feat: 添加种子数据初始化功能，重构多个处理程序以简化错误响应和用户验证

internal/service/texture_service.go

@@ -12,13 +12,9 @@ import (
 // CreateTexture 创建材质
 func CreateTexture(db *gorm.DB, uploaderID int64, name, description, textureType, url, hash string, size int, isPublic, isSlim bool) (*model.Texture, error) {
 	// 验证用户存在
-	user, err := repository.FindUserByID(uploaderID)
-	if err != nil {
+	if _, err := EnsureUserExists(uploaderID); err != nil {
 		return nil, err
 	}
-	if user == nil {
-		return nil, errors.New("用户不存在")
-	}
 
 	// 检查Hash是否已存在
 	existingTexture, err := repository.FindTextureByHash(hash)
@@ -30,14 +26,9 @@ func CreateTexture(db *gorm.DB, uploaderID int64, name, description, textureType
 	}
 
 	// 转换材质类型
-	var textureTypeEnum model.TextureType
-	switch textureType {
-	case "SKIN":
-		textureTypeEnum = model.TextureTypeSkin
-	case "CAPE":
-		textureTypeEnum = model.TextureTypeCape
-	default:
-		return nil, errors.New("无效的材质类型")
+	textureTypeEnum, err := parseTextureType(textureType)
+	if err != nil {
+		return nil, err
 	}
 
 	// 创建材质
@@ -65,58 +56,27 @@ func CreateTexture(db *gorm.DB, uploaderID int64, name, description, textureType
 
 // GetTextureByID 根据ID获取材质
 func GetTextureByID(db *gorm.DB, id int64) (*model.Texture, error) {
-	texture, err := repository.FindTextureByID(id)
-	if err != nil {
-		return nil, err
-	}
-	if texture == nil {
-		return nil, errors.New("材质不存在")
-	}
-	if texture.Status == -1 {
-		return nil, errors.New("材质已删除")
-	}
-	return texture, nil
+	return EnsureTextureExists(id)
 }
 
 // GetUserTextures 获取用户上传的材质列表
 func GetUserTextures(db *gorm.DB, uploaderID int64, page, pageSize int) ([]*model.Texture, int64, error) {
-	if page < 1 {
-		page = 1
-	}
-	if pageSize < 1 || pageSize > 100 {
-		pageSize = 20
-	}
-
+	page, pageSize = NormalizePagination(page, pageSize)
 	return repository.FindTexturesByUploaderID(uploaderID, page, pageSize)
 }
 
 // SearchTextures 搜索材质
 func SearchTextures(db *gorm.DB, keyword string, textureType model.TextureType, publicOnly bool, page, pageSize int) ([]*model.Texture, int64, error) {
-	if page < 1 {
-		page = 1
-	}
-	if pageSize < 1 || pageSize > 100 {
-		pageSize = 20
-	}
-
+	page, pageSize = NormalizePagination(page, pageSize)
 	return repository.SearchTextures(keyword, textureType, publicOnly, page, pageSize)
 }
 
 // UpdateTexture 更新材质
 func UpdateTexture(db *gorm.DB, textureID, uploaderID int64, name, description string, isPublic *bool) (*model.Texture, error) {
-	// 获取材质
-	texture, err := repository.FindTextureByID(textureID)
-	if err != nil {
+	// 获取材质并验证权限
+	if _, err := GetTextureWithPermissionCheck(textureID, uploaderID); err != nil {
 		return nil, err
 	}
-	if texture == nil {
-		return nil, errors.New("材质不存在")
-	}
-
-	// 检查权限：只有上传者可以修改
-	if texture.UploaderID != uploaderID {
-		return nil, errors.New("无权修改此材质")
-	}
 
 	// 更新字段
 	updates := make(map[string]interface{})
@@ -136,46 +96,27 @@ func UpdateTexture(db *gorm.DB, textureID, uploaderID int64, name, description s
 		}
 	}
 
