import { onRequest } from "firebase-functions/v2/https";
import { Request } from "firebase-functions/v2/https";
import { getCorsHandler } from "../../shared/middleware";
import { getAdmin, getLogger } from "../../shared/config";
import axios from "axios";
const { v4: uuidv4 } = require('uuid');

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

interface CashfreeLinkRequest {
    amount: number;
    customerName?: string;
    customerEmail: string;
    customerPhone: string;
    productInfo?: string;
    userId?: string;
    gymId?: string;
    orderId: string;
}

interface CashfreeLinkResponse {
    link_id: string;
    link_url: string;
    link_expiry_time: string;
    link_status: string;
    link_qrcode: string;
    [key: string]: any;
}

export const createCashfreeLink = onRequest({
    region: '#{SERVICES_RGN}#'
}, async (request: Request, response) => {
    return corsHandler(request, response, async () => {
        try {
            const authHeader = request.headers.authorization;
            if (!authHeader || !authHeader.startsWith('Bearer ')) {
                response.status(401).json({ error: 'Unauthorized' });
                return;
            }

            const idToken = authHeader.split('Bearer ')[1];
            const decodedToken = await admin.auth().verifyIdToken(idToken);
            const uid = decodedToken.uid;

            const linkRequest = request.body as CashfreeLinkRequest;
            if (!linkRequest.amount || !linkRequest.customerEmail || !linkRequest.customerPhone) {
                response.status(400).json({ error: 'Missing required fields' });
                return;
            }

            const clientId = process.env.CASHFREE_CLIENT_ID;
            const clientSecret = process.env.CASHFREE_CLIENT_SECRET;
            if (!clientId || !clientSecret) {
                logger.error('Cashfree credentials not configured');
                response.status(500).json({ error: 'Payment gateway configuration error' });
                return;
            }

            const expirationDate = new Date(Date.now() + 24 * 60 * 60 * 1000);
            const expirationString = expirationDate.toISOString();
            const apiUrl = process.env.CASHFREE_LINK_URL;
            const linkId = uuidv4();

            const requestHeaders = {
                'x-client-id': clientId,
                'x-client-secret': clientSecret,
                'x-api-version': '2025-01-01',
                'Content-Type': 'application/json'
            };

            const requestBody = {
                link_id: linkId,
                link_amount: linkRequest.amount,
                link_currency: "INR",
                link_purpose: linkRequest.productInfo,
                customer_details: {
                    customer_phone: linkRequest.customerPhone,
                    customer_email: linkRequest.customerEmail,
                    customer_name: linkRequest.customerName,
                },
                link_partial_payments: false,
                link_notify: {
                    send_sms: true,
                    send_email: true
                },
                link_expiry_time: expirationString,
                link_notes: {
                    order_id: linkRequest.orderId,
                    gym_id: linkRequest.gymId,
                    user_id: linkRequest.userId
                }
            };

            const cashfreeResponse = await axios.post<CashfreeLinkResponse>(
                apiUrl!,
                requestBody,
                { headers: requestHeaders }
            );

            await admin.firestore().collection('payment_links').doc(linkRequest.orderId).set({
                requestUserId: uid,
                amount: linkRequest.amount,
                customerEmail: linkRequest.customerEmail,
                customerPhone: linkRequest.customerPhone,
                userId: linkRequest.userId,
                gymId: linkRequest.gymId,
                orderId: linkRequest.orderId,
                ...cashfreeResponse.data,
                createdAt: admin.firestore.FieldValue.serverTimestamp(),
            });

            response.json({
                success: true,
                linkId: linkId,
                linkUrl: cashfreeResponse.data.link_url,
                linkExpiryTime: cashfreeResponse.data.link_expiry_time,
                linkStatus: cashfreeResponse.data.link_status,
                linkQRCode: cashfreeResponse.data.link_qrcode
            });

        } catch (error: any) {
            logger.error('Cashfree link creation error:', error);
            const statusCode = error.response?.status || 500;
            response.status(statusCode).json({
                success: false,
                error: error.response?.data?.message || 'Failed to create payment link',
                details: error.response?.data || error.message
            });
        }
    });
});