var protocol = {
	supportsTags: false,
	connected: function(){
		ircSend(handlers.newTags(), settings.ID, 'PASS', [settings.password]);
		ircSend(handlers.newTags(), settings.ID, 'PROTOCTL', ['NICKv2', 'VHP', 'UMODE2', 'NICKIP', 'SJOIN', 'SJOIN2', 'SJ3', 'NOQUIT', 'TKLEXT', 'MLOCK', 'SID', 'MTAGS']);
		ircSend(handlers.newTags(), settings.ID, 'PROTOCTL', ['EAUTH=' + settings.name + ',,,' + settings.version]);
		ircSend(handlers.newTags(), settings.ID, 'PROTOCTL', ['SID=' + settings.ID]);
		ircSend(handlers.newTags(), settings.ID, 'SERVER', [settings.name, '1', settings.description]);
	},
	processMessage: function(msg){
		if(!msg) return;
		if(msg.command in cmdBinds){
			cmdBinds[msg.command](msg);
		} else {
			console.log('Unhandled cmd: '+msg.command);
			console.log(msg);
		}
	},
	processSender: function(sender){
		if(sender.nick){
			if(server = handlers.findServer(sender.nick)){
				sender.nick = server.name;
				sender.server = server;
			} else if(user = handlers.findUser(sender.nick)){
				sender.nick = user.name
				sender.ident = user.ident;
				sender.host = user.host;
				sender.user = user;
			} else {
				handlers.killUser(sender.nick);
				return false;
			}
		}
		return sender;
	},
	setHandlers: function(newHandlers){
		handlers = newHandlers;
	},
	setSettings: function(newSettings){
		settings = newSettings;
	},
	setEvents: function(newEvents){
		events = newEvents;
	},
	// IRC actions
	introduceUser: function(user){
		var nick = user.name;
		var distance = user.distance.toString();
		var TS = user.TS.toString();
		var ident = user.ident;
		var host = user.host;
		var uid = user.uid;
		var account = '0';
		if(user.account){
			account = user.account;
		}
		var umodes = makeUmodeString(user.umodes, true);
		var vhost = '*';
		if(user.vhost){
			vhost = user.vhost;
		}
		var cloakedHost = '*';
		if(user.cloakedHost){
			cloakedHost = user.cloakedHost;
		}
		var ip = '*';
		if(user.ip){
			ip = user.ip;
		}
		var realname = user.realname;
		var args = [nick, distance, TS, ident, host, uid, account, umodes, vhost, cloakedHost, ip, realname];
		ircSend(handlers.newTags(), settings.ID, 'UID', args);
	},
	syncChannel: function(channel){
		var modes = null;
		var modeArgs = null;
		// prepare list modes
		var listModes = [];
		for(m in channel.listModes){
			var mode = channel.listModes[m];
			for(var i=0; i<mode.length; i++){
				switch(m){
					case 'BAN': listModes.push('&' + mode[i]); break;
					case 'EXCEPT': listModes.push('"' + mode[i]); break;
					case 'INVEX': listModes.push('\'' + mode[i]); break;
				}
			}
		}
		// prepare users
		var users = [];
		for(var i=0; i<channel.users.length; i++){
			var user = channel.users[i];
			if(user.uplink != settings.me) continue;
			var status = '';
			if(user.uid in channel.statusModes){
				var statusModes = channel.statusModes[user.uid];
				for(var j=0; j<statusModes.length; j++){
					var statusMode = statusModes[j];
					for(c in chmodeMap){
						if(chmodeMap[c].name == statusMode){
							for(sm in connection.statusmodes){
								if(connection.statusmodes[sm] == c){
									status += sm; // assign status character to user
									break;
								}
							}
							break;
						}
					}
				}
			}
			users.push(status + user.uid);
		}
		var done = false;
		var listCount = 0;
		var userCount = 0;
		do {
			var text = '';
			var count = 0;
			for(; listCount < listModes.length; listCount++){
				if(++count > 10) break;
				if(text.length > 0) text += ' ';
				text += listModes[listCount];
			}
			
			for(; userCount < users.length; userCount++){
				if(++count > 10) break;
				if(text.length > 0) text += ' ';
				text += users[userCount];
			}
			
