/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an 'AS IS' basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Bespin.
 *
 * The Initial Developer of the Original Code is
 * Mozilla.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Bespin Team (bespin@mozilla.com)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

var SC = require('sproutcore/runtime').SC;
var Promise = require('bespin:promise').Promise;

/**
 * Registers a new syntax module as it's discovered in a plugin.
 */
exports.discoveredNewSyntax = function(syntaxExtension) {
    exports.syntaxDirectory.registerExtension(syntaxExtension);
};

var SyntaxInfo = SC.Object.extend({
    /**
     * @property{Extension}
     *
     * The extension that defines this syntax. This property must be filled in
     * upon instantiating the syntax info.
     */
    extension: null,

    /**
     * @property{Array<string>}
     *
     * The set of file extensions that this syntax can handle.
     */
    fileExts: null,

    /**
     * @property{string}
     *
     * The unique identifier for this syntax.
     */
    name: null,

    init: function() {
        var extension = this.get('extension');
        this.set('name', extension.name);

        var fileExts = extension.fileexts;
        this.set('fileExts', SC.none(fileExts) ? [] : fileExts);
    }
});

exports.syntaxDirectory = SC.Object.create({
    _fileExts: {},
    _syntaxInfo: {},

    /**
     * Loads the syntax module with the given identifier and returns a promise
     * that the module will be loaded.
     */
    loadSyntax: function(name) {
        var syntaxInfo = this._syntaxInfo[name];
        if (syntaxInfo === undefined) {
            return null;
        }

        var promise = new Promise();
        syntaxInfo.get('extension').load(function(pointer) {
            promise.resolve(pointer);
        });

        return promise;
    },

    registerExtension: function(extension) {
        var syntaxInfo = SyntaxInfo.create({ extension: extension });

        var name = syntaxInfo.get('name');
        this._syntaxInfo[name] = syntaxInfo;

        // Add the file extensions to the index.
        var fileExts = this._fileExts;
        syntaxInfo.get('fileExts').forEach(function(fileExt) {
            fileExts[fileExt] = name;
        });
    },

    syntaxForFileExt: function(fileExt) {
        var syntax = this._fileExts[fileExt.toLowerCase()];
        return SC.none(syntax) ? 'plain' : syntax;
    }
});

