add

server/internal/db/exam_active.go

@@ -0,0 +1,52 @@
+package db
+
+import (
+	"time"
+
+	"server/internal/models"
+
+	"gorm.io/gorm"
+)
+
+// ActiveExamInfo — phòng thi đang diễn ra cho sinh viên
+type ActiveExamInfo struct {
+	Room       models.ExamRoom
+	Enrollment models.ExamRoomStudent
+	Paper      *models.ExamPaper
+}
+
+// FindActiveExamForStudent trả về phòng thi nếu sinh viên đang trong khung giờ thi.
+func FindActiveExamForStudent(db *gorm.DB, studentRkID int64) *ActiveExamInfo {
+	if studentRkID <= 0 {
+		return nil
+	}
+	now := time.Now()
+	var enrollment models.ExamRoomStudent
+	err := db.Table("exam_room_students AS ers").
+		Select("ers.*").
+		Joins("JOIN exam_rooms er ON er.id = ers.exam_room_id").
+		Where("ers.student_rk_id = ? AND er.status = ? AND er.start_time <= ? AND er.end_time >= ?",
+			studentRkID, models.ExamStatusReady, now, now).
+		Order("er.start_time DESC").
+		First(&enrollment).Error
+	if err != nil {
+		return nil
+	}
+	var room models.ExamRoom
+	if err := db.First(&room, enrollment.ExamRoomID).Error; err != nil {
+		return nil
+	}
+	info := &ActiveExamInfo{Room: room, Enrollment: enrollment}
+	if enrollment.AssignedPaperID != nil {
+		var paper models.ExamPaper
+		if err := db.First(&paper, *enrollment.AssignedPaperID).Error; err == nil {
+			info.Paper = &paper
+		}
+	}
+	return info
+}
+
+// IsStudentInActiveExam kiểm tra nhanh sinh viên có đang thi không.
+func IsStudentInActiveExam(db *gorm.DB, studentRkID int64) bool {
+	return FindActiveExamForStudent(db, studentRkID) != nil
+}