#!/usr/bin/env node

var fs=require("fs"),
    path=require("path"),
    http=require("http"),
    crypto=require("crypto"),
    dialog=require("dialog"),
    kbd=require("kbd");

var HOSTNAME="localhost",HTTPPORT=42420;

var userid="0",password="-";


var HOMEDIR=process.env.HOME||process.env.HOMEPATH||process.env.HOMEDIR||process.cwd();
var WATCHDIR=HOMEDIR+"/Desktop";
var ignored=[];

var currentState=[];

//lots of code taken/modified from tomsmeding/gvajnez
function collectDirState(dir){
	if(!dir)dir=directory;
	//console.log("collectDirState("+dir+")");
	var list=fs.readdirSync(dir);
	var result=[];
	var statinfo,i,j;
	for(i=0;i<list.length;i++){
		for(j=0;j<ignored.length;j++){
			if(etc.endsWith(path.normalize(dir+"/"+list[i]),"/"+ignored[j]))break;
		}
		if(j<ignored.length)continue;
		statinfo=fs.statSync(dir+"/"+list[i]);
		/*if(statinfo.isDirectory()){
			result=result.concat(collectDirState(dir+"/"+list[i]));
		} else if(statinfo.isFile()){*/
			result.push({
				name:path.resolve(dir+"/"+list[i]),
				mode:statinfo.mode,
				mtime:statinfo.mtime.getTime()
			});
		//}
	}
	return result;
}

function collectChanges(dir,state){
	if(!dir)dir=directory;
	var i,j,obj;
	var changes=[];
	for(i=0;i<state.length;i++){
		for(j=0;j<currentState.length;j++){
			if(state[i].name==currentState[j].name)break;
		}
		if(j==currentState.length||
				currentState[j].mode!=state[i].mode||
				currentState[j].mtime!=state[i].mtime){
			//either file didn't exist yet, or metadata has changed
			changes.push(state[i]);
		}
	}
	for(i=0;i<currentState.length;i++){
		for(j=0;j<state.length;j++){
			if(currentState[i].name==state[j].name)break;
		}
		if(j==state.length){
			//file doesn't exist anymore
			changes.push(currentState[i]);
		}
	}
	return changes;
}

function handleChanges(changes){
	var i,match,namedate,now;
	for(i=0;i<changes.length;i++){
		if(!fs.existsSync(changes[i].name))continue; //probably delete event
		match=changes[i].name.match(/\/Screen Shot (\d{4}-\d{2}-\d{2}) at (\d{2}\.\d{2}\.\d{2}).png$/);
		if(!match)continue;
		namedate=new Date(match[1]+" "+match[2].replace(/\./g,":"));
		if(!namedate)continue;
		changes[i].mtime=new Date(changes[i].mtime);
		now=new Date();
		if((now-changes[i].mtime)/1000>15||(now-namedate)/1000>15)continue; //15 seconds limit
		sendfile(changes[i].name);
	}
}

function authhash(challenge,password){
	var s=challenge+password;
	var hasher=crypto.createHash("sha256");
	hasher.update(s);
	return hasher.digest("hex");
}

function getchallenge(cb){
	console.log("Going to request challenge...");
	var req=http.request({
		hostname:HOSTNAME,
		port:HTTPPORT,
		path:"/challenge",
		method:"GET",
		keepAlive:true //speed up the next request
	},function(res){
		var body="";
		res.on("data",function(data){
			body+=data;
		});
		res.on("end",function(){
			if(res.statusCode!=200){
				dialog.warn("Could not request challenge! Is your internet connection alive?\n\n"+body);
				return;
			}
			console.log("challenge = "+body);
			cb(body);
		});
	});
	req.on("error",function(err){
		console.log(err);
	});
	req.end();
}
function sendfile(fname,retries){
	retries=retries!=null?retries:3;
	var barefname;
	var idx=fname.lastIndexOf("/");
	if(idx==-1)barefname=fname;
	else barefname=fname.slice(idx+1);
	getchallenge(function(challenge){
		var req=http.request({
			hostname:HOSTNAME,
			port:HTTPPORT,
			path:"/image/"+userid+"/"+authhash(challenge,password)+"/"+escape(barefname),
			method:"POST",
			headers:{
				"Content-Type":"image/png"
			}
		},function(res){
			var body="";
			res.on("data",function(data){
				body+=data;
			});
			res.on("end",function(){
				if(res.statusCode!=200){
					if(retries>0)sendfileChallenge(fname,challenge,retries-1);
					else {
						dialog.warn("Could not upload image! Are your credentials still okay?\n\n"+body);
						return;
					}
				}
				console.log("Successful upload");
				fs.unlink(fname); //not sync, take your time
				dialog.info(body);
			});
		});
		req.on("error",function(err){
			console.log(err);
		});
		req.end(fs.readFileSync(fname));
	});
}


