import { EventEmitter } from 'node:events';
import http from 'node:http';
import fs from 'node:fs';
import path from 'node:path';
import { describe, expect, it } from 'vitest';
import { WebSocket } from 'ws';

import { createTerminalRuntime } from './runtime.js';
import { createTerminalWsControlFrame, readTerminalWsControlFrame } from './terminal-ws-protocol.js';

function createResponse() {
  return {
    statusCode: 200,
    body: null,
    status(code) {
      this.statusCode = code;
      return this;
    },
    json(payload) {
      this.body = payload;
      return this;
    },
  };
}

async function openTerminalSocket(socketUrl) {
  const socket = new WebSocket(socketUrl);
  const messages = [];
  socket.on('message', (raw) => messages.push(readTerminalWsControlFrame(raw)));
  await new Promise((resolve, reject) => {
    socket.once('open', resolve);
    socket.once('error', reject);
  });
  const next = async (type, sessionId) => {
    for (let attempt = 0; attempt < 100; attempt += 1) {
      const index = messages.findIndex((message) => message?.t === type && (!sessionId || message.s === sessionId));
      if (index >= 0) return messages.splice(index, 1)[0];
      await new Promise((resolve) => setTimeout(resolve, 2));
    }
    throw new Error(`Timed out waiting for ${type}`);
  };
  await next('hello');
  return { socket, next, messages };
}

function deferred() {
  let resolve;
  let reject;
  const promise = new Promise((res, rej) => {
    resolve = res;
    reject = rej;
  });
  return { promise, resolve, reject };
}

function createHttpTestApp() {
  const routes = { GET: [], POST: [], DELETE: [] };
  const app = (req, res) => {
    const methodRoutes = routes[req.method] ?? [];
    const url = new URL(req.url, 'http://127.0.0.1');
    const chunks = [];
    req.on('data', (chunk) => chunks.push(chunk));
    req.on('end', async () => {
      const bodyText = Buffer.concat(chunks).toString('utf8');
      const route = methodRoutes.find(({ pattern }) => pattern.test(url.pathname));
      if (!route) {
        res.statusCode = 404;
        res.end('Not found');
        return;
      }
      const match = route.pattern.exec(url.pathname);
      const response = {
        statusCode: 200,
        headers: { 'content-type': 'application/json' },
        body: null,
        status(code) {
          this.statusCode = code;
          return this;
        },
        json(payload) {
          this.body = payload;
          return this;
        },
      };
      try {
        await route.handler({
          method: req.method,
          url: req.url,
          query: Object.fromEntries(url.searchParams.entries()),
          params: route.params.reduce((acc, name, index) => ({ ...acc, [name]: match[index + 1] }), {}),
          body: bodyText ? JSON.parse(bodyText) : {},
        }, response);
      } catch (error) {
        response.status(500).json({ error: error?.message || 'Route failed' });
      }
      res.writeHead(response.statusCode, response.headers);
      res.end(JSON.stringify(response.body));
    });
  };
  const register = (method, route, handler) => {
    const params = [];
    const escaped = route.replace(/:([^/]+)/g, (_, name) => {
      params.push(name);
      return '([^/]+)';
    });
    routes[method].push({
      pattern: new RegExp(`^${escaped}$`),
      params,
      handler,
    });
  };
  app.get = (route, handler) => register('GET', route, handler);
  app.post = (route, handler) => register('POST', route, handler);
  app.delete = (route, handler) => register('DELETE', route, handler);
  return app;
}

function createRuntime(server, overrides = {}) {
  const app = overrides.app ?? {
    post() {},
    get() {},
    delete() {},
  };

  return createTerminalRuntime({
    app,
    server,
    express: { text: () => (_req, _res, next) => next?.() },
    fs,
    path,
    uiAuthController: null,
    buildAugmentedPath: () => process.env.PATH || '',
    searchPathFor: () => null,
    isExecutable: () => false,
    isRequestOriginAllowed: async () => true,
    rejectWebSocketUpgrade() {},
    TERMINAL_INPUT_WS_HEARTBEAT_INTERVAL_MS: 30_000,
    TERMINAL_INPUT_WS_REBIND_WINDOW_MS: 1_000,
    TERMINAL_INPUT_WS_MAX_REBINDS_PER_WINDOW: 3,
    ...overrides,
  });
}

describe('terminal runtime', () => {
  const createHarness = (overrides = {}) => {
    const routes = { get: new Map(), post: new Map(), delete: new Map() };
    const processes = [];
    const spawnDeferred = overrides.spawnDeferred ?? null;
    const app = {
      post(route, handler) { routes.post.set(route, handler); },
      get(route, handler) { routes.get.set(route, handler); },
      delete(route, handler) { routes.delete.set(route, handler); },
    };
    const loadPtyProvider = async () => ({
      backend: 'fake-pty',
      spawn: async (shell, args, options) => {
        await spawnDeferred?.promise;
        const dataHandlers = new Set();
        const exitHandlers = new Set();
        const process = {
          pid: 123 + processes.length,
          shell,
          args,
          options,
          writes: [],
          resizes: [],
          killed: false,
          kills: [],
          write(data) { this.writes.push(data); },
          resize(cols, rows) { this.resizes.push([cols, rows]); },
          kill(signal) { this.killed = true; this.kills.push(signal ?? 'SIGTERM'); },
          onData(handler) { dataHandlers.add(handler); return { dispose: () => dataHandlers.delete(handler) }; },
          onExit(handler) { exitHandlers.add(handler); return { dispose: () => exitHandlers.delete(handler) }; },
          emitData(data) { for (const handler of dataHandlers) handler(data); },
          emitExit(exitCode = 0, signal = 0) { for (const handler of exitHandlers) handler({ exitCode, signal }); },
        };
        processes.push(process);
        return process;
      },
    });
    const server = new EventEmitter();
    const runtime = createRuntime(server, {
      app,
      loadPtyProvider,
      terminalTerminationGraceMs: 10,
      fs: { promises: { stat: async () => ({ isDirectory: () => true }) } },
      searchPathFor: () => '/bin/sh',
      isExecutable: () => true,
      ...overrides,
    });
    return { routes, processes, runtime };
  };

