feat: 多班级版 v2.0 - Go后端重写 + 43轮代码审查

- 后端从 Python FastAPI 重写为 Go Gin（端口 56789）
- 多班级完全隔离
- 超级管理员独立登录
- 课代表作业管理、排行榜分项排行
- 角色加减分上下限可配置
- 家长改密功能（可开关）
- 周度/月度重置功能
- MySQL 5.7 兼容
- 43轮代码审查+全部修复
- Apache 2.0 许可证

backend-go/internal/handler/student_handler.go

@@ -0,0 +1,192 @@
+// ===========================================
+// 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 handler
+
+import (
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/middleware"
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/repository"
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/schema"
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/internal/service"
+	"hz-gitea.sea-studio.top/canglan/SharedClassManager/pkg/response"
+)
+
+// StudentHandler 学生端处理器
+type StudentHandler struct {
+	studentService *service.StudentService
+	classRepo      *repository.ClassRepo
+}
+
+// NewStudentHandler 创建学生端处理器
+func NewStudentHandler(studentService *service.StudentService, classRepo *repository.ClassRepo) *StudentHandler {
+	return &StudentHandler{studentService: studentService, classRepo: classRepo}
+}
+
+// Dashboard 学生个人信息（仪表盘）
+func (h *StudentHandler) Dashboard(c *gin.Context) {
+	studentID := middleware.GetStudentID(c)
+	if studentID == 0 {
+		response.BadRequest(c, "非学生用户")
+		return
+	}
+
+	result, err := h.studentService.GetStudentInfo(studentID)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// resolveStudentID 校验学生归属：学生只能查看自己的数据，家长只能查看关联子女，管理员可查看指定学生
+func (h *StudentHandler) resolveStudentID(c *gin.Context) (int, bool) {
+	userType := middleware.GetUserType(c)
+	if userType == "student" {
+		// 学生只能查看自己的数据，忽略 URL 参数中的 student_id
+		studentID := middleware.GetStudentID(c)
+		if studentID == 0 {
+			response.BadRequest(c, "非学生用户")
+			return 0, false
+		}
+		return studentID, true
+	}
+
+	requestedID, ok := parseID(c, "student_id")
+	if !ok {
+		return 0, false
+	}
+
+	// 家长只能查看自己关联的子女数据
+	if userType == "parent" {
+		parentStudentID := middleware.GetStudentID(c)
+		if parentStudentID == 0 || parentStudentID != requestedID {
+			response.Forbidden(c, "无权访问该学生数据")
+			return 0, false
+		}
+		return requestedID, true
+	}
+
+	// 管理员/超级管理员允许查看（角色权限由路由中间件 RequireRole 控制）
+	return requestedID, true
+}
+
+// ConductHistory 学生操行分历史
+func (h *StudentHandler) ConductHistory(c *gin.Context) {
+	studentID, ok := h.resolveStudentID(c)
+	if !ok {
+		return
+	}
+
+	var query schema.StudentConductQuery
+	if err := c.ShouldBindQuery(&query); err != nil {
+		response.BadRequest(c, "参数错误")
+		return
+	}
+
+	result, err := h.studentService.GetConductHistory(studentID, query.Limit, query.Offset)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// Homework 学生作业情况
+func (h *StudentHandler) Homework(c *gin.Context) {
+	studentID, ok := h.resolveStudentID(c)
+	if !ok {
+		return
+	}
+
+	result, err := h.studentService.GetHomeworkStatus(studentID)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// Attendance 学生考勤记录
+func (h *StudentHandler) Attendance(c *gin.Context) {
+	studentID, ok := h.resolveStudentID(c)
+	if !ok {
+		return
+	}
+
+	month := c.Query("month")
+	result, err := h.studentService.GetAttendanceRecords(studentID, month)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// Ranking 操行分排行
+func (h *StudentHandler) Ranking(c *gin.Context) {
+	classID := middleware.GetClassID(c)
+
+	// 检查班级功能开关：学生查看排行榜
+	feature, err := h.classRepo.GetFeature(classID, "student_view_ranking")
+	if err == nil && feature != nil && feature.Enabled == 0 {
+		response.Forbidden(c, "该功能暂未开放")
+		return
+	}
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "50"))
+	if limit <= 0 {
+		limit = 50
+	}
+	if limit > 500 {
+		limit = 500
+	}
+
+	result, err := h.studentService.GetRanking(classID, limit)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// MyInfo 学生个人信息
+func (h *StudentHandler) MyInfo(c *gin.Context) {
+	studentID := middleware.GetStudentID(c)
+	if studentID == 0 {
+		response.BadRequest(c, "非学生用户")
+		return
+	}
+
+	result, err := h.studentService.GetStudentInfo(studentID)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}
+
+// SemesterRecords 学期归档记录
+func (h *StudentHandler) SemesterRecords(c *gin.Context) {
+	studentID := middleware.GetStudentID(c)
+	if studentID <= 0 {
+		response.BadRequest(c, "非学生用户")
+		return
+	}
+	result, err := h.studentService.GetSemesterRecords(studentID)
+	if err != nil {
+		response.InternalError(c, err.Error())
+		return
+	}
+	response.Success(c, result, "操作成功")
+}