#!/usr/bin/env node

var fs=require("fs"),
    path=require("path"),
    https=require("https"),
    crypto=require("crypto"),
    read=require("read"),
    toClipboard=require("to-clipboard"),
    notifier=require("node-notifier");

var HOSTNAME=process.argv[2]||"tomsmeding.com",HTTPSPORT=443;
console.log("Using server "+HOSTNAME);


var lockfiledesc;
var lockfilename="/tmp/.lock_serverstore_client_"+HOSTNAME;
try {lockfiledesc=fs.openSync(lockfilename,"wx");}
catch(e){
	var lockedpid=+fs.readFileSync(lockfilename);
	var canoverwrite=false;
	if(isNaN(lockedpid))canoverwrite=true;
	try {process.kill(lockedpid,0);}
	catch(e){canoverwrite=true;}
	if(!canoverwrite){
		console.log("Another copy of the serverstore client with the same hostname seems to be running.");
		console.log("If this is not the case, or intentional, delete the file "+lockfilename+" and try again.");
		process.exit(1);
	}
	lockfiledesc=fs.openSync(lockfilename,"w");
}
fs.writeSync(lockfiledesc,process.pid+"\n");
process.on("exit",function(){
	fs.closeSync(lockfiledesc);
	fs.unlinkSync(lockfilename);
});


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


var HOMEDIR=process.env.HOME||process.env.HOMEPATH||process.env.HOMEDIR||process.cwd();
var WATCHDIR;
if(process.platform=="darwin"){
	WATCHDIR=HOMEDIR+"/Desktop";
} else {
	WATCHDIR=HOMEDIR+"/screenshots";
}
var ignored=[];

var currentState=[];

function notify(message) {
	notifier.notify({
		title: "serverstore",
		message: message,
	});
}

//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>60||(now-namedate)/1000>60)continue; //1 minute limit
		setTimeout(function(n){
			return function(){sendfile(n);};
		}(changes[i].name),100);
	}
}

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=https.request({
		hostname:HOSTNAME,
		port:HTTPSPORT,
		path:"/ss/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){
				notify("Could not request challenge! Is your internet connection alive?\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=https.request({
			hostname:HOSTNAME,
			port:HTTPSPORT,
			path:"/ss/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)sendfile(fname,retries-1);
					else notify("Could not upload image! Are your credentials still okay?\n"+body);
					return;
				}
				console.log("Successful upload");
				toClipboard.sync(body.trim());
				notify("Uploaded, link copied");
				try {
					fs.unlinkSync(fname);
				} catch(e){
					console.log(e);
				}
			});
		});
		req.on("error",function(err){
			console.log(err);
		});
		try{req.end(fs.readFileSync(fname));}
		catch(e){console.log(e);}
	});
}


function userExists(userid,cb){
	var req=https.request({
		hostname:HOSTNAME,
		port:HTTPSPORT,
		path:"/ss/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,retries){
	retries=retries!=null?retries:3;
	getchallenge(function(challenge){
		var req=https.request({
			hostname:HOSTNAME,
			port:HTTPSPORT,
			path:"/ss/checklogin/"+userid+"/"+authhash(challenge,password),
			method:"GET"
		},function(res){
			if(res.statusCode==200)cb(true);
			else if(res.statusCode==404||res.statusCode==403){
				if(retries>0)checkLogin(userid,password,cb,retries-1);
				else 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=https.request({
		hostname:HOSTNAME,
		port:HTTPSPORT,
		path:"/ss/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);
}

var stdinFD = null;
if (!process.stdin.isTTY) {
	stdinFD = fs.openSync("/dev/stdin", "r");
}

function readStdinLine(options, callback) {
	console.log("Entering read with " + JSON.stringify(options));
	if (stdinFD) {
		var input = "", buf = Buffer.alloc(1), ch;
		while (true) {
			if (fs.readSync(stdinFD, buf, 0, 1, null) < 1) {
				console.log("Error reading from stdin");
				process.exit(1);
			}
			ch = buf.toString()
			if (ch == "\n") break;
			input += ch;
		}
		callback(input);
	} else {
		read(options, function(err, res) {
			console.log("Returned from read with " + JSON.stringify(options));
			if (err) {
				console.log("Error reading from stdin: " + err);
				process.exit(1);
			}
			callback(res);
		});
	}
}

function readUserPass(callback) {
	readStdinLine({prompt: "Username? "}, function(res) {
		userid = res;

		readStdinLine({prompt: "Password? ", silent: true}, function(passinput) {
			var hasher = crypto.createHash("sha256");
			hasher.update(passinput);
			password = hasher.digest("hex");

			callback();
		});
	});
}



readUserPass(function() {
	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;
		}
		readStdinLine({prompt: "That username doesn't seem to exist. Register it? [y/N] "}, function(response) {
			response = response[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.)");
});