const logger = require("../utils/logger");
const admin = require("firebase-admin");

/**
 *  Middleware to validate Firebase ID Tokens.
 *  This middleware is used to protect API endpoints from unauthorized access.
 *  It adds the following properties to the request object:
 *  - req.user - the decoded Firebase ID Token
 * @param req
 * @param res
 * @param next
 * @returns {Promise<void>}
 */
const validateFirebaseIdTokenMiddleware = async (req, res, next) => {
    if (
        (
            !req.headers.authorization ||
            !req.headers.authorization.startsWith("Bearer ")) &&
        !(req.cookies && req.cookies.__session
        )
    ) {
        console.error("Unauthorized attempt. No authorization provided.");
        return res.status(403).send("Unauthorized");
    }

    let idToken;

    if (
        req.headers.authorization &&
        req.headers.authorization.startsWith("Bearer ")
    ) {
        // console.log('Found "Authorization" header');
        // Read the ID Token from the Authorization header.
        idToken = req.headers.authorization.split("Bearer ")[1];
    } else if (req.cookies) {
        //console.log('Found "__session" cookie');
        // Read the ID Token from cookie.
        idToken = req.cookies.__session;
    } else {
        // No cookie
        console.error("Unauthorized attempt. No cookie provided.");
        logger.log("api-unauthorized-call", "WARN", null, null, {
            req,
            type: "no-cookie",
        });

        return res.status(403).send("Unauthorized");
    }

    try {
        const decodedIdToken = await admin.auth().verifyIdToken(idToken);
        //console.log("ID Token correctly decoded", decodedIdToken);
        req.user = decodedIdToken;
        next();

    } catch (error) {
        logger.log("api-unauthorized-call", "WARN", null, null, {
            path: req.path,
            body: req.body,

            type: "unauthroized",
            ...error,
        });

        return res.status(401).send("Unauthorized");
    }
};

module.exports = validateFirebaseIdTokenMiddleware;