package service

import (
	"fmt"

	"dd_fiber_api/internal/camp"
	"dd_fiber_api/internal/camp/dao"
	"dd_fiber_api/pkg/snowflake"
)

// SectionService 小节服务
type SectionService struct {
	sectionDAO *dao.SectionDAO
	campDAO    *dao.CampDAO
}

// NewSectionService 创建小节服务
func NewSectionService(sectionDAO *dao.SectionDAO, campDAO *dao.CampDAO) *SectionService {
	return &SectionService{
		sectionDAO: sectionDAO,
		campDAO:    campDAO,
	}
}

// CreateSection 创建小节
func (s *SectionService) CreateSection(req *camp.CreateSectionRequest) (*camp.CreateSectionResponse, error) {
	sectionID := snowflake.GetInstance().NextIDString()

	section := &camp.Section{
		ID:                     sectionID,
		CampID:                 req.CampID,
		Title:                  req.Title,
		SectionNumber:          req.SectionNumber,
		PriceFen:               req.PriceFen,
		RequirePreviousSection: req.RequirePreviousSection,
		TimeIntervalType:       req.TimeIntervalType,
		TimeIntervalValue:      req.TimeIntervalValue,
	}

	err := s.sectionDAO.Create(section)
	if err != nil {
		return &camp.CreateSectionResponse{
			Success: false,
			Message: fmt.Sprintf("创建小节失败: %v", err),
		}, nil
	}

	// 更新打卡营的小节数量
	if err := s.campDAO.UpdateSectionCount(req.CampID); err != nil {
		return &camp.CreateSectionResponse{
			Success: false,
			Message: fmt.Sprintf("创建小节成功，但更新打卡营小节数量失败: %v", err),
		}, nil
	}

	return &camp.CreateSectionResponse{
		ID:      sectionID,
		Success: true,
		Message: "创建小节成功",
	}, nil
}

// GetSection 获取小节
func (s *SectionService) GetSection(id string) (*camp.GetSectionResponse, error) {
	section, err := s.sectionDAO.GetByID(id)
	if err != nil {
		return &camp.GetSectionResponse{
			Success: false,
			Message: fmt.Sprintf("获取小节失败: %v", err),
		}, nil
	}

	return &camp.GetSectionResponse{
		Section: section,
		Success: true,
		Message: "获取小节成功",
	}, nil
}

// UpdateSection 更新小节
func (s *SectionService) UpdateSection(req *camp.UpdateSectionRequest) (*camp.UpdateSectionResponse, error) {
	// 先获取原有小节信息，检查 camp_id 是否变更，并保留 require_previous_section 原值（该字段已从管理端移除）
	var oldCampID string
	var existingRequirePreviousSection bool
	if existingSection, err := s.sectionDAO.GetByID(req.ID); err == nil {
		oldCampID = existingSection.CampID
		existingRequirePreviousSection = existingSection.RequirePreviousSection
	}

	section := &camp.Section{
		ID:                     req.ID,
		CampID:                 req.CampID,
		Title:                  req.Title,
		SectionNumber:          req.SectionNumber,
		PriceFen:               req.PriceFen,
		RequirePreviousSection: existingRequirePreviousSection, // 保留原值，不再接受请求体
		TimeIntervalType:       req.TimeIntervalType,
		TimeIntervalValue:      req.TimeIntervalValue,
	}

	err := s.sectionDAO.Update(section)
	if err != nil {
		return &camp.UpdateSectionResponse{
			Success: false,
			Message: fmt.Sprintf("更新小节失败: %v", err),
		}, nil
	}

	// 更新打卡营的小节数量
	// 如果 camp_id 变更，需要更新两个打卡营的数量
	if oldCampID != "" && oldCampID != req.CampID {
		// 更新原打卡营的小节数量
		if err := s.campDAO.UpdateSectionCount(oldCampID); err != nil {
			return &camp.UpdateSectionResponse{
				Success: false,
				Message: fmt.Sprintf("更新小节成功，但更新原打卡营小节数量失败: %v", err),
			}, nil
		}
	}

	// 更新新打卡营的小节数量
	if err := s.campDAO.UpdateSectionCount(req.CampID); err != nil {
		return &camp.UpdateSectionResponse{
			Success: false,
			Message: fmt.Sprintf("更新小节成功，但更新打卡营小节数量失败: %v", err),
		}, nil
	}

	return &camp.UpdateSectionResponse{
		Success: true,
		Message: "更新小节成功",
	}, nil
}

// DeleteSection 删除小节
func (s *SectionService) DeleteSection(id string) (*camp.DeleteSectionResponse, error) {
	// 先获取小节信息，以便知道属于哪个打卡营
	section, err := s.sectionDAO.GetByID(id)
	if err != nil {
		return &camp.DeleteSectionResponse{
			Success: false,
			Message: fmt.Sprintf("获取小节信息失败: %v", err),
		}, nil
	}

	campID := section.CampID

	// TODO: 检查是否存在未删除的任务和用户进度
	// 暂时先允许删除，后续可以添加检查逻辑

	// 删除小节
	err = s.sectionDAO.Delete(id)
	if err != nil {
		return &camp.DeleteSectionResponse{
			Success: false,
			Message: fmt.Sprintf("删除小节失败: %v", err),
		}, nil
	}

	// 更新打卡营的小节数量
	if err := s.campDAO.UpdateSectionCount(campID); err != nil {
		return &camp.DeleteSectionResponse{
			Success: false,
			Message: fmt.Sprintf("删除小节成功，但更新打卡营小节数量失败: %v", err),
		}, nil
	}

	return &camp.DeleteSectionResponse{
		Success: true,
		Message: "删除小节成功",
	}, nil
}

// ListSections 列出小节（支持关键词搜索和筛选）
func (s *SectionService) ListSections(req *camp.ListSectionsRequest) (*camp.ListSectionsResponse, error) {
	// 设置默认值
	if req.Page < 1 {
		req.Page = 1
	}
	if req.PageSize < 1 {
		req.PageSize = 10
	}
	if req.PageSize > 100 {
		req.PageSize = 100
	}

	sections, total, err := s.sectionDAO.List(req.Keyword, req.CampID, req.Page, req.PageSize)
	if err != nil {
		return &camp.ListSectionsResponse{
			Success: false,
			Message: fmt.Sprintf("获取小节列表失败: %v", err),
		}, nil
	}

	return &camp.ListSectionsResponse{
		Sections: sections,
		Total:     total,
		Success:   true,
		Message:   "获取小节列表成功",
	}, nil
}