Light12306/Web12306/js/platform/messageCoder.js

define(function (require, exports, module) {
	var keystr = "iFishMessagePack";
	var step = Math.pow(2, 32);

	exports.encode = function (item) {
		var buffer = [];
		var keyidx = Math.floor(Math.random() * keystr.length);
		var key = keystr.charCodeAt(keyidx);

		//helper
		var putInt16 = function (value) {
			value = value || 0;
			for (var i = 0; i < 2; i++) {
				buffer.push(value - (value >> 8 << 8));
				value >>= 8;
			}
		};

		var putInt32 = function (value) {
			value = value || 0;
			for (var i = 0; i < 4; i++) {
				buffer.push(value - (value >> 8 << 8));
				value >>= 8;
			}
		};

		var putInt64 = function (value) {
			value = value || 0;
			var int1 = value % step;
			var int2 = Math.floor((value - int1) / step);
			putInt32(int1);
			putInt32(int2);
		};

		var putBool = function (value) {
			value = value || false;
			buffer.push(value ? 1 : 0);
		};

		var putString = function (str, unicode, writeFlag, writeLengthPrefix) {
			str = str || "";

			if (typeof writeFlag === 'undefined')
				writeFlag = true;
			if (typeof writeLengthPrefix === 'undefined')
				writeLengthPrefix = true;
			unicode &= writeFlag;

			if (writeFlag) {
				buffer.push(unicode ? 1 : 0);
			}
			if (writeLengthPrefix) {
				putInt32((unicode ? 2 : 1) * str.length);
			}
			for (var i = 0; i < str.length; i++) {
				var code = str.charCodeAt(i);
				if (unicode)
					putInt16(code);
				else buffer.push(code);
			}
		};

		//1.
		buffer.push(keyidx);
		//2. keystr
		putString(keystr, false, false, false);
		//3.action
		putString(item.action, false, false);
		//4.success
		putBool(item.success);
		//5.time
		putInt64(item.time.getTime());
		//6.system message
		putBool(item.systemMessage);
		//7.8.
		putInt32(item.sysMsgType);
		putInt32(item.userMsgType);
		//9.content
		putString(item.content);
		//10.color
		putString(item.color, false, false);
		//11.images
		putInt32(item.images ? item.images.length || 0 : 0);
		if (item.images) {
			item.images.forEach(function (image) {
				putString(image, false, false);
			});
		}
		//12.from user
		putString(item.fromUser, false, false);
		//13.images
		putInt32(item.toUsers ? item.toUsers.length || 0 : 0);
		if (item.toUsers) {
			item.toUsers.forEach(function (user) {
				putString(user, false, false);
			});
		}

		//encrypt
		//for (var j = 1; j < buffer.length; j++) {
		//	key = buffer[j] ^= key;
		//}

		console.log(buffer);

		return buffer;
	};

	exports.decode = function (data) {
		var dv = new DataView(data, 0);
		var keyIndex = dv.getUint8(0);
		var key = keystr.charCodeAt(keyIndex);

		//decrypt
		//for (var i = 1; i < dv.byteLength; i++) {
		//	var bit = dv.getUint8(i);
		//	dv.setUint8(i, bit ^ key);
		//	key = bit;
		//}

		var pos = 1;

		//helper
		var readInt64 = function () {
			var int1 = dv.getInt32(pos, true);
			var int2 = dv.getInt32(pos + 4, true);

			pos += 8;
			return int2 * step + int1;
		};
		var readString = function (unicode, length) {
			if (typeof (unicode) === 'undefined') {
				unicode = dv.getUint8(pos++) === 1;
			}
			if (typeof (length) === 'undefined') {
				length = dv.getInt32(pos, true);
				pos += 4;
			}

			var buffer = [];
			for (var j = 0; j < length; j++) {
				if (unicode) {
					buffer.push(String.fromCharCode(dv.getUint16(pos, true)));
					pos += 2;
				} else {
					buffer.push(String.fromCharCode(dv.getUint8(pos++, true)));
				}
			}

			return buffer.join("");
		};


		//check package header
		if (readString(false, keystr.length) !== keystr)
			return null;

		var item = {};
		item.action = readString(false);
		item.success = dv.getUint8(pos++) === 1;
		item.time = new Date(readInt64());
		item.systemMessage = dv.getUint8(pos++) === 1;
		item.sysMsgType = dv.getInt32(pos, true);
		pos += 4;
		item.userMsgType = dv.getInt32(pos, true);
		pos += 4;
		item.content = readString();
		item.Color = readString(false);
		var imgCount = dv.getInt32(pos, true);
		pos += 4;
		if (imgCount > 0) {
			item.images = [];
			for (var j = 0; j < imgCount; j++) {
				item.images.push(readString(false));
			}
		}
		item.fromUser = readString(false);
		var toUserCount = dv.getInt32(pos, true);
		pos += 4;
		if (toUserCount > 0) {
			item.toUsers = [];
			for (var j = 0; j < toUserCount; j++) {
				item.images.push(readString(false));
			}
		}

		return item;
	};
});