  it('replaces only exited action runs and keeps session capacity available across reruns', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      await create({ body: { sessionId: 'interactive', cwd: '/repo' } }, createResponse());
      for (let index = 0; index < 25; index += 1) {
        const id = `execution-${index}`;
        const response = createResponse();
        await create({ body: { sessionId: id, cwd: '/repo', mode: 'command', command: 'echo hello', purpose: { type: 'project-action', actionId: 'build', executionId: id } } }, response);
        expect(response.statusCode).toBe(200);
        const listed = createResponse();
        harness.routes.get.get('/api/terminal/sessions')({ query: { cwd: '/repo' } }, listed);
        expect(listed.body.sessions.map(session => session.sessionId)).toEqual(['interactive', id]);
        expect(harness.processes[0].killed).toBe(false);
        harness.processes.at(-1).emitExit(0);
      }
    } finally { await harness.runtime.shutdown(); }
  });

  it('retains completed output when the replacement command fails to start', async () => {
    let available = true;
    const harness = createHarness({ fs: { promises: { stat: async () => ({ isDirectory: () => available }) } } });
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const options = { cwd: '/repo', mode: 'command', command: 'echo hello', purpose: { type: 'project-action', actionId: 'build', executionId: 'old' } };
      await create({ body: { ...options, sessionId: 'old' } }, createResponse());
      harness.processes[0].emitData('old output');
      harness.processes[0].emitExit(0);
      available = false;
      const response = createResponse();
      await create({ body: { ...options, sessionId: 'new', purpose: { ...options.purpose, executionId: 'new' } } }, response);
      expect(response.statusCode).toBe(400);
      const listed = createResponse();
      harness.routes.get.get('/api/terminal/sessions')({ query: { cwd: '/repo' } }, listed);
      expect(listed.body.sessions.map(session => session.sessionId)).toEqual(['old']);
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects regular files as terminal working directories', async () => {
    const postRoutes = new Map();
    const app = {
      post(route, ...handlers) {
        postRoutes.set(route, handlers.at(-1));
      },
      get() {},
      delete() {},
    };
    const server = new EventEmitter();
    const runtime = createRuntime(server, {
      app,
      fs: {
        promises: {
          stat: async () => ({ isDirectory: () => false }),
        },
      },
      uiAuthController: { enabled: false },
      buildAugmentedPath: () => '',
      TERMINAL_INPUT_WS_HEARTBEAT_INTERVAL_MS: 1000,
      TERMINAL_INPUT_WS_REBIND_WINDOW_MS: 1000,
    });

    try {
      const createRoute = postRoutes.get('/api/terminal/create');
      const res = createResponse();

      await createRoute({ body: { cwd: '/tmp/not-a-directory' } }, res);

      expect(res.statusCode).toBe(400);
      expect(res.body).toEqual({ error: 'Invalid working directory' });
    } finally {
      await runtime.shutdown();
    }
  });

  it('names a missing working directory so the client can recover the session', async () => {
    let cwdMissing = false;
    const harness = createHarness({
      fs: {
        promises: {
          stat: async () => {
            if (cwdMissing) throw Object.assign(new Error('ENOENT: no such file or directory'), { code: 'ENOENT' });
            return { isDirectory: () => true };
          },
        },
      },
    });
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const created = createResponse();
      await create({ body: { sessionId: 'worktree-terminal', cwd: '/repo/.worktrees/feature' } }, created);
      expect(created.statusCode).toBe(200);

      cwdMissing = true;
      const recreated = createResponse();
      await create({ body: { sessionId: 'worktree-terminal-2', cwd: '/repo/.worktrees/feature' } }, recreated);
      expect(recreated.statusCode).toBe(400);
      expect(recreated.body).toEqual({ error: 'Invalid working directory', code: 'TERMINAL_CWD_MISSING' });

      const restarted = createResponse();
      await harness.routes.post.get('/api/terminal/:sessionId/restart')(
        { params: { sessionId: 'worktree-terminal' }, body: { cwd: '/repo/.worktrees/feature' } },
        restarted,
      );
      expect(restarted.statusCode).toBe(400);
      expect(restarted.body).toEqual({ error: 'Invalid working directory', code: 'TERMINAL_CWD_MISSING' });
    } finally { await harness.runtime.shutdown(); }
  });

  it('removes its websocket upgrade listener on shutdown', async () => {
    const server = new EventEmitter();
    const runtime = createRuntime(server);

    expect(server.listenerCount('upgrade')).toBe(1);

    await runtime.shutdown();

    expect(server.listenerCount('upgrade')).toBe(0);
  });