			if(text.length == 0){
				break;
			}
			var args = [Math.floor(new Date() / 1000).toString(10), channel.name];
			if(modes) args.push(modes); else args.push('+');
			if(modeArgs) args.push(modeArgs);
			args.push(text);
			ircSend(handlers.newTags(), settings.ID, 'SJOIN', args);
		} while(true);
	},
	'makeUid': function(){
		return settings.me.sid + randomID();
	},
	'changeUmodes': function(user, umodes){
		if(user.uplink == settings.me){ // services bot
			ircSend(handlers.newTags(), user.uid, 'UMODE2', [makeUmodeString(umodes, true)]);
		} else { // normal user
			ircSend(handlers.newTags(), settings.ID, 'SVS2MODE', [user.uid, makeUmodeString(umodes, false)]);
		}
		user.changeUmodes(umodes);
	},
	'joinChannel': function(user, channel){
		ircSend(handlers.newTags(), settings.ID, 'SJOIN', [Math.floor(new Date() / 1000).toString(10), channel.name, user.uid]);
		channel.joinUser(user);
	}
}
//>>> @time=2020-03-17T08:14:32.290Z;msgid=uwGzT2VzSTEEGab0demOxX :093 SJOIN 1584303585 #test :0931Y7O8W
//>>> @time=2020-03-15T12:17:07.355Z;msgid=FhjgUp20YBKQ32TGPM28tS :143 SJOIN 1580651090 #help +nt :0931Y7O8W 093375CFR 123VTY20R

function randomID(){
	var length = 6;
	var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
	return handlers.randomID(characters, length);
}

module.exports = protocol;

var handlers = {
	sendHandler: null,
	findServer: null,
	findUser: null,
	killUser: null,
	newServer: null,
	newUser: null,
	getChannel: null,
	findChannel: null,
	quitUser: null,
	removeServer: null,
	randomID: null
};

var settings = {
	ID: null,
	password: null,
	name: null,
	description: null,
	version: null,
	me: null,
	maxUsers: null
};

var events = {};

var connection = {
	'protoctl': {},
	'prefixes': {},
	'statusmodes': [],
	'chmodes': [], // 0 - list modes, 1 - argument modes, 2 - argument modes (add only), 3 - standard modes
	'umodes': {}
};

var chmodeMap = {
	'b': { 'name': 'BAN', 'user': true, 'services': true },
	'e': { 'name': 'EXCEPT', 'user': true, 'services': true },
	'I': { 'name': 'INVEX', 'user': true, 'services': true },
	'v': { 'name': 'VOICE', 'user': true, 'services': true },
	'h': { 'name': 'HALFOP', 'user': true, 'services': true },
	'o': { 'name': 'OP', 'user': true, 'services': true },
	'a': { 'name': 'PROTECT', 'user': true, 'services': true },
	'q': { 'name': 'OWNER', 'user': true, 'services': true },
	'k': { 'name': 'KEY', 'user': true, 'services': true },
	'L': { 'name': 'CHANNELLINK', 'user': true, 'services': true },
	'f': { 'name': 'FLOODPROT', 'user': true, 'services': true },
	'l': { 'name': 'LIMIT', 'user': true, 'services': true },
	'H': { 'name': 'HISTORY', 'user': true, 'services': true },
	'p': { 'name': 'PRIVATE', 'user': true, 'services': true },
	's': { 'name': 'SECRET', 'user': true, 'services': true },
	'm': { 'name': 'MODERATED', 'user': true, 'services': true },
	'n': { 'name': 'NOEXTERNAL', 'user': true, 'services': true },
	't': { 'name': 'TOPIC', 'user': true, 'services': true },
	'i': { 'name': 'INVITE', 'user': true, 'services': true },
	'r': { 'name': 'REGISTERED', 'user': false, 'services': true },
	'z': { 'name': 'SECUREONLY', 'user': true, 'services': true },
	'M': { 'name': 'NONREGMODERATED', 'user': true, 'services': true },
	'Q': { 'name': 'NOKICK', 'user': true, 'services': true },
	'N': { 'name': 'NONICK', 'user': true, 'services': true },
	'R': { 'name': 'NONREGINVITE', 'user': true, 'services': true },
	'T': { 'name': 'NOCTCPS', 'user': true, 'services': true },
	'O': { 'name': 'OPERS', 'user': false, 'services': true },
	'V': { 'name': 'NOINVITE', 'user': true, 'services': true },
	'K': { 'name': 'NOKNOCK', 'user': true, 'services': true },
	'D': { 'name': 'OLDDELAYJOIN', 'user': false, 'services': false },
	'd': { 'name': 'DELAYJOIN', 'user': true, 'services': true },
	'G': { 'name': 'CENSOR', 'user': true, 'services': true },
	'P': { 'name': 'PERMANENT', 'user': false, 'services': true },
	'Z': { 'name': 'SECURE', 'user': false, 'services': false },
	'S': { 'name': 'COLORFILTER', 'user': true, 'services': true },
	'C': { 'name': 'NOCTCP', 'user': true, 'services': true },
	'c': { 'name': 'NOCOLOR', 'user': true, 'services': true }
};

