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

export const dynamic = "force-dynamic";

export async function GET(request: NextRequest) {
  try {
    const { searchParams } = new URL(request.url);
    const apartmentSlug = searchParams.get("apartmentSlug");
    const start = searchParams.get("start");
    const end = searchParams.get("end");

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

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

    const nights = nightsBetween(start, end);

    if (nights <= 0) {
      return NextResponse.json(
        { error: "End date must be after start date" },
        { status: 400 }
      );
    }

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

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

    // Fetch Beds24's own short-stay rate for the same arrival date, purely to
    // display a genuine "savings vs. short-term rate" figure — this never
    // changes the actual price charged (see calculatePrice()).
    let referenceNightlyRate: number | undefined;
    if (availability.available && nights > bookingConfig.referenceStayNights) {
      try {
        const reference = await getAvailability({
          houseId: apartment.houseId,
          propertyId: apartment.beds24PropertyId,
          roomId: apartment.beds24RoomId,
          start,
          end: addDays(start, bookingConfig.referenceStayNights),
        });
        if (reference.available) {
          referenceNightlyRate = reference.price;
        }
      } catch (referenceError) {
        console.error("Reference price lookup failed:", referenceError);
      }
    }

    const price = calculatePrice(
      availability.price,
      nights,
      availability.currency,
      referenceNightlyRate
    );

    return NextResponse.json({
      apartmentSlug,
      start,
      end,
      nights,
      available: availability.available,
      minStayValid,
      minStayNights,
      maxGuests: apartment.maxGuests,
      price,
    });
  } catch (error) {
    console.error("Availability API error:", error);
    return NextResponse.json(
      { error: "Failed to fetch availability" },
      { status: 500 }
    );
  }
}