// Runs the transport, the capture hook, and the popup event path against a REAL veloxd
// — not FakeDaemon. Everything else in this suite is faithful to the documented wire
// protocol, but "faithful" isn't "real"; this is what actually proves it.
//
// Requires VELOXD_BIN (path to a built veloxd) in the environment. Skips itself with a
// clear message otherwise, so `npm test` and CI (no daemon binary lying around) are
// unaffected. Run it like:
//
//   VELOXD_BIN=/path/to/build/dev/bin/veloxd npx vitest run tests/live
//
// Each veloxd instance gets its own scratch XDG_RUNTIME_DIR/XDG_DATA_HOME/
// XDG_CONFIG_HOME/HOME (main.cpp's single-instance lock is keyed to the runtime dir, so
// this can run alongside another developer's or CI's own veloxd on the same machine).
// VELOX_PAIR_AUTO=1 stands in for the GUI's Allow-prompt approver during dev/test
// (rpc/pairing.hpp's EnvAutoApprover) — pairing itself is exercised for real, only the
// human click is stubbed.
import { spawn, type ChildProcessWithoutNullStreams } from 'node:child_process';
import { mkdtempSync, mkdirSync, rmSync } from 'node:fs';
import { readFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import { afterAll, beforeAll, describe, expect, it } from 'vitest';
import { WebSocket as WsClient } from 'ws';

import { RpcError, TransportClosedError } from '../../src/background/transport/types.js';
import { WebSocketTransport, type WebSocketCtor, type WebSocketTransportDeps } from '../../src/background/transport/websocket.js';
import { CaptureHook } from '../../src/background/capture/index.js';
import type { OnHeadersReceivedDetails } from '../../src/background/capture/index.js';
import type { CaptureRules, DownloadSpec, TaskProgressEvent, TaskStateEvent } from '../../src/shared/protocol/index.js';

const VELOXD_BIN = process.env.VELOXD_BIN;
const REPO_ROOT = resolve(dirname(fileURLToPath(import.meta.url)), '../../..');
const TESTSERVER_PY = join(REPO_ROOT, 'tools/testserver/testserver.py');

// A fixed moz-extension origin, used both as session.pair's extensionId and as the WS
// upgrade's Origin header — real Firefox sets the latter itself; ws's client needs it
// spelled out (docs/05 §4: the daemon refuses the upgrade without a moz-extension:// Origin).
const EXTENSION_ID = '11111111-2222-3333-4444-555555555555';
const ORIGIN = `moz-extension://${EXTENSION_ID}`;

class OriginWebSocket extends WsClient {
  constructor(url: string) {
    super(url, { origin: ORIGIN });
  }
}
const CTOR = OriginWebSocket as unknown as WebSocketCtor;

function sleep(ms: number): Promise<void> {
  return new Promise((r) => setTimeout(r, ms));
}

async function waitFor(cond: () => Promise<boolean> | boolean, timeoutMs: number, what: string): Promise<void> {
  const deadline = Date.now() + timeoutMs;
  for (;;) {
    if (await cond()) return;
    if (Date.now() > deadline) throw new Error(`timed out waiting for ${what}`);
    await sleep(50);
  }
}

interface VeloxdInstance {
  proc: ChildProcessWithoutNullStreams;
  scratch: string;
  wsPort: number;
  /** True once the process has actually exited, by signal or otherwise. Node only sets
   *  `proc.exitCode` for a normal exit — a signal-killed process reports its death via
   *  `signalCode` and an `exit` event instead, never a non-null `exitCode`. */
  hasExited(): boolean;
  kill(signal?: NodeJS.Signals): void;
}

async function startVeloxd(bin: string): Promise<VeloxdInstance> {
  const scratch = mkdtempSync(join(tmpdir(), 'velox-live-'));
  const runtime = join(scratch, 'rt');
  const data = join(scratch, 'data');
  const config = join(scratch, 'cfg');
  const home = join(scratch, 'home');
  mkdirSync(runtime, { mode: 0o700 });
  mkdirSync(data, { recursive: true });
  mkdirSync(config, { recursive: true });
  mkdirSync(join(home, 'Downloads'), { recursive: true });

