import * as Koa from 'koa';
import * as bcrypt from 'bcryptjs';
import * as speakeasy from 'speakeasy';
import signin from '../common/signin';
import config from '../../../config';
import { Users, Signins, UserProfiles, UserSecurityKeys, AttestationChallenges } from '../../../models';
import { ILocalUser } from '../../../models/entities/user';
import { genId } from '../../../misc/gen-id';
import { ensure } from '../../../prelude/ensure';
import { verifyLogin, hash } from '../2fa';
import { randomBytes } from 'crypto';

export default async (ctx: Koa.Context) => {
	ctx.set('Access-Control-Allow-Origin', config.url);
	ctx.set('Access-Control-Allow-Credentials', 'true');

	const body = ctx.request.body as any;
	const username = body['username'];
	const password = body['password'];
	const token = body['token'];

	if (typeof username != 'string') {
		ctx.status = 400;
		return;
	}

	if (typeof password != 'string') {
		ctx.status = 400;
		return;
	}

	if (token != null && typeof token != 'string') {
		ctx.status = 400;
		return;
	}

	// Fetch user
	const user = await Users.findOne({
		usernameLower: username.toLowerCase(),
		host: null
	}) as ILocalUser;

	if (user == null) {
		ctx.throw(404, {
			error: 'user not found'
		});
		return;
	}

	const profile = await UserProfiles.findOne(user.id).then(ensure);

	// Compare password
	const same = await bcrypt.compare(password, profile.password!);

	async function fail(status?: number, failure?: { error: string }) {
		// Append signin history
		await Signins.save({
			id: genId(),
			createdAt: new Date(),
			userId: user.id,
			ip: ctx.ip,
			headers: ctx.headers,
			success: false
		});

		ctx.throw(status || 500, failure || { error: 'someting happened' });
	}

	if (!profile.twoFactorEnabled) {
		if (same) {
			signin(ctx, user);
			return;
		} else {
			await fail(403, {
				error: 'incorrect password'
			});
			return;
		}
	}

	if (token) {
		if (!same) {
			await fail(403, {
				error: 'incorrect password'
			});
			return;
		}

		const verified = (speakeasy as any).totp.verify({
			secret: profile.twoFactorSecret,
			encoding: 'base32',
			token: token,
			window: 2
		});

		if (verified) {
			signin(ctx, user);
			return;
		} else {
			await fail(403, {
				error: 'invalid token'
			});
			return;
		}
	} else if (body.credentialId) {
		if (!same && !profile.usePasswordLessLogin) {
			await fail(403, {
				error: 'incorrect password'
			});
			return;
		}

		const clientDataJSON = Buffer.from(body.clientDataJSON, 'hex');
		const clientData = JSON.parse(clientDataJSON.toString('utf-8'));
		const challenge = await AttestationChallenges.findOne({
			userId: user.id,
			id: body.challengeId,
			registrationChallenge: false,
			challenge: hash(clientData.challenge).toString('hex')
		});

		if (!challenge) {
			await fail(403, {
				error: 'non-existent challenge'
			});
			return;
		}

		await AttestationChallenges.delete({
			userId: user.id,
			id: body.challengeId
		});

		if (new Date().getTime() - challenge.createdAt.getTime() >= 5 * 60 * 1000) {
			await fail(403, {
				error: 'non-existent challenge'
			});
			return;
		}

		const securityKey = await UserSecurityKeys.findOne({
			id: Buffer.from(
				body.credentialId
					.replace(/-/g, '+')
					.replace(/_/g, '/'),
					'base64'
			).toString('hex')
		});

		if (!securityKey) {
			await fail(403, {
				error: 'invalid credentialId'
			});
			return;
		}

		const isValid = verifyLogin({
			publicKey: Buffer.from(securityKey.publicKey, 'hex'),
			authenticatorData: Buffer.from(body.authenticatorData, 'hex'),
			clientDataJSON,
			clientData,
			signature: Buffer.from(body.signature, 'hex'),
			challenge: challenge.challenge
		});

		if (isValid) {
			signin(ctx, user);
			return;
		} else {
			await fail(403, {
				error: 'invalid challenge data'
			});
			return;
		}
	} else {
		if (!same && !profile.usePasswordLessLogin) {
			await fail(403, {
				error: 'incorrect password'
			});
			return;
		}

		const keys = await UserSecurityKeys.find({
			userId: user.id
		});

		if (keys.length === 0) {
			await fail(403, {
				error: 'no keys found'
			});
			return;
		}

		// 32 byte challenge
		const challenge = randomBytes(32).toString('base64')
			.replace(/=/g, '')
			.replace(/\+/g, '-')
			.replace(/\//g, '_');

		const challengeId = genId();

		await AttestationChallenges.save({
			userId: user.id,
			id: challengeId,
			challenge: hash(Buffer.from(challenge, 'utf-8')).toString('hex'),
			createdAt: new Date(),
			registrationChallenge: false
		});

		ctx.body = {
			challenge,
			challengeId,
			securityKeys: keys.map(key => ({
				id: key.id
			}))
		};
		ctx.status = 200;
		return;
	}
	// never get here
};