var umodeMap = {
	'i': { 'name': 'INVISIBLE', 'user': true, 'services': true },
	'o': { 'name': 'OPER', 'user': false, 'services': false },
	'w': { 'name': 'WALLOP', 'user': true, 'services': true },
	'r': { 'name': 'REGISTEREDNICK', 'user': false, 'services': true },
	's': { 'name': 'SNOTICE', 'user': true, 'services': true },
	'x': { 'name': 'CLOAK', 'user': true, 'services': true },
	'z': { 'name': 'SECUREUSER', 'user': false, 'services': false },
	'd': { 'name': 'DEAF', 'user': true, 'services': true },
	'H': { 'name': 'HIDEIRCOP', 'user': false, 'services': false },
	't': { 'name': 'VHOST', 'user': false, 'services': true },
	'I': { 'name': 'HIDEIDLE', 'user': false, 'services': false },
	'D': { 'name': 'PRIVDEAF', 'user': true, 'services': true },
	'Z': { 'name': 'SECUREMESSAGES', 'user': true, 'services': true },
	'R': { 'name': 'REGISTEREDMESSAGES', 'user': true, 'services': true },
	'q': { 'name': 'UNKICKABLE', 'user': false, 'services': false },
	'p': { 'name': 'HIDECHANNELS', 'user': true, 'services': true },
	'W': { 'name': 'WHOISNOTICE', 'user': false, 'services': false },
	'G': { 'name': 'CENSORMESSAGES', 'user': true, 'services': true },
	'T': { 'name': 'NOCTCPMESSAGES', 'user': true, 'services': true },
	'S': { 'name': 'SERVICEUSER', 'user': false, 'services': false },
	'B': { 'name': 'BOT', 'user': true, 'services': true }
};

function parseChannelModes(modes, args){
	var plus = true;
	var argIndex = 0;
	var output = {};
	output['status'] = [];
	output['list'] = [];
	for(var i=0; i<modes.length; i++){
		var c = modes.charAt(i);
		if(c in chmodeMap){
			var name = chmodeMap[c].name;
		} else {
			var name = c;
		}
		if(c == '+'){
			plus = true;
		} else if(c == '-'){
			plus = false;
		} else if(connection.chmodes[0].indexOf(c) >= 0){
			output['list'].push({ 'name': name, 'value': args[argIndex++], 'status': plus });
		} else if(connection.chmodes[1].indexOf(c) >= 0){
			if(plus){
				output[name] = args[argIndex++];
			} else {
				output[name] = false;
				argIndex++;
			}
		} else if(connection.chmodes[2].indexOf(c) >= 0){
			if(plus){
				output[name] = args[argIndex++];
			} else {
				output[name] = false;
			}
		} else if(connection.statusmodes.indexOf(c) >= 0){
			var user = handlers.findUser(args[argIndex++]);
			if(user){
				output['status'].push({ 'name': name, 'user': user, 'status': plus });
			} else {
				throw 'User not found';
			}
		} else { // treat unknown chars as type 3
			if(connection.chmodes[3].indexOf(c) < 0){
				console.log('Unknown mode '+name);
			}
			output[name] = plus;
		}
	}
	return output;
}

