import { afterEach, beforeEach, describe, expect, it } from 'bun:test';
import { request as httpRequest } from 'http';
import { spawn, spawnSync, type ChildProcess } from 'child_process';
import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';

const BROWSER_PROMPT_SNIPPET = 'prefer the CCS MCP Browser tool';

interface RunResult {
  status: number | null;
  stdout: string;
  stderr: string;
}

async function waitForMockDevtoolsPort(portFilePath: string, timeoutMs = 5000): Promise<string> {
  const deadline = Date.now() + timeoutMs;

  while (Date.now() <= deadline) {
    try {
      const port = fs.readFileSync(portFilePath, 'utf8').trim();
      if (/^\d+$/.test(port)) {
        return port;
      }
    } catch {
      // Keep polling until timeout.
    }
    await new Promise((resolve) => setTimeout(resolve, 25));
  }

  throw new Error('Timed out waiting for mock DevTools server port to become ready');
}

async function waitForDevtoolsVersionEndpoint(port: string, timeoutMs = 5000): Promise<void> {
  const deadline = Date.now() + timeoutMs;

  while (Date.now() <= deadline) {
    try {
      await new Promise<void>((resolve, reject) => {
        const req = httpRequest(
          {
            hostname: '127.0.0.1',
            port: Number.parseInt(port, 10),
            path: '/json/version',
            method: 'GET',
          },
          (res) => {
            res.resume();
            if (res.statusCode === 200) {
              resolve();
              return;
            }
            reject(new Error(`Unexpected status: ${res.statusCode ?? 'unknown'}`));
          }
        );
        req.on('error', reject);
        req.end();
      });
      return;
    } catch {
      await new Promise((resolve) => setTimeout(resolve, 25));
    }
  }

  throw new Error('Timed out waiting for mock DevTools endpoint to become ready');
}

function runCcs(args: string[], env: NodeJS.ProcessEnv): RunResult {
  const ccsEntry = path.join(process.cwd(), 'src', 'ccs.ts');
  const result = spawnSync(process.execPath, [ccsEntry, ...args], {
    encoding: 'utf8',
    env,
    timeout: 5000,
  });

  return {
    status: result.status,
    stdout: result.stdout || '',
    stderr: result.stderr || '',
  };
}

describe('default profile browser launch', () => {
  let tmpHome = '';
  let fakeClaudePath = '';
  let claudeArgsLogPath = '';
  let claudeEnvLogPath = '';
  let browserProfileDir = '';
  let devtoolsServer: ChildProcess | undefined;
  let baseEnv: NodeJS.ProcessEnv;

  beforeEach(() => {
    if (process.platform === 'win32') {
      return;
    }

    tmpHome = fs.mkdtempSync(path.join(os.tmpdir(), 'ccs-default-browser-launch-'));
    fakeClaudePath = path.join(tmpHome, 'fake-claude.sh');
    claudeArgsLogPath = path.join(tmpHome, 'claude-args.txt');
    claudeEnvLogPath = path.join(tmpHome, 'claude-env.txt');
    browserProfileDir = path.join(tmpHome, 'chrome-user-data');

    fs.writeFileSync(
      fakeClaudePath,
      `#!/bin/sh
printf "%s\n" "$@" > "${claudeArgsLogPath}"
{
  printf "userDataDir=%s\n" "$CCS_BROWSER_USER_DATA_DIR"
  printf "host=%s\n" "$CCS_BROWSER_DEVTOOLS_HOST"
  printf "port=%s\n" "$CCS_BROWSER_DEVTOOLS_PORT"
  printf "httpUrl=%s\n" "$CCS_BROWSER_DEVTOOLS_HTTP_URL"
  printf "wsUrl=%s\n" "$CCS_BROWSER_DEVTOOLS_WS_URL"
} > "${claudeEnvLogPath}"
exit 0
`,
      { encoding: 'utf8', mode: 0o755 }
    );
    fs.chmodSync(fakeClaudePath, 0o755);

    baseEnv = {
      ...process.env,
      CI: '1',
      NO_COLOR: '1',
      CCS_HOME: tmpHome,
      CCS_CLAUDE_PATH: fakeClaudePath,
      CCS_DEBUG: '1',
    };
  });

  afterEach(() => {
    if (devtoolsServer) {
      devtoolsServer.kill();
      devtoolsServer = undefined;
    }
    if (process.platform === 'win32') {
      return;
    }

    fs.rmSync(tmpHome, { recursive: true, force: true });
  });

