#!/usr/bin/env node
/*
 * Chrome native messaging host for JoboCop.
 * Chrome starts this process, sends one JSON message on stdin, reads one reply on stdout.
 *
 *   { type: "ping", cwd? }                 -> { ok, version, cwd }
 *   { type: "ask", prompt, cwd?, model? }  -> { ok, text }
 *
 * The prompt is passed to `claude -p` (headless mode) on stdin. In headless mode
 * Claude Code can read files in the working folder but cannot run commands or
 * edit files without permission, so it cannot change anything on this computer.
 */
const { spawn } = require('child_process');
const fs = require('fs');
const os = require('os');
const path = require('path');

const CONFIG = (() => {
  try {
    return JSON.parse(fs.readFileSync(path.join(__dirname, 'config.json'), 'utf8').replace(/^\uFEFF/, ''));
  } catch {
    return {};
  }
})();
const CLAUDE = CONFIG.claudePath || 'claude';
const TIMEOUT_MS = 180_000;

// ---------- native messaging framing (4-byte little-endian length + JSON) ----------
function send(obj) {
  const data = Buffer.from(JSON.stringify(obj), 'utf8');
  const header = Buffer.alloc(4);
  header.writeUInt32LE(data.length, 0);
  process.stdout.write(Buffer.concat([header, data]));
}

let buf = Buffer.alloc(0);
process.stdin.on('data', (chunk) => {
  buf = Buffer.concat([buf, chunk]);
  while (buf.length >= 4) {
    const len = buf.readUInt32LE(0);
    if (buf.length < 4 + len) break;
    const raw = buf.subarray(4, 4 + len).toString('utf8');
    buf = buf.subarray(4 + len);
    let msg;
    try {
      msg = JSON.parse(raw);
    } catch {
      send({ ok: false, error: 'Bad message from the extension.' });
      continue;
    }
    handle(msg).then(send, (e) => send({ ok: false, error: String(e?.message || e) }));
  }
});
process.stdin.on('end', () => setTimeout(() => process.exit(0), 50));

// ---------- running claude ----------
function workingDir(cwd) {
  const dir = cwd ? cwd.replace(/^~(?=$|[\\/])/, os.homedir()) : '';
  try {
    if (dir && fs.statSync(dir).isDirectory()) return dir;
  } catch {}
  return os.homedir();
}

function runClaude(args, input, cwd) {
  return new Promise((resolve) => {
    const isWin = process.platform === 'win32';
    const viaShell = isWin && /\.(cmd|bat)$/i.test(CLAUDE);
    const env = { ...process.env, ...(CONFIG.path ? { PATH: CONFIG.path } : {}) };
    let child;
    try {
      child = spawn(viaShell ? `"${CLAUDE}"` : CLAUDE, args, { cwd, env, shell: viaShell, windowsHide: true });
    } catch (e) {
      return resolve({ ok: false, error: e.message });
    }
    let out = '';
    let err = '';
    let finished = false;
    const done = (r) => {
      if (finished) return;
      finished = true;
      clearTimeout(timer);
      resolve(r);
    };
    const timer = setTimeout(() => {
      child.kill();
      done({ ok: false, error: 'Claude Code took longer than 3 minutes. Try fewer questions at once.' });
    }, TIMEOUT_MS);
    child.stdout.on('data', (d) => (out += d));
    child.stderr.on('data', (d) => (err += d));
    child.on('error', (e) =>
      done({ ok: false, error: e.code === 'ENOENT' ? `Claude Code was not found at "${CLAUDE}". Run the installer again.` : e.message })
    );
    child.on('close', (code) => done({ ok: code === 0, code, out, err }));
    child.stdin.on('error', () => {});
    child.stdin.end(input ?? '');
  });
}

async function handle(msg) {
  const cwd = workingDir(msg.cwd);

  if (msg.type === 'ping') {
    const r = await runClaude(['--version'], '', cwd);
    if (!r.ok) return { ok: false, error: r.error || r.err.trim() || 'Claude Code did not start.' };
    return { ok: true, version: r.out.trim(), cwd };
  }

  if (msg.type === 'ask') {
    if (!msg.prompt) return { ok: false, error: 'Empty prompt.' };
    const args = ['-p', '--output-format', 'json'];
    if (msg.model) args.push('--model', String(msg.model));
    const r = await runClaude(args, msg.prompt, cwd);
    if (r.error) return { ok: false, error: r.error };
    let parsed = null;
    try {
      parsed = JSON.parse(r.out);
    } catch {}
    if (!r.ok || !parsed || parsed.is_error) {
      const detail = parsed?.result || r.err.trim() || r.out.trim().slice(0, 300);
      const login = /log ?in|auth|api key/i.test(detail) ? ' Open a terminal and run `claude` once to sign in.' : '';
      return { ok: false, error: `Claude Code failed: ${detail || `exit code ${r.code}`}.${login}` };
    }
    return { ok: true, text: String(parsed.result ?? '') };
  }

  return { ok: false, error: `Unknown request: ${msg.type}` };
}