import { EventEmitter } from 'node:events';
import { lstat, mkdtemp, mkdir, rm, symlink, writeFile } from 'node:fs/promises';
import { createServer } from 'node:http';
import { tmpdir } from 'node:os';
import { join, resolve } from 'node:path';
import { afterEach, describe, expect, it, vi } from 'vitest';
import { createRuntimeConfig, GATEWAY_AUTH_HEADER } from './runtime-config.js';
import { buildApp } from './app.js';
import { createCanaryGateway, type CanaryGateway } from './canary-gateway.js';
import { createProductionReadiness } from './production-readiness.js';
import { defaultKeychainMetadataCheck } from './production-readiness.js';
import { readCanaryRuntimeOptions } from './canary-runtime.js';
import { installBoundedShutdown } from './shutdown.js';
import { secureTokenEqual } from './app.js';
import { openDatabase } from './infrastructure/database/database.js';
import { migrateDatabase } from './infrastructure/database/migrations.js';

const cleanup: Array<() => Promise<void>> = [];
afterEach(async () => {
  await Promise.all(cleanup.splice(0).map((fn) => fn()));
});
const token = 'runtime-gateway-token-with-at-least-32-bytes';

describe('production runtime foundation', () => {
  it('creates one deeply immutable fixed-listener config and validates before side effects', () => {
    const root = resolve('/tmp/multi-simadmin-data');
    const config = createRuntimeConfig({
      MULTI_SIMADMIN_DATA_ROOT: root,
      MULTI_SIMADMIN_DATABASE_PATH: join(root, 'db.sqlite'),
      MULTI_SIMADMIN_GATEWAY_TOKEN: token,
      MULTI_SIMADMIN_WEB_DIST: root,
      API_HOST: '127.0.0.1',
      API_PORT: '8790',
    });
    expect(config).toEqual({
      api: { host: '127.0.0.1', port: 8790 },
      dataRoot: root,
      databasePath: join(root, 'db.sqlite'),
      gatewayToken: token,
      webDist: root,
    });
    expect(Object.isFrozen(config)).toBe(true);
    expect(Object.isFrozen(config.api)).toBe(true);
    expect(() =>
      createRuntimeConfig({
        MULTI_SIMADMIN_DATA_ROOT: root,
        MULTI_SIMADMIN_DATABASE_PATH: '/tmp/escape.sqlite',
        MULTI_SIMADMIN_GATEWAY_TOKEN: token,
        MULTI_SIMADMIN_WEB_DIST: root,
      }),
    ).toThrow(/data root/i);
    expect(() =>
      createRuntimeConfig({
        MULTI_SIMADMIN_DATA_ROOT: root,
        MULTI_SIMADMIN_DATABASE_PATH: join(root, 'db.sqlite'),
        MULTI_SIMADMIN_GATEWAY_TOKEN: 'weak',
      }),
    ).toThrow(/token/i);
  });

  it('rejects a database path whose existing symlink ancestor escapes before creating a DB', async () => {
    const directory = await mkdtemp(join(tmpdir(), 'runtime-containment-'));
    cleanup.push(() => rm(directory, { recursive: true, force: true }));
    const root = join(directory, 'data');
    const outside = join(directory, 'outside');
    await mkdir(root);
    await mkdir(outside);
    await symlink(outside, join(root, 'escape'));
    const databasePath = join(root, 'escape', 'db.sqlite');

    expect(() =>
      createRuntimeConfig({
        MULTI_SIMADMIN_DATA_ROOT: root,
        MULTI_SIMADMIN_DATABASE_PATH: databasePath,
        MULTI_SIMADMIN_GATEWAY_TOKEN: token,
        MULTI_SIMADMIN_WEB_DIST: root,
      }),
    ).toThrow(/data root|symlink/i);
    await expect(lstat(join(outside, 'db.sqlite'))).rejects.toMatchObject({ code: 'ENOENT' });
  });

  it('reads and validates the canary gateway token from its environment', () => {
    expect(
      readCanaryRuntimeOptions({
        MULTI_SIMADMIN_GATEWAY_TOKEN: token,
        CANARY_DIST_DIR: '/tmp/dist',
        CANARY_PORT: '8789',
        CANARY_UPSTREAM_PORT: '8790',
      }),
    ).toMatchObject({
      gatewayToken: token,
      port: 8789,
      upstreamPort: 8790,
    });
    expect(() => readCanaryRuntimeOptions({ CANARY_DIST_DIR: '/tmp/dist' })).toThrow(/token/i);
    expect(() =>
      readCanaryRuntimeOptions({
        CANARY_DIST_DIR: '/tmp/dist',
        MULTI_SIMADMIN_GATEWAY_TOKEN: 'weak',
      }),
    ).toThrow(/token/i);
  });

