const fs = require('fs');
const path = require('path');
const { spawnSync } = require('child_process');

const ROOT = __dirname;
const pkg = require('./package.json');
const PRODUCT = pkg.productName || 'PeopleLib';
const TARGET = `${PRODUCT}-windows-x64`;
const REQUESTED_OUT = process.env.PEOPLELIB_OUT_DIR
  ? path.resolve(process.env.PEOPLELIB_OUT_DIR)
  : path.join(ROOT, 'dist', TARGET);
const OUT = REQUESTED_OUT;
const APP = path.join(OUT, 'resources', 'app');

function rimraf(p) { if (fs.existsSync(p)) fs.rmSync(p, { recursive: true, force: true }); }
function clearOutput(dir) {
  if (!fs.existsSync(dir)) return;
  const executable = path.join(dir, `${PRODUCT}.exe`);
  const probe = executable + '.build-lock-check';
  if (fs.existsSync(executable)) {
    try {
      fs.renameSync(executable, probe);
      fs.renameSync(probe, executable);
    } catch (error) {
      if (!fs.existsSync(executable) && fs.existsSync(probe)) {
        try { fs.renameSync(probe, executable); } catch (restoreError) { /* report the original lock error */ }
      }
      if (error && (error.code === 'EPERM' || error.code === 'EBUSY' || error.code === 'EACCES')) {
        throw new Error(`无法清理固定输出目录 ${dir}，请先关闭其中正在运行的 ${PRODUCT}.exe 后重试`);
      }
      throw error;
    }
  }
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    if (entry.name === 'data') continue;
    const target = path.join(dir, entry.name);
    try {
      fs.rmSync(target, { recursive: true, force: true });
    } catch (error) {
      if (error && (error.code === 'EPERM' || error.code === 'EBUSY')) {
        throw new Error(`无法清理固定输出目录 ${dir}，请先关闭其中正在运行的 ${PRODUCT}.exe 后重试`);
      }
      throw error;
    }
  }
}

function ensureElectronRuntime() {
  const electronDir = path.join(ROOT, 'node_modules', 'electron');
  const distDir = path.join(electronDir, 'dist');
  const executable = path.join(distDir, 'electron.exe');
  const versionFile = path.join(distDir, 'version');
  const expected = String(pkg.devDependencies && pkg.devDependencies.electron || '').replace(/^v/, '');
  const installed = fs.existsSync(versionFile)
    ? fs.readFileSync(versionFile, 'utf8').trim().replace(/^v/, '')
    : '';
  if (installed === expected && fs.existsSync(executable)) return distDir;

  const installer = path.join(electronDir, 'install.js');
  if (!fs.existsSync(installer)) throw new Error('缺少 Electron 安装脚本，请先运行 npm ci');
  console.log(`准备 Electron ${expected} 运行时...`);
  const result = spawnSync(process.execPath, [installer], {
    cwd: electronDir,
    env: {
      ...process.env,
      ELECTRON_MIRROR: process.env.ELECTRON_MIRROR
        || process.env.npm_config_electron_mirror
        || 'https://npmmirror.com/mirrors/electron/'
    },
    stdio: 'inherit'
  });
  if (result.error) throw result.error;
  if (result.status !== 0) throw new Error(`Electron 运行时安装失败（退出码 ${result.status}）`);

  const prepared = fs.existsSync(versionFile)
    ? fs.readFileSync(versionFile, 'utf8').trim().replace(/^v/, '')
    : '';
  if (prepared !== expected || !fs.existsSync(executable)) {
    throw new Error(`Electron 运行时版本无效（期望 ${expected || '未知'}，实际 ${prepared || '缺失'}）`);
  }
  return distDir;
}

function copyDir(src, dst, skip) {
  fs.mkdirSync(dst, { recursive: true });
  for (const e of fs.readdirSync(src, { withFileTypes: true })) {
    if (skip && skip(e)) continue;
    const s = path.join(src, e.name);
    const d = path.join(dst, e.name);
    if (e.isDirectory()) copyDir(s, d, skip);
    else fs.copyFileSync(s, d);
  }
}

function pruneLocales(dir) {
  const keep = new Set(['zh-CN.pak', 'en-US.pak']);
  for (const name of fs.readdirSync(dir)) {
    if (!keep.has(name)) fs.unlinkSync(path.join(dir, name));
  }
}

