import { Router, Response } from 'express'
import multer from 'multer'
import path from 'path'
import fs from 'fs'
import pool from '../db/connection'
import { AuthRequest } from '../middleware/auth'

const router = Router()

// 头像上传配置
const UPLOAD_DIR = process.env.UPLOAD_DIR || './uploads'
const AVATAR_DIR = path.resolve(UPLOAD_DIR, 'avatars')
if (!fs.existsSync(AVATAR_DIR)) {
  fs.mkdirSync(AVATAR_DIR, { recursive: true })
}

const storage = multer.diskStorage({
  destination: (_req, _file, cb) => {
    // 确保目录存在（可能被手动删除）
    if (!fs.existsSync(AVATAR_DIR)) {
      fs.mkdirSync(AVATAR_DIR, { recursive: true })
    }
    cb(null, AVATAR_DIR)
  },
  filename: (req: AuthRequest, file, cb) => {
    const extMap: Record<string, string> = {
      'image/jpeg': '.jpg', 'image/png': '.png', 'image/webp': '.webp'
    }
    const ext = extMap[file.mimetype] || '.jpg'
    cb(null, `${req.userId}_${Date.now()}${ext}`)
  }
})

const upload = multer({
  storage,
  limits: { fileSize: 2 * 1024 * 1024 }, // 最大 2MB
  fileFilter: (_req, file, cb) => {
    const allowed = ['image/jpeg', 'image/png', 'image/webp']
    if (allowed.includes(file.mimetype)) {
      cb(null, true)
    } else {
      cb(new Error('仅支持 JPEG、PNG、WebP 格式'))
    }
  }
})

/** 获取当前用户信息 */
router.get('/me', async (req: AuthRequest, res: Response) => {
  try {
    const [rows] = await pool.query(
      'SELECT id, nickname, avatar_url, slogan, role, created_at FROM users WHERE id = ? AND deleted_at IS NULL',
      [req.userId]
    )
    const user = (rows as any[])[0]
    if (!user) {
      return res.status(404).json({ code: 40400, message: '用户不存在' })
    }
    res.json({ code: 0, data: user })
  } catch (err) {
    console.error('[User] GET /me error:', err)
    res.status(500).json({ code: 50000, message: '服务器错误' })
  }
})

/** 更新用户昵称/签名 */
router.put('/me', async (req: AuthRequest, res: Response) => {
  try {
    const { nickname, slogan } = req.body

    if (nickname !== undefined) {
      if (typeof nickname !== 'string' || nickname.trim().length === 0) {
        return res.status(400).json({ code: 40001, message: '昵称不能为空' })
      }
      if (nickname.length > 50) {
        return res.status(400).json({ code: 40001, message: '昵称不能超过50个字符' })
      }
    }

    if (slogan !== undefined) {
      if (typeof slogan !== 'string') {
        return res.status(400).json({ code: 40001, message: '签名格式错误' })
      }
      if (slogan.length > 100) {
        return res.status(400).json({ code: 40001, message: '签名不能超过100个字符' })
      }
    }

    const updates: string[] = []
    const params: any[] = []

    if (nickname !== undefined) {
      updates.push('nickname = ?')
      params.push(nickname.trim())
    }

    if (slogan !== undefined) {
      updates.push('slogan = ?')
      params.push(slogan.trim())
    }

    if (updates.length === 0) {
      return res.status(400).json({ code: 40001, message: '没有需要更新的字段' })
    }

    params.push(req.userId)
    await pool.query(`UPDATE users SET ${updates.join(', ')} WHERE id = ?`, params)

    res.json({ code: 0 })
  } catch (err) {
    console.error('[User] PUT /me error:', err)
    res.status(500).json({ code: 50000, message: '服务器错误' })
  }
})

/** 上传头像 */
router.post('/avatar', (req: AuthRequest, res: Response) => {
  upload.single('file')(req, res, async (err) => {
    if (err) {
      return res.status(400).json({ code: 40001, message: err.message })
    }
    if (!req.file) {
      return res.status(400).json({ code: 40001, message: '请选择图片文件' })
    }
    try {
      // 先查询旧头像
      const [rows] = await pool.query('SELECT avatar_url FROM users WHERE id = ? AND deleted_at IS NULL', [req.userId])
      const oldUrl = (rows as any[])[0]?.avatar_url

      // 先更新 DB，再删旧文件（保证 DB 和文件至少有一个正确）
      await pool.query('UPDATE users SET avatar_url = ? WHERE id = ?', [req.file.filename, req.userId])

      if (oldUrl) {
        const oldPath = path.join(AVATAR_DIR, oldUrl)
        if (fs.existsSync(oldPath)) {
          try {
            fs.unlinkSync(oldPath)
          } catch (e) {
            console.warn('[User] 删除旧头像失败:', e)
          }
        }
      }

      res.json({ code: 0, data: { avatar_url: req.file.filename } })
    } catch (err) {
      console.error('[User] avatar upload error:', err)
      res.status(500).json({ code: 50000, message: '服务器错误' })
    }
  })
})

export default router