const express = require('express');
const db = require('../db');
const { authMiddleware, adminOnly } = require('../middleware/auth');

const router = express.Router();

// slug 生成：name 小写、空格转连字符、去特殊字符（仅 [a-z0-9-]），空则随机后缀
function makeSlug(name) {
  const base = String(name || '')
    .toLowerCase()
    .replace(/\s+/g, '-')
    .replace(/[^a-z0-9-]/g, '')
    .replace(/-+/g, '-')
    .replace(/^-|-$/g, '')
    .slice(0, 32);
  return base || ('panel-' + Math.random().toString(36).slice(2, 8));
}

// 确保 slug 唯一：存在同名则追加 -2/-3/...
function uniqueSlug(slug, excludeId) {
  let s = slug;
  let i = 1;
  const exists = (x) => {
    if (excludeId) return db.get('SELECT id FROM admin_links WHERE slug = ? AND id != ?', [x, excludeId]);
    return db.get('SELECT id FROM admin_links WHERE slug = ?', [x]);
  };
  while (exists(s)) { s = slug + '-' + (++i); }
  return s;
}

// 校验面板代理配置字段（返回 { ok, data?, error? }）
function validateProxyFields(body, current) {
  const data = {};
  // proxy_headers：合法 JSON 对象（空串允许）
  if (body.proxy_headers !== undefined) {
    const raw = String(body.proxy_headers);
    if (raw.trim() !== '') {
      try {
        const parsed = JSON.parse(raw);
        if (!parsed || typeof parsed !== 'object' || Array.isArray(parsed)) return { ok: false, error: 'proxy_headers 需为 JSON 对象' };
        data.proxy_headers = raw;
      } catch { return { ok: false, error: 'proxy_headers 不是合法 JSON' }; }
    } else {
      data.proxy_headers = '';
    }
  }
  // permissions：JSON 数组
  if (body.permissions !== undefined) {
    const raw = String(body.permissions);
    if (raw.trim() !== '') {
      try {
        const parsed = JSON.parse(raw);
        if (!Array.isArray(parsed)) return { ok: false, error: 'permissions 需为 JSON 数组' };
        data.permissions = raw;
      } catch { return { ok: false, error: 'permissions 不是合法 JSON' }; }
    } else {
      data.permissions = '';
    }
  }
  // scale：0.1-3
  if (body.scale !== undefined) {
    const s = parseFloat(body.scale);
    if (!Number.isFinite(s) || s < 0.1 || s > 3) return { ok: false, error: 'scale 需在 0.1-3 之间' };
    data.scale = s;
  }
  // trusted：0/1
  if (body.trusted !== undefined) {
    const t = Number(body.trusted);
    if (t !== 0 && t !== 1) return { ok: false, error: 'trusted 需为 0 或 1' };
    data.trusted = t;
  }
  // proxy_skip_tls_verify：0/1
  if (body.proxy_skip_tls_verify !== undefined) {
    data.proxy_skip_tls_verify = Number(body.proxy_skip_tls_verify) ? 1 : 0;
  }
  // slug：唯一（[a-z0-9-]），空则自动生成
  if (body.slug !== undefined) {
    const raw = String(body.slug || '').trim().toLowerCase();
    if (raw !== '') {
      if (!/^[a-z0-9-]{1,32}$/.test(raw)) return { ok: false, error: 'slug 仅限小写字母/数字/连字符，≤32 字符' };
      if (['token', 'fetch'].includes(raw)) return { ok: false, error: 'slug 为保留名，请更换' };
      data.slug = uniqueSlug(raw, current && current.id);
    } else {
      data.slug = uniqueSlug(makeSlug((body.title || (current && current.title) || '')), current && current.id);
    }
  }
  return { ok: true, data };
}

router.get('/', authMiddleware, adminOnly, (req, res) => {
  res.json(db.all('SELECT * FROM admin_links ORDER BY sort_order ASC, id ASC'));
});

router.post('/', authMiddleware, adminOnly, (req, res) => {
  const { title, url, embed_url, description, icon, category, sort_order, use_proxy, version } = req.body;
  if (!title || !url) return res.status(400).json({ error: '标题和链接不能为空' });
  const vf = validateProxyFields(req.body);
  if (!vf.ok) return res.status(400).json({ error: vf.error });
  const d = vf.data;
  const id = db.run(
    `INSERT INTO admin_links (title, url, embed_url, description, icon, category, sort_order, use_proxy, version,
       proxy_headers, proxy_skip_tls_verify, permissions, scale, trusted, slug) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
    [title, url, embed_url || '', description || '', icon || '', category || '默认', sort_order || 0, use_proxy ? 1 : 0, version || '',
     d.proxy_headers || '', d.proxy_skip_tls_verify || 0, d.permissions || '', d.scale !== undefined ? d.scale : 1.0, d.trusted !== undefined ? d.trusted : 1,
     d.slug || uniqueSlug(makeSlug(title))]);
  res.json(db.get('SELECT * FROM admin_links WHERE id = ?', [id]));
});

router.put('/:id', authMiddleware, adminOnly, (req, res) => {
  const existing = db.get('SELECT * FROM admin_links WHERE id = ?', [req.params.id]);
  if (!existing) return res.status(404).json({ error: '链接不存在' });
  const { title, url, embed_url, description, icon, category, sort_order, use_proxy, version } = req.body;
  const vf = validateProxyFields(req.body, existing);
  if (!vf.ok) return res.status(400).json({ error: vf.error });
  const d = vf.data;
  db.run(
    `UPDATE admin_links SET title=?, url=?, embed_url=?, description=?, icon=?, category=?, sort_order=?, use_proxy=?, version=?,
       proxy_headers=?, proxy_skip_tls_verify=?, permissions=?, scale=?, trusted=?, slug=? WHERE id=?`,
    [title || '', url || '', embed_url || '', description || '', icon || '', category || '默认', sort_order || 0, use_proxy ? 1 : 0, version || '',
     d.proxy_headers !== undefined ? d.proxy_headers : existing.proxy_headers,
     d.proxy_skip_tls_verify !== undefined ? d.proxy_skip_tls_verify : existing.proxy_skip_tls_verify,
     d.permissions !== undefined ? d.permissions : existing.permissions,
     d.scale !== undefined ? d.scale : existing.scale,
     d.trusted !== undefined ? d.trusted : existing.trusted,
     d.slug !== undefined ? d.slug : (existing.slug || uniqueSlug(makeSlug(existing.title))),
     req.params.id]);
  res.json(db.get('SELECT * FROM admin_links WHERE id = ?', [req.params.id]));
});

router.delete('/:id', authMiddleware, adminOnly, (req, res) => {
  if (!db.get('SELECT id FROM admin_links WHERE id = ?', [req.params.id]))
    return res.status(404).json({ error: '链接不存在' });
  db.run('DELETE FROM admin_links WHERE id = ?', [req.params.id]);
  res.json({ message: '删除成功' });
});

module.exports = router;