  it('creates client-identified sessions and forwards bounded resize operations', async () => {
    const harness = createHarness();
    try {
      const response = createResponse();
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-1', cwd: '/repo', cols: 120, rows: 40, themeMode: 'light', terminalBackground: '#faf8f0', terminalForeground: '#1b1b1b' } }, response);
      expect(response.body).toEqual({ sessionId: 'term-1', cols: 120, rows: 40, status: 'running', mode: 'interactive', purpose: { type: 'terminal' } });
      expect(harness.processes[0].options.cwd).toBe('/repo');
      expect(harness.processes[0].options.env.COLORFGBG).toBe('0;15');
      expect(harness.processes[0].options.env).not.toHaveProperty('NODE_CHANNEL_FD');
      expect(harness.processes[0].options.env).not.toHaveProperty('ARGV0');
      expect(harness.processes[0].options.env).not.toHaveProperty('ELECTRON_RUN_AS_NODE');
      if (process.platform !== 'win32') {
        expect(harness.processes[0].shell).toMatch(/\/env$/);
        expect(harness.processes[0].args.slice(0, 5)).toEqual(['-u', 'ARGV0', '-u', 'NODE_CHANNEL_FD', expect.any(String)]);
      }
      harness.processes[0].emitData('\u001b[?2031h\u001b]10;?\u0007\u001b]11;?\u0007\u001b[0c');
      expect(harness.processes[0].writes).toEqual(['\u001b]10;rgb:1b1b/1b1b/1b1b\u001b\\', '\u001b]11;rgb:fafa/f8f8/f0f0\u001b\\', '\u001b[?1;2c']);

      const appearance = createResponse();
      harness.routes.post.get('/api/terminal/:sessionId/appearance')({ params: { sessionId: 'term-1' }, body: { themeMode: 'dark' } }, appearance);
      expect(appearance.body).toEqual({ success: true });
      expect(harness.processes[0].writes.at(-1)).toBe('\u001b[?997;1n');

      const resize = createResponse();
      harness.routes.post.get('/api/terminal/:sessionId/resize')({ params: { sessionId: 'term-1' }, body: { cols: 200, rows: 60 } }, resize);
      expect(resize.statusCode).toBe(200);
      expect(harness.processes[0].resizes).toEqual([[200, 60]]);

      const invalid = createResponse();
      harness.routes.post.get('/api/terminal/:sessionId/resize')({ params: { sessionId: 'term-1' }, body: { cols: 1001, rows: 60 } }, invalid);
      expect(invalid.statusCode).toBe(400);
    } finally { await harness.runtime.shutdown(); }
  });

  it('lists sessions scoped to a working directory and refreshes activity via touch', async () => {
    const harness = createHarness();
    try {
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-a', cwd: '/repo' } }, createResponse());
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-b', cwd: '/other' } }, createResponse());

      const all = createResponse();
      harness.routes.get.get('/api/terminal/sessions')({ query: {} }, all);
      expect(all.body.sessions.map((s) => s.sessionId).sort()).toEqual(['term-a', 'term-b']);

      const scoped = createResponse();
      harness.routes.get.get('/api/terminal/sessions')({ query: { cwd: '/repo' } }, scoped);
      expect(scoped.body.sessions).toEqual([
        { sessionId: 'term-a', cwd: '/repo', status: 'running', createdAt: expect.any(Number), mode: 'interactive', purpose: { type: 'terminal' } },
      ]);

      const touch = createResponse();
      harness.routes.post.get('/api/terminal/touch')({ body: { sessionIds: ['term-a', 'missing', 42] } }, touch);
      expect(touch.body).toEqual({ touched: 1 });

      const malformed = createResponse();
      harness.routes.post.get('/api/terminal/touch')({ body: {} }, malformed);
      expect(malformed.body).toEqual({ touched: 0 });
    } finally { await harness.runtime.shutdown(); }
  });

  it('strips AppImage ARGV0 from PTY child environments', async () => {
    const previousArgv0 = process.env.ARGV0;
    process.env.ARGV0 = '/path/to/OpenChamber/OpenChamber-1.17.2-linux-x86_64.AppImage';
    const harness = createHarness();
    try {
      const response = createResponse();
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-argv0', cwd: '/repo', cols: 80, rows: 24 } }, response);
      expect(response.statusCode).toBe(200);
      expect(harness.processes[0].options.env).not.toHaveProperty('ARGV0');
      if (process.platform !== 'win32') {
        expect(harness.processes[0].shell).toMatch(/\/env$/);
        expect(harness.processes[0].args[0]).toBe('-u');
        expect(harness.processes[0].args[1]).toBe('ARGV0');
      }
    } finally {
      if (previousArgv0 === undefined) delete process.env.ARGV0;
      else process.env.ARGV0 = previousArgv0;
      await harness.runtime.shutdown();
    }
  });

  it('lists available shells and uses the selected shell for create and restart', async () => {
    const executables = new Set(['/bin/zsh', '/bin/bash', '/bin/sh']);
    const harness = createHarness({
      fs: {
        promises: {
          stat: async () => ({ isDirectory: () => true }),
          readFile: async () => '/bin/zsh\n/bin/bash\n/bin/false\n',
        },
      },
      searchPathFor: (name) => executables.has(`/bin/${name}`) ? `/bin/${name}` : null,
      isExecutable: (candidate) => executables.has(candidate),
    });
    try {
      const listed = createResponse();
      await harness.routes.get.get('/api/terminal/shells')({}, listed);
      expect(listed.body).toEqual(expect.arrayContaining([
        { id: 'auto', name: 'Auto', supportsLogin: true },
        { id: 'zsh', name: 'zsh', supportsLogin: true },
        { id: 'bash', name: 'bash', supportsLogin: true },
        { id: 'sh', name: 'sh', supportsLogin: false },
      ]));

