import {NextApiRequest, NextApiResponse} from "next";
import {createUserWithEmailAndPassword, getAuth} from "firebase/auth";
import {app} from "@/firebase";
import {sessionOptions} from "@/lib/session";
import {withIronSessionApiRoute} from "iron-session/next";
import {getFirestore, doc, setDoc, query, collection, where, getDocs} from "firebase/firestore";
import {DemographicInformation, Type} from "@/interfaces/user";
import {addUserToGroupOnCreation} from "@/utils/registration";

const auth = getAuth(app);
const db = getFirestore(app);

export default withIronSessionApiRoute(login, sessionOptions);

const DEFAULT_DESIRED_LEVELS = {
	reading: 9,
	listening: 9,
	writing: 9,
	speaking: 9,
};

const DEFAULT_LEVELS = {
	reading: 0,
	listening: 0,
	writing: 0,
	speaking: 0,
};

async function login(req: NextApiRequest, res: NextApiResponse) {
	const {email, password, code} = req.body as {email: string; password: string; code: string; demographicInformation: DemographicInformation};

	const codeQuery = query(collection(db, "codes"), where("code", "==", code));
	const codeDocs = (await getDocs(codeQuery)).docs.filter((x) => !Object.keys(x.data()).includes("userId"));

	if (codeDocs.length === 0) {
		res.status(400).json({error: "Invalid Code!"});
		return;
	}

	const codeData = codeDocs[0].data() as {code: string; type: Type; creator?: string; expiryDate: Date | null};

	createUserWithEmailAndPassword(auth, email, password)
		.then(async (userCredentials) => {
			const userId = userCredentials.user.uid;
			delete req.body.password;

			const user = {
				...req.body,
				desiredLevels: DEFAULT_DESIRED_LEVELS,
				levels: DEFAULT_LEVELS,
				bio: "",
				isFirstLogin: codeData.type === "student",
				focus: "academic",
				type: codeData.type,
				subscriptionExpirationDate: codeData.expiryDate,
				registrationDate: new Date(),
			};

			await setDoc(doc(db, "users", userId), user);
			await setDoc(codeDocs[0].ref, {userId: userId}, {merge: true});
			if (codeData.creator) await addUserToGroupOnCreation(userId, codeData.type, codeData.creator);

			req.session.user = {...user, id: userId};
			await req.session.save();

			res.status(200).json({user: {...user, id: userId}});
		})
		.catch((error) => {
			console.log(error);
			res.status(401).json({error});
		});
}