import fs from 'node:fs';
import path from 'node:path';

const root = process.cwd();
const docsRoot = path.join(root, 'docs');
const readmePath = path.join(docsRoot, 'README.md');
const indexPath = path.join(
  docsRoot,
  '【协作规范】文档生命周期与现状索引-2026-09-12.md',
);

const read = (file) => fs.readFileSync(file, 'utf8');
const rel = (file) => path.relative(root, file).replaceAll(path.sep, '/');
const resolveDocPath = (value) => {
  const decoded = decodeURIComponent(value.replaceAll('\\', '/'));
  const withoutPrefix = decoded.startsWith('./') ? decoded.slice(2) : decoded;
  const target = path.normalize(path.join(docsRoot, withoutPrefix));
  const relative = path.relative(docsRoot, target);
  if (relative.startsWith('..') || path.isAbsolute(relative)) {
    throw new Error(`docs/README.md 链接越过 docs 根目录: ${value}`);
  }
  return target;
};

const readme = read(readmePath);
const index = read(indexPath);
const current = new Set(['docs/README.md', 'docs/project-memory/README.md']);

for (const match of readme.matchAll(/\]\((?:<)?([^)>]+)(?:>)?\)/g)) {
  const value = match[1];
  if (
    value.startsWith('http') ||
    value.includes('#') ||
    !(value.endsWith('.md') || value.endsWith('.json'))
  )
    continue;
  const file = resolveDocPath(value);
  if (!fs.existsSync(file)) {
    throw new Error(`docs/README.md 链接不存在: ${value}`);
  }
  if (value.endsWith('.md')) current.add(rel(file));
}

for (const file of fs.readdirSync(
  path.join(docsRoot, 'project-memory', 'shared-memory'),
)) {
  if (file.endsWith('.md'))
    current.add(`docs/project-memory/shared-memory/${file}`);
}

const sectionPaths = (heading, nextHeading) => {
  const body = index.split(heading, 2)[1]?.split(nextHeading, 2)[0] ?? '';
  return new Set(
    [...body.matchAll(/^- `([^`]+\.md)`$/gm)].map((match) => match[1]),
  );
};

const historical = sectionPaths('## 历史集合', '## 待复核集合');
const review = sectionPaths('## 待复核集合', '## 开放事项与活动计划');
for (const file of historical) {
  if (review.has(file))
    throw new Error(`文件同时出现在 historical 和 review: ${file}`);
}
const allDocs = [...walkMarkdown(docsRoot)].map(rel);
const classified = new Set([...current, ...historical, ...review]);

for (const file of [...historical, ...review]) {
  const absolute = path.join(root, file);
  if (!fs.existsSync(absolute)) throw new Error(`索引中的文件不存在: ${file}`);
  const body = read(absolute).slice(0, 1200);
  const expected = historical.has(file) ? 'historical' : 'review';
  if (!body.includes(`文档状态：\`${expected}\``)) {
    throw new Error(`${file} 缺少 ${expected} 状态头`);
  }
  if (current.has(file))
    throw new Error(`${file} 同时被 current 和 ${expected} 分类`);
}

for (const file of current) {
  if (!file.endsWith('.md')) continue;
  if (file === rel(indexPath)) continue;
  const body = read(path.join(root, file)).slice(0, 1200);
  if (/^> 文档状态：`(?:historical|review)`/m.test(body)) {
    throw new Error(
      `${file} 已进入 current，但仍保留 historical/review 状态头`,
    );
  }
}

for (const file of allDocs) {
  if (file.includes('/plans/') || file.includes('/todos/')) continue;
  if (!classified.has(file)) throw new Error(`文档未分类: ${file}`);
}

for (const file of [...historical, ...review]) {
  if (!allDocs.includes(file))
    throw new Error(`索引包含非 Markdown 文件: ${file}`);
}

console.log(
  `文档索引检查通过：${allDocs.length} 份 Markdown，current=${current.size}，historical=${historical.size}，review=${review.size}`,
);

function* walkMarkdown(directory) {
  for (const entry of fs.readdirSync(directory, { withFileTypes: true })) {
    const file = path.join(directory, entry.name);
    if (entry.isDirectory()) yield* walkMarkdown(file);
    else if (entry.isFile() && entry.name.endsWith('.md')) yield file;
  }
}