import { NextRequest, NextResponse } from "next/server";
import { getStripe, getStripeAccountId } from "@/src/lib/stripe";
import { prisma } from "@/src/lib/prisma";
import { getApartmentBySlug, bookingConfig } from "@/src/config/apartments";
import { getAvailability, getEffectiveMinStay } from "@/src/lib/beds24";
import { calculatePrice } from "@/src/lib/pricing";
import { nightsBetween } from "@/src/lib/date";

export const dynamic = "force-dynamic";

export async function POST(request: NextRequest) {
  try {
    const body = await request.json();
    const {
      apartmentSlug,
      start,
      end,
      guestEmail,
      guestName,
      successUrl,
      cancelUrl,
    } = body;

    if (!apartmentSlug || !start || !end || !guestEmail || !guestName) {
      return NextResponse.json(
        { error: "Missing required booking parameters" },
        { status: 400 }
      );
    }

    const apartment = getApartmentBySlug(apartmentSlug);
    if (!apartment) {
      return NextResponse.json(
        { error: "Apartment not found" },
        { status: 404 }
      );
    }

    const startDate = new Date(start);
    const endDate = new Date(end);
    const nights = nightsBetween(start, end);

    const minStayNights = await getEffectiveMinStay(
      apartment.houseId,
      apartment.beds24PropertyId,
      apartment.beds24RoomId,
      start,
      bookingConfig.minStayNights
    );

    if (nights < minStayNights) {
      return NextResponse.json(
        { error: `Minimum stay is ${minStayNights} nights` },
        { status: 400 }
      );
    }

    const availability = await getAvailability({
      houseId: apartment.houseId,
      propertyId: apartment.beds24PropertyId,
      roomId: apartment.beds24RoomId,
      start,
      end,
    });

    if (!availability.available) {
      return NextResponse.json(
        { error: "Apartment not available for selected dates" },
        { status: 409 }
      );
    }

    const price = calculatePrice(availability.price, nights, availability.currency);
    const depositAmount = Math.round(price.depositAmount * 100); // cents

    const stripe = getStripe(apartment.houseId);
    const accountId = getStripeAccountId(apartment.houseId);

    // Create or update Stripe customer
    let customer;
    const existingCustomers = await stripe.customers.list({
      email: guestEmail,
      limit: 1,
    });

    if (existingCustomers.data.length > 0) {
      customer = existingCustomers.data[0];
    } else {
      customer = await stripe.customers.create({
        email: guestEmail,
        name: guestName,
      });
    }

    const bookingReference = `BB-${Date.now()}-${Math.random().toString(36).substring(2, 7).toUpperCase()}`;

    // Create pending booking in database
    await prisma.booking.create({
      data: {
        bookingReference,
        apartmentSlug,
        houseId: apartment.houseId,
        beds24PropertyId: apartment.beds24PropertyId,
        beds24RoomId: apartment.beds24RoomId,
        guestEmail,
        guestName,
        checkIn: startDate,
        checkOut: endDate,
        nights,
        totalAmount: price.totalAfterDiscount,
        depositAmount: price.depositAmount,
        currency: price.currency,
        status: "pending",
        stripeAccountId: accountId,
        stripeCustomerId: customer.id,
      },
    });

    const session = await stripe.checkout.sessions.create({
      customer: customer.id,
      payment_method_types: ["card"],
      line_items: [
        {
          price_data: {
            currency: price.currency.toLowerCase(),
            product_data: {
              name: `Anzahlung Apartment ${apartment.name}`,
              description: `Aufenthalt: ${start} bis ${end} (${nights} Nächte)`,
            },
            unit_amount: depositAmount,
          },
          quantity: 1,
        },
      ],
      mode: "payment",
      success_url: successUrl || `${process.env.NEXT_PUBLIC_BASE_URL}/de/booking-success?reference=${bookingReference}`,
      cancel_url: cancelUrl || `${process.env.NEXT_PUBLIC_BASE_URL}/de/apartments/${apartmentSlug}`,
      metadata: {
        bookingReference,
        apartmentSlug,
        houseId: apartment.houseId,
      },
    });

    await prisma.booking.update({
      where: { bookingReference },
      data: { stripeCheckoutSessionId: session.id },
    });

    return NextResponse.json({
      sessionId: session.id,
      bookingReference,
      url: session.url,
    });
  } catch (error) {
    console.error("Checkout session error:", error);
    return NextResponse.json(
      { error: "Failed to create checkout session" },
      { status: 500 }
    );
  }
}