import { Injectable } from '@nestjs/common';
import { Prisma, PrismaClient } from '@prisma/client';
import crypto from 'crypto';
import Razorpay from 'razorpay';

import ApiError from '../../../common/utils/helper/ApiError';

const razorpay = new Razorpay({
  key_id: process.env.RAZORPAY_KEY_ID!,
  key_secret: process.env.RAZORPAY_KEY_SECRET!,
});

@Injectable()
export class PaymentService {
  constructor(private prisma: PrismaClient) {}

  async createOrder(
    userXid: number,
    payload: {
      amount: number;
      currency?: string;
      receipt?: string;
      notes?: Record<string, string | number | boolean | null>;
      itineraryHeaderXid?: number;
    },
  ) {
    if (!process.env.RAZORPAY_KEY_ID || !process.env.RAZORPAY_KEY_SECRET) {
      throw new ApiError(500, 'Razorpay credentials are not configured.');
    }

    if (!Number.isFinite(payload.amount) || payload.amount <= 0) {
      throw new ApiError(400, 'amount must be a positive number.');
    }

    if (
      payload.itineraryHeaderXid !== undefined &&
      payload.itineraryHeaderXid !== null
    ) {
      const itineraryHeader = await this.prisma.itineraryHeader.findFirst({
        where: {
          id: payload.itineraryHeaderXid,
          ownerXid: userXid,
          isActive: true,
          deletedAt: null,
        },
        select: {
          id: true,
        },
      });

      if (!itineraryHeader) {
        throw new ApiError(
          404,
          'Itinerary not found for the logged-in user.',
        );
      }
    }

    const amountInPaise = Math.round(payload.amount * 100);
    const receipt = payload.receipt ?? `receipt_${Date.now()}`;
    const currency = payload.currency ?? 'INR';

    const order = (await razorpay.orders.create({
      amount: amountInPaise,
      currency,
      receipt,
      notes: payload.notes ?? undefined,
    } as any)) as any;

    const paymentOrder = await this.prisma.paymentOrders.create({
      data: {
        userXid,
        itineraryHeaderXid: payload.itineraryHeaderXid ?? null,
        razorpayOrderId: order.id,
        receipt: order.receipt ?? receipt,
        amount: order.amount ?? amountInPaise,
        currency: order.currency ?? currency,
        paymentStatus: order.status ?? 'created',
        notes: payload.notes
          ? (payload.notes as Prisma.InputJsonValue)
          : null,
        isActive: true,
      },
    });

    return {
      paymentOrderId: paymentOrder.id,
      orderId: order.id,
      amount: paymentOrder.amount,
      currency: paymentOrder.currency,
      receipt: paymentOrder.receipt,
      status: paymentOrder.paymentStatus,
    };
  }

  async verifyPayment(
    userXid: number,
    payload: {
      paymentId: string;
      orderId: string;
      signature: string;
    },
  ) {
    if (!process.env.RAZORPAY_KEY_SECRET) {
      throw new ApiError(500, 'Razorpay credentials are not configured.');
    }

    const paymentId = payload.paymentId?.trim();
    const orderId = payload.orderId?.trim();
    const signature = payload.signature?.trim();

    if (!paymentId || !orderId || !signature) {
      throw new ApiError(
        400,
        'paymentId, orderId and signature are required.',
      );
    }

    const generatedSignature = crypto
      .createHmac('sha256', process.env.RAZORPAY_KEY_SECRET)
      .update(`${orderId}|${paymentId}`)
      .digest('hex');

    if (generatedSignature !== signature) {
      throw new ApiError(400, 'Invalid signature.');
    }

    const paymentOrder = await this.prisma.paymentOrders.findFirst({
      where: {
        razorpayOrderId: orderId,
        userXid,
        isActive: true,
        deletedAt: null,
      },
    });

    if (!paymentOrder) {
      throw new ApiError(404, 'Payment order not found.');
    }

    if (
      paymentOrder.paymentStatus === 'paid' &&
      paymentOrder.razorpayPaymentId === paymentId
    ) {
      return {
        paymentOrderId: paymentOrder.id,
        orderId: paymentOrder.razorpayOrderId,
        paymentId: paymentOrder.razorpayPaymentId,
        status: paymentOrder.paymentStatus,
        verifiedAt: paymentOrder.verifiedAt,
        paidAt: paymentOrder.paidAt,
      };
    }

    const updatedPaymentOrder = await this.prisma.paymentOrders.update({
      where: {
        id: paymentOrder.id,
      },
      data: {
        razorpayPaymentId: paymentId,
        razorpaySignature: signature,
        paymentStatus: 'paid',
        verifiedAt: new Date(),
        paidAt: new Date(),
      },
    });

    return {
      paymentOrderId: updatedPaymentOrder.id,
      orderId: updatedPaymentOrder.razorpayOrderId,
      paymentId: updatedPaymentOrder.razorpayPaymentId,
      status: updatedPaymentOrder.paymentStatus,
      verifiedAt: updatedPaymentOrder.verifiedAt,
      paidAt: updatedPaymentOrder.paidAt,
    };
  }
}