"use strict";

var cmn=require("../$common.js"),
    persist=require("node-persist"),
    bcrypt=require("bcrypt"),
    basicAuth=require("basic-auth"),
    fs=require("fs");

var bcryptHashRounds=10;

var moddir=null;

persist=persist.create({
	dir:"persist/todo",
	continuous:false,
	interval:false
});
persist.initSync();

//tasks: {"user": [{id: Int,subject: String,repweeks: Int,date: Date}]}
//accounts: {"user": hash (String)}
//repweeks==0 implies no repetition
var nextid=persist.getItemSync("nextid");
if(nextid==null){
	nextid=1;
	persist.setItemSync("nextid",nextid);
}
var tasks=persist.getItemSync("tasks");
(function(){
	if(tasks==null){
		tasks={};
		persist.setItemSync("tasks",tasks);
	} else {
		for(var user in tasks){
			for(var task of tasks[user]){
				task.date=new Date(task.date);
				if(nextid<=task.id)nextid=task.id+1;
			}
		}
		persist.setItemSync("nextid",nextid);
	}
})();
var accounts=persist.getItemSync("accounts");
if(accounts==null){
	accounts={};
	persist.setItemSync("accounts",accounts);
}
var naccounts=0;
(function(){
	var user;
	for(user in accounts)naccounts++;
})();


function shiftDate(date,repweeks){
	var Y=date.getFullYear(),
	    M=date.getMonth(),
	    D=date.getDate(),
	    h=date.getHours(),
	    m=date.getMinutes(),
	    s=date.getSeconds(),
	    ms=date.getMilliseconds();
	return new Date(Y,M,D+7*repweeks,h,m,s,ms);
}


function sendUnauth(res){
	res.set("WWW-Authenticate","Basic realm=Authorization required");
	return res.sendStatus(401);
}

function unknownUserHandler(req,res,next){
	res.sendFile(moddir+"/unknownuser.html");
}

function authMiddleware(req,res,next){
	var user=basicAuth(req);
	req.authuser=null;
	if(!user||!user.name){
		sendUnauth(res);
		return;
	}
	req.authuser=user.name;
	if(accounts[req.authuser]){
		bcrypt.compare(user.pass,accounts[req.authuser],function(err,ok){
			if(ok)next();
			else sendUnauth(res);
		});
	} else {
		unknownUserHandler(req,res,next);
	}
}

function asciiValid(str){
	var i,c;
	for(i=0;i<str.length;i++){
		c=str.charCodeAt(i);
		if(c<32||c>=127)return false;
	}
	return true;
}


module.exports=function(app,io,_moddir){
	moddir=_moddir;

	//first the endpoints that need to bypass authMiddleware
	app.get("/todo/authfail",function(req,res){
		sendUnauth(res);
	});
	app.post("/todo/createuser",function(req,res){
		var user=basicAuth(req);
		if(!user||!user.name){
			res.status(400).send("No credentials sent");
			return;
		}
		if(user.name.length<3||user.name.length>32||!asciiValid(user.name)){
			res.status(400).send("Invalid username");
			return;
		}
		if(user.pass.length<3||user.pass.length>32||!asciiValid(user.pass)){
			res.status(400).send("Invalid password");
			return;
		}
		if(accounts[user.name]){
			res.status(400).send("User already exists");
			return;
		}
		if(naccounts>=20){
			res.status(500).send("Too many accounts created, please contact Tom...");
			return;
		}
		bcrypt.hash(user.pass,bcryptHashRounds,function(err,hash){
			if(!hash){
				res.status(500).send("Something went wrong...");
				console.log(err);
				return;
			}
			accounts[user.name]=hash;
			tasks[user.name]=[];
			persist.setItemSync("accounts",accounts);
			persist.setItemSync("tasks",tasks);
			res.status(200).end();
		});
	});

	app.all(["/todo","/todo/*"],authMiddleware); //for all the other endpoints

	app.get("/todo",function(req,res){
		var contents=fs.readFileSync(moddir+"/todo.html","utf8");
		var replaced=contents.replace("/*REPLACEME*/null/*TODOLIST*/",
		                              JSON.stringify(tasks[req.authuser]));
		res.send(replaced);
	});
	app.get("/todo/list",function(req,res){
		res.json(tasks[req.authuser]);
	});
	app.delete("/todo/task",function(req,res){
		var id=+req.body;
		var i;
		var fail=false;
		var usertasks=tasks[req.authuser];
		if(id<0||~~id!=id||isNaN(id)||!usertasks){
			fail=true;
		} else {
			for(i=0;i<usertasks.length;i++)if(usertasks[i].id==id)break;
			if(i==usertasks.length)fail=true;
			else {
				usertasks.splice(i,1);
				persist.setItemSync("tasks",tasks);
			}
		}
		if(fail)res.status(404).send("Unknown id");
		else res.status(200).end();
	});
	app.post("/todo/task/shiftahead",function(req,res){
		var id=+req.body;
		var i;
		var fail=false;
		var usertasks=tasks[req.authuser];
		var now;
		if(id<0||~~id!=id||isNaN(id)||!usertasks){
			fail=true;
		} else {
			for(i=0;i<usertasks.length;i++)if(usertasks[i].id==id)break;
			if(i==usertasks.length)fail=true;
			else if(usertasks[i].repweeks==0){
				res.status(400).send("Can't shiftahead a non-repeating task");
				return;
			} else {
				now=new Date();
				while(usertasks[i].date<now){ // First move up to now
					usertasks[i].date=shiftDate(usertasks[i].date,usertasks[i].repweeks);
				}
				// Then for the actual shiftahead:
				usertasks[i].date=shiftDate(usertasks[i].date,usertasks[i].repweeks);
				persist.setItemSync("tasks",tasks);
			}
		}
		if(fail)res.status(404).send("Unknown id");
		else res.status(200).end();
	});
	app.post("/todo/task",function(req,res){
		var obj;
		try {
			obj=JSON.parse(req.body);
		} catch(e){
			res.status(400).send("Invalid request");
			return;
		}
		var subject=obj.subject+"",repweeks=+obj.repweeks,date=new Date(obj.date);
		if(subject.length==0||
		   isNaN(repweeks)||repweeks<0||repweeks!=~~repweeks||
		   isNaN(date.getTime())){
			res.status(400).send("Invalid data");
			return;
		}
		if(tasks[req.authuser].length>=40){
			res.status(400).send("Isn't 40 tasks enough for you?");
			return;
		}
		tasks[req.authuser].push({
			id:nextid++,
			subject:subject,
			repweeks:repweeks,
			date:date
		});
		persist.setItemSync("tasks",tasks);
		persist.setItemSync("nextid",nextid);
		res.status(200).end();
	});
};