feat(story-2.2): add feed parser with gofeed and article repository

internal/service/fetch.go

@@ -0,0 +1,98 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/michael/flowreader/internal/domain"
+	"github.com/michael/flowreader/internal/parser"
+)
+
+// FetchService handles feed fetching and article ingestion.
+type FetchService struct {
+	feedRepo    domain.FeedRepository
+	articleRepo domain.ArticleRepository
+	parser      *parser.FeedParser
+}
+
+// NewFetchService creates a new fetch service.
+func NewFetchService(feedRepo domain.FeedRepository, articleRepo domain.ArticleRepository) *FetchService {
+	return &FetchService{
+		feedRepo:    feedRepo,
+		articleRepo: articleRepo,
+		parser:      parser.NewFeedParser(),
+	}
+}
+
+// FetchFeed fetches a single feed and updates articles.
+func (s *FetchService) FetchFeed(ctx context.Context, feedID uuid.UUID) error {
+	feed, err := s.feedRepo.GetByID(feedID)
+	if err != nil {
+		return fmt.Errorf("getting feed: %w", err)
+	}
+	if feed == nil {
+		return fmt.Errorf("feed not found: %s", feedID)
+	}
+
+	// Parse the feed
+	parsed, err := s.parser.Parse(ctx, feed.URL, feed.ID)
+	if err != nil {
+		// Update feed with error
+		s.feedRepo.UpdateFetchStatus(feed.ID, time.Now(), err.Error())
+		return fmt.Errorf("parsing feed: %w", err)
+	}
+
+	// Update feed metadata
+	feed.Title = parsed.Title
+	feed.Description = parsed.Description
+	feed.SiteURL = parsed.SiteURL
+	feed.ImageURL = parsed.ImageURL
+	if err := s.feedRepo.Update(feed); err != nil {
+		log.Printf("Warning: failed to update feed metadata: %v", err)
+	}
+
+	// Insert new articles (ON CONFLICT DO NOTHING handles duplicates)
+	if len(parsed.Articles) > 0 {
+		if err := s.articleRepo.CreateBatch(parsed.Articles); err != nil {
+			return fmt.Errorf("creating articles: %w", err)
+		}
+	}
+
+	// Mark fetch as successful
+	s.feedRepo.UpdateFetchStatus(feed.ID, time.Now(), "")
+
+	return nil
+}
+
+// FetchAllPending fetches all feeds that need updating.
+func (s *FetchService) FetchAllPending(ctx context.Context, concurrency int) (int, error) {
+	feeds, err := s.feedRepo.GetFeedsToFetch(100)
+	if err != nil {
+		return 0, fmt.Errorf("getting feeds to fetch: %w", err)
+	}
+
+	if len(feeds) == 0 {
+		return 0, nil
+	}
+
+	// Simple sequential fetch for now (Story 2.5 will add worker pool)
+	fetchedCount := 0
+	for _, feed := range feeds {
+		select {
+		case <-ctx.Done():
+			return fetchedCount, ctx.Err()
+		default:
+		}
+
+		if err := s.FetchFeed(ctx, feed.ID); err != nil {
+			log.Printf("Error fetching feed %s: %v", feed.URL, err)
+		} else {
+			fetchedCount++
+		}
+	}
+
+	return fetchedCount, nil
+}