var passport = require('passport'),
	LocalStrategy = require('passport-local').Strategy;

// some static users
var users = [{
	id: 1,
	username: 'bob',
	password: 'secret',
	email: 'bob@example.com'
}, {
	id: 2,
	username: 'joe',
	password: 'birthday',
	email: 'joe@example.com'
}];

// helper functions


function findById(id, fn) {
	var idx = id - 1;
	if (users[idx]) {
		fn(null, users[idx]);
	} else {
		fn(new Error('User ' + id + ' does not exist'));
	}
}

function findByUsername(username, fn) {
	for (var i = 0, len = users.length; i < len; i++) {
		var user = users[i];
		if (user.username === username) {
			return fn(null, user);
		}
	}
	return fn(null, null);
}


// Passport session setup.
// To support persistent login sessions, Passport needs to be able to
// serialize users into and deserialize users out of the session. Typically,
// this will be as simple as storing the user ID when serializing, and finding
// the user by ID when deserializing.
passport.serializeUser(function(user, done) {
	done(null, user.id);
});

passport.deserializeUser(function(id, done) {
	findById(id, function(err, user) {
		done(err, user);
	});
});


// Use the LocalStrategy within Passport.
// Strategies in passport require a `verify` function, which accept
// credentials (in this case, a username and password), and invoke a callback
// with a user object. In the real world, this would query a database;
// however, in this example we are using a baked-in set of users.
passport.use(new LocalStrategy(

function(username, password, done) {
	// asynchronous verification, for effect...
	process.nextTick(function() {

		// Find the user by username. If there is no user with the given
		// username, or the password is not correct, set the user to `false` to
		// indicate failure and set a flash message. Otherwise, return the
		// authenticated `user`.
		findByUsername(username, function(err, user) {
			if (err) {
				return done(err);
			}
			if (!user) {
				return done(null, false, {
					message: 'Unknown user ' + username
				});
			}
			if (user.password != password) {
				return done(null, false, {
					message: 'Invalid password'
				});
			}
			return done(null, user);
		});
	});
}));

module.exports = {

	// SNIP ...

	// Custom express middleware - we use this to register the passport middleware
	express: {
		customMiddleware: function(app) {
			app.use(passport.initialize());
			app.use(passport.session());
		}
	}

};