// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
import type {NextApiRequest, NextApiResponse} from "next";
import {app} from "@/firebase";
import {getFirestore, getDoc, doc, deleteDoc, setDoc, getDocs, collection, where, query} from "firebase/firestore";
import {withIronSessionApiRoute} from "iron-session/next";
import {sessionOptions} from "@/lib/session";
import {Ticket} from "@/interfaces/ticket";
import {Invite} from "@/interfaces/invite";
import {CorporateUser, Group, User} from "@/interfaces/user";
import {v4} from "uuid";
import {sendEmail} from "@/email";
import {updateExpiryDateOnGroup} from "@/utils/groups.be";

const db = getFirestore(app);

export default withIronSessionApiRoute(handler, sessionOptions);

async function handler(req: NextApiRequest, res: NextApiResponse) {
	if (req.method === "GET") return await get(req, res);

	res.status(404).json(undefined);
}

async function addToInviterGroup(user: User, invitedBy: User) {
	const invitedByGroupsRef = await getDocs(query(collection(db, "groups"), where("admin", "==", invitedBy.id)));
	const invitedByGroups = invitedByGroupsRef.docs.map((g) => ({
		...g.data(),
		id: g.id,
	})) as Group[];

	const typeGroupName = user.type === "student" ? "Students" : user.type === "teacher" ? "Teachers" : undefined;

	if (typeGroupName) {
		const typeGroup: Group = invitedByGroups.find((g) => g.name === typeGroupName) || {
			id: v4(),
			admin: invitedBy.id,
			name: typeGroupName,
			participants: [],
			disableEditing: true,
		};
		await setDoc(
			doc(db, "groups", typeGroup.id),
			{
				...typeGroup,
				participants: [...typeGroup.participants.filter((x) => x !== user.id), user.id],
			},
			{merge: true},
		);
	}

	const invitationsGroup: Group = invitedByGroups.find((g) => g.name === "Invited") || {
		id: v4(),
		admin: invitedBy.id,
		name: "Invited",
		participants: [],
		disableEditing: true,
	};
	await setDoc(
		doc(db, "groups", invitationsGroup.id),
		{
			...invitationsGroup,
			participants: [...invitationsGroup.participants.filter((x) => x !== user.id), user.id],
		},
		{
			merge: true,
		},
	);
}

async function deleteFromPreviousCorporateGroups(user: User, invitedBy: User) {
	const corporatesRef = await getDocs(query(collection(db, "users"), where("type", "==", "corporate")));
	const corporates = (corporatesRef.docs.map((x) => ({...x.data(), id: x.id})) as CorporateUser[]).filter((x) => x.id !== invitedBy.id);

	const userGroupsRef = await getDocs(query(collection(db, "groups"), where("participants", "array-contains", user.id)));
	const userGroups = userGroupsRef.docs.map((x) => ({...x.data(), id: x.id})) as Group[];

	const corporateGroups = userGroups.filter((x) => corporates.map((c) => c.id).includes(x.admin));
	await Promise.all(
		corporateGroups.map(async (group) => {
			await setDoc(doc(db, "groups", group.id), {participants: group.participants.filter((x) => x !== user.id)}, {merge: true});
		}),
	);
}

async function get(req: NextApiRequest, res: NextApiResponse) {
	if (!req.session.user) {
		res.status(401).json({ok: false});
		return;
	}

	const {id} = req.query as {id: string};
	const snapshot = await getDoc(doc(db, "invites", id));

	if (snapshot.exists()) {
		const invite = {...snapshot.data(), id: snapshot.id} as Invite;
		if (invite.to !== req.session.user.id) return res.status(403).json({ok: false});

		await deleteDoc(snapshot.ref);
		const invitedByRef = await getDoc(doc(db, "users", invite.from));
		if (!invitedByRef.exists()) return res.status(404).json({ok: false});

		await updateExpiryDateOnGroup(invite.to, invite.from);

		const invitedBy = {...invitedByRef.data(), id: invitedByRef.id} as User;

		if (invitedBy.type === "corporate") await deleteFromPreviousCorporateGroups(req.session.user, invitedBy);
		await addToInviterGroup(req.session.user, invitedBy);

		try {
			await sendEmail(
				"respondedInvite",
				{
					corporateName: invitedBy.name,
					name: req.session.user.name,
					decision: "accept",
					environment: process.env.ENVIRONMENT,
				},
				[invitedBy.email],
				`${req.session.user.name} has accepted your invite!`,
			);
		} catch (e) {
			console.log(e);
		}

		res.status(200).json({ok: true});
	} else {
		res.status(404).json(undefined);
	}
}