      const created = createResponse();
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-shell', cwd: '/repo', shell: 'zsh', loginShell: true } }, created);
      expect(created.statusCode).toBe(200);
      if (process.platform !== 'win32') {
        expect(harness.processes[0].shell).toMatch(/\/env$/);
        expect(harness.processes[0].args).toEqual(['-u', 'ARGV0', '-u', 'NODE_CHANNEL_FD', '/bin/zsh', '-l']);
      } else {
        expect(harness.processes[0].shell).toBe('/bin/zsh');
        expect(harness.processes[0].args).toEqual(['-l']);
      }

      const restarted = createResponse();
      await harness.routes.post.get('/api/terminal/:sessionId/restart')({ params: { sessionId: 'term-shell' }, body: { shell: 'bash', loginShell: true } }, restarted);
      expect(restarted.statusCode).toBe(200);
      if (process.platform !== 'win32') {
        expect(harness.processes[1].shell).toMatch(/\/env$/);
        expect(harness.processes[1].args).toEqual(['-u', 'ARGV0', '-u', 'NODE_CHANNEL_FD', '/bin/bash', '-l']);
      } else {
        expect(harness.processes[1].shell).toBe('/bin/bash');
        expect(harness.processes[1].args).toEqual(['-l']);
      }
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects invalid and unavailable explicit shells', async () => {
    const harness = createHarness({
      fs: {
        promises: {
          stat: async () => ({ isDirectory: () => true }),
          readFile: async () => '/bin/sh\n',
        },
      },
      searchPathFor: (name) => name === 'sh' ? '/bin/sh' : null,
      isExecutable: (candidate) => candidate === '/bin/sh',
    });
    try {
      for (const [shell, error] of [
        ['zsh -c whoami', 'Invalid terminal shell'],
        ['fish', 'Terminal shell "fish" is not available'],
      ]) {
        const response = createResponse();
        await harness.routes.post.get('/api/terminal/create')({ body: { cwd: '/repo', shell } }, response);
        expect(response.statusCode).toBe(400);
        expect(response.body).toEqual({ error });
      }
      expect(harness.processes).toHaveLength(0);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects invalid and unsupported login modes', async () => {
    const harness = createHarness({
      fs: {
        promises: {
          stat: async () => ({ isDirectory: () => true }),
          readFile: async () => '/bin/sh\n',
        },
      },
      searchPathFor: (name) => name === 'sh' ? '/bin/sh' : null,
      isExecutable: (candidate) => candidate === '/bin/sh',
    });
    try {
      for (const [loginShell, error] of [
        ['true', 'Invalid terminal login mode'],
        [true, 'Terminal shell "sh" does not support login mode'],
      ]) {
        const response = createResponse();
        await harness.routes.post.get('/api/terminal/create')({ body: { cwd: '/repo', shell: 'sh', loginShell } }, response);
        expect(response.statusCode).toBe(400);
        expect(response.body).toEqual({ error });
      }
      expect(harness.processes).toHaveLength(0);
    } finally { await harness.runtime.shutdown(); }
  });

  it('preserves the running process when a replacement shell is unavailable', async () => {
    const harness = createHarness({
      fs: {
        promises: {
          stat: async () => ({ isDirectory: () => true }),
          readFile: async () => '/bin/sh\n',
        },
      },
      searchPathFor: (name) => name === 'sh' ? '/bin/sh' : null,
      isExecutable: (candidate) => candidate === '/bin/sh',
    });
    try {
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-1', cwd: '/repo', shell: 'sh' } }, createResponse());
      const restarted = createResponse();

      await harness.routes.post.get('/api/terminal/:sessionId/restart')({ params: { sessionId: 'term-1' }, body: { shell: 'fish' } }, restarted);

      expect(restarted.statusCode).toBe(400);
      expect(restarted.body.error).toBe('Terminal shell "fish" is not available');
      expect(harness.processes).toHaveLength(1);
      expect(harness.processes[0].killed).toBe(false);
    } finally { await harness.runtime.shutdown(); }
  });

  it('deduplicates concurrent creates and rejects cross-directory id reuse', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const first = createResponse();
      const second = createResponse();
      await Promise.all([
        create({ body: { sessionId: 'term-shared', cwd: '/repo' } }, first),
        create({ body: { sessionId: 'term-shared', cwd: '/repo' } }, second),
      ]);
      expect(harness.processes).toHaveLength(1);
      expect(first.body.sessionId).toBe('term-shared');
      expect(second.body.sessionId).toBe('term-shared');

      const conflicting = createResponse();
      await create({ body: { sessionId: 'term-shared', cwd: '/other' } }, conflicting);
      expect(conflicting.statusCode).toBe(400);
      expect(conflicting.body.error).toBe('Terminal session belongs to a different working directory');
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects concurrent creates with conflicting shell preferences', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const first = createResponse();
      const conflicting = createResponse();
      await Promise.all([
        create({ body: { sessionId: 'term-shared', cwd: '/repo', shell: 'auto' } }, first),
        create({ body: { sessionId: 'term-shared', cwd: '/repo', shell: 'zsh' } }, conflicting),
      ]);

      expect(first.statusCode).toBe(200);
      expect(conflicting.statusCode).toBe(400);
      expect(conflicting.body.error).toBe('Terminal session is already being created with a different shell');
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects concurrent creates with conflicting login modes', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const first = createResponse();
      const conflicting = createResponse();
      await Promise.all([
        create({ body: { sessionId: 'term-shared', cwd: '/repo', shell: 'auto', loginShell: false } }, first),
        create({ body: { sessionId: 'term-shared', cwd: '/repo', shell: 'auto', loginShell: true } }, conflicting),
      ]);

