#!/usr/bin/env node

"use strict";

var fs=require("fs"),
    http=require("http"),
    util=require("util"),
    assert=require("assert"),
    WebSocketServer=require("ws").Server,
    Naampje=require("naampje").name;
var HTTPPORT=83,WSPORT=8383;

var conns=[],games=[];

var genid=(function(){
	var $=1;
	return function(){return $++;};
})();

function findby(a,key,val){
	for(var i=0;i<a.length;i++)if(a[i][key]==val)return i;
	return -1;
}

function nickIsTaken(nick){
	var i;
	for(i=0;i<conns.length;i++)if(conns[i].nick==nick)return true;
	return false;
}

function numberiseNick(nick){
	var i;
	for(i=0;;i++){
		if(!nickIsTaken(nick+i))return nick+i;
	}
}

function gennick(){
	var i,nick;
	for(i=0;i<10;i++){
		nick=Naampje();
		if(!nickIsTaken(nick))break;
	}
	if(i<10)return nick;
	else return numberiseNick(nick);
}

function Connection(ws){
	if(!(this instanceof Connection))return new Connection(ws);
	this.id=genid();
	this.nick=gennick();
	this.ws=ws;
	this.gameid=null;
}

function Game(c1,c2){
	if(!(this instanceof Game))return new Game(c1,c2);
	this.id=genid();
	this.i1=c1.id;
	this.i2=c2.id;
	this.board=[1,1,1,1,1,
	            0,0,0,0,0,
	            0,0,3,0,0,
	            0,0,0,0,0,
	            2,2,2,2,2];
	this.onturn=1; //1 or 2
	this.firstmove=true; //in first move, neudir==-1
}

function saveFinishedBoard(bd){
	var fname=process.hrtime();
	if(fs.existsSync("winboards")){
		if(!fs.lstatPath("winboards").isDirectory()){
			console.log("winboards is not a directory. Bleh.");
			return;
		}
	} else {
		fs.mkdirSync("winboards");
	}
	fname="winboards/"+fname[0]+("000000000"+fname[1]).slice(-9)+".txt";
	if(fs.existsSync(fname)){ //don't think this'll happen often
		console.log("saveFinishedBoard: file '"+fname+"' already exists!");
		return;
	}
	fs.writeFileSync(fname,bd.join(""));
}

var idxAfterSlide__xy_deltas=[[0,-1],[1,-1],[1,0],[1,1],[0,1],[-1,1],[-1,0],[-1,-1]];
function idxAfterSlide(bd,idx,dir){
	var x=idx%5,y=~~(idx/5),x2,y2,d=idxAfterSlide__xy_deltas[dir],dx=d[0],dy=d[1];
	while(true){
		x2=x+dx; y2=y+dy;
		if(x2<0||x2>=5||y2<0||y2>=5||bd[5*y2+x2]!=0)return 5*y+x;
		x=x2; y=y2;
	}
}

function applyMove(bd,mv){
	var neuidx=-1,newidx,i;
	bd=bd.slice();
	for(i=0;i<25;i++)if(bd[i]==3){neuidx=i;break;}
	assert(neuidx!=-1);
	if(mv[0]!=-1){
		newidx=idxAfterSlide(bd,neuidx,mv[0]);
		bd[newidx]=3;
		bd[neuidx]=0;
	}
	if(mv[1]!=-1&&mv[2]!=-1){
		newidx=idxAfterSlide(bd,mv[1],mv[2]);
		bd[newidx]=bd[mv[1]];
		bd[mv[1]]=0;
	}
	return bd;
}

function moveIsLegal(bd,mv,forpl){
	var neuidx=-1,newidx,i;
	if(bd[mv[1]]!=forpl)return false;
	for(i=0;i<25;i++)if(bd[i]==3){neuidx=i;break;}
	assert(neuidx!=-1);
	if(mv[0]!=-1){
		newidx=idxAfterSlide(bd,neuidx,mv[0]);
		if(newidx==neuidx)return false;
	}
	newidx=idxAfterSlide(applyMove(bd,[mv[0],-1,-1]),mv[1],mv[2]);
	if(newidx==mv[1])return false;
	return true;
}

function checkWin(bd,pljustmoved){
	var i,neuidx=-1,newidx;
	for(i=0;i<25;i++)if(bd[i]==3){neuidx=i;break;}
	assert(neuidx!=-1);
	if(neuidx<5)return 1;
	if(neuidx>=20)return 2;
	for(i=0;i<8;i++){
		newidx=idxAfterSlide(bd,neuidx,i);
		if(newidx!=neuidx)break;
	}
	if(i==8){ //no shifts of the neutron possible
		return pljustmoved;
	}
	return 0;
}

