const express = require('express');
const { db } = require('../database');

const router = express.Router();

router.get('/', (req, res) => {
  const userId = req.user.userId;

  db.all(
    'SELECT date, status, updated_at FROM calendar_marks WHERE user_id = ?',
    [userId],
    (err, rows) => {
      if (err) {
        return res.status(500).json({ success: false, error: '获取数据失败' });
      }

      const markedDates = {};
      rows.forEach((row) => {
        markedDates[row.date] = {
          status: row.status,
          updatedAt: row.updated_at
        };
      });

      res.json({ success: true, markedDates });
    }
  );
});

router.post('/', (req, res) => {
  const userId = req.user.userId;
  const { markedDates } = req.body || {};

  if (!markedDates || typeof markedDates !== 'object') {
    return res.status(400).json({ success: false, error: '无效的数据格式' });
  }

  // Helper function to get current timestamp in ISO format (UTC)
  const getLocalTimestamp = () => {
    return new Date().toISOString();
  };

  const dbOperations = Object.entries(markedDates).map(([date, status]) => {
    return new Promise((resolve, reject) => {
      // First check if this date exists and if status has changed
      db.get(
        'SELECT status FROM calendar_marks WHERE user_id = ? AND date = ?',
        [userId, date],
        (err, row) => {
          if (err) {
            return reject(err);
          }
          
          // Only update timestamp if status changed or it's a new entry
          const statusChanged = !row || row.status !== status;
          
          if (statusChanged) {
            // Status changed - update with new timestamp
            const currentTimestamp = getLocalTimestamp();
            db.run(
              `INSERT INTO calendar_marks (user_id, date, status, updated_at)
               VALUES (?, ?, ?, ?)
               ON CONFLICT(user_id, date) DO UPDATE SET
               status = excluded.status,
               updated_at = excluded.updated_at`,
              [userId, date, status, currentTimestamp],
              (err) => {
                if (err) reject(err);
                else resolve();
              }
            );
          } else {
            // Status unchanged - keep existing timestamp
            db.run(
              `INSERT INTO calendar_marks (user_id, date, status, updated_at)
               VALUES (?, ?, ?, (SELECT updated_at FROM calendar_marks WHERE user_id = ? AND date = ?))
               ON CONFLICT(user_id, date) DO UPDATE SET
               status = excluded.status`,
              [userId, date, status, userId, date],
              (err) => {
                if (err) reject(err);
                else resolve();
              }
            );
          }
        }
      );
    });
  });

  const dates = Object.keys(markedDates);
  if (dates.length > 0) {
    const placeholders = dates.map(() => '?').join(',');
    dbOperations.push(
      new Promise((resolve, reject) => {
        db.run(
          `DELETE FROM calendar_marks WHERE user_id = ? AND date NOT IN (${placeholders})`,
          [userId, ...dates],
          (err) => {
            if (err) reject(err);
            else resolve();
          }
        );
      })
    );
  } else {
    dbOperations.push(
      new Promise((resolve, reject) => {
        db.run(
          'DELETE FROM calendar_marks WHERE user_id = ?',
          [userId],
          (err) => {
            if (err) reject(err);
            else resolve();
          }
        );
      })
    );
  }

  Promise.all(dbOperations)
    .then(() => {
      res.json({ success: true, message: '数据保存成功' });
    })
    .catch((err) => {
      console.error('保存数据失败:', err);
      res.status(500).json({ success: false, error: '保存数据失败' });
    });
});

module.exports = router;