  const proc = spawn(bin, [], {
    env: {
      ...process.env,
      VELOX_PAIR_AUTO: '1',
      XDG_RUNTIME_DIR: runtime,
      XDG_DATA_HOME: data,
      XDG_CONFIG_HOME: config,
      HOME: home,
    },
  });
  let exited = false;
  proc.on('exit', () => {
    exited = true;
  });
  let stderr = '';
  proc.stderr.on('data', (d) => {
    stderr += String(d);
  });

  const portFile = join(runtime, 'velox', 'ws.port');
  try {
    await waitFor(async () => {
      if (exited) throw new Error(`veloxd exited early (code ${proc.exitCode}, signal ${proc.signalCode}): ${stderr}`);
      try {
        await readFile(portFile);
        return true;
      } catch {
        return false;
      }
    }, 10_000, 'veloxd to write ws.port');
  } catch (e) {
    proc.kill('SIGKILL');
    rmSync(scratch, { recursive: true, force: true });
    throw e;
  }
  const wsPort = Number((await readFile(portFile, 'utf8')).trim());

  return {
    proc,
    scratch,
    wsPort,
    hasExited: () => exited,
    kill(signal: NodeJS.Signals = 'SIGTERM') {
      proc.kill(signal);
    },
  };
}

interface TestServerInstance {
  proc: ChildProcessWithoutNullStreams;
  baseUrl: string;
}

async function startTestServer(): Promise<TestServerInstance> {
  const proc = spawn('python3', [TESTSERVER_PY, '--port', '0'], {});
  let stdout = '';
  let port: number | null = null;
  proc.stdout.on('data', (d) => {
    stdout += String(d);
    const m = /^(\d+)\s*$/m.exec(stdout);
    if (m) port = Number(m[1]);
  });
  await waitFor(() => port !== null, 5_000, 'testserver to print its port');
  const baseUrl = `http://127.0.0.1:${port}`;
  await waitFor(async () => {
    try {
      const res = await fetch(`${baseUrl}/__health`);
      return res.ok;
    } catch {
      return false;
    }
  }, 5_000, 'testserver /__health');
  return { proc, baseUrl };
}

function memDeps(init: { token?: string | null } = {}): { deps: WebSocketTransportDeps; store: { token: string | null } } {
  const store = { token: init.token ?? null };
  return {
    store,
    deps: {
      getToken: async () => store.token,
      setToken: async (t) => {
        store.token = t;
      },
      getCachedPort: async () => null,
      setCachedPort: async () => undefined,
      extensionId: EXTENSION_ID,
    },
  };
}

function makeTransport(port: number, deps: WebSocketTransportDeps, extra: Partial<WebSocketTransportDeps> = {}): WebSocketTransport {
  return new WebSocketTransport({
    ...deps,
    ...extra,
    webSocketCtor: CTOR,
    portRange: { start: port, end: port },
    openTimeoutMs: 2000,
  });
}

const maybeDescribe = VELOXD_BIN ? describe : describe.skip;

if (!VELOXD_BIN) {
  console.warn('tests/live/real-veloxd.test.ts: VELOXD_BIN not set — skipping (see file header).');
}

maybeDescribe('WebSocketTransport against a real veloxd', () => {
  let daemon: VeloxdInstance;
  let testserver: TestServerInstance;
  // The mid-test fail-open case kills `daemon` and a later test starts a replacement —
  // every scratch dir that ever existed gets cleaned up here, not just the last one.
  const allScratchDirs: string[] = [];

  async function freshVeloxd(): Promise<VeloxdInstance> {
    const d = await startVeloxd(VELOXD_BIN!);
    allScratchDirs.push(d.scratch);
    return d;
  }

  beforeAll(async () => {
    daemon = await freshVeloxd();
    testserver = await startTestServer();
  }, 20_000);

  afterAll(() => {
    daemon?.kill('SIGKILL');
    testserver?.proc.kill('SIGKILL');
    for (const dir of allScratchDirs) rmSync(dir, { recursive: true, force: true });
  });

