var express = require('express');
var app = express();
var bodyParser = require('body-parser');
app.use(bodyParser.text());   // Use defaults for now, size limit is 100kb.
app.use(bodyParser.urlencoded({ extended: true }));   // Also need url encoding to handle login form.
var winston = require('winston');
winston.add(winston.transports.File, { filename: './logs/notes.kaplon.us.log', maxsize: 5000000 });  // 5MB
var fileSystem = require('fs');
var notePath = __dirname + '/note-data/allNotes.txt';
var favicon = require('serve-favicon');
app.use(favicon(__dirname + '/assets/favicon.ico'));  // Put this before setting static dir.
app.use(express.static(__dirname + '/assets'));

/*-----------------------------------------
Ordering of these configs is important, don't shuffle them around.
------------------------------------------*/
var passport = require('passport');
var Strategy = require('passport-local').Strategy;
var db = require('./db');
var Session = require('express-session');
var SessionStore = require('session-file-store')(Session);
var session = Session({ secret: 'here kitty kitty', resave: false, saveUninitialized: false, store: new SessionStore({path: __dirname+'/tmp/sessions'}) });
app.use(session);

//----------------------------
// Configure the local strategy for use by Passport.
// The local strategy require a `verify` function which receives the credentials
// (`username` and `password`) submitted by the user.  The function must verify
// that the password is correct and then invoke `cb` with a user object, which
// will be set at `req.user` in route handlers after authentication.
passport.use(new Strategy(
  function(username, password, cb) {
    db.users.findByUsername(username, function(err, user) {
      winston.info('trying to lookup user.');
      if (err) { winston.info('db.users.findByUsername error.'); return cb(err); }
      if (!user) { winston.info('bad user'); return cb(null, false); }
      if (user.password != password) { winston.info('bad pw'); return cb(null, false); }
      return cb(null, user);
    });
  }));

// Configure Passport authenticated session persistence.
//
// In order to restore authentication state across HTTP requests, Passport needs
// to serialize users into and deserialize users out of the session.  The
// typical implementation of this is as simple as supplying the user ID when
// serializing, and querying the user record by ID from the database when
// deserializing.
passport.serializeUser(function(user, cb) {
  cb(null, user.id);
});
passport.deserializeUser(function(id, cb) {
  db.users.findById(id, function (err, user) {
    if (err) { return cb(err); }
    cb(null, user);
  });
});

// Initialize Passport and restore authentication state, if any, from the session.
app.use(passport.initialize());
app.use(passport.session());

// As with any middleware it is quintessential to call next() if the user is authenticated
var isAuthenticated = function (req, res, next) {
    if (req.isAuthenticated()) {
        return next();
        res.redirect('/');
    } else {
        // If user NOT authenticated, redirect to login page, do not call next().
        res.redirect('/login');
    }
}

app.get('/', isAuthenticated, function(req, res){
    winston.info("GET /");
    // Respond with static file, contents will be loaded via websocket.
    res.sendFile('index.html', { root: __dirname + '/views/' });
});

app.get('/login', function(req, res){
    winston.info('GET /login');
    res.sendFile('login.html', { root: __dirname + '/views/' });
});
  
app.post('/login', 
  passport.authenticate('local', { failureRedirect: '/login' }),
  function(req, res) {
    winston.info('sucessful login for user, ' + req.user.username);
    res.redirect('/');
});
  
app.get('/logout', function(req, res){
    req.logout();
    res.redirect('/');
});

var http = require('http').Server(app);
var io = require('socket.io')(http);

//io.set('authorization', function (handshakeData, accept) {
    //if (handshakeData.headers.cookie) {
	//if (handshakeData.headers.cookie) {
            //winston.info('cookie object test, ' + handshakeData.headers.cookie);
	    //winston.info('parse test 1, ' + cookieParser.signedCookies(handshakeData.headers.cookie, 'here kitty kitty'));
	    //winston.info('parse test 2, ' + cookieParser.signedCookie(handshakeData.headers.cookie['connect.sid'], 'here kitty kitty'));
	    //winston.info('parse test 3, ' + cookieParser.signedCookie(handshakeData.headers.cookie, 'here kitty kitty'));
	    //handshakeData.sessionID = cookieParser.signedCookie(handshakeData.headers.cookie['connect.sid'], 'here kitty kitty');
            //winston.info('sess test 1, ' + session);  // this prints alot!
            //winston.info('sess test 2, ' + session.id);  // undefined
            //winston.info('Got session ID = ' + handshakeData.sessionID);  // undefined
	    // save the session store to the data object 
	    // (as required by the Session constructor)
	    //handshakeData.sessionStore = session.store;
	    //session.store.get(handshakeData.sessionID, function (err, session) {
		//if (err || !session) {
		    //accept('Error', false);
		//} else {
		    // create a session object, passing data as request and our
		    // just acquired session data
		    //handshakeData.session = new Session(handshakeData, session);
		    //accept(null, true);
		//}
	    //});
	//} else {
	    //return accept('No cookie transmitted.', false);
	//}
    //}
//});

io.on('connection', function(socket){
    //winston.info('a user connected');
    fileSystem.readFile(notePath, {encoding: 'utf-8'}, function(err,data){
        if (!err){
            winston.info('file read on connection');
            socket.emit('download allNotes',data);  // Send content only to newly connected client.
        } else { winston.error(err); }
    });
    socket.on('upload allNotes', function(msg){
        winston.info('WS data received');
        var now = Date.now();
        // Overwrite allNotes.txt with new contents from client.
        fileSystem.readFile(notePath, 'utf-8', function(err, data){
            if (err) { 
                winston.error(err); 
            } else {
                fileSystem.writeFile(notePath, msg, 'utf-8', function(err) {
                    if (err) { winston.error(err); }
                    var exec = require('child_process').exec;
                    var cmd = `
                        cd note-data && \
                        git checkout -b ${now} && \
                        git commit -am "Notes modified via websocket, ${now}" && \
                        git checkout master && \
                        git merge ${now}
                    `;
                    //winston.info(cmd);
                    exec(cmd, function(error, stdout, stderr) {
                        if (error) { winston.error(error); }
                        if (!stdout.includes('CONFLICT')) {   // Case-sensitivity seems brittle here. Better to check return code rather than stdout? Can child_process be called w/signature to include return code?
                            var cmd2 = `cd note-data && git branch -d ${now}`
                            exec(cmd2, function(error, stdout, stderr) {
                                if (error) { winston.error(error); }
                                winston.info('temp branch deleted; new content written to allNotes.txt');
                                // Send new content to all other clients EXCEPT the orig sender.
                                socket.broadcast.emit('download allNotes',msg);
                                winston.info('sent content update to other clients');
                            });
                        } else {
                            // Auto-merge failed, keep the new branch.
                            // Send a conflict warning message to socket.io clients (prompt for IAP ;-).
                            socket.emit('conflict', `Auto-merge failed, manually merge ${now} branch to rescue recent edit.`);
                            socket.emit('download allNotes',data);  // Send pre-conflict content back down to client.
                            winston.info(`Auto-merge failed, manually merge ${now} branch to rescue recent edit.`);
                            // MVP for now, can deal w/merge conflicts with git on the server if the cotent needs to be saved.
                        }
                        winston.info(stdout);
                    });
                });
            }
        });
    });
    socket.on('cm-save', function(msg){
        winston.info(msg);
    });
});

http.listen(3000, function() {
    winston.info("Started on PORT 3000");
});