const fs = require('fs');
const path = require('path');
const xlsx = require('xlsx');
const pool = require('../db');

const classManager = {
    addClass: async (req, res) => {
        // 创建students表的SQL语句
        const createTableQuery = `
        CREATE TABLE IF NOT EXISTS students (
            student_id INT AUTO_INCREMENT PRIMARY KEY,
            student_name VARCHAR(255) NOT NULL,
            score DECIMAL(5, 2),
            call_count INT DEFAULT 0
        );
        `;
        try {
            // 先创建表
            await pool.query(createTableQuery);

            const filePath = req.file.path;

            // 读取并解析Excel文件
            const workbook = xlsx.readFile(filePath);
            const sheetName = workbook.SheetNames[0];
            const worksheet = workbook.Sheets[sheetName];

            const students = xlsx.utils.sheet_to_json(worksheet);

            // 定义所需的字段
            const requiredFields = ['student_id','student_name'];
            let hasError = false;

            students.forEach(student => {
                // 数据验证
                const missingFields = requiredFields.filter(field =>!(field in student));
                if (missingFields.length > 0) {
                    console.error(`Student data is missing fields: ${missingFields.join(', ')}`);
                    hasError = true;
                    return;
                }

                // 将学生数据插入数据库
                const query = 'INSERT INTO students (student_id, student_name, score, call_count) VALUES (?,?, 2, 0)';
                pool.query(query, [student.student_id, student.student_name], (error) => {
                    if (error) {
                        console.error(`Error inserting student: ${student.name}`, error);
                        hasError = true;
                    }
                });
            });

            if (hasError) {
                res.status(500).json({ message: 'Error adding class. Some students were not added successfully.' });
            } else {
                res.status(200).json({ message: 'Class added successfully!' });
            }
        } catch (err) {
            console.error('Error creating students table:', err);
            res.status(500).json({ message: 'Error creating table during class addition.' });
        }
    }
};

module.exports = classManager;