  it('does not consume an empty mock DevTools port file before the port is written', async () => {
    if (process.platform === 'win32') return;

    const delayedPortFile = path.join(tmpHome, 'delayed-port.txt');
    fs.writeFileSync(delayedPortFile, '', 'utf8');
    setTimeout(() => {
      fs.writeFileSync(delayedPortFile, '43123', 'utf8');
    }, 50);

    await expect(waitForMockDevtoolsPort(delayedPortFile, 500)).resolves.toBe('43123');
  });

  it('ignores stale default Chrome DevTools metadata unless browser reuse is explicitly configured', () => {
    if (process.platform === 'win32') return;

    const defaultChromeDir = path.join(
      tmpHome,
      'Library',
      'Application Support',
      'Google',
      'Chrome'
    );
    fs.mkdirSync(defaultChromeDir, { recursive: true });
    fs.writeFileSync(
      path.join(defaultChromeDir, 'DevToolsActivePort'),
      '9222\n/devtools/browser/stale-default',
      'utf8'
    );

    const result = runCcs(['default', 'smoke'], {
      ...baseEnv,
      HOME: tmpHome,
      USERPROFILE: tmpHome,
    });

    expect(result.status).toBe(0);
    expect(result.stderr).not.toContain('Chrome DevTools endpoint is unreachable');

    const launchedArgs = fs.readFileSync(claudeArgsLogPath, 'utf8');
    expect(launchedArgs).not.toContain(BROWSER_PROMPT_SNIPPET);

    const launchedEnv = fs.readFileSync(claudeEnvLogPath, 'utf8');
    expect(launchedEnv).not.toContain('9222');
    expect(launchedEnv).not.toContain('devtools/browser/stale-default');
  });

  it('passes browser runtime env through default Claude launches when reuse is configured', async () => {
    if (process.platform === 'win32') return;

    const mockServerScriptPath = path.join(tmpHome, 'mock-devtools-server.js');
    const mockServerPortPath = path.join(tmpHome, 'mock-devtools-port.txt');
    fs.writeFileSync(
      mockServerScriptPath,
      `const { createServer } = require('http');
const fs = require('fs');
const server = createServer((req, res) => {
  if (req.url === '/json/version') {
    res.writeHead(200, { 'content-type': 'application/json' });
    res.end(JSON.stringify({ Browser: 'Chrome/136.0.0.0', webSocketDebuggerUrl: 'ws://127.0.0.1/devtools/browser/default-target' }));
    return;
  }
  res.writeHead(404);
  res.end('not found');
});
server.listen(0, '127.0.0.1', () => {
  const address = server.address();
  fs.writeFileSync(${JSON.stringify(mockServerPortPath)}, String(address.port), 'utf8');
});
`,
      'utf8'
    );

    devtoolsServer = spawn(process.execPath, [mockServerScriptPath], {
      stdio: 'ignore',
      env: baseEnv,
    });

    const port = await waitForMockDevtoolsPort(mockServerPortPath);
    await waitForDevtoolsVersionEndpoint(port);

    fs.mkdirSync(browserProfileDir, { recursive: true });
    fs.writeFileSync(
      path.join(browserProfileDir, 'DevToolsActivePort'),
      `${port}\n/devtools/browser/default-target`,
      'utf8'
    );

    const result = runCcs(['default', 'smoke'], {
      ...baseEnv,
      CCS_BROWSER_PROFILE_DIR: browserProfileDir,
    });

    expect(result.stderr).not.toContain('Browser MCP is enabled, but CCS could not prepare the local browser tool.');
    expect(result.stderr).not.toContain('could not sync the browser MCP config');
    expect(result.stderr).not.toContain('Chrome reuse metadata not found');
    expect(result.status).toBe(0);
    const launchedArgs = fs.readFileSync(claudeArgsLogPath, 'utf8');
    expect(launchedArgs).toContain('--append-system-prompt');
    expect(launchedArgs).toContain(BROWSER_PROMPT_SNIPPET);

    const launchedEnv = fs.readFileSync(claudeEnvLogPath, 'utf8');
    expect(launchedEnv).toContain(`userDataDir=${browserProfileDir}`);
    expect(launchedEnv).toContain(`port=${port}`);
    expect(launchedEnv).toContain(`httpUrl=http://127.0.0.1:${port}`);
    expect(launchedEnv).toContain('wsUrl=ws://127.0.0.1/devtools/browser/default-target');
  });
});