      expect(first.statusCode).toBe(200);
      expect(conflicting.statusCode).toBe(400);
      expect(conflicting.body.error).toBe('Terminal session is already being created with a different login mode');
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('restarts atomically with the same identity and closes the previous process', async () => {
    const harness = createHarness();
    try {
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-1', cwd: '/repo' } }, createResponse());
      const restarted = createResponse();
      await harness.routes.post.get('/api/terminal/:sessionId/restart')({ params: { sessionId: 'term-1' }, body: { cwd: '/other', cols: 90, rows: 30 } }, restarted);
      expect(restarted.body).toEqual({ sessionId: 'term-1', cols: 90, rows: 30, status: 'running' });
      expect(harness.processes).toHaveLength(2);
      expect(harness.processes[0].killed).toBe(true);
      expect(harness.processes[1].options.cwd).toBe('/other');
    } finally { await harness.runtime.shutdown(); }
  });

  it('serializes concurrent restarts without orphaning replacement processes', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const restart = harness.routes.post.get('/api/terminal/:sessionId/restart');
      await create({ body: { sessionId: 'term-1', cwd: '/repo' } }, createResponse());
      const first = createResponse();
      const second = createResponse();

      await Promise.all([
        restart({ params: { sessionId: 'term-1' }, body: { cwd: '/first' } }, first),
        restart({ params: { sessionId: 'term-1' }, body: { cwd: '/second' } }, second),
      ]);

      expect(first.statusCode).toBe(200);
      expect(second.statusCode).toBe(200);
      expect(harness.processes).toHaveLength(3);
      expect(harness.processes[0].killed).toBe(true);
      expect(harness.processes[1].killed).toBe(true);
      expect(harness.processes[2].killed).toBe(false);
      expect(harness.processes[2].options.cwd).toBe('/second');
    } finally { await harness.runtime.shutdown(); }
  });

  it('retains exited sessions until explicit close', async () => {
    const harness = createHarness();
    try {
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-1', cwd: '/repo' } }, createResponse());
      harness.processes[0].emitData('last output');
      harness.processes[0].emitExit(7, 0);
      const resize = createResponse();
      harness.routes.post.get('/api/terminal/:sessionId/resize')({ params: { sessionId: 'term-1' }, body: { cols: 80, rows: 24 } }, resize);
      expect(resize.statusCode).toBe(200);
      const closed = createResponse();
      await harness.routes.delete.get('/api/terminal/:sessionId')({ params: { sessionId: 'term-1' } }, closed);
      expect(closed.body).toEqual({ success: true });
    } finally { await harness.runtime.shutdown(); }
  });

  it('escalates close to SIGKILL when a running process ignores SIGTERM', async () => {
    const harness = createHarness();
    try {
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-1', cwd: '/repo' } }, createResponse());
      await harness.routes.delete.get('/api/terminal/:sessionId')({ params: { sessionId: 'term-1' } }, createResponse());
      expect(harness.processes[0].kills).toEqual(['SIGTERM', 'SIGKILL']);
    } finally { await harness.runtime.shutdown(); }
  });

  it('runs snapshot-first attach, scoped I/O, replay, reconnect, and close over a real websocket', async () => {
    const app = createHttpTestApp();
    const server = http.createServer(app);
    const processes = [];
    const loadPtyProvider = async () => ({
      backend: 'fake-pty',
      spawn: () => {
        const data = new Set();
        const exits = new Set();
        const process = {
          pid: 99123,
          killed: false,
          writes: [],
          write(value) { this.writes.push(value); }, resize() {}, kill() { this.killed = true; },
          onData(handler) { data.add(handler); return { dispose: () => data.delete(handler) }; },
          onExit(handler) { exits.add(handler); return { dispose: () => exits.delete(handler) }; },
          emitData(value) { for (const handler of data) handler(value); },
          emitExit(exitCode) { for (const handler of exits) handler({ exitCode, signal: 0 }); },
        };
        processes.push(process);
        return process;
      },
    });
    const runtime = createRuntime(server, {
      app, loadPtyProvider,
      terminalTerminationGraceMs: 10,
      fs: { promises: { stat: async () => ({ isDirectory: () => true }) } },
      searchPathFor: () => '/bin/sh', isExecutable: () => true,
    });
    await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
    const address = server.address();
    const base = `http://127.0.0.1:${address.port}`;
    const socketUrl = `ws://127.0.0.1:${address.port}/api/terminal/ws`;
    const sockets = [];

    try {
      const created = await fetch(`${base}/api/terminal/create`, {
        method: 'POST', headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ sessionId: 'term-live', cwd: '/repo', cols: 80, rows: 24 }),
      });
      expect(created.status).toBe(200);
      const secondCreated = await fetch(`${base}/api/terminal/create`, {
        method: 'POST', headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ sessionId: 'term-second', cwd: '/other', cols: 80, rows: 24 }),
      });
      expect(secondCreated.status).toBe(200);

      const first = await openTerminalSocket(socketUrl);
      sockets.push(first.socket);
      first.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'term-live' }));
      first.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'term-second' }));
      expect(await first.next('snapshot', 'term-live')).toMatchObject({ s: 'term-live', q: 0, history: '', status: 'running', cols: 80, rows: 24 });
      expect(await first.next('snapshot', 'term-second')).toMatchObject({ s: 'term-second', q: 0, history: '', status: 'running', cols: 80, rows: 24 });
      first.socket.send(createTerminalWsControlFrame({ t: 'write', v: 3, s: 'term-live', d: 'echo ok\r' }));
      first.socket.send(createTerminalWsControlFrame({ t: 'write', v: 3, s: 'term-second', d: 'pwd\r' }));
      first.socket.send(createTerminalWsControlFrame({ t: 'write', v: 3, s: 'term-live', d: 'echo next\r' }));
      await new Promise((resolve) => setTimeout(resolve, 5));
      expect(processes[0].writes).toEqual(['echo ok\r', 'echo next\r']);
      expect(processes[1].writes).toEqual(['pwd\r']);