  it('session.hello without a token surfaces NotPaired / needsPairing', async () => {
    const { deps } = memDeps();
    const t = makeTransport(daemon.wsPort, deps, { autoPair: false });
    await expect(t.connect()).rejects.toBeInstanceOf(RpcError);
    expect(t.status.needsPairing).toBe(true);
    t.disconnect();
  });

  let pairedToken: string;

  it('pairs (VELOX_PAIR_AUTO=1 stands in for the human Allow click) and hellos with the issued token', async () => {
    const { deps, store } = memDeps();
    const t = makeTransport(daemon.wsPort, deps); // autoPair: true (default)
    await t.connect();
    expect(t.state).toBe('connected');
    expect(t.status.daemonVersion).toBeTruthy();
    expect(store.token).toBeTruthy();
    pairedToken = store.token!;
    t.disconnect();
  });

  it('the pairing token survives a reconnect: a fresh transport reuses it with no fresh pairing', async () => {
    const { deps } = memDeps({ token: pairedToken });
    // autoPair: false — if this succeeds at all, it can only be because the stored
    // token from the previous test was accepted outright, not because this transport
    // silently re-paired.
    const t = makeTransport(daemon.wsPort, deps, { autoPair: false });
    await t.connect();
    expect(t.state).toBe('connected');
    t.disconnect();
  });

  it('a wrong token is rejected, and repeating it rate-limits the next pairing attempt', async () => {
    // Five failed session.hello attempts from this origin (ws_server.cpp records a
    // rate-limiter failure on every not-paired hello, not only on a failed session.pair)
    // exhausts the window; the sixth thing this origin tries — a pairing attempt — gets
    // RateLimited rather than a fresh token.
    for (let i = 0; i < 5; i += 1) {
      const { deps } = memDeps({ token: 'not-the-real-token' });
      const t = makeTransport(daemon.wsPort, deps, { autoPair: false });
      await expect(t.connect()).rejects.toBeInstanceOf(RpcError);
      t.disconnect();
    }

    const { deps } = memDeps(); // no token -> autoPair kicks in -> session.pair
    const t = makeTransport(daemon.wsPort, deps);
    await expect(t.connect()).rejects.toBeInstanceOf(RpcError);
    expect(t.status.needsPairing).toBe(true);
    expect(t.status.retryAfterSec).toBeGreaterThan(0);
    t.disconnect();
  });

  it('download.add creates a real task the engine picks up', async () => {
    const { deps } = memDeps({ token: pairedToken });
    const t = makeTransport(daemon.wsPort, deps, { autoPair: false });
    await t.connect();
    try {
      const spec: DownloadSpec = { url: `${testserver.baseUrl}/plain/file/64K`, filename: 'plain-download.bin' };
      const added = await t.call('download.add', spec);
      expect(added.taskId).toBeTruthy();

      await waitFor(async () => {
        const detail = await t.call('download.get', { taskId: added.taskId });
        const state = detail.summary.state;
        return state === 'complete' || state === 'downloading' || state === 'verifying';
      }, 10_000, 'the task to leave the queued state');
    } finally {
      t.disconnect();
    }
  }, 15_000);

  it('capture.offer end to end: the real capture path takes a monitored download, ignores its own duplicate, and fails open when the daemon dies mid-offer', async () => {
    const { deps } = memDeps({ token: pairedToken });
    const t = makeTransport(daemon.wsPort, deps, { autoPair: false });
    await t.connect();

    const rules: CaptureRules = await t.call('capture.getRules', {});
    expect(rules.monitoredExtensions).toContain('zip'); // seeded default (0001_initial.sql)

    const hook = new CaptureHook({
      offer: (params, opts) => t.call('capture.offer', params, opts),
      stash: { take: () => undefined, peek: () => undefined },
      getCookies: async () => [],
      getRules: () => rules,
      origin: ORIGIN,
    });

