add article

internal/domains/article/entities/article.go

@@ -0,0 +1,195 @@
+package entities
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+)
+
+// ArticleStatus 文章状态枚举
+type ArticleStatus string
+
+const (
+	ArticleStatusDraft     ArticleStatus = "draft"     // 草稿
+	ArticleStatusPublished ArticleStatus = "published" // 已发布
+	ArticleStatusArchived  ArticleStatus = "archived"  // 已归档
+)
+
+// Article 文章聚合根
+// 系统的核心内容实体，提供文章的完整生命周期管理
+// 支持草稿、发布、归档状态，实现Entity接口便于统一管理
+type Article struct {
+	// 基础标识
+	ID         string `gorm:"primaryKey;type:varchar(36)" json:"id" comment:"文章唯一标识"`
+	Title      string `gorm:"type:varchar(200);not null" json:"title" comment:"文章标题"`
+	Content    string `gorm:"type:text;not null" json:"content" comment:"文章内容"`
+	Summary    string `gorm:"type:varchar(500)" json:"summary" comment:"文章摘要"`
+	CoverImage string `gorm:"type:varchar(500)" json:"cover_image" comment:"封面图片"`
+
+	// 分类
+	CategoryID string `gorm:"type:varchar(36)" json:"category_id" comment:"分类ID"`
+
+	// 状态管理
+	Status      ArticleStatus `gorm:"type:varchar(20);not null;default:'draft'" json:"status" comment:"文章状态"`
+	IsFeatured  bool          `gorm:"default:false" json:"is_featured" comment:"是否推荐"`
+	PublishedAt *time.Time    `json:"published_at" comment:"发布时间"`
+	ScheduledAt *time.Time    `json:"scheduled_at" comment:"定时发布时间"`
+
+	// 统计信息
+	ViewCount int `gorm:"default:0" json:"view_count" comment:"阅读量"`
+
+	// 时间戳字段
+	CreatedAt time.Time      `gorm:"autoCreateTime" json:"created_at" comment:"创建时间"`
+	UpdatedAt time.Time      `gorm:"autoUpdateTime" json:"updated_at" comment:"更新时间"`
+	DeletedAt gorm.DeletedAt `gorm:"index" json:"-" comment:"软删除时间"`
+
+	// 关联关系
+	Category *Category `gorm:"foreignKey:CategoryID" json:"category,omitempty" comment:"分类信息"`
+	Tags     []Tag     `gorm:"many2many:article_tag_relations;" json:"tags,omitempty" comment:"标签列表"`
+
+	// 领域事件 (不持久化)
+	domainEvents []interface{} `gorm:"-" json:"-"`
+}
+
+// TableName 指定表名
+func (Article) TableName() string {
+	return "articles"
+}
+
+// BeforeCreate GORM钩子：创建前自动生成UUID
+func (a *Article) BeforeCreate(tx *gorm.DB) error {
+	if a.ID == "" {
+		a.ID = uuid.New().String()
+	}
+	return nil
+}
+
+// 实现 Entity 接口 - 提供统一的实体管理接口
+// GetID 获取实体唯一标识
+func (a *Article) GetID() string {
+	return a.ID
+}
+
+// GetCreatedAt 获取创建时间
+func (a *Article) GetCreatedAt() time.Time {
+	return a.CreatedAt
+}
+
+// GetUpdatedAt 获取更新时间
+func (a *Article) GetUpdatedAt() time.Time {
+	return a.UpdatedAt
+}
+
+// Validate 验证文章信息
+// 检查文章必填字段是否完整，确保数据的有效性
+func (a *Article) Validate() error {
+	if a.Title == "" {
+		return NewValidationError("文章标题不能为空")
+	}
+	if a.Content == "" {
+		return NewValidationError("文章内容不能为空")
+	}
+
+	// 验证标题长度
+	if len(a.Title) > 200 {
+		return NewValidationError("文章标题不能超过200个字符")
+	}
+
+	// 验证摘要长度
+	if a.Summary != "" && len(a.Summary) > 500 {
+		return NewValidationError("文章摘要不能超过500个字符")
+	}
+
+	return nil
+}
+
+// Publish 发布文章
+func (a *Article) Publish() error {
+	if a.Status == ArticleStatusPublished {
+		return NewValidationError("文章已经是发布状态")
+	}
+
+	a.Status = ArticleStatusPublished
+	now := time.Now()
+	a.PublishedAt = &now
+	a.ScheduledAt = nil // 清除定时发布时间
+
+	return nil
+}
+
+// SchedulePublish 定时发布文章
+func (a *Article) SchedulePublish(scheduledTime time.Time) error {
+	if a.Status == ArticleStatusPublished {
+		return NewValidationError("文章已经是发布状态")
+	}
+
+	if scheduledTime.Before(time.Now()) {
+		return NewValidationError("定时发布时间不能早于当前时间")
+	}
+
+	a.Status = ArticleStatusDraft // 保持草稿状态，等待定时发布
+	a.ScheduledAt = &scheduledTime
+
+	return nil
+}
+
+// IsScheduled 判断是否已设置定时发布
+func (a *Article) IsScheduled() bool {
+	return a.ScheduledAt != nil && a.Status == ArticleStatusDraft
+}
+
+// GetScheduledTime 获取定时发布时间
+func (a *Article) GetScheduledTime() *time.Time {
+	return a.ScheduledAt
+}
+
+// Archive 归档文章
+func (a *Article) Archive() error {
+	if a.Status == ArticleStatusArchived {
+		return NewValidationError("文章已经是归档状态")
+	}
+
+	a.Status = ArticleStatusArchived
+	return nil
+}
+
+// IncrementViewCount 增加阅读量
+func (a *Article) IncrementViewCount() {
+	a.ViewCount++
+}
+
+// SetFeatured 设置推荐状态
+func (a *Article) SetFeatured(featured bool) {
+	a.IsFeatured = featured
+}
+
+// IsPublished 判断是否已发布
+func (a *Article) IsPublished() bool {
+	return a.Status == ArticleStatusPublished
+}
+
+// IsDraft 判断是否为草稿
+func (a *Article) IsDraft() bool {
+	return a.Status == ArticleStatusDraft
+}
+
+// IsArchived 判断是否已归档
+func (a *Article) IsArchived() bool {
+	return a.Status == ArticleStatusArchived
+}
+
+// CanEdit 判断是否可以编辑
+func (a *Article) CanEdit() bool {
+	return a.Status == ArticleStatusDraft
+}
+
+// CanPublish 判断是否可以发布
+func (a *Article) CanPublish() bool {
+	return a.Status == ArticleStatusDraft
+}
+
+// CanArchive 判断是否可以归档
+func (a *Article) CanArchive() bool {
+	return a.Status == ArticleStatusPublished
+}