function handleMessage(conn,msg){
	var cmd=msg.split(" "),list,i,game,c2,mv,won;
	switch(cmd[0]){
	case "nick":
		conn.ws.send("nick \""+conn.nick+"\"");
		break;
	/*case "list_free_users":
		list=[];
		for(i=0;i<conns.length;i++)if(conns[i].gameid==null)list.push(conns[i].nick);
		conn.ws.send("list_free_users "+JSON.stringify(list));
		break;*/
	case "game_create":
		c2=cmd.slice(1).join(" ");
		if(conn.gameid!=null){
			conn.ws.send("game_create [false,\"Already in a game\"]");
			break;
		}
		if(c2==conn.nick){
			conn.ws.send("game_create [false,\"Cannot create a game with yourself\"]");
			break;
		}
		c2=findby(conns,"nick",c2);
		if(c2==-1){
			conn.ws.send("game_create [false,\"Non-existent nick\"]");
			break;
		}
		c2=conns[c2];
		if(c2.gameid!=null){
			conn.ws.send("game_create [false,\"Other already in a game\"]");
			break;
		}
		console.log("new game between "+conn.nick+" and "+c2.nick);
		game=new Game(conn,c2);
		conn.gameid=game.id;
		c2.gameid=game.id;
		games.push(game);
		conn.ws.send("game_create true");
		c2.ws.send("joined_game true");
		conn.ws.send("your_turn false");
		break;
	case "game_info":
		if(conn.gameid==null){
			conn.ws.send("game_info null");
			break;
		}
		game=games[findby(games,"id",conn.gameid)];
		conn.ws.send("game_info "+JSON.stringify([
			[
				conns[findby(conns,"id",game.i1)].nick,
				conns[findby(conns,"id",game.i2)].nick
			],
			game.board,
			game.onturn
		]));
		break;
	case "game_doturn": //neudir stoneidx stonedir
		if(conn.gameid==null){
			conn.ws.send("game_doturn [false,\"Not in a game\"]");
			break;
		}
		game=games[findby(games,"id",conn.gameid)];
		mv=[+cmd[1],+cmd[2],+cmd[3]];
		if(mv[0]==undefined||isNaN(mv[0])||mv[0]%1!=0||
		       (game.firstmove ? mv[0]!=-1 : mv[0]<0||mv[0]>=8) ||
		   mv[1]==undefined||isNaN(mv[1])||mv[1]%1!=0||mv[1]<0||mv[1]>=25||
		   mv[2]==undefined||isNaN(mv[2])||mv[2]%1!=0||mv[2]<0||mv[2]>=8){
			conn.ws.send("game_doturn [false,\"Invalid move\"]");
			break;
		}
		if(!moveIsLegal(game.board,mv,game.onturn)){
			conn.ws.send("game_doturn [false,\"Illegal move\"]");
			break;
		}
		game.board=applyMove(game.board,mv);
		console.log("new board:");
		console.log(game.board);
		conn.ws.send("game_doturn "+JSON.stringify([true,mv]));
		game.onturn=3-game.onturn;
		c2=conns[findby(conns,"id",conn.id==game.i1?game.i2:game.i1)];
		c2.ws.send("other_turn "+JSON.stringify(mv));
		won=checkWin(game.board,3-game.onturn); //player that just moved
		if(won){
			saveFinishedBoard(game.board);
			conn.ws.send("game_win "+won);
			c2.ws.send("game_win "+won);
			games.splice(findby(games,"id",conn.gameid),1);
			conn.gameid=null;
			c2.gameid=null;
			break;
		}
		c2.ws.send("your_turn true");
		game.firstmove=false;
		break;
	default:
		conn.ws.send("error "+cmd[0]);
		break;
	}
}

new WebSocketServer({port:WSPORT}).on("connection",function(ws){
	var conn=new Connection(ws);
	conns.push(conn);
	ws.on("message",function(msg){
		console.log(msg,util.inspect(conn,{depth:0}));
		handleMessage(conn,msg);
	});
	ws.on("open",function(){
		//hi!
	});
	ws.on("close",function(){
		if(conn.gameid!=null){
			var gameidx=findby(games,"id",conn.gameid);
			var game=games[gameidx];
			var otherplayeridx=findby(conns,"id",game.i1==conn.id?game.i2:game.i1)
			console.log("otherplayeridx="+otherplayeridx);
			conns[otherplayeridx].gameid=null;
			conn.gameid=null;
			games.splice(gameidx,1);
			conns[otherplayeridx].ws.send("game_stop \"Other player quit\"");
		}
	});
});
console.log("Websocket server started on port "+WSPORT+".");

http.createServer(function(req,res){
	if(req.url=="/"){
		res.writeHead(200,{"Content-Type":"text/html"});
		res.end(String(fs.readFileSync("gameserver.html")));
	} else {
		res.writeHead(404,{"Content-Type":"text/plain"});
		res.end("404 Not found");
	}
}).listen(HTTPPORT);
console.log("HTTP server started on port "+HTTPPORT+".");