    // A throttled URL so the task the first offer creates is still active (not yet
    // complete) when the dedupe offer for the same URL follows immediately after.
    const url = `${testserver.baseUrl}/throttled/file/512K`;
    const details: OnHeadersReceivedDetails = {
      requestId: 'live-1',
      url,
      method: 'GET',
      type: 'other',
      statusCode: 200,
      tabId: 1,
      responseHeaders: [{ name: 'content-disposition', value: 'attachment; filename="live-capture.zip"' }],
    };

    const first = await hook.handle(details);
    expect(first).toEqual({ cancel: true }); // the daemon took it — Firefox never starts its own download

    const list = await t.call('download.list', { filter: { query: 'live-capture' } });
    expect(list.items.length).toBeGreaterThan(0);
    const task = list.items[0]!;
    expect(task.categoryId).toBe('programs'); // "zip" routes to the built-in Programs category
    expect(task.saveDir).toContain('Downloads/Programs');

    // Same URL again, task still active: the daemon's own dedupe (has_active_duplicate)
    // says Ignore, so the hook proceeds instead of cancelling a second time.
    const dup = await hook.handle({ ...details, requestId: 'live-2' });
    expect(dup).toEqual({});

    // Now kill the daemon mid-offer and prove fail-open holds against the REAL binary,
    // not just FakeDaemon: the hook must still resolve to {} (Firefox downloads
    // normally) well inside its own 750 ms budget.
    daemon.kill('SIGKILL');
    await waitFor(() => daemon.hasExited(), 5_000, 'veloxd to actually die');

    const started = Date.now();
    const afterDeath = await hook.handle({ ...details, requestId: 'live-3', url: `${url}?after-death=1` });
    const elapsedMs = Date.now() - started;
    expect(afterDeath).toEqual({}); // fail open — never {cancel: true} with a dead daemon
    expect(elapsedMs).toBeLessThan(900); // budget is 750ms; the hook's own timer bounds this

    t.disconnect();
  }, 20_000);

  it('event.task.progress reaches a subscribed client (the popup\'s own path)', async () => {
    if (daemon.hasExited()) {
      // The previous test kills the daemon on purpose to prove fail-open; start a fresh
      // one so this test still exercises the real event path end to end.
      daemon = await freshVeloxd();
    }
    const { deps } = memDeps();
    const t = makeTransport(daemon.wsPort, deps); // fresh daemon instance -> fresh pairing
    await t.connect();
    try {
      await t.call('session.subscribe', {
        events: ['event.task.added', 'event.task.state', 'event.task.progress'],
      });

      const progressEvents: TaskProgressEvent[] = [];
      const stateEvents: TaskStateEvent[] = [];
      t.on('event.task.progress', (p) => progressEvents.push(p as TaskProgressEvent));
      t.on('event.task.state', (p) => stateEvents.push(p as TaskStateEvent));

      const spec: DownloadSpec = { url: `${testserver.baseUrl}/throttled/file/1M`, filename: 'progress-check.bin' };
      const added = await t.call('download.add', spec);

      // /throttled defaults to 1 MiB/s, so a 1 MiB file takes ~1s — long enough that at
      // least one 4 Hz progress tick (event.task.progress's documented cap) lands before
      // it completes, exactly the path popup/store.ts consumes in the real extension.
      await waitFor(
        () => progressEvents.some((e) => e.tasks.some((row) => row.taskId === added.taskId)),
        8_000,
        'a live event.task.progress tick for our task',
      );
      expect(stateEvents.some((e) => e.taskId === added.taskId)).toBe(true);
    } finally {
      t.disconnect();
    }
  }, 15_000);

  it('fail-open also holds through the transport itself: a call against a dead socket rejects, never hangs past its deadline', async () => {
    const { deps } = memDeps();
    const t = makeTransport(daemon.wsPort, deps);
    await t.connect();
    t.disconnect(); // closes the socket without telling the daemon anything is wrong
    await expect(t.call('capture.offer', { url: 'https://example.com/x.zip', method: 'GET', tabUrl: '' }, { timeoutMs: 200 })).rejects.toBeInstanceOf(
      TransportClosedError,
    );
  });
});