// 构建：src/ → dist/，渲染 {{变量}}，拷入 APK，并校验页面引用的本地资源都存在
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
const SRC = path.join(ROOT, 'src');
const DIST = path.join(ROOT, 'dist');
const RELEASES = path.join(ROOT, 'releases');

export function loadConfig() {
  return JSON.parse(fs.readFileSync(path.join(ROOT, 'site.config.json'), 'utf8'));
}

export function apkFileName(cfg) {
  return `douba-v${cfg.version}.apk`;
}

// 2026-10-29 → 2026 年 10 月 29 日
function cnDate(iso) {
  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(iso || '');
  if (!m) throw new Error(`日期格式应为 YYYY-MM-DD：${iso}`);
  return `${m[1]} 年 ${Number(m[2])} 月 ${Number(m[3])} 日`;
}

// 字节 → "61.5 MB"（十进制，和手机系统显示一致）
function mb(bytes) {
  return `${(bytes / 1e6).toFixed(1)} MB`;
}

function walk(dir) {
  return fs.readdirSync(dir, { withFileTypes: true }).flatMap((e) => {
    const p = path.join(dir, e.name);
    return e.isDirectory() ? walk(p) : [p];
  });
}

function render(text, vars, file) {
  return text.replace(/\{\{\s*([\w.]+)\s*\}\}/g, (_, key) => {
    if (!(key in vars)) throw new Error(`${file}: 未定义的模板变量 {{${key}}}`);
    return vars[key];
  });
}

// 找出 HTML 的 src/href 和 CSS 的 url()，确认指向 /app 内的文件都存在
function checkRefs(files) {
  const missing = [];
  for (const file of files) {
    const ext = path.extname(file);
    if (ext !== '.html' && ext !== '.css') continue;
    const text = fs.readFileSync(file, 'utf8');
    const re = ext === '.html' ? /\s(?:src|href|content)="([^"]+)"/g : /url\(["']?([^"')]+)["']?\)/g;
    for (let [, raw] of text.matchAll(re)) {
      raw = raw.replace(/^https:\/\/shop\.douba\.top(?=\/app)/, ''); // og:image 等写的是本站完整地址
      if (/\s/.test(raw) || (!raw.includes('/') && !raw.includes('.'))) continue; // content 里的普通文本
      const ref = raw.split(/[?#]/)[0];
      if (!ref || /^(https?:|data:|mailto:|tel:|\/\/)/.test(raw) || /^(#|%23)/.test(raw)) continue; // %23 = 内联 SVG 里的 url(#id)
      let target;
      if (ref.startsWith('/app/')) target = path.join(DIST, ref.slice(5));
      else if (ref === '/app' || ref === '/app/') target = path.join(DIST, 'index.html');
      else if (ref.startsWith('/')) continue; // 站点根下的商城页面（如 /protocol.html），不归本项目管
      else target = path.join(path.dirname(file), ref);
      if (fs.existsSync(target) && fs.statSync(target).isDirectory()) target = path.join(target, 'index.html');
      if (!fs.existsSync(target)) missing.push(`${path.relative(DIST, file)} → ${raw}`);
    }
  }
  if (missing.length) throw new Error(`以下引用的文件不存在：\n  ${missing.join('\n  ')}`);
}

export function build() {
  const cfg = loadConfig();
  const apkFile = apkFileName(cfg);
  const apkSrc = path.join(RELEASES, apkFile);
  if (!fs.existsSync(apkSrc)) {
    throw new Error(`找不到安装包 releases/${apkFile}（site.config.json 的 version 是 ${cfg.version}）`);
  }
  const apkBytes = fs.statSync(apkSrc).size;

  const vars = {
    version: cfg.version,
    channel: cfg.channel,
    releaseDate: cfg.releaseDate,
    screenshotVersion: cfg.screenshotVersion,
    'permissions.version': cfg.permissions.version,
    'permissions.updatedCn': cnDate(cfg.permissions.updated),
    apkFile,
    apkSize: mb(apkBytes),
  };
  cnDate(cfg.releaseDate); // 只做格式校验

  fs.rmSync(DIST, { recursive: true, force: true });
  for (const file of walk(SRC)) {
    const out = path.join(DIST, path.relative(SRC, file));
    fs.mkdirSync(path.dirname(out), { recursive: true });
    if (path.extname(file) === '.html') {
      fs.writeFileSync(out, render(fs.readFileSync(file, 'utf8'), vars, path.relative(ROOT, file)));
    } else {
      fs.copyFileSync(file, out);
    }
  }
  fs.mkdirSync(path.join(DIST, 'download'), { recursive: true });
  fs.copyFileSync(apkSrc, path.join(DIST, 'download', apkFile));

  checkRefs(walk(DIST));
  return { cfg, apkFile, apkBytes, vars };
}

if (process.argv[1] === fileURLToPath(import.meta.url)) {
  try {
    const { cfg, apkFile, vars } = build();
    console.log(`构建完成 → dist/`);
    console.log(`  版本 v${cfg.version}（${cfg.channel}） · ${apkFile} · ${vars.apkSize} · 更新时间 ${cfg.releaseDate}`);
  } catch (e) {
    console.error(`构建失败：${e.message}`);
    process.exit(1);
  }
}