import { onRequest } from "firebase-functions/v2/https";
import { getCorsHandler } from "../shared/middleware";
import { getAdmin, getLogger } from "../shared/config";

const corsHandler = getCorsHandler();
const admin = getAdmin();
const logger = getLogger();

export const registerClient = onRequest({
    region: '#{SERVICES_RGN}#'
}, async (req, res) => {
    return corsHandler(req, res, async () => {
        try {
            if (req.method !== 'POST') {
                return res.status(405).json({ error: 'Method not allowed. Please use POST.' });
            }
            const authHeader = req.headers.authorization;
            if (!authHeader || !authHeader.startsWith('Bearer ')) {
                return res.status(401).json({ error: 'Unauthorized. Missing or invalid authorization header.' });
            }
            const idToken = authHeader.split('Bearer ')[1];
            try {
                const decodedToken = await admin.auth().verifyIdToken(idToken);
                const uid = decodedToken.uid;
                const userDoc = await admin.firestore().collection('users').doc(uid).get();

                if (!userDoc.exists) {
                    return res.status(403).json({ error: 'Forbidden. User not found.' });
                }

                const userData = userDoc.data();
                if (!userData || !userData.roles || !userData.roles.includes('gym_owner')) {
                    return res.status(403).json({ error: 'Forbidden. Only gym owners can register clients.' });
                }
                const gymUser = req.body;
                if (!gymUser.phoneNumber) {
                    return res.status(400).json({ error: 'Phone number is required' });
                }

                const isdCode = gymUser.isdCode || '91';
                const formattedPhoneNumber = gymUser.phoneNumber.startsWith('+')
                    ? gymUser.phoneNumber
                    : `${isdCode}${gymUser.phoneNumber}`;

                let clientUid;
                try {
                    const userRecord = await admin.auth().getUserByPhoneNumber(formattedPhoneNumber)
                        .catch(() => null);

                    if (userRecord) {
                        clientUid = userRecord.uid;
                    } else {
                        const newUser = await admin.auth().createUser({
                            phoneNumber: formattedPhoneNumber,
                            displayName: gymUser.name || '',
                            email: gymUser.email || null,
                        });
                        clientUid = newUser.uid;
                    }
                } catch (error) {
                    logger.error('Error creating authentication user:', error);
                    return res.status(500).json({
                        error: 'Failed to create authentication user',
                        details: error
                    });
                }

                try {
                    gymUser.uid = clientUid;
                    gymUser.registeredBy = uid;

                    if (gymUser.name) {
                        gymUser.normalizedName = gymUser.name.toLowerCase();
                    }

                    if (gymUser.dateOfBirth && !(typeof gymUser.dateOfBirth === 'string')) {
                        gymUser.dateOfBirth = new Date(gymUser.dateOfBirth).toISOString();
                    }

                    const clientData = {
                        ...gymUser,
                        phoneNumber: formattedPhoneNumber,
                    };

                    await admin.firestore().collection('client_profiles').doc(clientUid).set(clientData);

                    return res.status(201).json({
                        success: true,
                        message: 'Client registered successfully',
                        clientId: clientUid
                    });
                } catch (error) {
                    logger.error('Error creating client profile:', error);

                    try {
                        if (!gymUser.uid) {
                            await admin.auth().deleteUser(clientUid);
                        }
                    } catch (deleteError) {
                        logger.error('Error deleting auth user after failed profile creation:', deleteError);
                    }

                    return res.status(500).json({
                        error: 'Failed to create client profile',
                        details: error
                    });
                }

            } catch (authError) {
                logger.error('Authentication error:', authError);
                return res.status(401).json({ error: 'Unauthorized. Invalid token.' });
            }
        } catch (error) {
            logger.error('Unexpected error in client registration:', error);
            return res.status(500).json({
                error: 'Internal server error',
                details: error
            });
        }
    });
});