AnCao/internal/handlers/exam_grading.go

package handlers

import (
	"ankao/internal/database"
	"ankao/internal/models"
	"ankao/internal/services"
	"encoding/json"
	"fmt"
	"log"

	"gorm.io/datatypes"
)

// ReGradeExam 公开的重新阅卷函数,可被外部调用
func ReGradeExam(recordID uint, examID uint, userID uint) {
	gradeExam(recordID, examID, userID)
}

// gradeExam 异步阅卷函数
func gradeExam(recordID uint, examID uint, userID uint) {
	db := database.GetDB()

	// 查询考试记录
	var record models.ExamRecord
	if err := db.Where("id = ?", recordID).First(&record).Error; err != nil {
		log.Printf("查询考试记录失败: %v", err)
		return
	}

	// 查询试卷
	var exam models.Exam
	if err := db.Where("id = ?", examID).First(&exam).Error; err != nil {
		log.Printf("查询试卷失败: %v", err)
		return
	}

	// 从 ExamUserAnswer 表读取所有答案
	var userAnswers []models.ExamUserAnswer
	if err := db.Where("exam_record_id = ?", recordID).Find(&userAnswers).Error; err != nil {
		log.Printf("查询用户答案失败: %v", err)
		return
	}

	// 转换为 map 格式方便查找
	answersMap := make(map[int64]interface{})
	for _, ua := range userAnswers {
		var answer interface{}
		if err := json.Unmarshal(ua.Answer, &answer); err != nil {
			log.Printf("解析答案失败: %v", err)
			continue
		}
		answersMap[ua.QuestionID] = answer
	}

	// 解析题目ID列表
	var questionIDs []uint
	if err := json.Unmarshal(exam.QuestionIDs, &questionIDs); err != nil {
		log.Printf("解析题目ID失败: %v", err)
		return
	}

	// 查询题目详情
	var questions []models.PracticeQuestion
	if err := db.Where("id IN ?", questionIDs).Find(&questions).Error; err != nil {
		log.Printf("查询题目失败: %v", err)
		return
	}

	// 使用固定的题型分值映射
	scoreMap := map[string]float64{
		"fill-in-blank":      2.0,
		"true-false":         2.0,
		"multiple-choice":    1.0,
		"multiple-selection": 2.5,
		"short-answer":       10.0,
		"ordinary-essay":     5.0,
		"management-essay":   5.0,
	}

	// 评分
	totalScore := 0.0
	aiService := services.NewAIGradingService()

	for _, question := range questions {
		userAnswerRaw, answered := answersMap[question.ID]

		if !answered {
			// 更新数据库中的 ExamUserAnswer 记录为未作答
			var userAnswer models.ExamUserAnswer
			result := db.Where("exam_record_id = ? AND question_id = ?", recordID, question.ID).First(&userAnswer)
			if result.Error == nil {
				updates := map[string]interface{}{
					"is_correct": false,
					"score":      0.0,
				}
				db.Model(&userAnswer).Updates(updates)
			}
			continue
		}

		// 根据题型判断答案
		var isCorrect bool
		var score float64
		var aiGrading *models.AIGrading

		switch question.Type {
		case "fill-in-blank":
			// 填空题：比较数组
			userAnswerArr, ok := userAnswerRaw.([]interface{})
			if !ok {
				isCorrect = false
				score = 0
				// 更新数据库
				var userAnswer models.ExamUserAnswer
				if result := db.Where("exam_record_id = ? AND question_id = ?", recordID, question.ID).First(&userAnswer); result.Error == nil {
					db.Model(&userAnswer).Updates(map[string]interface{}{
						"is_correct": false,
						"score":      0.0,
					})
				}
				continue
			}
			var correctAnswers []string
			if err := json.Unmarshal([]byte(question.AnswerData), &correctAnswers); err != nil {
				log.Printf("解析填空题答案失败: %v", err)
				continue
			}
			isCorrect = len(userAnswerArr) == len(correctAnswers)
			if isCorrect {
				for i, ua := range userAnswerArr {
					if i >= len(correctAnswers) || fmt.Sprintf("%v", ua) != correctAnswers[i] {
						isCorrect = false
						break
					}
				}
			}
			if isCorrect {
				score = scoreMap["fill-in-blank"]
			}

