import { chmod, mkdtemp, readFile, writeFile } from 'node:fs/promises';
import { spawn } from 'node:child_process';
import { tmpdir } from 'node:os';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';

function waitForExit(child, timeoutMs = 1500) {
  return new Promise((resolve, reject) => {
    const timeout = setTimeout(() => {
      child.kill('SIGKILL');
      reject(new Error(`wrapper did not exit within ${timeoutMs}ms`));
    }, timeoutMs);

    child.on('error', (error) => {
      clearTimeout(timeout);
      reject(error);
    });

    child.on('close', (code) => {
      clearTimeout(timeout);
      resolve(code ?? 0);
    });
  });
}

async function runWrapperWithFakePi(requestedModel) {
  const dir = await mkdtemp(join(tmpdir(), 'pi-subagents-wrapper-'));
  const metaPath = join(dir, 'meta.json');
  const resultPath = join(dir, 'result.json');
  const capturePath = join(dir, 'capture.json');
  const piPath = join(dir, 'pi');

  const resolved = requestedModel;
  await writeFile(
    piPath,
    [
      `#!${process.execPath}`,
      "const fs = require('fs');",
      `const capturePath = ${JSON.stringify(capturePath)};`,
      "const obj = {",
      "  PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR: process.env.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR || '',",
      "  PI_SUBAGENTS_CHILD: process.env.PI_SUBAGENTS_CHILD || '',",
      "  argv: process.argv.slice(2)",
      "};",
      "fs.writeFileSync(capturePath, JSON.stringify(obj), 'utf8');",
      "console.log(JSON.stringify({type:'message_end',message:{role:'assistant',content:[{type:'text',text:'done'}],model:'github-copilot/gpt-4o',stopReason:'stop'}}));",
    ].join('\n'),
    'utf8',
  );
  await chmod(piPath, 0o755);

  await writeFile(
    metaPath,
    JSON.stringify(
      {
        runId: 'run-1',
        mode: 'single',
        task: 'inspect auth',
        cwd: dir,
        requestedModel,
        resolvedModel: resolved,
        startedAt: '2026-04-09T00:00:00.000Z',
        sessionPath: join(dir, 'child-session.jsonl'),
        eventsPath: join(dir, 'events.jsonl'),
        resultPath,
        stdoutPath: join(dir, 'stdout.log'),
        stderrPath: join(dir, 'stderr.log'),
        transcriptPath: join(dir, 'transcript.log'),
        tools: ['read', 'grep'],
        systemPromptPath: join(dir, 'system-prompt.md'),
      },
      null,
      2,
    ),
    'utf8',
  );

  const wrapperPath = join(dirname(fileURLToPath(import.meta.url)), 'src/wrapper/cli.mjs');
  const child = spawn(process.execPath, [wrapperPath, metaPath], {
    env: {
      ...process.env,
      PATH: dir,
    },
    stdio: ['ignore', 'pipe', 'pipe'],
  });

  const exitCode = await waitForExit(child);
  console.log('exitCode', exitCode);

  const captureJson = JSON.parse(await readFile(capturePath, 'utf8'));
  return { flags: captureJson };
}

(async () => {
  try {
    const captured = await runWrapperWithFakePi('github-copilot/gpt-4o');
    console.log('captured', captured);
  } catch (err) {
    console.error('error', err);
    process.exit(1);
  }
})();