/**

 * Copyright (c) 2009-2010 Symbian Foundation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Nokia Corporation - initial contribution.

 * 

 * Contributors:

 * 

 * Description:

 * 

 */

/**

 * MediaManagement.js

 * 

 * Web Runtime Service API emulation 

 * WRT v1.1

 * 

 */

(function(){

	var provider = 'Service.MediaManagement' ,

		Interface = 'IDataSource';

	/**

	 * MediaManagement service

	 */

	var MediaManagementService = function(){

		this.GetList 	= __GetList;

		this.Cancel 	= __Cancel;

	}

	device.implementation.extend(provider, Interface, new MediaManagementService() );

	/******************************************************/	

	/******************************************************/	

	/******************************************************/	

	var	context = device.implementation.context,

		_t = context._t,

		method = '',

		result = false,

		DBase = null;

	/**

	 * MediaManagement: GetList

	 * @param {Object} criteria

	 * @param {Function} callback function for async call (mandatory)

	 */

	function __GetList(criteria, callback, _flag){

		if ((result = validator.apply('GetList', arguments)) !== false)

			return result; 

		// _flag=true indicates re-called state

		_flag = _flag || false;

		if (!_flag) {

			// callback is mandatory

			if (typeof callback != 'function')

				return error(device.implementation.ERR_MISSING_ARGUMENT, msg.badAsync);

			// continue validation after callback check		

			if (!criteria.Filter) 

				return error(device.implementation.ERR_MISSING_ARGUMENT, msg.is_missing, 'Filter');

			if (!criteria.Filter.FileType) 

				return error(device.implementation.ERR_MISSING_ARGUMENT, msg.is_missing, 'FileType');

			if (!/^(Music|Sound|Image|Video|StreamingURL)$/i.test(criteria.Filter.FileType)) 

				return error(device.implementation.ERR_BAD_ARGUMENT_TYPE);

			// process callback

			_flag = true;

			return context.callAsync(this, arguments.callee, criteria, callback, _flag);

		}

		var returnValue = [], 

			match = null,

			fileType = criteria.Filter.FileType,

			filter = criteria.Filter;

 		// normalize filetype

		fileType = fileType[0].toUpperCase() + fileType.substr(1).toLowerCase();

		fileType = fileType.replace(/url/i, 'URL');

		DBase = context.getData(provider);

		// unsupported filters 

		if (filter 

			&& (match = context.keys(filter).join().match(/Key|StartRange|EndRange/ig)) ) {

			context.notify(_t('%s:: GetList : filter %s not implemented in preview').arg(provider, match.join()));

		}

		// unsupported sort			

		if (criteria.Sort) { 

			context.notify(_t('%s:: GetList : sort not implemented in preview').arg(provider));

		}

		returnValue = DBase[fileType];

		return context.Result(context.Iterator(returnValue));

	}

	/**

	 * MediaManagement: Cancel

	 * @param {Object} criteria

	 */

	function __Cancel(criteria){

		method = 'Cancel';

		if (!criteria || !criteria.TransactionID)

			return error(device.implementation.ERR_MISSING_ARGUMENT, msg.missingTID);

		clearTimeout(criteria.TransactionID);

		return context.ErrorResult(device.implementation.ERR_SUCCESS);

	}

	/*******************************

	 * helper functions

	 *******************************/

	function error(code, msg /*, args...*/){

		var args = ['MediaMgmt',method].concat([].slice.call(arguments,2));

		msg = msg ? _t().arg.apply(msg,args) : undefined;

		return context.ErrorResult(code, msg);

	}

	/**

	 * validate common input arguments

	 * 'this' is string (object) name of calling function

	 * 

	 * @param {arguments} arguments of calling function

	 * @return {Result} Result object if error, false if no error.

	 */

	function validator() {

		method = ''+this;

		var	failed = false,

			criteria = arguments[0] || false;

		if (!criteria || typeof criteria != 'object' || typeof criteria.Type == 'undefined')

			return error(device.implementation.ERR_MISSING_ARGUMENT, msg.is_missing, 'Type');

		if (!/^FileInfo$/i.test(criteria.Type)) 

			return error(device.implementation.ERR_SERVICE_NOT_SUPPORTED, msg.badType);

		return failed;

	}

	/** 

	 * error messages

	 * order of %s args: Service name, method name, parameter name 

	 */

	var msg = {

		badType			: '%s : %s : Type not supported',

		missingTID 		: '%s : %s : TransactionID is missing',

		badAsync		: '%s : %s : Insufficient arguments for async request',

		is_missing		: '%s : %s : %s is missing',

		is_invalid		: '%s : %s : %s is invalid'

	};