package service

import (
	"fmt"

	"dd_fiber_api/internal/question"
	"dd_fiber_api/internal/question/dao"
)

// QuestionService 题目服务
type QuestionService struct {
	questionDAO dao.QuestionDAOInterface
}

// NewQuestionService 创建题目服务
func NewQuestionService(questionDAO dao.QuestionDAOInterface) *QuestionService {
	return &QuestionService{
		questionDAO: questionDAO,
	}
}

// CreateQuestion 创建题目
func (s *QuestionService) CreateQuestion(req *CreateQuestionRequest) (*question.Question, error) {
	questionID := question.GenerateID()

	// 确保 KnowledgeTreeIds 不为 nil
	knowledgeTreeIds := req.KnowledgeTreeIds
	if knowledgeTreeIds == nil {
		knowledgeTreeIds = []string{}
	}

	questionObj := &question.Question{
		ID:               questionID,
		Type:             question.QuestionType(req.Type),
		Name:             req.Name,
		Source:           req.Source,
		MaterialID:       req.MaterialID,
		Content:          req.Content,
		Options:          req.Options,
		Answer:           req.Answer,
		Explanation:      req.Explanation,
		KnowledgeTreeIDs: knowledgeTreeIds,
		CreatedAt:        question.GetCurrentTimestamp(),
		UpdatedAt:        question.GetCurrentTimestamp(),
	}

	err := s.questionDAO.Create(questionObj)
	if err != nil {
		return nil, fmt.Errorf("创建题目失败: %v", err)
	}

	return questionObj, nil
}

// GetQuestion 获取题目
func (s *QuestionService) GetQuestion(id string) (*question.Question, error) {
	questionObj, err := s.questionDAO.GetByID(id)
	if err != nil {
		return nil, fmt.Errorf("题目不存在: %v", err)
	}

	return questionObj, nil
}

// SearchQuestions 搜索题目
func (s *QuestionService) SearchQuestions(query string, qType question.QuestionType, knowledgeTreeIds []string, page, pageSize int32) ([]*question.Question, int32, error) {
	questions, total, err := s.questionDAO.Search(query, qType, knowledgeTreeIds, page, pageSize)
	if err != nil {
		return nil, 0, fmt.Errorf("搜索题目失败: %v", err)
	}

	return questions, total, nil
}

// UpdateQuestion 更新题目
func (s *QuestionService) UpdateQuestion(req *UpdateQuestionRequest) error {
	// 获取现有题目
	questionObj, err := s.questionDAO.GetByID(req.Id)
	if err != nil {
		return fmt.Errorf("题目不存在: %v", err)
	}

	// 确保 KnowledgeTreeIds 不为 nil
	knowledgeTreeIds := req.KnowledgeTreeIds
	if knowledgeTreeIds == nil {
		knowledgeTreeIds = []string{}
	}

	// 更新字段
	questionObj.Type = question.QuestionType(req.Type)
	questionObj.Name = req.Name
	questionObj.Source = req.Source
	questionObj.MaterialID = req.MaterialID
	questionObj.Content = req.Content
	questionObj.Options = req.Options
	questionObj.Answer = req.Answer
	questionObj.Explanation = req.Explanation
	questionObj.KnowledgeTreeIDs = knowledgeTreeIds
	questionObj.UpdatedAt = question.GetCurrentTimestamp()

	// 保存
	err = s.questionDAO.Update(questionObj)
	if err != nil {
		return fmt.Errorf("更新题目失败: %v", err)
	}

	return nil
}

// DeleteQuestion 删除题目
func (s *QuestionService) DeleteQuestion(id string) error {
	err := s.questionDAO.Delete(id)
	if err != nil {
		return fmt.Errorf("删除题目失败: %v", err)
	}

	return nil
}

// BatchDeleteQuestions 批量删除题目
func (s *QuestionService) BatchDeleteQuestions(ids []string) (int, []string, error) {
	deletedCount, failedIDs, err := s.questionDAO.BatchDelete(ids)
	if err != nil {
		return 0, nil, fmt.Errorf("批量删除失败: %v", err)
	}

	return deletedCount, failedIDs, nil
}

// CreateQuestionRequest 创建题目请求
type CreateQuestionRequest struct {
	Type             int32    `json:"type"`
	Name             string   `json:"name,omitempty"`        // 题目名称（可选）
	Source           string   `json:"source,omitempty"`      // 题目出处（可选）
	MaterialID       string   `json:"material_id,omitempty"` // 关联材料ID（可选）
	Content          string   `json:"content"`
	Options          []string `json:"options"`
	Answer           string   `json:"answer"`
	Explanation      string   `json:"explanation"`
	KnowledgeTreeIds []string `json:"knowledge_tree_ids"` // 关联的知识树ID列表（替代原来的tags）
}

// UpdateQuestionRequest 更新题目请求
type UpdateQuestionRequest struct {
	Id               string   `json:"id"`
	Type             int32    `json:"type"`
	Name             string   `json:"name,omitempty"`        // 题目名称（可选）
	Source           string   `json:"source,omitempty"`      // 题目出处（可选）
	MaterialID       string   `json:"material_id,omitempty"` // 关联材料ID（可选）
	Content          string   `json:"content"`
	Options          []string `json:"options"`
	Answer           string   `json:"answer"`
	Explanation      string   `json:"explanation"`
	KnowledgeTreeIds []string `json:"knowledge_tree_ids"` // 关联的知识树ID列表（替代原来的tags）
}