function parseUmodes(modeString){
	var plus = true;
	var modes = {};
	for(var i=0; i<modeString.length; i++){
		var c = modeString.charAt(i);
		switch(c){
			case '+': plus = true; break;
			case '-': plus = false; break;
			default:
				var modeName = umodeMap[c].name;
				if(!modeName) modeName = c;
				modes[modeName] = plus;
				break;
		}
	}
	return modes;
}

function makeUmodeString(umodes, own){
	var out = '';
	var plus = false;
	var addPM = true;
	for(char in umodeMap){
		var name = umodeMap[char].name;
		if(name in umodes){
			if(own || umodeMap[char].services){
				if(umodes[name] && (addPM || !plus)){
					addPM = false;
					plus = true;
					out += '+';
				} else if(!umodes[name] && (addPM || plus)){
					addPM = false;
					plus = false;
					out += '-';
				}
				out += char;
			} else {
				console.log('Attempted to set umode ' + char + ' which is not settable by services');
			}
		}
	}
	return out;
}

function parseModePrefix(text){
	var modes = {'status': [], 'list': [] };
	var isUser = false;
	var c = text.charAt(0);
	if(c == '&'){ // +b
		modes.list.push({ 'name': 'BAN', 'value': text.substring(1), 'status': true });
	} else if(c == '"'){ // +e
		modes.list.push({ 'name': 'EXCEPT', 'value': text.substring(1), 'status': true });
	} else if(c == '\''){ // +I
		modes.list.push({ 'name': 'INVEX', 'value': text.substring(1), 'status': true });
	} else {
		isUser = true;
		for(var i=0; i<text.length; i++){
			c = text.charAt(i);
			if(c in connection.prefixes){
				modes.status.push({ 'name': chmodeMap[connection.prefixes[c]].name, 'user': false /* setting it later */, 'status': true });
				// can be more than 1
			} else {
				break;
			}
		}
	}

	var user = null;
	if(isUser){
		var uid = text.substring(i);
		user = handlers.findUser(uid);
		if(!user){
			handlers.killUser(uid);
			modes.status = [];
		}
		for(var i=0; i<modes.status.length; i++){
			modes.status[i].user = user;
		}
	}

	return { 'modes': modes, 'user': user };
}

function ircSend(tags, from, cmd, args){
	handlers.send(tags, from, cmd, args);
}

var cmdBinds = {
	'PROTOCTL': function(msg){
		for(var i=0; i<msg.args.length; i++){
			var arg = msg.args[i];
			if(arg.indexOf('=') >= 0){
				var arg = arg.split('=');
				connection.protoctl[arg[0]] = arg[1];
				switch(arg[0]){
					case 'PREFIX':
						var data = arg[1].substring(1).split(')');
						var modes = data[0].split('');
						var chars = data[1].split('');
						for(var i=0; i<modes.length; i++){
							connection.prefixes[chars[i]] = modes[i];
							connection.statusmodes.push(modes[i]);
						}
						break;
					case 'CHANMODES':
						connection.chmodes = arg[1].split(',');
						break;
					case 'USERMODES':
						connection.umodes = arg[1];
						break;						
				}
			} else {
				switch(arg){
					case 'MTAGS': protocol.supportsTags = true; break;
				}
				connection.protoctl[arg] = true;
			}
		}
		console.log(protocol);
	},
	
	'SERVER': function(msg){
		var expr = /^([^-]+)-([^-]+)-([^ ]+) (.*)$/;
		var match = expr.exec(msg.args[2]);
		if(match){
			settings.me.uplink = handlers.newServer(msg.args[0], match[3], match[4], msg.args[1], settings.me);
		} else {
			throw 'Unknown SERVER message';
		}
		events.doEvent('netSynced');
		ircSend(handlers.newTags(), settings.ID, 'EOS');
	},
	
	'MD': function(msg){
		switch(msg.args[0]){
			case 'client':
				var user = handlers.findUser(msg.args[1]);
				if(!user) return;
				switch(msg.args[2]){
					case 'certfp':
						if(!msg.args[3] || msg.args[3].length == 0) break;
						user.setSecure(true);
						user.setFingerprint(msg.args[3]);
						break;
					default: break;
				}
				break;
			default: break;
		}
	},
	
	'SMOD': function(msg){ // ignore
	},
	
	'EOS': function(msg){ // ?
		console.log(connection);
	},
	
	'SINFO': function(msg){
		console.log(msg);
	},

	'SID': function(msg){
		handlers.newServer(msg.args[0], msg.args[2], msg.args[3], msg.args[1], msg.sender.server);
	},
	
