feat(story-2.1): add feed model and add-feed-by-url API

internal/domain/article.go

@@ -0,0 +1,44 @@
+package domain
+
+import (
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// Article represents an item from an RSS/Atom feed.
+type Article struct {
+	ID          uuid.UUID  `json:"id"`
+	FeedID      uuid.UUID  `json:"feed_id"`
+	GUID        string     `json:"guid"`
+	Title       string     `json:"title"`
+	URL         string     `json:"url,omitempty"`
+	Content     string     `json:"content,omitempty"`
+	Summary     string     `json:"summary,omitempty"`
+	Author      string     `json:"author,omitempty"`
+	ImageURL    string     `json:"image_url,omitempty"`
+	PublishedAt *time.Time `json:"published_at,omitempty"`
+	IsRead      bool       `json:"is_read"`
+	IsFavorite  bool       `json:"is_favorite"`
+	ReadAt      *time.Time `json:"read_at,omitempty"`
+	CreatedAt   time.Time  `json:"created_at"`
+
+	// Virtual fields (from joins)
+	FeedTitle string `json:"feed_title,omitempty"`
+}
+
+// ArticleRepository defines the interface for article data access.
+type ArticleRepository interface {
+	Create(article *Article) error
+	CreateBatch(articles []*Article) error
+	GetByID(id uuid.UUID) (*Article, error)
+	GetByFeedID(feedID uuid.UUID, limit, offset int) ([]*Article, error)
+	GetByUserID(userID uuid.UUID, limit, offset int, unreadOnly bool) ([]*Article, error)
+	GetByGUID(feedID uuid.UUID, guid string) (*Article, error)
+	MarkAsRead(id uuid.UUID) error
+	MarkAsUnread(id uuid.UUID) error
+	MarkAllAsRead(feedID uuid.UUID) error
+	ToggleFavorite(id uuid.UUID) error
+	GetFavorites(userID uuid.UUID, limit, offset int) ([]*Article, error)
+	CountUnread(feedID uuid.UUID) (int, error)
+}