// npm run backend:setup —— 用 uv 建 / 同步后端 Python 环境（.venv，Python 3.12）
//
// - 有 backend/requirements.lock（uv pip compile 生成、带哈希）时按锁精确同步（会卸掉锁外的包）
// - 没有锁时按 requirements.txt + requirements-build.txt 安装
// - 找不到 uv 时用系统 Python 的 pip 把 uv 装进 native/build/uv-bootstrap，不动系统环境
// - 结束时核对 browser-use 0.13.10 和 PyInstaller 版本
import { spawn, spawnSync } from 'node:child_process';
import { existsSync } from 'node:fs';
import { mkdir } from 'node:fs/promises';
import { homedir } from 'node:os';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
const win = process.platform === 'win32';
const python = path.join(root, '.venv', win ? 'Scripts/python.exe' : 'bin/python');
const lock = path.join(root, 'backend/requirements.lock');
const requirements = path.join(root, 'backend/requirements.txt');
const buildRequirements = path.join(root, 'backend/requirements-build.txt');
const bootstrap = path.join(root, 'native/build/uv-bootstrap');
const uvName = win ? 'uv.exe' : 'uv';

function run(command, args) {
  return new Promise((resolve, reject) => {
    const child = spawn(command, args, { cwd: root, stdio: 'inherit', windowsHide: true });
    child.once('error', reject);
    child.once('exit', code => (code === 0 ? resolve() : reject(new Error(`${command} ${args.join(' ')} 退出码 ${code}`))));
  });
}

function available(command, args) {
  return spawnSync(command, args, { encoding: 'utf8', windowsHide: true }).status === 0;
}

async function findUv() {
  const override = process.argv.slice(2).find(argument => argument.startsWith('--uv='));
  if (override) {
    const executable = path.resolve(override.slice('--uv='.length));
    if (!available(executable, ['--version'])) throw new Error(`指定的 uv 不可用: ${executable}`);
    return executable;
  }
  const candidates = [
    'uv',
    path.join(homedir(), '.local/bin', uvName),
    path.join(homedir(), '.cargo/bin', uvName),
    ...['bin', 'Scripts', 'uv'].map(folder => path.join(bootstrap, folder, uvName)),
  ];
  for (const executable of candidates) if (available(executable, ['--version'])) return executable;
  // 只把 uv 装到本项目忽略目录里，不改系统 Python 的 site-packages
  const pythons = win ? [['py', ['-3.12']], ['python', []]] : [['python3.12', []], ['python3', []]];
  const found = pythons.find(([command, args]) => available(command, [...args, '-m', 'pip', '--version']));
  if (!found) throw new Error('没有 uv，也没有带 pip 的 Python 3.12，先装其中一个再跑 backend:setup');
  await mkdir(bootstrap, { recursive: true });
  await run(found[0], [...found[1], '-m', 'pip', '--isolated', '--disable-pip-version-check', 'install',
    '--no-compile', '--no-deps', '--target', bootstrap, 'uv>=0.12']);
  const bundled = ['bin', 'Scripts', 'uv'].map(folder => path.join(bootstrap, folder, uvName)).find(exe => available(exe, ['--version']));
  if (!bundled) throw new Error('uv 引导安装没有产出可执行文件');
  return bundled;
}

try {
  const uv = await findUv();
  console.log(`[backend:setup] uv: ${uv}`);
  if (!existsSync(python)) await run(uv, ['venv', '--python', '3.12', path.join(root, '.venv')]);
  const version = spawnSync(python, ['-c', 'import sys; assert sys.version_info[:2] == (3, 12), sys.version'], { encoding: 'utf8', windowsHide: true });
  if (version.status !== 0) throw new Error(`.venv 必须是 Python 3.12：${version.stderr.trim()}`);
  if (existsSync(lock)) {
    await run(uv, ['pip', 'sync', '--python', python, '--require-hashes', lock]);
  } else {
    console.warn('[backend:setup] 没有 backend/requirements.lock，按 requirements.txt 安装（建议之后运行 npm run backend:lock）');
    await run(uv, ['pip', 'install', '--python', python, '-r', requirements, '-r', buildRequirements]);
  }
  await run(python, ['-c', [
    'import importlib.metadata as m',
    "assert m.version('browser-use') == '0.13.10', m.version('browser-use')",
    "print('[backend:setup] browser-use', m.version('browser-use'), '/ PyInstaller', m.version('pyinstaller'), '/ psycopg', m.version('psycopg'))",
  ].join('; ')]);
} catch (error) {
  console.error(`[backend:setup] 失败：${error.message}`);
  process.exitCode = 1;
}