// @vitest-environment node
/**
 * AuthGatedRequestHandler — unit + E2E tests.
 *
 * What is tested:
 *   - getTask / cancelTask / resubscribe reject UnauthenticatedUser (or missing context)
 *     with A2AError code -32600 (INVALID_REQUEST).
 *   - Authenticated contexts pass the auth gate and reach the underlying store
 *     (which throws taskNotFound -32001, not the auth error).
 *   - E2E via supertest: unauthenticated `tasks/get` HTTP request → proper JSON-RPC
 *     error response (not 500).
 *
 * Test approach: unit-test AuthGatedRequestHandler directly with InMemoryTaskStore
 * and a stub executor (fastest, no HTTP round-trip needed for unit assertions).
 * One E2E supertest case covers the full HTTP path.
 */
import { describe, it, expect } from 'vitest';
import express from 'express';
import request from 'supertest';
import {
  A2AError,
  InMemoryTaskStore,
  ServerCallContext,
  UnauthenticatedUser,
} from '@a2a-js/sdk/server';
import { Repository } from '../../db/repository.js';
import { buildBaseCard } from './agent-card.js';
import { AuthGatedRequestHandler, mountA2aRequestHandler } from './request-handler.js';
import { A2aAuthenticatedUser } from './user-builder.js';
import type { A2aPrincipal } from './token-auth.js';

// ─── fixtures ─────────────────────────────────────────────────────────────────

const BASE_DEPS = { baseUrl: 'https://m', issuer: 'https://m/oidc', version: '1.0.0' };

const FAKE_PRINCIPAL: A2aPrincipal = {
  actingUserId: 'u1', clientId: 'cli1', grantId: 'g1',
  delegation: {
    id: 'd1', userId: 'u1', clientId: 'cli1', grantId: 'g1',
    grantedSpaceIds: ['s1'], grantedSkills: ['research'],
    expiresAt: null, revokedAt: null,
  },
};

/** Helper — construct AuthGatedRequestHandler with an in-memory store. */
function makeHandler() {
  const store = new InMemoryTaskStore();
  const fakeExecutor = { execute: async () => {} } as any;
  const baseCard = buildBaseCard(BASE_DEPS);
  return new AuthGatedRequestHandler(baseCard, store, fakeExecutor);
}

const UNAUTH_CTX = new ServerCallContext(undefined, new UnauthenticatedUser());
const AUTH_CTX   = new ServerCallContext(undefined, new A2aAuthenticatedUser(FAKE_PRINCIPAL));

// ─── getTask ──────────────────────────────────────────────────────────────────

describe('AuthGatedRequestHandler.getTask', () => {
  it('rejects UnauthenticatedUser with A2AError', async () => {
    const h = makeHandler();
    await expect(h.getTask({ id: 'x' }, UNAUTH_CTX)).rejects.toBeInstanceOf(A2AError);
  });

  it('rejected error carries INVALID_REQUEST code (-32600)', async () => {
    const h = makeHandler();
    await expect(h.getTask({ id: 'x' }, UNAUTH_CTX))
      .rejects.toMatchObject({ code: -32600 });
  });

  it('fail-closed: undefined context also rejects', async () => {
    const h = makeHandler();
    await expect(h.getTask({ id: 'x' }, undefined)).rejects.toMatchObject({ code: -32600 });
  });

  it('authenticated context passes auth gate (taskNotFound, not auth error)', async () => {
    const h = makeHandler();
    const err = await h.getTask({ id: 'nonexistent' }, AUTH_CTX).catch(e => e);
    expect(err).toBeInstanceOf(A2AError);
    // -32001 = TASK_NOT_FOUND (auth gate was cleared, underlying store was reached)
    expect(err.code).not.toBe(-32600);
  });
});

// ─── cancelTask ───────────────────────────────────────────────────────────────

describe('AuthGatedRequestHandler.cancelTask', () => {
  it('rejects UnauthenticatedUser with INVALID_REQUEST (-32600)', async () => {
    const h = makeHandler();
    await expect(h.cancelTask({ id: 'x' }, UNAUTH_CTX))
      .rejects.toMatchObject({ code: -32600 });
  });

  it('fail-closed: undefined context rejects', async () => {
    const h = makeHandler();
    await expect(h.cancelTask({ id: 'x' }, undefined)).rejects.toMatchObject({ code: -32600 });
  });

  it('authenticated context passes auth gate (taskNotFound, not auth error)', async () => {
    const h = makeHandler();
    const err = await h.cancelTask({ id: 'nonexistent' }, AUTH_CTX).catch(e => e);
    expect(err).toBeInstanceOf(A2AError);
    expect(err.code).not.toBe(-32600);
  });
});

// ─── resubscribe ──────────────────────────────────────────────────────────────

describe('AuthGatedRequestHandler.resubscribe', () => {
  it('rejects UnauthenticatedUser synchronously (throws before returning generator)', () => {
    const h = makeHandler();
    expect(() => h.resubscribe({ id: 'x' }, UNAUTH_CTX)).toThrow(A2AError);
  });

  it('thrown error carries INVALID_REQUEST code (-32600)', () => {
    const h = makeHandler();
    let caught: unknown;
    try { h.resubscribe({ id: 'x' }, UNAUTH_CTX); } catch (e) { caught = e; }
    expect(caught).toBeInstanceOf(A2AError);
    expect((caught as A2AError).code).toBe(-32600);
  });

  it('fail-closed: undefined context throws synchronously', () => {
    const h = makeHandler();
    expect(() => h.resubscribe({ id: 'x' }, undefined)).toThrow(A2AError);
  });

  it('authenticated context returns an AsyncGenerator without throwing', () => {
    const h = makeHandler();
    let gen: ReturnType<typeof h.resubscribe> | undefined;
    expect(() => { gen = h.resubscribe({ id: 'x' }, AUTH_CTX); }).not.toThrow();
    expect(gen).toBeDefined();
    expect(typeof gen![Symbol.asyncIterator]).toBe('function');
    gen!.return?.(undefined); // clean up
  });
});

// ─── E2E: tasks/get via HTTP → JSON-RPC error when unauthenticated ───────────

describe('mountA2aRequestHandler – tasks/get auth gate (E2E)', () => {
  function seedRepo(repo: Repository) {
    (repo as any).db.prepare(
      "INSERT INTO users (id, email, name, avatar_url, role, status, created_at, updated_at) " +
      "VALUES ('u1','u1@test','User One',NULL,'user','active','2026-01-01','2026-01-01')",
    ).run();
  }

  function fakeProvider() {
    return { AccessToken: { async find(_v: string) { return undefined; } } } as any;
  }

  it('unauthenticated tasks/get returns JSON-RPC error (not 500, code=-32600)', async () => {
    const repo = new Repository(':memory:');
    seedRepo(repo);
    const app = express();
    mountA2aRequestHandler(app, { provider: fakeProvider(), repo, ...BASE_DEPS });

    const res = await request(app)
      .post('/a2a')
      .set('Content-Type', 'application/json')
      .send({ jsonrpc: '2.0', id: 99, method: 'tasks/get', params: { id: 'some-task-id' } });

    expect(res.status).not.toBe(500);
    expect(res.headers['content-type']).toMatch(/json/);
    expect(res.body.jsonrpc).toBe('2.0');
    expect(res.body).toHaveProperty('error');
    expect(res.body.error.code).toBe(-32600); // INVALID_REQUEST = unauthorized
  });
});