      processes[1].emitData('/other\r\n');
      expect(await first.next('output', 'term-second')).toMatchObject({ s: 'term-second', q: 1, d: '/other\r\n' });
      first.socket.send(createTerminalWsControlFrame({ t: 'detach', v: 3, s: 'term-second' }));
      await new Promise((resolve) => setTimeout(resolve, 5));
      processes[1].emitData('detached\r\n');
      await new Promise((resolve) => setTimeout(resolve, 5));
      expect(first.messages.some((message) => message?.t === 'output' && message.s === 'term-second')).toBe(false);

      processes[0].emitData('ok\r\n');
      expect(await first.next('output', 'term-live')).toMatchObject({ s: 'term-live', q: 1, d: 'ok\r\n' });
      processes[0].emitData('\u001b[6n');
      expect(await first.next('output', 'term-live')).toMatchObject({ s: 'term-live', q: 2, d: '\u001b[6n', r: '' });
      const secondClosed = await fetch(`${base}/api/terminal/term-second`, { method: 'DELETE' });
      expect(secondClosed.status).toBe(200);
      first.socket.close();

      // A reconnecting client replays history at the size the PTY currently has.
      const resized = await fetch(`${base}/api/terminal/term-live/resize`, {
        method: 'POST', headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ cols: 120, rows: 40 }),
      });
      expect(resized.status).toBe(200);

      const second = await openTerminalSocket(socketUrl);
      sockets.push(second.socket);
      second.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'term-live' }));
      expect(await second.next('snapshot')).toMatchObject({ s: 'term-live', q: 2, history: 'ok\r\n', status: 'running', cols: 120, rows: 40 });
      processes[0].emitExit(7);
      expect(await second.next('exit')).toMatchObject({ s: 'term-live', q: 3, exitCode: 7 });

      const closed = await fetch(`${base}/api/terminal/term-live`, { method: 'DELETE' });
      expect(closed.status).toBe(200);
      expect(await second.next('error')).toMatchObject({ s: 'term-live', code: 'CLOSED', fatal: true });

      await fetch(`${base}/api/terminal/create`, {
        method: 'POST', headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ sessionId: 'term-kill', cwd: '/repo' }),
      });
      second.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'term-kill' }));
      await second.next('snapshot');
      const killed = await fetch(`${base}/api/terminal/force-kill`, {
        method: 'POST', headers: { 'content-type': 'application/json' },
        body: JSON.stringify({ cwd: '/repo' }),
      });
      expect(await killed.json()).toEqual({ success: true, killedCount: 1, killedSessionIds: ['term-kill'] });
      expect(await second.next('error')).toMatchObject({ s: 'term-kill', code: 'KILLED', fatal: true });
      expect(processes[2].killed).toBe(true);
    } finally {
      for (const socket of sockets) socket.terminate();
      await runtime.shutdown();
      server.closeAllConnections?.();
      await new Promise((resolve) => server.close(resolve));
    }
  }, 15_000);

  it('creates command-mode sessions and echoes the effective mode', async () => {
    const harness = createHarness({
      searchPathFor: (name) => name === 'bash' ? '/bin/bash' : '/bin/sh',
      isExecutable: (candidate) => candidate === '/bin/bash' || candidate === '/bin/sh',
    });
    try {
      const response = createResponse();
      await harness.routes.post.get('/api/terminal/create')({ body: { sessionId: 'term-command', cwd: '/repo', mode: 'command', command: 'printf ready', shell: 'bash', loginShell: true } }, response);

      expect(response.statusCode).toBe(200);
      expect(response.body).toEqual({ sessionId: 'term-command', cols: 80, rows: 24, status: 'running', mode: 'command', purpose: { type: 'terminal' } });
      if (process.platform !== 'win32') {
        expect(harness.processes[0].shell).toMatch(/\/env$/);
        expect(harness.processes[0].args).toEqual(['-u', 'ARGV0', '-u', 'NODE_CHANNEL_FD', '/bin/bash', '-l', '-i', '-c', 'printf ready']);
      } else {
        expect(harness.processes[0].args).toEqual(['-l', '-i', '-c', 'printf ready']);
      }
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects invalid terminal mode and command combinations', async () => {
    const harness = createHarness();
    try {
      for (const [body, error] of [
        [{ cwd: '/repo', mode: 'script' }, 'Invalid terminal mode'],
        [{ cwd: '/repo', mode: 'command' }, 'Terminal command is required'],
        [{ cwd: '/repo', mode: 'command', command: '   ' }, 'Terminal command is required'],
        [{ cwd: '/repo', mode: 'interactive', command: 'echo nope' }, 'Interactive terminal create does not accept a command'],
        [{ cwd: '/repo', mode: 'command', command: 'x'.repeat(65_537) }, 'Terminal command exceeds the input limit'],
      ]) {
        const response = createResponse();
        await harness.routes.post.get('/api/terminal/create')({ body }, response);
        expect(response.statusCode).toBe(400);
        expect(response.body).toEqual({ error });
      }
      expect(harness.processes).toHaveLength(0);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects same-id running creates when mode or command do not match', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      await create({ body: { sessionId: 'term-shared', cwd: '/repo' } }, createResponse());

