "" in webodf) as
         * ":default". The ":" is disallowed in an NCName, so this
         * avoids clashes with other styles.
         */

        this.value = function () {
            var value = select.get('value');
            if (value === defaultStyleUIId) {
                value = "";
            }
            return value;
        };

        this.setValue = function (value) {
            if (value === "") {
                value = defaultStyleUIId;
            }
            select.set('value', value);
        };

        // events
        this.onAdd = null;
        this.onRemove = null;
        this.onChange = function () {};

        function populateStyles() {
            var i, selectionList, availableStyles;

            if (! select) {
                return;
            }

            // Populate the Default Style always 
            selectionList = [{
                label: translator("defaultStyle"),
                value: defaultStyleUIId
            }];
            availableStyles = editorSession ? editorSession.getAvailableParagraphStyles() : [];

            for (i = 0; i < availableStyles.length; i += 1) {
                selectionList.push({
                    label: availableStyles[i].displayName,
                    value: availableStyles[i].name
                });
            }

            select.removeOption(select.getOptions());
            select.addOption(selectionList);
        }

        function addStyle(styleInfo) {
            var stylens = "urn:oasis:names:tc:opendocument:xmlns:style:1.0",
                newStyleElement;

            if (styleInfo.family !== 'paragraph') {
                return;
            }

            newStyleElement = editorSession.getParagraphStyleElement(styleInfo.name);
            if (select) {
                select.addOption({
                    value: styleInfo.name,
                    label: newStyleElement.getAttributeNS(stylens, 'display-name')
                });
            }

            if (self.onAdd) {
                self.onAdd(styleInfo.name);
            }
        }

        function removeStyle(styleInfo) {
            if (styleInfo.family !== 'paragraph') {
                return;
            }

            if (select) {
                select.removeOption(styleInfo.name);
            }

            if (self.onRemove) {
                self.onRemove(styleInfo.name);
            }
        }

        function init(cb) {
            require(["dijit/form/Select"], function (Select) {
                select = new Select({
                    name: 'ParagraphStyles',
                    maxHeight: 200,
                    style: {
                        width: '100px'
                    }
                });

                populateStyles();

                // Call ParagraphStyles's onChange handler every time
                // the select's onchange is called, and pass the value
                // as reported by ParagraphStyles.value(), because we do not
                // want to expose the internal naming like ":default" outside this
                // class.
                select.onChange = function () {
                    self.onChange(self.value());
                };

                return cb();
            });
        }

        this.setEditorSession = function(session) {
            if (editorSession) {
                editorSession.unsubscribe(EditorSession.signalCommonStyleCreated, addStyle);
                editorSession.unsubscribe(EditorSession.signalCommonStyleDeleted, removeStyle);
            }
            editorSession = session;
            if (editorSession) {
                editorSession.subscribe(EditorSession.signalCommonStyleCreated, addStyle);
                editorSession.subscribe(EditorSession.signalCommonStyleDeleted, removeStyle);
                populateStyles();
            }
        };

        // init
        init(function () {
            return callback(self);
        });
    };

    return ParagraphStyles;
});