-	// 返回更新后的材质
 	return repository.FindTextureByID(textureID)
 }
 
 // DeleteTexture 删除材质
 func DeleteTexture(db *gorm.DB, textureID, uploaderID int64) error {
-	// 获取材质
-	texture, err := repository.FindTextureByID(textureID)
-	if err != nil {
+	if _, err := GetTextureWithPermissionCheck(textureID, uploaderID); err != nil {
 		return err
 	}
-	if texture == nil {
-		return errors.New("材质不存在")
-	}
-
-	// 检查权限：只有上传者可以删除
-	if texture.UploaderID != uploaderID {
-		return errors.New("无权删除此材质")
-	}
-
 	return repository.DeleteTexture(textureID)
 }
 
 // RecordTextureDownload 记录下载
 func RecordTextureDownload(db *gorm.DB, textureID int64, userID *int64, ipAddress, userAgent string) error {
-	// 检查材质是否存在
-	texture, err := repository.FindTextureByID(textureID)
-	if err != nil {
+	if _, err := EnsureTextureExists(textureID); err != nil {
 		return err
 	}
-	if texture == nil {
-		return errors.New("材质不存在")
-	}
 
-	// 增加下载次数
 	if err := repository.IncrementTextureDownloadCount(textureID); err != nil {
 		return err
 	}
 
-	// 创建下载日志
 	log := &model.TextureDownloadLog{
 		TextureID: textureID,
 		UserID:    userID,
@@ -188,23 +129,17 @@ func RecordTextureDownload(db *gorm.DB, textureID int64, userID *int64, ipAddres
 
 // ToggleTextureFavorite 切换收藏状态
 func ToggleTextureFavorite(db *gorm.DB, userID, textureID int64) (bool, error) {
-	// 检查材质是否存在
-	texture, err := repository.FindTextureByID(textureID)
-	if err != nil {
+	if _, err := EnsureTextureExists(textureID); err != nil {
 		return false, err
 	}
-	if texture == nil {
-		return false, errors.New("材质不存在")
-	}
 
-	// 检查是否已收藏
 	isFavorited, err := repository.IsTextureFavorited(userID, textureID)
 	if err != nil {
 		return false, err
 	}
 
 	if isFavorited {
-		// 取消收藏
+		// 已收藏 -> 取消收藏
 		if err := repository.RemoveTextureFavorite(userID, textureID); err != nil {
 			return false, err
 		}
@@ -213,7 +148,7 @@ func ToggleTextureFavorite(db *gorm.DB, userID, textureID int64) (bool, error) {
 		}
 		return false, nil
 	} else {
-		// 添加收藏
+		// 未收藏 -> 添加收藏
 		if err := repository.AddTextureFavorite(userID, textureID); err != nil {
 			return false, err
 		}
@@ -226,13 +161,7 @@ func ToggleTextureFavorite(db *gorm.DB, userID, textureID int64) (bool, error) {
 
 // GetUserTextureFavorites 获取用户收藏的材质列表
 func GetUserTextureFavorites(db *gorm.DB, userID int64, page, pageSize int) ([]*model.Texture, int64, error) {
-	if page < 1 {
-		page = 1
-	}
-	if pageSize < 1 || pageSize > 100 {
-		pageSize = 20
-	}
-
+	page, pageSize = NormalizePagination(page, pageSize)
 	return repository.GetUserTextureFavorites(userID, page, pageSize)
 }
 
@@ -249,3 +178,15 @@ func CheckTextureUploadLimit(db *gorm.DB, uploaderID int64, maxTextures int) err
 
 	return nil
 }
+
+// parseTextureType 解析材质类型
+func parseTextureType(textureType string) (model.TextureType, error) {
+	switch textureType {
+	case "SKIN":
+		return model.TextureTypeSkin, nil
+	case "CAPE":
+		return model.TextureTypeCape, nil
+	default:
+		return "", errors.New("无效的材质类型")
+	}
+}