      const modeMismatch = createResponse();
      await create({ body: { sessionId: 'term-shared', cwd: '/repo', mode: 'command', command: 'printf ready' } }, modeMismatch);
      expect(modeMismatch.statusCode).toBe(400);
      expect(modeMismatch.body).toEqual({ error: 'Terminal session is already running with a different mode' });

      await create({ body: { sessionId: 'term-command', cwd: '/repo', mode: 'command', command: 'printf ready' } }, createResponse());

      const commandMismatch = createResponse();
      await create({ body: { sessionId: 'term-command', cwd: '/repo', mode: 'command', command: 'printf other' } }, commandMismatch);
      expect(commandMismatch.statusCode).toBe(400);
      expect(commandMismatch.body).toEqual({ error: 'Terminal session is already running with a different command' });
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects pending creates when command mode does not match the in-flight request', async () => {
    const spawnDeferred = deferred();
    const harness = createHarness({ spawnDeferred });
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const first = createResponse();
      const conflictingMode = createResponse();
      const conflictingCommand = createResponse();

      const firstPromise = create({ body: { sessionId: 'term-pending', cwd: '/repo', mode: 'command', command: 'printf ready' } }, first);
      await Promise.resolve();
      const secondPromise = create({ body: { sessionId: 'term-pending', cwd: '/repo' } }, conflictingMode);
      const thirdPromise = create({ body: { sessionId: 'term-pending', cwd: '/repo', mode: 'command', command: 'printf other' } }, conflictingCommand);
      spawnDeferred.resolve();
      await Promise.all([firstPromise, secondPromise, thirdPromise]);

      expect(first.statusCode).toBe(200);
      expect(conflictingMode.statusCode).toBe(400);
      expect(conflictingMode.body).toEqual({ error: 'Terminal session is already being created with a different mode' });
      expect(conflictingCommand.statusCode).toBe(400);
      expect(conflictingCommand.body).toEqual({ error: 'Terminal session is already being created with a different command' });
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('validates purpose payloads and round-trips purpose through create, list, and snapshot without listing command text', async () => {
    const app = createHttpTestApp();
    const server = http.createServer(app);
    const runtime = createRuntime(server, {
      app,
      loadPtyProvider: async () => ({
        backend: 'fake-pty',
        spawn: async () => ({
          pid: 42,
          write() {},
          resize() {},
          kill() {},
          onData() { return { dispose() {} }; },
          onExit() { return { dispose() {} }; },
        }),
      }),
      terminalTerminationGraceMs: 10,
      fs: { promises: { stat: async () => ({ isDirectory: () => true }) } },
      searchPathFor: () => '/bin/sh',
      isExecutable: () => true,
    });
    await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
    const { port } = server.address();
    const base = `http://127.0.0.1:${port}`;
    const socketUrl = `ws://127.0.0.1:${port}/api/terminal/ws`;
    const sockets = [];

    try {
      for (const [body, error] of [
        [{ cwd: '/repo', purpose: 'terminal' }, 'Invalid terminal purpose'],
        [{ cwd: '/repo', purpose: { type: 'project-action' } }, 'Terminal project action id is required'],
        [{ cwd: '/repo', purpose: { type: 'project-action', actionId: 'build' } }, 'Terminal execution id is required'],
        [{ cwd: '/repo', purpose: { type: 'project-action', actionId: ' ', executionId: 'exec-1' } }, 'Terminal project action id is required'],
        [{ cwd: '/repo', purpose: { type: 'project-action', actionId: 'build', executionId: ' ' } }, 'Terminal execution id is required'],
      ]) {
        const response = await fetch(`${base}/api/terminal/create`, {
          method: 'POST',
          headers: { 'content-type': 'application/json' },
          body: JSON.stringify(body),
        });
        expect(response.status).toBe(400);
        expect(await response.json()).toEqual({ error });
      }

      const created = await fetch(`${base}/api/terminal/create`, {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify({
          sessionId: 'action-tab',
          cwd: '/repo',
          mode: 'command',
          command: 'printf ready',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
        }),
      });
      expect(created.status).toBe(200);
      expect(await created.json()).toEqual({
        sessionId: 'action-tab',
        cols: 80,
        rows: 24,
        status: 'running',
        mode: 'command',
        purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
      });

      const listed = await fetch(`${base}/api/terminal/sessions?cwd=%2Frepo`);
      expect(listed.status).toBe(200);
      expect(await listed.json()).toEqual({
        sessions: [{
          sessionId: 'action-tab',
          cwd: '/repo',
          status: 'running',
          createdAt: expect.any(Number),
          mode: 'command',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
        }],
      });

      const socket = await openTerminalSocket(socketUrl);
      sockets.push(socket.socket);
      socket.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'action-tab' }));
      expect(await socket.next('snapshot', 'action-tab')).toMatchObject({
        s: 'action-tab',
        status: 'running',
        mode: 'command',
        purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
      });
    } finally {
      for (const socket of sockets) socket.terminate();
      await runtime.shutdown();
      server.closeAllConnections?.();
      await new Promise((resolve) => server.close(resolve));
    }
  }, 15_000);

  it('deduplicates running project actions by resolved cwd and action id across session ids and clients', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const first = createResponse();
      await create({
        body: {
          sessionId: 'action-a',
          cwd: '/repo/./nested/..',
          mode: 'command',
          command: 'npm run build',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
        },
      }, first);
      expect(first.statusCode).toBe(200);

      const adopted = createResponse();
      await create({
        body: {
          sessionId: 'action-b',
          cwd: '/repo',
          mode: 'command',
          command: 'npm run build --watch',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-2' },
        },
      }, adopted);

