import { checkStringParam, errorOut, notYet, randomElement, requestIp, reverseString, hours, minutes } from '../logic/utils.js';
import { Animals } from '../misc/animals.js';
import { reissueToken, generateToken, newTokenExpiry, hashPassword, doesPasswordMatch, isEndpointAllowedForBannedUsers, isEndpointProtected, generateRestoreCode, restoreValidity, restoreAttempts } from '../logic/security.js';
import { sendRestorationLink } from '../logic/email.js';
import { UserSession } from '../logic/session.js';
import { SpamCache } from '../logic/cache.js';

/**
 * @param {Object} props
 * @param {import('fastify').FastifyInstance} props.app
 * @param {import('sequelize/types').Sequelize} props.db
 */

function AuthController({app, db}){
	const { Users } = db.models;

	const signInSpam = new SpamCache();
	const signUpSpam = new SpamCache();
	const restoreApplySpam = new SpamCache();

	{ //validate token header and put .session in every request
		app.decorateRequest('session', null);
		app.addHook('preHandler', async (request, reply) => {
			if(isEndpointProtected(request.url)){				
				const token = request.headers.authorization;
				let session = UserSession.find(token);
				if(!session){
					const userData = await Users.findOne({where: {token}});
					if(userData){
						session = new UserSession(userData, request);
					}
				}
				const tokenNotExpired = notYet(session?.user.tokenExpiry);
				const userNotBanned = (!notYet(session?.user.bannedUntil)) || isEndpointAllowedForBannedUsers(request.url);
				if(session?.user && tokenNotExpired && userNotBanned){
					request.session = session;
				}else{
					errorOut(reply, 'Unauthorized', 401);
					return true; //abort
				}
			}
		});
	}
	
	app.post('/auth/sign-in', async (request, reply) => {
		const {email, paswd} = request.body || {};

		if(signInSpam.check(requestIp(request), [[5000, 2*hours]])){
			return errorOut(reply, 'error.too_fast');
		}

		{ //form validation
			if(!isValidEmail(email))    return errorOut(reply, 'auth.bad_email');
			if(!isValidPassword(paswd)) return errorOut(reply, 'auth.bad_paswd');
		}
		const fixedEmail = fixEmail(email);
		const user = await Users.findOne({where: {email: fixedEmail}});

		if(user && doesPasswordMatch(reverseString(paswd), user.paswd)){
			let token = user.token;
			if(new Date() > user.tokenExpiry){
				token = await reissueToken(user);
			}
			return {token};
		}else{
			errorOut(reply, 'auth.not_found');
		}
	});

	app.post('/auth/sign-up', async (request, reply) => {
		const {email, username, paswd} = request.body || {};

		if(signUpSpam.check(requestIp(request), [[5000, 2*hours], [100, 10*minutes]])){
			return errorOut(reply, 'error.too_fast');
		}
		
		{ //form validation
			if(!isValidEmail(email))       return errorOut(reply, 'auth.bad_email');
			if(!isValidPassword(paswd))    return errorOut(reply, 'auth.bad_paswd');
			if(!isValidUsername(username)) return errorOut(reply, 'auth.bad_username');
		}
		const fixedEmail = fixEmail(email);
		const fixedUsername = fixUsername(username);

		{ //check if email is already in use
			const existingUser = await Users.findOne({where: {email: fixedEmail}});
			if(existingUser) return errorOut(reply, 'auth.email_taken');
		}
		{ //check if username taken
			const existingUser = await Users.findOne({where: {username: fixedUsername}});
			if(existingUser) return errorOut(reply, 'auth.username_taken');
		}
		{ //check if this ip already registered a bunch of accounts
			const countByIp = await Users.count({where: {firstIp: request.ip}});
			if(countByIp >= 10) return errorOut(reply, 'error.suspicious');
		}
		const newUser = {
			email: fixedEmail,
			username: fixedUsername,
			token: generateToken(),
			tokenExpiry: newTokenExpiry(),
			paswd: hashPassword(reverseString(paswd)),
			role: 'user',
			firstIp: requestIp(request)
		};
		await Users.create(newUser);
		return {token: newUser.token};
	});

	app.post('/auth/restore/request', async (request, reply) => {
		const {email} = request.body || {};
		
		if(!isValidEmail(email)) return errorOut(reply, 'auth.bad_email');
		const fixedEmail = fixEmail(email);

		const user = await Users.findOne({where: {email: fixedEmail}});
		if(!user) return errorOut(reply, 'restore.not_found');
		if(user.restoreExpiry && notYet(user.restoreExpiry)){
			return errorOut(reply, 'restore.already_sent');
		}

		const restoreCode = generateRestoreCode();
		const restoreExpiry = new Date(Date.now() + restoreValidity);
		await user.update({restoreCode, restoreExpiry});
		const success = await sendRestorationLink(user, app);
		return {success, lifetime: restoreValidity};
	});

	app.post('/auth/restore/apply', async (request, reply) => {
		const {email, code, newpaswd} = request.body || {};
		const changeRequested = (newpaswd != null);

		if(restoreApplySpam.check(requestIp(request), [[100, 12*hours], [25, 30*minutes]])){
			return errorOut(reply, 'error.too_fast');
		}

		if(!isValidEmail(email)) return errorOut(reply, 'auth.bad_email');
		if(changeRequested && (!isValidPassword(newpaswd))){
			return errorOut(reply, 'auth.bad_paswd');
		}
		const fixedEmail = fixEmail(email);

		const user = await Users.findOne({where: {email: fixedEmail}});
		if(!user) return errorOut(reply, 'restore.not_found');
		if((!notYet(user.restoreExpiry)) || (!user.restoreCode)){
			return errorOut(reply, 'restore.expired');
		}

		if(user.restoreCode != code){
			const restoreExpiry = user.restoreExpiry - (restoreValidity / restoreAttempts);
			await user.update({restoreExpiry});
			return errorOut(reply, 'restore.wrong_code');
		}

		if(changeRequested){
			const hash = hashPassword(reverseString(newpaswd));
			await user.update({paswd: hash, restoreCode: null, restoreExpiry: null});
		}
		return '👌';
	});

}

function fixEmail(email){
	const plusPortion = /\+.*@/m; //gmail exploit
	return email.toLowerCase().replace(plusPortion, '');
}

function fixUsername(username){
	if(username){
		const profanities = /nigger|nigga|faggot/gi;
		const badSymbols = /[\x00-\x1F\xCC\xCD]/g;
		return username.replace(profanities, '💩').replace(badSymbols, '');
	}else{
		const nick = randomElement(Animals);
		const tag = Date.now().toString().slice(-4);
		return `Little ${nick} #${tag}`;
	}
}

function isValidEmail(email){
	return checkStringParam(email, 3, 128) && !!email.match('@');
}

function isValidUsername(username){
	return (!username) || checkStringParam(username, 3, 64);
}

function isValidPassword(paswd){
	return checkStringParam(paswd, 6, 256);
}

export default AuthController;