const {onRequest} = require("firebase-functions/v2/https");
const {getAuth} = require("firebase-admin/auth");
const {getFirestore} = require("firebase-admin/firestore");
const logger = require("firebase-functions/logger");
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const {Expo} = require('expo-server-sdk');

admin.initializeApp();
const db = admin.firestore();

let expo = new Expo({accessToken: process.env.EXPO_ACCESS_TOKEN});

// Firestore trigger that listens for new events in the 'Events' collection
exports.sendNotificationOnEventCreation = functions.firestore
    .document('Events/{eventId}')
    .onCreate(async (snapshot, context) => {
        const eventData = snapshot.data();
        const { familyId, creatorId } = eventData;

        if (!familyId || !creatorId) {
            console.error('Missing familyId or creatorId in event data');
            return;
        }

        const pushTokens = await getPushTokensForFamilyExcludingCreator(familyId, creatorId);

        if (!pushTokens.length) {
            console.log('No push tokens available for the event.');
            return;
        }

        let messages = [];
        for (let pushToken of pushTokens) {
            if (!Expo.isExpoPushToken(pushToken)) {
                console.error(`Push token ${pushToken} is not a valid Expo push token`);
                continue;
            }

            messages.push({
                to: pushToken,
                sound: 'default',
                title: 'New Event Added!',
                body: `An event "${eventData.title}" has been added. Check it out!`,
                data: { eventId: context.params.eventId },
            });
        }

        let chunks = expo.chunkPushNotifications(messages);
        let tickets = [];
        for (let chunk of chunks) {
            try {
                let ticketChunk = await expo.sendPushNotificationsAsync(chunk);
                tickets.push(...ticketChunk);

                for (let ticket of ticketChunk) {
                    if (ticket.status === 'ok') {
                        console.log('Notification successfully sent:', ticket.id);
                    } else if (ticket.status === 'error') {
                        console.error(`Notification error: ${ticket.message}`);
                        if (ticket.details && ticket.details.error) {
                            console.error('Error details:', ticket.details.error);
                            if (ticket.details.error === 'DeviceNotRegistered') {
                                console.log(`Removing invalid push token: ${ticket.to}`);
                                await removeInvalidPushToken(ticket.to);
                            }
                        }
                    }
                }
            } catch (error) {
                console.error('Error sending notification:', error);
            }
        }

        // Retrieve and handle notification receipts
        let receiptIds = [];
        for (let ticket of tickets) {
            if (ticket.id) {
                receiptIds.push(ticket.id);
            }
        }

        let receiptIdChunks = expo.chunkPushNotificationReceiptIds(receiptIds);
        for (let chunk of receiptIdChunks) {
            try {
                let receipts = await expo.getPushNotificationReceiptsAsync(chunk);
                console.log('Receipts:', receipts);

                for (let receiptId in receipts) {
                    let { status, message, details } = receipts[receiptId];
                    if (status === 'ok') {
                        console.log(`Notification with receipt ID ${receiptId} was delivered successfully`);
                    } else if (status === 'error') {
                        console.error(`Notification error: ${message}`);
                        if (details && details.error) {
                            console.error(`Error details: ${details.error}`);
                        }
                    }
                }
            } catch (error) {
                console.error('Error retrieving receipts:', error);
            }
        }

        return null;
    });

exports.createSubUser = onRequest(async (request, response) => {
    const authHeader = request.get('Authorization');

    if (!authHeader || !authHeader.startsWith('Bearer ')) {
        logger.warn("Missing or incorrect Authorization header", {authHeader});
        response.status(401).json({error: 'Unauthorized'});
        return;
    }

    try {
        const token = authHeader.split('Bearer ')[1];
        logger.info("Verifying ID token", {token});

        let decodedToken;
        try {
            decodedToken = await getAuth().verifyIdToken(token);
            logger.info("ID token verified successfully", {uid: decodedToken.uid});
        } catch (verifyError) {
            logger.error("ID token verification failed", {error: verifyError.message});
            response.status(401).json({error: 'Unauthorized: Invalid token'});
            return;
        }

        logger.info("Processing user creation", {requestBody: request.body.data});

        const {userType, firstName, lastName, email, password, familyId} = request.body.data;

        if (!email || !password || !firstName || !userType || !familyId) {
            logger.warn("Missing required fields in request body", {requestBody: request.body.data});
            response.status(400).json({error: "Missing required fields"});
            return;
        }

        let userRecord;
        try {
            userRecord = await getAuth().createUser({
                email, password, displayName: `${firstName} ${lastName}`,
            });
            logger.info("User record created", {userId: userRecord.uid});
        } catch (createUserError) {
            logger.error("User creation failed", {error: createUserError.message});
            response.status(500).json({error: "Failed to create user"});
            return;
        }

        const userProfile = {
            userType, firstName, lastName, familyId, email, uid: userRecord.uid
        };

        try {
            await getFirestore().collection("Profiles").doc(userRecord.uid).set(userProfile);
            logger.info("User profile saved to Firestore", {userId: userRecord.uid});
        } catch (firestoreError) {
            logger.error("Failed to save user profile to Firestore", {error: firestoreError.message});
            response.status(500).json({error: "Failed to save user profile"});
            return;
        }

        response.status(200).json({
            data: {
                message: "User created successfully", userId: userRecord.uid,
            }
        });
    } catch (error) {
        logger.error("Error in createSubUser function", {error: error.message});
        response.status(500).json({data: {error: error.message}});
    }
});

exports.generateCustomToken = onRequest(async (request, response) => {
    try {
        const {userId} = request.body.data;

        console.log("Generating custom token for userId", {userId});

        if (!userId) {
            response.status(400).json({error: 'Missing userId'});
            return;
        }

        const customToken = await getAuth().createCustomToken(userId);
        response.status(200).json({data: {token: customToken}});
    } catch (error) {
        console.error("Error generating custom token", {error: error.message});
        response.status(500).json({error: "Failed to generate custom token"});
    }
});

async function getPushTokensForEvent() {
    const usersRef = db.collection('Profiles');
    const snapshot = await usersRef.get();
    let pushTokens = [];

    snapshot.forEach(doc => {
        const data = doc.data();
        if (data.pushToken) {
            pushTokens.push(data.pushToken);
        }
    });

    console.log('Push Tokens:', pushTokens);
    return pushTokens;
}

async function getPushTokensForFamilyExcludingCreator(familyId, creatorId) {
    const usersRef = db.collection('Profiles');
    const snapshot = await usersRef.where('familyId', '==', familyId).get();
    let pushTokens = [];

    snapshot.forEach(doc => {
        const data = doc.data();
        // Exclude the creator
        if (data.uid !== creatorId && data.pushToken) {
            pushTokens.push(data.pushToken);
        }
    });

    return pushTokens;
}