	'UID': function(msg){
		var nick = msg.args[0];
		var distance = msg.args[1];
		var TS = msg.args[2];
		var ident = msg.args[3];
		var host = msg.args[4];
		var uid = msg.args[5];
		var account = msg.args[6];
		var umodes = msg.args[7];
		var vhost = msg.args[8];
		var cloakedHost = msg.args[9];
		var ip = msg.args[10];
		var realname = msg.args[11];
		if(ip != '*'){
			var ipBinary = Buffer.from(ip, 'base64');
			if(ipBinary.byteLength == 4){ // IPv4
				ip = ipBinary[0].toString(10) + '.' + ipBinary[1].toString(10) + '.' + ipBinary[2].toString(10) + '.' + ipBinary[3].toString(10);
			} else if(ipBinary.byteLength == 16){ // IPv6
				ip = '';
				for(var i=0; i<8; i++){
					if(i > 0) ip += ':';
					ip += ipBinary[i*2].toString(16).padStart(2, '0') + ipBinary[i*2+1].toString(16).padStart(2, '0');
				}
			} else {
				throw 'unknown IP format';
			}
		} else {
			ip = null;
		}
		if(vhost == '*'){
			vhost = null;
		}
		if(cloakedHost == '*'){
			cloakedHost = null;
		}
		if(account == '0'){
			account = null;
		}
		handlers.newUser(nick, distance, TS, ident, host, uid, account, parseUmodes(umodes), vhost, cloakedHost, ip, realname, msg.sender.server);
	},

	'SJOIN': function(msg){
		var channel = handlers.getChannel(msg.args[1]);
		channel.setTS(msg.args[0]);
		if(msg.args.length > 3){
			var modeArgs = [];
			for(var i=3; i<msg.args.length - 1; i++){
				modeArgs.push(msg.args[i]);
			}
			channel.changeModes(parseChannelModes(msg.args[2], modeArgs));
		}
		var members = msg.text.split(' ');
		for(var i=0; i<members.length; i++){
			var member = members[i];
			var c = member.charAt(0);
			var udata = parseModePrefix(member);
			if(udata.user){
				console.log(udata.user.name + ' joined ' + msg.args[1]);
				channel.joinUser(udata.user);
			}
			channel.changeModes(udata.modes);
		}
	},
	
	'SENDUMODE': function(msg){ // ignore
	},
	
	'SENDSNO': function(msg){ // ignore
	},
	
	'PASS': function(msg){ // ignore
	},
	
	'SWHOIS': function(msg){
		console.log(msg);
		//TODO
	},

	'MODE': function(msg){
		var channel = handlers.findChannel(msg.args[0]);
		if(channel){
			var modeArgs = [];
			for(var i=2; i<msg.args.length; i++){
				modeArgs.push(msg.args[i]);
			}
			var chmodes = parseChannelModes(msg.args[1], modeArgs);
			channel.changeModes(chmodes);
		}
	},
	
	'TKL': function(msg){
//		console.log(msg);
		//TODO
	},
	
	'METADATA': function(msg){
		var what = msg.args[0];
		var name = msg.args[1];
		var visibility = msg.args[2];
		if(msg.args.length > 3){
			var value = msg.args[3];
		} else {
			var value = null;
		}
		var channel = handlers.findChannel(what);
		if(channel){
			channel.setMetadata(name, visibility, value);
			return;
		}
		var user = handlers.findUser(what);
		if(user){
			user.setMetadata(name, visibility, value);
		}
	},
	
	'NETINFO': function(msg){
		ircSend(handlers.newTags(), null, 'NETINFO', [settings.maxUsers.toString(10), Math.floor(new Date() / 1000).toString(10), msg.args[2], msg.args[3], "0", "0", "0", msg.args[7]]);
	},
	
	'SASL': function(msg){
		console.log(msg);
		//TODO
	},
	
	'PING': function(msg){
		msg.reply(null, 'PONG', msg.args);
	},

	'QUIT': function(msg){
		handlers.quitUser(msg.sender.user);
	},

	'PART': function(msg){
		var channel = handlers.getChannel(msg.args[0]);
		channel.removeUser(msg.sender.user);
	},
	
