const express = require('express');
const multer = require('multer');
const path = require('path');
const fs = require('fs');

const app = express();
const PORT = process.env.PORT || 3000;

// 中间件配置
app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use(express.static('public'));
app.use('/uploads', express.static('uploads'));

// 确保必要的目录存在
const dataDir = path.join(__dirname, 'data');
const uploadsDir = path.join(__dirname, 'uploads');
if (!fs.existsSync(dataDir)) fs.mkdirSync(dataDir);
if (!fs.existsSync(uploadsDir)) fs.mkdirSync(uploadsDir);

// 数据文件路径
const dataFile = path.join(dataDir, 'data.json');

// 初始化数据文件
if (!fs.existsSync(dataFile)) {
  fs.writeFileSync(dataFile, JSON.stringify({ records: [], nextId: 1 }, null, 2));
}

// 读取数据
function readData() {
  const raw = fs.readFileSync(dataFile, 'utf-8');
  return JSON.parse(raw);
}

// 写入数据
function writeData(data) {
  fs.writeFileSync(dataFile, JSON.stringify(data, null, 2));
}

// 配置 multer 图片上传
const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, uploadsDir);
  },
  filename: (req, file, cb) => {
    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
    cb(null, uniqueSuffix + path.extname(file.originalname));
  }
});

const upload = multer({
  storage: storage,
  limits: { fileSize: 5 * 1024 * 1024 }, // 5MB
  fileFilter: (req, file, cb) => {
    const allowedTypes = /jpeg|jpg|png|gif|webp/;
    const extname = allowedTypes.test(path.extname(file.originalname).toLowerCase());
    const mimetype = allowedTypes.test(file.mimetype);
    
    if (extname && mimetype) {
      cb(null, true);
    } else {
      cb(new Error('只支持图片格式：jpeg, jpg, png, gif, webp'));
    }
  }
});

// URL 格式校验
function isValidUrl(string) {
  try {
    const url = new URL(string);
    return url.protocol === 'http:' || url.protocol === 'https:';
  } catch (_) {
    return false;
  }
}

// 格式化时间为精确到分钟
function getFormattedTime() {
  const now = new Date();
  const year = now.getFullYear();
  const month = String(now.getMonth() + 1).padStart(2, '0');
  const day = String(now.getDate()).padStart(2, '0');
  const hours = String(now.getHours()).padStart(2, '0');
  const minutes = String(now.getMinutes()).padStart(2, '0');
  return `${year}-${month}-${day} ${hours}:${minutes}`;
}

// API: 获取所有记录
app.get('/api/list', (req, res) => {
  try {
    const data = readData();
    res.json({ success: true, records: data.records });
  } catch (error) {
    res.status(500).json({ success: false, message: '读取数据失败: ' + error.message });
  }
});

// API: 普通用户提交记录（不含图片）
app.post('/api/submit', (req, res) => {
  try {
    const { name, link, note } = req.body;

    // 数据校验
    if (!name || !name.trim()) {
      return res.status(400).json({ success: false, message: '人名不能为空' });
    }
    if (!link || !link.trim()) {
      return res.status(400).json({ success: false, message: '牌谱链接不能为空' });
    }
    if (!isValidUrl(link)) {
      return res.status(400).json({ success: false, message: '牌谱链接格式不正确' });
    }
    // 备注改为非必填，仅验证长度
    if (note && note.trim() && note.length > 200) {
      return res.status(400).json({ success: false, message: '备注说明不能超过 200 字' });
    }

    const data = readData();

    // 创建新记录（无图片）
    const newRecord = {
      id: data.nextId,
      submitTime: getFormattedTime(),
      name: name.trim(),
      link: link.trim(),
      note: note ? note.trim() : '',
      nagaLink: '',
      nagaNote: '',
      images: []
    };

    data.records.push(newRecord);
    data.nextId += 1;
    writeData(data);

    res.json({ success: true, message: '提交成功', record: newRecord });
  } catch (error) {
    res.status(500).json({ success: false, message: '提交失败: ' + error.message });
  }
});

