const db = require('../config/database');

class Course {
    static async findByTeacherId(teacherId) {
        return await db.query(
            'SELECT * FROM courses WHERE teacher_id = ? ORDER BY course_code',
            [teacherId]
        );
    }
    
    static async findById(id) {
        const rows = await db.query('SELECT * FROM courses WHERE id = ?', [id]);
        return rows[0];
    }

    static async findByStudentId(studentId) {
        const sql = `
            SELECT c.*, u.name as teacher_name
            FROM courses c
            JOIN classes cl ON c.class_id = cl.id
            JOIN students s ON cl.class_name = s.class
            JOIN users u ON c.teacher_id = u.id
            WHERE s.id = ?
            ORDER BY c.course_code
        `;
        return await db.query(sql, [studentId]);
    }
}

module.exports = Course;