const TeacherService = require('../services/teacherService');
const { success, error } = require('../utils/response');

class TeacherController {
    static async getCourses(req, res) {
        try {
            const teacherId = req.session.user.id; // 注意：这里假设 user.id 就是 teacher_id，需要根据 users 表设计确认
            // 在之前的 SQL 中，courses.teacher_id 是 INT，而 users.id 是 VARCHAR。
            // 这里可能存在类型不匹配的问题。
            // 假设 users 表中 id 既是学号/工号，也是关联键。
            // 实际上，之前的 teacher.js 中是直接用 req.session.user.id 查询。
            
            const courses = await TeacherService.getCourses(teacherId);
            success(res, { courses });
        } catch (err) {
            console.error('Get Courses Error:', err);
            error(res, '服务器错误');
        }
    }

    static async getClasses(req, res) {
        try {
            const classes = await TeacherService.getClasses();
            success(res, { classes });
        } catch (err) {
             console.error('Get Classes Error:', err);
             error(res, '服务器错误');
        }
    }

    static async getMyClasses(req, res) {
        try {
            const teacherId = req.session.user.id;
            const classes = await TeacherService.getTeacherClasses(teacherId);
            success(res, { classes });
        } catch (err) {
            console.error('Get My Classes Error:', err);
            error(res, '服务器错误');
        }
    }

    static async createCourse(req, res) {
        try {
            const teacherId = req.session.user.id;
            const courseId = await TeacherService.createCourse(teacherId, req.body);
            success(res, { courseId }, '课程创建成功');
        } catch (err) {
            console.error('Create Course Error:', err);
            error(res, '服务器错误');
        }
    }

    static async updateCourse(req, res) {
        try {
            const teacherId = req.session.user.id;
            const courseId = req.params.id;
            await TeacherService.updateCourse(teacherId, courseId, req.body);
            success(res, null, '课程更新成功');
        } catch (err) {
            if (err.message === '无权修改该课程或课程不存在') {
                return error(res, err.message, 403);
            }
            console.error('Update Course Error:', err);
            error(res, '服务器错误');
        }
    }

    static async getGrades(req, res) {
        try {
            const teacherId = req.session.user.id;
            const filters = {
                courseId: req.query.courseId,
                studentName: req.query.studentName
            };
            const grades = await TeacherService.getGrades(teacherId, filters);
            success(res, { grades });
        } catch (err) {
            console.error('Get Grades Error:', err);
            error(res, '服务器错误');
        }
    }

    static async addScore(req, res) {
        try {
            const teacherId = req.session.user.id;
            const { studentId, courseId, score } = req.body;

            if (!studentId || !courseId || score === undefined) {
                return error(res, '请填写必填字段', 400);
            }

            const gradeId = await TeacherService.addScore(teacherId, req.body);
            success(res, { gradeId }, '成绩录入成功');
        } catch (err) {
            if (err.message === '学生不存在' || err.message === '该学生此课程成绩已存在') {
                return error(res, err.message, 400);
            }
            console.error('Add Score Error:', err);
            error(res, '服务器错误');
        }
    }
}

module.exports = TeacherController;