  it('always compares fixed-size token digests with timingSafeEqual', () => {
    const compare = vi.fn(() => false);
    expect(secureTokenEqual('x', token, compare)).toBe(false);
    expect(compare).toHaveBeenCalledOnce();
    const [actual, expected] = compare.mock.calls[0] as unknown as [Buffer, Buffer];
    expect(actual).toHaveLength(32);
    expect(expected).toHaveLength(32);
  });

  it('forces pluggable termination when graceful shutdown exceeds its deadline', async () => {
    vi.useFakeTimers();
    const target = new EventEmitter();
    const terminate = vi.fn();
    const stop = installBoundedShutdown(
      target,
      { close: () => new Promise(() => undefined) },
      { timeoutMs: 25, terminate },
    );
    const stopping = stop();
    await vi.advanceTimersByTimeAsync(25);
    await stopping;
    expect(terminate).toHaveBeenCalledOnce();
    vi.useRealTimers();
  });

  it('default Keychain readiness checks only Darwin security executable metadata', async () => {
    const stat = vi.fn(async () => ({ isFile: () => true, mode: 0o100755 }));
    await expect(defaultKeychainMetadataCheck('darwin', stat)).resolves.toBe(true);
    expect(stat).toHaveBeenCalledExactlyOnceWith('/usr/bin/security');
    stat.mockClear();
    await expect(defaultKeychainMetadataCheck('linux', stat)).resolves.toBe(false);
    expect(stat).not.toHaveBeenCalled();
  });

  it('authenticates internal requests without reflecting credentials', async () => {
    const app = buildApp({ gatewayToken: token });
    cleanup.push(() => app.close());
    expect((await app.inject({ url: '/healthz' })).statusCode).toBe(401);
    expect(
      (
        await app.inject({
          url: '/healthz',
          headers: { [GATEWAY_AUTH_HEADER]: 'wrong-but-same-length-xxxxxxxxxxxxxxxxx' },
        })
      ).statusCode,
    ).toBe(401);
    const ok = await app.inject({ url: '/healthz', headers: { [GATEWAY_AUTH_HEADER]: token } });
    expect(ok.statusCode).toBe(200);
    expect(ok.payload).not.toContain(token);
  });

  it('readiness checks a live migrated DB and auth configuration without reading secrets', async () => {
    const directory = await mkdtemp(join(tmpdir(), 'runtime-ready-'));
    cleanup.push(() => rm(directory, { recursive: true, force: true }));
    const db = openDatabase(join(directory, 'db.sqlite'));
    migrateDatabase(db);
    const keychainMetadataCheck = vi.fn(async () => true);
    const readiness = createProductionReadiness({
      db,
      gatewayToken: token,
      keychainMetadataCheck,
      assetsCheck: async () => true,
      recoveryMarkersCheck: async () => 0,
      upstreamGatewayCheck: async () => true,
    });
    expect(await readiness()).toEqual({
      ready: true,
      checks: {
        database: 'ready',
        migrations: 'ready',
        gatewayAuth: 'ready',
        keychain: 'ready',
        pendingCredentials: 'ready',
        assets: 'ready',
        recoveryMarkers: 'ready',
        upstreamGateway: 'ready',
      },
    });
    expect(keychainMetadataCheck).toHaveBeenCalledOnce();
    db.close();
    expect((await readiness()).ready).toBe(false);
  });

  it('gateway replaces forged auth and only falls back for extensionless routes', async () => {
    const directory = await mkdtemp(join(tmpdir(), 'runtime-gateway-'));
    await mkdir(join(directory, 'assets'));
    await writeFile(join(directory, 'index.html'), '<main>SPA</main>');
    cleanup.push(() => rm(directory, { recursive: true, force: true }));
    let seen: string | string[] | undefined;
    const upstream = createServer((request, response) => {
      seen = request.headers[GATEWAY_AUTH_HEADER];
      response.end('ok');
    });
    await new Promise<void>((done) => upstream.listen(0, '127.0.0.1', done));
    cleanup.push(() => new Promise<void>((done) => upstream.close(() => done())));
    const address = upstream.address();
    if (!address || typeof address === 'string') throw new Error('address');
    const gateway: CanaryGateway = createCanaryGateway({
      distDir: directory,
      port: 0,
      upstreamPort: address.port,
      gatewayToken: token,
    });
    await gateway.start();
    cleanup.push(() => gateway.stop());
    await fetch(`${gateway.origin}/healthz`, { headers: { [GATEWAY_AUTH_HEADER]: 'forged' } });
    expect(seen).toBe(token);
    expect((await fetch(`${gateway.origin}/assets/missing.js`)).status).toBe(404);
    expect((await fetch(`${gateway.origin}/missing.css`)).status).toBe(404);
    expect((await fetch(`${gateway.origin}/instances/one`)).status).toBe(200);
  });
});