define([
	'exports',
	'../errors/RequestError',
	'../errors/CancelError',
	'../Deferred',
	'../io-query',
	'../_base/array',
	'../_base/lang',
	'../promise/Promise'
], function(exports, RequestError, CancelError, Deferred, ioQuery, array, lang, Promise){
	exports.deepCopy = function deepCopy(target, source){
		for(var name in source){
			var tval = target[name],
				sval = source[name];
			if(tval !== sval){
				if(tval && typeof tval === 'object' && sval && typeof sval === 'object'){
					exports.deepCopy(tval, sval);
				}else{
					target[name] = sval;
				}
			}
		}
		return target;
	};

	exports.deepCreate = function deepCreate(source, properties){
		properties = properties || {};
		var target = lang.delegate(source),
			name, value;

		for(name in source){
			value = source[name];

			if(value && typeof value === 'object'){
				target[name] = exports.deepCreate(value, properties[name]);
			}
		}
		return exports.deepCopy(target, properties);
	};

	var freeze = Object.freeze || function(obj){ return obj; };
	function okHandler(response){
		return freeze(response);
	}
	function dataHandler (response) {
		return response.data || response.text;
	}

	exports.deferred = function deferred(response, cancel, isValid, isReady, handleResponse, last){
		var def = new Deferred(function(reason){
			cancel && cancel(def, response);

			if(!reason || !(reason instanceof RequestError) && !(reason instanceof CancelError)){
				return new CancelError('Request canceled', response);
			}
			return reason;
		});

		def.response = response;
		def.isValid = isValid;
		def.isReady = isReady;
		def.handleResponse = handleResponse;

		function errHandler(error){
			error.response = response;
			throw error;
		}
		var responsePromise = def.then(okHandler).otherwise(errHandler);

		if(exports.notify){
			responsePromise.then(
				lang.hitch(exports.notify, 'emit', 'load'),
				lang.hitch(exports.notify, 'emit', 'error')
			);
		}

		var dataPromise = responsePromise.then(dataHandler);

		// http://bugs.dojotoolkit.org/ticket/16794
		// The following works around a leak in IE9 through the
		// prototype using lang.delegate on dataPromise and
		// assigning the result a property with a reference to
		// responsePromise.
		var promise = new Promise();
		for (var prop in dataPromise) {
			if (dataPromise.hasOwnProperty(prop)) {
				promise[prop] = dataPromise[prop];
			}
		}
		promise.response = responsePromise;
		freeze(promise);
		// End leak fix


		if(last){
			def.then(function(response){
				last.call(def, response);
			}, function(error){
				last.call(def, response, error);
			});
		}

		def.promise = promise;
		def.then = promise.then;

		return def;
	};

	exports.addCommonMethods = function addCommonMethods(provider, methods){
		array.forEach(methods||['GET', 'POST', 'PUT', 'DELETE'], function(method){
			provider[(method === 'DELETE' ? 'DEL' : method).toLowerCase()] = function(url, options){
				options = lang.delegate(options||{});
				options.method = method;
				return provider(url, options);
			};
		});
	};

	exports.parseArgs = function parseArgs(url, options, skipData){
		var data = options.data,
			query = options.query;
		
		if(data && !skipData){
			if(typeof data === 'object'){
				options.data = ioQuery.objectToQuery(data);
			}
		}

		if(query){
			if(typeof query === 'object'){
				query = ioQuery.objectToQuery(query);
			}
			if(options.preventCache){
				query += (query ? '&' : '') + 'request.preventCache=' + (+(new Date));
			}
		}else if(options.preventCache){
			query = 'request.preventCache=' + (+(new Date));
		}

		if(url && query){
			url += (~url.indexOf('?') ? '&' : '?') + query;
		}

		return {
			url: url,
			options: options,
			getHeader: function(headerName){ return null; }
		};
	};

	exports.checkStatus = function(stat){
		stat = stat || 0;
		return (stat >= 200 && stat < 300) || // allow any 2XX response code
			stat === 304 ||                 // or, get it out of the cache
			stat === 1223 ||                // or, Internet Explorer mangled the status code
			!stat;                         // or, we're Titanium/browser chrome/chrome extension requesting a local file
	};
});
