import { randomUUID } from "crypto";

import { requireAuth } from "@/lib/jwt";
import { createCheckoutSession } from "@/lib/areeba";
import { createOrder } from "@/lib/payment-orders";

// Only these return URLs may be handed to the gateway. Anything else
// (including open redirects) is rejected and we fall back to the deep link.
const isAllowedReturnUrl = (url: string): boolean => {
  try {
    const parsed = new URL(url);

    // The app's own deep link is always allowed.
    if (parsed.protocol === "waseel:") return true;

    // The configured server origin (EXPO_PUBLIC_SERVER_URL), if set.
    const serverUrl = process.env.EXPO_PUBLIC_SERVER_URL;
    if (serverUrl) {
      const server = new URL(serverUrl);
      if (parsed.protocol === server.protocol && parsed.host === server.host)
        return true;
    }

    return false;
  } catch {
    return false;
  }
};

// Resolve the fare to integer cents. Accept fare_cents directly, or fare /
// amount in dollars (legacy client field) and convert.
const resolveAmountCents = (fareCents: unknown, fare: unknown, amount: unknown): number | null => {
  let cents: number;
  if (fareCents !== undefined && fareCents !== null) {
    cents = Math.round(Number(fareCents));
  } else if (fare !== undefined && fare !== null) {
    cents = Math.round(Number(fare) * 100);
  } else if (amount !== undefined && amount !== null) {
    cents = Math.round(Number(amount) * 100);
  } else {
    return null;
  }

  if (!Number.isFinite(cents) || cents <= 0) return null;
  return cents;
};

export async function POST(req: Request) {
  const auth = requireAuth(req);
  if ("error" in auth) return auth.error;

  const body = await req.json().catch(() => ({}));
  const {
    name,
    email,
    amount,
    fare_cents,
    fare,
    returnUrl,
    driver_id,
    origin_address,
    destination_address,
    origin_latitude,
    origin_longitude,
    destination_latitude,
    destination_longitude,
    ride_time,
  } = body;

  if (!name || !email)
    return Response.json(
      { error: "Missing required payment information." },
      { status: 400 },
    );

  const amountCents = resolveAmountCents(fare_cents, fare, amount);
  if (amountCents === null)
    return Response.json({ error: "Invalid fare amount." }, { status: 400 });

  const finalReturnUrl =
    typeof returnUrl === "string" && isAllowedReturnUrl(returnUrl)
      ? returnUrl
      : "waseel://book-ride";

  try {
    const orderId = randomUUID();

    const session = await createCheckoutSession({
      orderId,
      amount: amountCents / 100,
      currency: "USD",
      description: `Waseel ride payment for ${name}`,
      returnUrl: finalReturnUrl,
    });

    // The successIndicator stays server-side; the client never sees it.
    if (!session.successIndicator)
      throw new Error("Areeba did not return a successIndicator.");

    await createOrder({
      order_id: orderId,
      user_id: auth.userId,
      amount_cents: amountCents,
      currency: "USD",
      driver_id: driver_id ?? null,
      origin_address: origin_address ?? null,
      destination_address: destination_address ?? null,
      origin_latitude: origin_latitude ?? null,
      origin_longitude: origin_longitude ?? null,
      destination_latitude: destination_latitude ?? null,
      destination_longitude: destination_longitude ?? null,
      ride_time: ride_time ?? null,
      success_indicator: session.successIndicator,
      status: "pending",
    });

    return Response.json({ orderId, checkoutUrl: session.checkoutUrl });
  } catch (err) {
    console.log("[AREEBA_PAYMENT_CREATE]: ", err);

    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
}