import { NextResponse } from "next/server";
import { auth } from "@/lib/auth";
import { prisma } from "@/lib/prisma";
import { captureOrder, creditsPerUnit, isPayPalConfigured } from "@/lib/services/paypal";
import { rcon } from "@/lib/services/rcon";
import { sendCurrency } from "@/lib/services/send-currency";
import { env } from "@/env";
import { logger } from "@/lib/logger";

export const dynamic = "force-dynamic";

/**
 * POST /api/paypal/capture — capture an approved order and credit the buyer.
 * Body: { orderId: string } (PayPal order id from /api/paypal/create).
 *
 * On a COMPLETED capture we:
 *   1. record the payment in website_paypal_transactions (idempotent on
 *      transaction_id so a double-submit can't double-credit), and
 *   2. credit the buyer's `credits` wallet via sendCurrency (RCON-first, DB
 *      fallback). NOTE: the schema has no dedicated website-balance column —
 *      User.credits is the website/in-game wallet, so the top-up lands there,
 *      consistent with the voucher redeem flow.
 *
 * Auth-gated via auth(); the crediting user id is the session user, not a body
 * field, so a captured order always credits the person who is signed in.
 */
export async function POST(req: Request): Promise<Response> {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json({ error: "You must be signed in." }, { status: 401 });
  }
  const userId = Number(session.user.id);
  if (!Number.isFinite(userId)) {
    return NextResponse.json({ error: "Invalid session." }, { status: 401 });
  }

  if (!isPayPalConfigured()) {
    return NextResponse.json(
      { error: "PayPal is not configured. Set PAYPAL_CLIENT_ID and PAYPAL_SECRET." },
      { status: 503 },
    );
  }

  let body: unknown;
  try {
    body = await req.json();
  } catch {
    return NextResponse.json({ error: "Invalid JSON body." }, { status: 400 });
  }

  const orderId = String((body as { orderId?: unknown })?.orderId ?? "").trim();
  if (!orderId) {
    return NextResponse.json({ error: "Missing orderId." }, { status: 422 });
  }

  // Idempotency: if this order was already recorded, don't capture/credit again.
  try {
    const existing = await prisma.websitePaypalTransactions.findFirst({
      where: { transactionId: orderId },
      select: { id: true, status: true },
    });
    if (existing) {
      return NextResponse.json({
        ok: existing.status === "COMPLETED",
        alreadyProcessed: true,
        status: existing.status,
      });
    }
  } catch {
    // If the lookup fails we fall through; the capture call itself is the source
    // of truth and PayPal rejects a second capture of the same order.
  }

  let result;
  try {
    result = await captureOrder(orderId);
  } catch (e) {
    logger.error("PayPal capture failed", { module: "paypal/capture", error: (e as Error).message });
    return NextResponse.json(
      { error: "Could not capture the PayPal payment. If you were charged, contact staff." },
      { status: 502 },
    );
  }

  if (result.status !== "COMPLETED") {
    // Record the non-completed attempt so support can trace it.
    try {
      await prisma.websitePaypalTransactions.create({
        data: {
          userId,
          transactionId: result.id || orderId,
          status: result.status,
          description: `${env.HOTEL_NAME} top-up (not completed)`,
          amount: result.amount,
          currency: result.currency,
          createdAt: new Date(),
          updatedAt: new Date(),
        },
      });
    } catch {
      /* best-effort logging */
    }
    return NextResponse.json(
      { ok: false, status: result.status, error: "Payment was not completed." },
      { status: 402 },
    );
  }

  const credits = Math.floor(result.amount * creditsPerUnit());

  // Record the transaction BEFORE crediting so a crash mid-grant can't be
  // reprocessed into a double credit (the idempotency check above keys on this).
  try {
    await prisma.websitePaypalTransactions.create({
      data: {
        userId,
        transactionId: result.captureId ?? result.id,
        status: "COMPLETED",
        description: `${env.HOTEL_NAME} top-up: ${credits} credits`,
        amount: result.amount,
        currency: result.currency,
        createdAt: new Date(),
        updatedAt: new Date(),
      },
    });
  } catch (e) {
    logger.error("PayPal capture record failed", { module: "paypal/capture", error: (e as Error).message });
    return NextResponse.json(
      { error: "Payment captured but could not be recorded. Contact staff with your order id." },
      { status: 500 },
    );
  }

  // Credit the buyer's website credits wallet (RCON-first, DB fallback).
  try {
    await sendCurrency({ rcon, db: prisma }, userId, "credits", credits);
  } catch (e) {
    logger.error("PayPal capture credit failed", { module: "paypal/capture", error: (e as Error).message });
    return NextResponse.json(
      {
        ok: false,
        error: "Payment recorded but credits could not be delivered. Contact staff.",
      },
      { status: 500 },
    );
  }

  return NextResponse.json({
    ok: true,
    status: "COMPLETED",
    amount: result.amount,
    currency: result.currency,
    credits,
  });
}