// Next.js API route support: https://nextjs.org/docs/api-routes/introduction
import type {NextApiRequest, NextApiResponse} from "next";
import {app} from "@/firebase";
import {getFirestore, setDoc, doc, query, collection, where, getDocs} from "firebase/firestore";
import {withIronSessionApiRoute} from "iron-session/next";
import {sessionOptions} from "@/lib/session";
import {Type} from "@/interfaces/user";
import {PERMISSIONS} from "@/constants/userPermissions";
import {uuidv4} from "@firebase/util";
import {prepareMailer, prepareMailOptions} from "@/email";

const db = getFirestore(app);

export default withIronSessionApiRoute(handler, sessionOptions);

async function handler(req: NextApiRequest, res: NextApiResponse) {
	if (!req.session.user) {
		res.status(401).json({ok: false, reason: "You must be logged in to generate a code!"});
		return;
	}

	const {type, codes, emails, expiryDate} = req.body as {type: Type; codes: string[]; emails?: string[]; expiryDate: null | Date};
	const permission = PERMISSIONS.generateCode[type];

	if (!permission.includes(req.session.user.type)) {
		res.status(403).json({ok: false, reason: "Your account type does not have permissions to generate a code for that type of user!"});
		return;
	}

	if (req.session.user.type === "corporate") {
		const codesGeneratedByUserSnapshot = await getDocs(query(collection(db, "codes"), where("creator", "==", req.session.user.id)));
		const totalCodes = codesGeneratedByUserSnapshot.docs.length + codes.length;
		const allowedCodes = req.session.user.corporateInformation?.companyInformation.userAmount || 0;

		if (totalCodes > allowedCodes) {
			res.status(403).json({
				ok: false,
				reason: `You have or would have exceeded your amount of allowed codes, you currently are allowed to generate ${
					allowedCodes - codesGeneratedByUserSnapshot.docs.length
				} codes.`,
			});
			return;
		}
	}

	const codePromises = codes.map(async (code, index) => {
		const codeRef = doc(db, "codes", code);
		await setDoc(codeRef, {type, code, creator: req.session.user!.id, expiryDate});

		if (emails && emails.length > index) {
			const transport = prepareMailer();
			const mailOptions = prepareMailOptions(
				{
					type,
					code,
				},
				[emails[index]],
				"EnCoach Registration",
				"main",
			);

			await transport.sendMail(mailOptions);
		}
	});

	Promise.all(codePromises).then(() => {
		res.status(200).json({ok: true});
	});
}