function skipDevFiles(e) {
  const name = e.name.toLowerCase();
  if (e.isDirectory()) return false;
  if (/\.(d\.ts|d\.ts\.map|ts|tsx|map|flow)$/.test(name)) return true;
  if (/^(readme|changelog|history|license|licence|notice|authors|contributing|security)/.test(name)) return true;
  if (/\.(md|markdown)$/.test(name)) return true;
  return false;
}

function copyUndici(dst) {
  const src = path.join(ROOT, 'node_modules', 'undici');
  fs.mkdirSync(dst, { recursive: true });
  for (const name of ['package.json', 'index.js', 'index-fetch.js', 'LICENSE']) {
    const file = path.join(src, name);
    if (fs.existsSync(file)) fs.copyFileSync(file, path.join(dst, name));
  }
  copyDir(path.join(src, 'lib'), path.join(dst, 'lib'), skipDevFiles);
}

function copyFoliate(dst) {
  const src = path.join(ROOT, 'node_modules', 'foliate-js');
  fs.mkdirSync(path.join(dst, 'vendor'), { recursive: true });
  for (const name of ['package.json', 'LICENSE', 'mobi.js']) {
    fs.copyFileSync(path.join(src, name), path.join(dst, name));
  }
  fs.copyFileSync(
    path.join(src, 'vendor', 'fflate.js'),
    path.join(dst, 'vendor', 'fflate.js')
  );
}

async function build() {
  const electronDist = ensureElectronRuntime();

  console.log('清理固定输出目录（保留 data）...');
  clearOutput(OUT);

  console.log('复制 Electron 运行时...');
  copyDir(electronDist, OUT);

  console.log('精简语言包...');
  pruneLocales(path.join(OUT, 'locales'));

  console.log('重命名可执行文件...');
  const executable = path.join(OUT, PRODUCT + '.exe');
  fs.renameSync(path.join(OUT, 'electron.exe'), executable);
  rimraf(path.join(OUT, 'resources', 'default_app.asar'));

  console.log(`应用 ${PRODUCT} 图标...`);
  const { rcedit } = await import('rcedit');
  await rcedit(executable, {
    icon: path.join(ROOT, 'icons', 'dist', 'book-ai-dark.ico'),
    'file-version': pkg.version,
    'product-version': pkg.version,
    'version-string': {
      ProductName: PRODUCT,
      FileDescription: PRODUCT,
      InternalName: PRODUCT,
      OriginalFilename: `${PRODUCT}.exe`
    }
  });

  console.log('组装 app 源码...');
  fs.mkdirSync(APP, { recursive: true });
  fs.copyFileSync(path.join(ROOT, 'main.js'), path.join(APP, 'main.js'));
  fs.copyFileSync(path.join(ROOT, 'preload.js'), path.join(APP, 'preload.js'));
  fs.copyFileSync(
    path.join(ROOT, 'manga-online-preload.js'),
    path.join(APP, 'manga-online-preload.js')
  );
  copyDir(path.join(ROOT, 'src'), path.join(APP, 'src'), (e) => e.name.startsWith('_test'));
  const iconDir = path.join(APP, 'icons', 'dist');
  fs.mkdirSync(iconDir, { recursive: true });
  for (const name of ['book-ai-dark.ico', 'book-ai-light.ico']) {
    fs.copyFileSync(path.join(ROOT, 'icons', 'dist', name), path.join(iconDir, name));
  }
  for (const theme of ['dark', 'light']) {
    const themeDir = path.join(iconDir, theme);
    fs.mkdirSync(themeDir, { recursive: true });
    fs.copyFileSync(
      path.join(ROOT, 'icons', 'dist', theme, 'icon-32.png'),
      path.join(themeDir, 'icon-32.png')
    );
  }
  copyUndici(path.join(APP, 'node_modules', 'undici'));
  copyFoliate(path.join(APP, 'node_modules', 'foliate-js'));

  fs.writeFileSync(path.join(APP, 'package.json'), JSON.stringify({
    name: pkg.name, version: pkg.version, description: pkg.description,
    productName: PRODUCT,
    main: 'main.js', author: pkg.author, license: pkg.license,
    dependencies: {
      undici: pkg.dependencies.undici,
      'foliate-js': pkg.dependencies['foliate-js']
    }
  }, null, 2));

  console.log('\n构建完成:');
  console.log('  目录:', OUT);
  console.log('  可执行文件:', executable);
}

build().catch((error) => {
  console.error('构建失败:', error && error.message ? error.message : error);
  process.exitCode = 1;
});