feat: 多班级版班级管理系统 v2.0

技术栈：Go (Gin + GORM) + PHP + MySQL 5.7 + Redis

主要功能：
- 多班级完全隔离（class_id 贯穿全系统）
- 后端 Go Gin（端口 56789），Nginx 反代
- 超级管理员独立登录（env 配置，默认账密 admin/Admin123）
- bcrypt 密码加密（无 PASSWORD_SALT）
- 科任老师/课代表新角色
- 课代表作业管理页面
- 排行榜分项排行（操行分/考勤/作业）
- 角色加减分上下限由班主任配置
- 家长改密功能（可开关）
- 班级角色按需开关
- 宿舍号格式：南0-000
- 周度/月度重置功能
- MySQL 5.7 兼容
- 43 轮代码审查 + 全部修复

开发者: Canglan
版权归属: Sea Network Technology Studio
许可证: Apache License 2.0

backend-go/internal/service/student_service.go

@@ -0,0 +1,171 @@
+// ===========================================
+// 多班级版班级管理系统 - Go 后端
+//
+// 开发者: Canglan
+// 联系方式: admin@sea-studio.top
+// 版权归属: Sea Network Technology Studio
+// 许可证: Apache License 2.0
+//
+// 版权所有 © Sea Network Technology Studio
+// ===========================================
+
+package service
+
+import (
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/repository"
+)
+
+// StudentService 学生端服务
+type StudentService struct {
+	studentRepo    *repository.StudentRepo
+	conductRepo    *repository.ConductRepo
+	attendanceRepo *repository.AttendanceRepo
+	semesterRepo   *repository.SemesterRepo
+}
+
+// NewStudentService 创建学生端服务
+func NewStudentService(
+	studentRepo *repository.StudentRepo,
+	conductRepo *repository.ConductRepo,
+	attendanceRepo *repository.AttendanceRepo,
+	semesterRepo *repository.SemesterRepo,
+) *StudentService {
+	return &StudentService{
+		studentRepo:    studentRepo,
+		conductRepo:    conductRepo,
+		attendanceRepo: attendanceRepo,
+		semesterRepo:   semesterRepo,
+	}
+}
+
+// GetStudentInfo 获取学生个人信息
+func (s *StudentService) GetStudentInfo(studentID int) (map[string]interface{}, error) {
+	student, err := s.studentRepo.GetByID(studentID)
+	if err != nil {
+		return nil, err
+	}
+	return map[string]interface{}{
+		"student": student,
+	}, nil
+}
+
+// GetConductHistory 获取学生操行分历史
+func (s *StudentService) GetConductHistory(studentID int, limit, offset int) (map[string]interface{}, error) {
+	student, err := s.studentRepo.GetByID(studentID)
+	if err != nil {
+		return nil, err
+	}
+
+	records, err := s.conductRepo.GetStudentRecords(studentID, limit, offset, false, "", "", 0)
+	if err != nil {
+		return nil, err
+	}
+
+	// 扣分项的操作人统一显示为"班主任"
+	for i := range records {
+		if records[i].PointsChange < 0 {
+			name := "班主任"
+			records[i].RecorderReal = &name
+		}
+	}
+
+	return map[string]interface{}{
+		"student_id":   studentID,
+		"student_name": student.Name,
+		"total_points": student.TotalPoints,
+		"records":      records,
+	}, nil
+}
+
+// GetHomeworkStatus 获取学生作业情况
+func (s *StudentService) GetHomeworkStatus(studentID int) (map[string]interface{}, error) {
+	student, err := s.studentRepo.GetByID(studentID)
+	if err != nil {
+		return nil, err
+	}
+
+	records, err := s.conductRepo.GetStudentRecords(studentID, 1000, 0, false, "", "", 0)
+	if err != nil {
+		return nil, err
+	}
+
+	// 过滤出作业相关记录
+	var homeworkRecords []interface{}
+	for _, r := range records {
+		if r.RelatedType == "homework" {
+			homeworkRecords = append(homeworkRecords, r)
+		}
+	}
+
+	return map[string]interface{}{
+		"student_id":   studentID,
+		"student_name": student.Name,
+		"homework":     homeworkRecords,
+	}, nil
+}
+
+// GetAttendanceRecords 获取学生考勤记录
+func (s *StudentService) GetAttendanceRecords(studentID int, month string) (map[string]interface{}, error) {
+	student, err := s.studentRepo.GetByID(studentID)
+	if err != nil {
+		return nil, err
+	}
+
+	records, err := s.attendanceRepo.GetStudentRecords(studentID, month)
+	if err != nil {
+		return nil, err
+	}
+
+	// 统计
+	present, absent, late, leave := 0, 0, 0, 0
+	for _, r := range records {
+		switch r.Status {
+		case "present":
+			present++
+		case "absent":
+			absent++
+		case "late":
+			late++
+		case "leave":
+			leave++
+		}
+	}
+
+	return map[string]interface{}{
+		"student_id":   studentID,
+		"student_name": student.Name,
+		"statistics": map[string]interface{}{
+			"present": present,
+			"absent":  absent,
+			"late":    late,
+			"leave":   leave,
+			"total":   len(records),
+		},
+		"records": records,
+	}, nil
+}
+
+// GetRanking 获取排行榜
+func (s *StudentService) GetRanking(classID int, limit int) (map[string]interface{}, error) {
+	ranking, err := s.studentRepo.GetRanking(classID, limit)
+	if err != nil {
+		return nil, err
+	}
+	totalStudents, _ := s.studentRepo.GetTotalCount(classID)
+
+	return map[string]interface{}{
+		"ranking":        ranking,
+		"total_students": totalStudents,
+	}, nil
+}
+
+// GetSemesterRecords 获取学生学期归档记录
+func (s *StudentService) GetSemesterRecords(studentID int) (map[string]interface{}, error) {
+	archives, err := s.semesterRepo.GetArchivesByStudent(studentID)
+	if err != nil {
+		return nil, err
+	}
+	return map[string]interface{}{
+		"records": archives,
+	}, nil
+}