		case "true-false":
			// 判断题 - AnswerData 直接存储 "true" 或 "false" 字符串
			correctAnswer := question.AnswerData
			isCorrect = fmt.Sprintf("%v", userAnswerRaw) == correctAnswer
			if isCorrect {
				score = scoreMap["true-false"]
			}

		case "multiple-choice":
			correctAnswer := question.AnswerData
			isCorrect = fmt.Sprintf("\"%v\"", userAnswerRaw) == correctAnswer
			if isCorrect {
				score = scoreMap["multiple-choice"]
			}
		case "multiple-selection":
			// 多选题：比较数组（顺序无关）
			userAnswerArr, ok := userAnswerRaw.([]interface{})
			if !ok {
				isCorrect = false
				score = 0
				// 更新数据库
				var userAnswer models.ExamUserAnswer
				if result := db.Where("exam_record_id = ? AND question_id = ?", recordID, question.ID).First(&userAnswer); result.Error == nil {
					db.Model(&userAnswer).Updates(map[string]interface{}{
						"is_correct": false,
						"score":      0.0,
					})
				}
				continue
			}
			var correctAnswers []string
			if err := json.Unmarshal([]byte(question.AnswerData), &correctAnswers); err != nil {
				log.Printf("解析多选题答案失败: %v", err)
				continue
			}
			userAnswerSet := make(map[string]bool)
			for _, ua := range userAnswerArr {
				userAnswerSet[fmt.Sprintf("%v", ua)] = true
			}
			isCorrect = len(userAnswerSet) == len(correctAnswers)
			if isCorrect {
				for _, ca := range correctAnswers {
					if !userAnswerSet[ca] {
						isCorrect = false
						break
					}
				}
			}
			if isCorrect {
				score = scoreMap["multiple-selection"]
			}

		case "short-answer", "ordinary-essay", "management-essay":
			// 简答题和论述题：使用AI评分
			// AnswerData 直接存储答案文本
			correctAnswer := question.AnswerData
			userAnswerStr := fmt.Sprintf("%v", userAnswerRaw)
			aiResult, err := aiService.GradeShortAnswer(question.Question, correctAnswer, userAnswerStr)
			if err != nil {
				log.Printf("AI评分失败: %v", err)
				isCorrect = false
				score = 0
			} else {
				isCorrect = aiResult.IsCorrect
				// 按AI评分比例计算
				var questionScore float64
				if question.Type == "short-answer" {
					questionScore = scoreMap["short-answer"]
				} else if question.Type == "ordinary-essay" {
					questionScore = scoreMap["ordinary-essay"]
				} else if question.Type == "management-essay" {
					questionScore = scoreMap["management-essay"]
				}
				score = questionScore * (aiResult.Score / 100.0)
				aiGrading = &models.AIGrading{
					Score:      aiResult.Score,
					Feedback:   aiResult.Feedback,
					Suggestion: aiResult.Suggestion,
				}
			}
		}

		totalScore += score

		// 更新数据库中的 ExamUserAnswer 记录
		var userAnswer models.ExamUserAnswer
		result := db.Where("exam_record_id = ? AND question_id = ?", recordID, question.ID).First(&userAnswer)
		if result.Error == nil {
			// 序列化 AI 评分数据
			var aiGradingJSON datatypes.JSON
			if aiGrading != nil {
				aiGradingData, _ := json.Marshal(aiGrading)
				aiGradingJSON = datatypes.JSON(aiGradingData)
			}

			// 更新评分结果
			updates := map[string]interface{}{
				"is_correct":      isCorrect,
				"score":           score,
				"ai_grading_data": aiGradingJSON,
			}
			db.Model(&userAnswer).Updates(updates)
		}
	}

	// 保存分数和状态到考试记录
	record.Score = totalScore
	record.Status = "graded"
	record.IsPassed = totalScore >= float64(exam.PassScore)

	if err := db.Save(&record).Error; err != nil {
		log.Printf("保存考试记录失败: %v", err)
		return
	}

	log.Printf("阅卷完成: 考试记录ID=%d, 总分=%.2f, 是否通过=%v", recordID, totalScore, record.IsPassed)
}