	'CHGHOST': function(msg){
		var user = handlers.findUser(msg.args[0]);
		if(!user) return;
		user.changeVHost(msg.args[1]);
	},
	
	'CHGIDENT': function(msg){
		var user = handlers.findUser(msg.args[0]);
		if(!user) return;
		user.changeVIdent(msg.args[1]);
	},
	
	'CHGNAME': function(msg){
		var user = handlers.findUser(msg.args[0]);
		if(!user) return;
		user.setRealname(msg.args[1]);
	},
	
	'SETNAME': function(msg){
		msg.sender.user.setRealname(msg.args[0]);
	},
	
	'SETHOST': function(msg){
		msg.sender.user.changeVHost(msg.args[0]);
	},
	
	'SETIDENT': function(msg){
		msg.sender.user.changeVIdent(msg.args[0]);
	},
	
	'NICK': function(msg){
		msg.sender.user.changeNick(msg.args[0]);
	},
	
	'SDESC': function(msg){
		msg.sender.uplink.setDescription(msg.args[0]);
	},
	
	'TOPIC': function(msg){
		var channel = handlers.findChannel(msg.args[0]);
		if(!channel) return;
		var setter = msg.args[1];
		var TS = msg.args[2];
		var text = msg.args[3];
		channel.setTopic({'setter': setter, 'TS': TS, 'text': text });
	},
/*
messagedata {
  text: '0',
  args: [ '183.89.186.94', '0' ],
  tags: [],
  command: 'REPUTATION',
  sender: {
    nick: 'test1.pirc.pl',
    ident: '',
    host: '',
    server: server {
      name: 'test1.pirc.pl',
      sid: '093',
      description: 'serwer testowy!',
      distance: '3',
      uplink: [Object],
      introduce: [Function]
    },
    user: false
  },
  time: 2020-03-14T10:48:06.207Z,
  reply: [Function],
  originalString: ':093 REPUTATION 183.89.186.94 0'
}
*/
	'REPUTATION': function(msg){
		//TODO
	},

	'UMODE2': function(msg){
		msg.sender.user.changeUmodes(parseUmodes(msg.args[0]));
	},
	
	'KILL': function(msg){
		var user = handlers.findUser(msg.args[0]);
		if(!user) return;
		handlers.quitUser(user);
	},

	'SQUIT': function(msg){
		var server = handlers.findServer(msg.args[0]);
		if(!server) return;
		handlers.removeServer(server);
	},
/*messagedata {
  text: 'TestServ',
  args: [ '11K3R1VLH', 'TestServ' ],
  tags: [],
  command: 'WHOIS',
  sender: {
    nick: 'k4be',
    ident: 'testowy',
    host: 'localhost',
    server: false,
    user: user {
      name: 'k4be',
      TS: '1583056052',
      ident: 'testowy',
      host: 'localhost',
      account: null,
      umodes: [Object],
      vhost: 'staff:netadmin',
      cloakedHost: 'ukryty-18D8A42D',
      ip: '0000:0000:0000:0000:0000:0000:0000:0001',
      realname: 'realname',
      uid: '143ZQ0B02',
      distance: '0',
      uplink: [server],
      secure: false,
      certfp: null,
      vident: null,
      metadata: {},
      introduce: [Function],
      setSecure: [Function],
      setFingerprint: [Function],
      changeVHost: [Function],
      changeVIdent: [Function],
      setRealname: [Function],
      changeNick: [Function],
      changeUmodes: [Function],
      setMetadata: [Function]
    }
  },
  time: 2020-03-16T14:02:45.252Z,
  reply: [Function],
  originalString: ':143ZQ0B02 WHOIS 11K3R1VLH :TestServ'
}*/
	'WHOIS': function(msg){
	},

	'PRIVMSG': function(msg){
		if(msg.args[0].charAt(0) == '#'){
			events.doEvent('channelMessage', msg);
		} else {
			events.doEvent('botMessage', msg);
		}
	},
	
	'NOTICE': function(msg){
		if(msg.args[0].charAt(0) == '#'){
			events.doEvent('channelNotice', msg);
		} else {
			events.doEvent('botNotice', msg);
		}
	}
};