function userExists(userid,cb){
	var req=http.request({
		hostname:HOSTNAME,
		port:HTTPPORT,
		path:"/exists/"+userid,
		method:"GET"
	},function(res){
		if(res.statusCode==200)cb(true);
		else if(res.statusCode==404)cb(false);
		else {
			console.log("Server returned status code "+res.statusCode+" for exists query!");
		}
	});
	req.on("error",function(err){
		console.log(err);
	});
	req.end();
}

function checkLogin(userid,password,cb){
	getchallenge(function(challenge){
		var req=http.request({
			hostname:HOSTNAME,
			port:HTTPPORT,
			path:"/checklogin/"+userid+"/"+authhash(challenge,password),
			method:"GET"
		},function(res){
			if(res.statusCode==200)cb(true);
			else if(res.statusCode==404||res.statusCode==403)cb(false);
			else {
				console.log("Server returned status code "+res.statusCode+" for checklogin query!");
			}
		});
		req.on("error",function(err){
			console.log(err);
		});
		req.end();
	});
}

function registerUser(userid,password){
	var req=http.request({
		hostname:HOSTNAME,
		port:HTTPPORT,
		path:"/registerx/"+userid,
		method:"POST",
		headers:{
			"Content-Type":"text/plain"
		}
	},function(res){
		var body="";
		res.on("data",function(data){
			body+=data;
		});
		res.on("end",function(){
			if(res.statusCode==200)console.log("Successfully registered user "+userid);
			else if(res.statusCode==409)console.log("Conflict: "+body);
			else console.log("Error: "+body);
		});
	});
	req.on("error",function(err){
		console.log(err);
	});
	req.end(password);
}



process.stdout.write("Username? ");
userid=kbd.getLineSync().replace(/[^a-zA-Z0-9_-]/g,"");
process.stdout.write("Password? ");
kbd.setEcho(false);
password=kbd.getLineSync();
kbd.setEcho(true);
console.log("\nChecking existence...");

userExists(userid,function(exists){
	if(exists){
		checkLogin(userid,password,function(ok){
			if(ok)console.log("User login ok.");
			else {
				console.log("Username or password incorrect!");
				process.exit();
			}
		});
		return;
	}
	process.stdout.write("That username doesn't seem to exist. Register it? [y/N] ");
	var response=kbd.getLineSync()[0];
	if(response=="y"||response=="Y")registerUser(userid,password);
	else {
		console.log("Not registered. Exiting.");
		process.exit();
	}
});

var timeout=null;
var watcher=fs.watch(WATCHDIR,{persistent:true,recursive:false},function(ev,fname){
	//console.log("change in directory "+WATCHDIR+" (fname "+fname+")");
	if(timeout)return;
	timeout=setTimeout(function(){
		var newstate=collectDirState(WATCHDIR);
		var changes=collectChanges(WATCHDIR,newstate).map(function(o){o.name=o.name.replace(/^\.\//,"");return o;});
		currentState=newstate;
		if(changes.length!=0)handleChanges(changes);
		timeout=null;
		//console.log(currentState);
	},500);
});
currentState=collectDirState(WATCHDIR);
console.log("-- (Client ready.)");