      expect(adopted.statusCode).toBe(200);
      expect(adopted.body).toEqual({
        sessionId: 'action-a',
        cols: 80,
        rows: 24,
        status: 'running',
        mode: 'command',
        purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
      });
      expect(harness.processes).toHaveLength(1);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects purpose mismatches when the same session id is reused for a different action', async () => {
    const harness = createHarness();
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      await create({
        body: {
          sessionId: 'action-tab',
          cwd: '/repo',
          mode: 'command',
          command: 'npm run build',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
        },
      }, createResponse());

      const mismatch = createResponse();
      await create({
        body: {
          sessionId: 'action-tab',
          cwd: '/repo',
          mode: 'command',
          command: 'npm run test',
          purpose: { type: 'project-action', actionId: 'test', executionId: 'exec-2' },
        },
      }, mismatch);

      expect(mismatch.statusCode).toBe(400);
      expect(mismatch.body).toEqual({ error: 'Terminal session is already running with a different purpose' });
    } finally { await harness.runtime.shutdown(); }
  });

  it('keeps an immediately exited command session attachable once listeners are registered', async () => {
    const app = createHttpTestApp();
    const server = http.createServer(app);
    const runtime = createRuntime(server, {
      app,
      loadPtyProvider: async () => ({
        backend: 'fake-pty',
        spawn: async () => {
          const dataHandlers = new Set();
          const exitHandlers = new Set();
          return {
            pid: 404,
            write() {},
            resize() {},
            kill() {},
            onData(handler) { dataHandlers.add(handler); return { dispose: () => dataHandlers.delete(handler) }; },
            onExit(handler) {
              exitHandlers.add(handler);
              queueMicrotask(() => {
                for (const registered of exitHandlers) registered({ exitCode: 0, signal: 0 });
              });
              return { dispose: () => exitHandlers.delete(handler) };
            },
          };
        },
      }),
      terminalTerminationGraceMs: 10,
      fs: { promises: { stat: async () => ({ isDirectory: () => true }) } },
      searchPathFor: () => '/bin/sh',
      isExecutable: () => true,
    });
    await new Promise((resolve) => server.listen(0, '127.0.0.1', resolve));
    const { port } = server.address();
    const base = `http://127.0.0.1:${port}`;
    const socketUrl = `ws://127.0.0.1:${port}/api/terminal/ws`;
    const sockets = [];

    try {
      const created = await fetch(`${base}/api/terminal/create`, {
        method: 'POST',
        headers: { 'content-type': 'application/json' },
        body: JSON.stringify({
          sessionId: 'fast-exit',
          cwd: '/repo',
          mode: 'command',
          command: 'true',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-fast' },
        }),
      });
      expect(created.status).toBe(200);
      await new Promise((resolve) => setTimeout(resolve, 0));

      const socket = await openTerminalSocket(socketUrl);
      sockets.push(socket.socket);
      socket.socket.send(createTerminalWsControlFrame({ t: 'attach', v: 3, s: 'fast-exit' }));
      expect(await socket.next('snapshot', 'fast-exit')).toMatchObject({
        s: 'fast-exit',
        status: 'exited',
        exitCode: 0,
        purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-fast' },
      });
    } finally {
      for (const socket of sockets) socket.terminate();
      await runtime.shutdown();
      server.closeAllConnections?.();
      await new Promise((resolve) => server.close(resolve));
    }
  }, 15_000);

  it('tombstones a pending create when delete arrives first and kills the eventual pty', async () => {
    const spawnDeferred = deferred();
    const harness = createHarness({ spawnDeferred });
    try {
      const create = harness.routes.post.get('/api/terminal/create');
      const close = harness.routes.delete.get('/api/terminal/:sessionId');
      const created = createResponse();
      const closed = createResponse();

      const createPromise = create({
        body: {
          sessionId: 'pending-action',
          cwd: '/repo',
          mode: 'command',
          command: 'npm run build',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-pending' },
        },
      }, created);
      await Promise.resolve();

      const closePromise = close({ params: { sessionId: 'pending-action' } }, closed);
      spawnDeferred.resolve();
      await Promise.all([createPromise, closePromise]);

      expect(closed.statusCode).toBe(200);
      expect(closed.body).toEqual({ success: true });
      expect(created.statusCode).toBe(400);
      expect(created.body).toEqual({ error: 'Terminal session was closed during creation' });

      const listed = createResponse();
      harness.routes.get.get('/api/terminal/sessions')({ query: {} }, listed);
      expect(listed.body).toEqual({ sessions: [] });
      expect(harness.processes).toHaveLength(1);
      expect(harness.processes[0].killed).toBe(true);
    } finally { await harness.runtime.shutdown(); }
  });

  it('rejects restart for command-mode sessions', async () => {
    const harness = createHarness();
    try {
      await harness.routes.post.get('/api/terminal/create')({
        body: {
          sessionId: 'action-tab',
          cwd: '/repo',
          mode: 'command',
          command: 'npm run build',
          purpose: { type: 'project-action', actionId: 'build', executionId: 'exec-1' },
        },
      }, createResponse());

      const restarted = createResponse();
      await harness.routes.post.get('/api/terminal/:sessionId/restart')({ params: { sessionId: 'action-tab' }, body: {} }, restarted);

      expect(restarted.statusCode).toBe(400);
      expect(restarted.body).toEqual({ error: 'Command-mode terminal sessions cannot be restarted' });
      expect(harness.processes).toHaveLength(1);
      expect(harness.processes[0].killed).toBe(false);
    } finally { await harness.runtime.shutdown(); }
  });
});