/**
 * Property-based tests for the webhook handler
 * Feature: paypal-payment-integration
 */
import { describe, it, expect, vi, beforeEach } from "vitest";
import * as fc from "fast-check";
import { NextRequest } from "next/server";

// ---------------------------------------------------------------------------
// Mocks
// ---------------------------------------------------------------------------
const mockVerifyWebhookSignature = vi.fn();
const mockMarkPaymentPaid = vi.fn();

vi.mock("@/lib/paypal", () => ({
  verifyWebhookSignature: (...args: unknown[]) => mockVerifyWebhookSignature(...args),
}));

vi.mock("@/lib/summit-requests", () => ({
  markPaymentPaid: (...args: unknown[]) => mockMarkPaymentPaid(...args),
}));

function makeRequest(body: unknown, headers: Record<string, string> = {}): NextRequest {
  const defaultHeaders: Record<string, string> = {
    "paypal-transmission-id": "tx-123",
    "paypal-transmission-time": "2026-01-01T00:00:00Z",
    "paypal-cert-url": "https://api.paypal.com/cert",
    "paypal-auth-algo": "SHA256withRSA",
    "paypal-transmission-sig": "sig-abc",
    "content-type": "application/json",
    ...headers,
  };
  return new NextRequest("http://localhost/api/payments/webhook", {
    method: "POST",
    headers: defaultHeaders,
    body: JSON.stringify(body),
  });
}

// ---------------------------------------------------------------------------
// Property 8: Webhook với signature không hợp lệ → HTTP 401
// ---------------------------------------------------------------------------
describe("webhook handler — signature validation", () => {
  beforeEach(() => {
    mockVerifyWebhookSignature.mockReset();
    mockMarkPaymentPaid.mockReset();
    process.env.PAYPAL_WEBHOOK_ID = "test-webhook-id";
  });

  it(
    "Feature: paypal-payment-integration, Property 8: Webhook signature không hợp lệ → 401",
    async () => {
      await fc.assert(
        fc.asyncProperty(
          fc.record({
            event_type: fc.string(),
            resource: fc.record({ id: fc.string() }),
          }),
          async (payload) => {
            mockVerifyWebhookSignature.mockResolvedValue(false);
            mockMarkPaymentPaid.mockResolvedValue(undefined);

            const { POST } = await import("../route");
            const req = makeRequest(payload);
            const res = await POST(req);

            expect(res.status).toBe(401);
            expect(mockMarkPaymentPaid).not.toHaveBeenCalled();
          }
        ),
        { numRuns: 30 }
      );
    }
  );

  it(
    "Feature: paypal-payment-integration, Property 8b: Webhook thiếu headers → 401",
    async () => {
      await fc.assert(
        fc.asyncProperty(
          fc.record({
            event_type: fc.string(),
            resource: fc.record({ id: fc.string() }),
          }),
          async (payload) => {
            // Missing all PayPal signature headers
            const { POST } = await import("../route");
            const req = makeRequest(payload, {
              "paypal-transmission-id": "",
              "paypal-transmission-time": "",
              "paypal-cert-url": "",
              "paypal-auth-algo": "",
              "paypal-transmission-sig": "",
            });
            const res = await POST(req);

            expect(res.status).toBe(401);
          }
        ),
        { numRuns: 20 }
      );
    }
  );
});

// ---------------------------------------------------------------------------
// Property 9: Webhook idempotent — valid signature, already paid → 200
// Property 10: Webhook hợp lệ cập nhật trạng thái sang paid
// ---------------------------------------------------------------------------
describe("webhook handler — PAYMENT.CAPTURE.COMPLETED", () => {
  beforeEach(() => {
    mockVerifyWebhookSignature.mockReset();
    mockMarkPaymentPaid.mockReset();
    process.env.PAYPAL_WEBHOOK_ID = "test-webhook-id";
  });

  it(
    "Feature: paypal-payment-integration, Property 10: Webhook hợp lệ cập nhật trạng thái sang paid",
    async () => {
      await fc.assert(
        fc.asyncProperty(
          fc.string({ minLength: 1, maxLength: 30 }),
          fc.string({ minLength: 1, maxLength: 30 }),
          async (orderId, captureId) => {
            mockVerifyWebhookSignature.mockResolvedValue(true);
            mockMarkPaymentPaid.mockResolvedValue(undefined);

            const payload = {
              event_type: "PAYMENT.CAPTURE.COMPLETED",
              resource: {
                id: captureId,
                supplementary_data: {
                  related_ids: { order_id: orderId },
                },
              },
            };

            const { POST } = await import("../route");
            const req = makeRequest(payload);
            const res = await POST(req);

            expect(res.status).toBe(200);
            expect(mockMarkPaymentPaid).toHaveBeenCalledWith(orderId, captureId);
          }
        ),
        { numRuns: 30 }
      );
    }
  );

  it(
    "Feature: paypal-payment-integration, Property 9: Webhook idempotent — trả về 200 kể cả khi đã paid",
    async () => {
      // markPaymentPaid is idempotent (no-op if already paid) — webhook should still return 200
      mockVerifyWebhookSignature.mockResolvedValue(true);
      mockMarkPaymentPaid.mockResolvedValue(undefined); // no-op

      const payload = {
        event_type: "PAYMENT.CAPTURE.COMPLETED",
        resource: {
          id: "capture-already-done",
          supplementary_data: { related_ids: { order_id: "order-already-paid" } },
        },
      };

      const { POST } = await import("../route");
      const req = makeRequest(payload);
      const res = await POST(req);

      expect(res.status).toBe(200);
    }
  );
});