package radio

import (
	"errors"
	"sundynix-go/global"
	"sundynix-go/model/radio"
	radioReq "sundynix-go/model/radio/request"

	"gorm.io/gorm"
)

type CategoryService struct{}

// GetCategoryList 获取分类列表
func (s *CategoryService) GetCategoryList(info radioReq.GetCategoryList) ([]radio.RadioCategory, int64, error) {
	db := global.DB.Model(&radio.RadioCategory{}).Where("status = ?", 1)
	var list []radio.RadioCategory
	var total int64

	if info.Name != "" {
		db = db.Where("name LIKE ?", "%"+info.Name+"%")
	}
	if info.Status > 0 {
		db = db.Where("status = ?", info.Status)
	}

	err := db.Count(&total).Error
	if err != nil {
		return nil, 0, err
	}

	offset := (info.Current - 1) * info.PageSize
	err = db.Offset(offset).Limit(info.PageSize).Order("sort ASC").Find(&list).Error
	return list, total, err
}

// GetCategoryTree 返回带频道的分类树
func (s *CategoryService) GetCategoryTree() ([]radio.RadioCategory, error) {
	var res []radio.RadioCategory

	// 1. 查询分类并预加载关联的频道
	// Preload("Channels") 会自动根据 CategoryId 匹配
	// Preload("Icon") 和 Preload("Cover") 用于加载 OSS 信息
	err := global.DB.Model(&radio.RadioCategory{}).
		Preload("Channels", "status = ?", 1). // 只加载启用的频道
		Order("sort desc").
		Find(&res).Error
	return res, err
}

func (s *CategoryService) GetAllCategory() ([]radio.RadioCategory, error) {
	var res []radio.RadioCategory
	err := global.DB.Where("status = ?", 1).Find(&res).Error
	return res, err
}

// GetCategoryById 获取分类详情
func (s *CategoryService) GetCategoryById(id string) (*radio.RadioCategory, error) {
	var category radio.RadioCategory
	err := global.DB.Where("id = ?", id).First(&category).Error
	return &category, err
}

// SaveCategory 保存分类
func (s *CategoryService) SaveCategory(req radioReq.SaveCategory) error {
	category := radio.RadioCategory{
		Name:        req.Name,
		Description: req.Description,
		Sort:        req.Sort,
		Status:      req.Status,
	}
	return global.DB.Create(&category).Error
}

// UpdateCategory 更新分类
func (s *CategoryService) UpdateCategory(req radioReq.UpdateCategory) error {
	updates := map[string]interface{}{
		"name":        req.Name,
		"description": req.Description,
		"sort":        req.Sort,
		"status":      req.Status,
	}
	return global.DB.Model(&radio.RadioCategory{}).Where("id = ?", req.Id).Updates(updates).Error
}

// DeleteCategory 删除分类
func (s *CategoryService) DeleteCategory(id string) error {
	return global.DB.Transaction(func(tx *gorm.DB) error {
		// 检查是否有频道使用此分类
		var count int64
		tx.Model(&radio.RadioChannel{}).Where("category_id = ?", id).Count(&count)
		if count > 0 {
			return errors.New("该分类下存在频道，无法删除")
		}
		return tx.Where("id = ?", id).Delete(&radio.RadioCategory{}).Error
	})
}