// API: 管理员更新 Naga 字段和图片
app.post('/api/admin/update', upload.array('images', 10), (req, res) => {
  try {
    const { id, nagaLink, nagaNote, existingImages } = req.body;

    if (!id) {
      return res.status(400).json({ success: false, message: '记录 ID 不能为空' });
    }

    // Naga 链接校验（如果填写）
    if (nagaLink && nagaLink.trim() && !isValidUrl(nagaLink)) {
      return res.status(400).json({ success: false, message: 'Naga 链接格式不正确' });
    }

    // Naga 说明字数校验（如果填写）
    if (nagaNote && nagaNote.length > 200) {
      return res.status(400).json({ success: false, message: 'Naga 说明不能超过 200 字' });
    }

    const data = readData();
    const record = data.records.find(r => r.id === parseInt(id));

    if (!record) {
      return res.status(404).json({ success: false, message: '记录不存在' });
    }

    // 处理新上传的图片
    const newImages = req.files ? req.files.map(file => `/uploads/${file.filename}`) : [];
    
    // 合并已有图片和新图片
    let allImages = [];
    if (existingImages) {
      // existingImages 可能是字符串或数组
      if (typeof existingImages === 'string') {
        try {
          allImages = JSON.parse(existingImages);
        } catch (e) {
          allImages = existingImages ? [existingImages] : [];
        }
      } else if (Array.isArray(existingImages)) {
        allImages = existingImages;
      }
    }
    allImages = [...allImages, ...newImages];

    // 更新 Naga 字段和图片
    record.nagaLink = nagaLink ? nagaLink.trim() : '';
    record.nagaNote = nagaNote ? nagaNote.trim() : '';
    record.images = allImages;

    writeData(data);

    res.json({ success: true, message: '更新成功', record: record });
  } catch (error) {
    res.status(500).json({ success: false, message: '更新失败: ' + error.message });
  }
});

// API: 管理员删除单张图片
app.delete('/api/admin/delete-image', (req, res) => {
  try {
    const { id, imagePath } = req.body;

    if (!id || !imagePath) {
      return res.status(400).json({ success: false, message: '参数不完整' });
    }

    const data = readData();
    const record = data.records.find(r => r.id === parseInt(id));

    if (!record) {
      return res.status(404).json({ success: false, message: '记录不存在' });
    }

    // 从记录中移除图片路径
    const imageIndex = record.images.indexOf(imagePath);
    if (imageIndex > -1) {
      record.images.splice(imageIndex, 1);
    }

    // 删除物理文件
    const filePath = path.join(__dirname, imagePath.replace(/^\//, ''));
    if (fs.existsSync(filePath)) {
      fs.unlinkSync(filePath);
    }

    writeData(data);

    res.json({ success: true, message: '图片删除成功', record: record });
  } catch (error) {
    res.status(500).json({ success: false, message: '删除图片失败: ' + error.message });
  }
});

// API: 删除记录
app.delete('/api/admin/delete/:id', (req, res) => {
  try {
    const id = parseInt(req.params.id);
    const data = readData();
    const index = data.records.findIndex(r => r.id === id);

    if (index === -1) {
      return res.status(404).json({ success: false, message: '记录不存在' });
    }

    // 删除关联的图片文件
    const record = data.records[index];
    if (record.images && record.images.length > 0) {
      record.images.forEach(imagePath => {
        const filePath = path.join(__dirname, imagePath.replace(/^\//, ''));
        if (fs.existsSync(filePath)) {
          fs.unlinkSync(filePath);
        }
      });
    }

    data.records.splice(index, 1);
    writeData(data);

    res.json({ success: true, message: '删除成功' });
  } catch (error) {
    res.status(500).json({ success: false, message: '删除失败: ' + error.message });
  }
});

// 启动服务器
app.listen(PORT, '0.0.0.0', () => {
  console.log(`服务器运行在端口 ${PORT}`);
  console.log(`普通访客页面: http://localhost:${PORT}`);
  console.log(`管理员页面: http://localhost:${PORT}/admin.html`);
});