import { requireAuth } from "@/lib/jwt";
import { sql, transaction } from "@/lib/db";
import { getOrder, consumeOrderForRide } from "@/lib/payment-orders";
import { matchNextDriver } from "@/lib/dispatch";
import { isServiceId } from "@/lib/driver";
import { DEFAULT_SERVICE } from "@/constants/services";

// Explicit missing check — a truthy check would reject legitimate 0 values
// like latitude 0.0 (the equator) or a zero fare.
const isMissing = (v: unknown): boolean => v === undefined || v === null;

// POST — request a ride. The rider no longer picks a driver; the ride is
// created with status='requested' and driver_id=NULL, then auto-match offers
// it to the nearest eligible driver of the requested service. `driver_id` in
// the body is accepted for backward compatibility but ignored.
export async function POST(request: Request) {
  const auth = requireAuth(request);
  if ("error" in auth) return auth.error;

  try {
    const body = await request.json();
    const {
      origin_address,
      destination_address,
      origin_latitude,
      origin_longitude,
      destination_latitude,
      destination_longitude,
      ride_time,
      fare_price,
      payment_method,
      payment_order_id,
      service,
    } = body;

    if (
      isMissing(origin_address) ||
      isMissing(destination_address) ||
      isMissing(origin_latitude) ||
      isMissing(origin_longitude) ||
      isMissing(destination_latitude) ||
      isMissing(destination_longitude) ||
      isMissing(ride_time) ||
      isMissing(fare_price)
    ) {
      return Response.json(
        { error: "Missing required fields" },
        { status: 400 },
      );
    }

    if (payment_method !== "card" && payment_method !== "cash")
      return Response.json(
        { error: "Invalid payment method." },
        { status: 400 },
      );

    const rideService = isServiceId(service) ? service : DEFAULT_SERVICE;
    const fareCents = Math.round(Number(fare_price));

    if (payment_method === "card") {
      // Card: the ride is only recorded once a paid, server-authoritative
      // payment order is consumed. The client can no longer self-declare
      // payment_status='paid'.
      if (isMissing(payment_order_id))
        return Response.json(
          { error: "Missing payment order id." },
          { status: 400 },
        );

      const order = await getOrder(payment_order_id);
      if (!order)
        return Response.json(
          { error: "Payment order not found." },
          { status: 404 },
        );

      if (order.user_id !== auth.userId)
        return Response.json({ error: "Unauthorized." }, { status: 403 });

      if (order.status !== "paid")
        return Response.json(
          { error: "Payment not verified." },
          { status: 400 },
        );

      if (order.amount_cents !== fareCents)
        return Response.json(
          { error: "Payment amount mismatch." },
          { status: 400 },
        );

      // Reconcile route intent (driver isn't known yet, so driver_id is no
      // longer part of the intent check). Null intent fields are skipped.
      const intentsMatch =
        (order.origin_address === null ||
          order.origin_address === origin_address) &&
        (order.destination_address === null ||
          order.destination_address === destination_address) &&
        (order.ride_time === null || order.ride_time === Number(ride_time));

      if (!intentsMatch)
        return Response.json(
          { error: "Payment does not match this ride." },
          { status: 400 },
        );

      // Consume the order and insert the ride on one connection, so a failure
      // rolls back both and no paid order is wasted without a ride.
      const inserted = await transaction(async (tx) => {
        const consumed = await consumeOrderForRide(
          payment_order_id,
          auth.userId,
          tx,
        );
        if (!consumed) throw new Error("PAYMENT_ORDER_NOT_CONSUMABLE");

        const rows = await tx`
          INSERT INTO rides (
            origin_address,
            destination_address,
            origin_latitude,
            origin_longitude,
            destination_latitude,
            destination_longitude,
            ride_time,
            fare_price,
            payment_status,
            driver_id,
            user_id,
            payment_order_id,
            status,
            service
          ) VALUES (
            ${origin_address},
            ${destination_address},
            ${origin_latitude},
            ${origin_longitude},
            ${destination_latitude},
            ${destination_longitude},
            ${ride_time},
            ${fareCents},
            'paid',
            NULL,
            ${auth.userId},
            ${payment_order_id},
            'requested',
            ${rideService}
          )
          RETURNING *
        `;
        return rows[0];
      });

      // Kick off auto-match asynchronously — don't block the response on it.
      void matchNextDriver(inserted.ride_id);

      return Response.json({ data: inserted }, { status: 201 });
    }

    // Cash: settled directly with the driver at drop-off. No order involved.
    const response = await sql`
      INSERT INTO rides (
        origin_address,
        destination_address,
        origin_latitude,
        origin_longitude,
        destination_latitude,
        destination_longitude,
        ride_time,
        fare_price,
        payment_status,
        driver_id,
        user_id,
        status,
        service
      ) VALUES (
        ${origin_address},
        ${destination_address},
        ${origin_latitude},
        ${origin_longitude},
        ${destination_latitude},
        ${destination_longitude},
        ${ride_time},
        ${fareCents},
        'cash',
        NULL,
        ${auth.userId},
        'requested',
        ${rideService}
      )
      RETURNING *
    `;

    void matchNextDriver(response[0].ride_id);

    return Response.json({ data: response[0] }, { status: 201 });
  } catch (error) {
    console.error("[CREATE_RIDES]: ", error);
    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
}