refactor: extract watchlist feature to its own domain slice

internal/features/watchlist/service.go

@@ -0,0 +1,164 @@
+package watchlist
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+
+	"malago/internal/database"
+)
+
+type Service struct {
+	db database.Querier
+}
+
+func NewService(db database.Querier) *Service {
+	return &Service{db: db}
+}
+
+type AddRequest struct {
+	AnimeID       int64
+	TitleOriginal string
+	TitleEnglish  string
+	TitleJapanese string
+	ImageURL      string
+	Status        string
+}
+
+func (s *Service) AddEntry(ctx context.Context, userID string, req AddRequest) error {
+	if req.AnimeID == 0 {
+		return fmt.Errorf("invalid anime ID")
+	}
+
+	_, err := s.db.UpsertAnime(ctx, database.UpsertAnimeParams{
+		ID:            req.AnimeID,
+		TitleOriginal: req.TitleOriginal,
+		TitleEnglish:  sql.NullString{String: req.TitleEnglish, Valid: req.TitleEnglish != ""},
+		TitleJapanese: sql.NullString{String: req.TitleJapanese, Valid: req.TitleJapanese != ""},
+		ImageUrl:      req.ImageURL,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to save anime reference: %w", err)
+	}
+
+	entryID := uuid.New().String()
+	_, err = s.db.UpsertWatchListEntry(ctx, database.UpsertWatchListEntryParams{
+		ID:      entryID,
+		UserID:  userID,
+		AnimeID: req.AnimeID,
+		Status:  req.Status,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update watchlist: %w", err)
+	}
+
+	return nil
+}
+
+func (s *Service) RemoveEntry(ctx context.Context, userID string, animeID int64) (database.Anime, error) {
+	if animeID == 0 {
+		return database.Anime{}, fmt.Errorf("invalid anime ID")
+	}
+
+	anime, err := s.db.GetAnime(ctx, animeID)
+	if err != nil {
+		return database.Anime{}, fmt.Errorf("anime not found: %w", err)
+	}
+
+	err = s.db.DeleteWatchListEntry(ctx, database.DeleteWatchListEntryParams{
+		UserID:  userID,
+		AnimeID: animeID,
+	})
+	if err != nil {
+		return database.Anime{}, fmt.Errorf("failed to delete from watchlist: %w", err)
+	}
+
+	return anime, nil
+}
+
+func (s *Service) GetUserWatchlist(ctx context.Context, userID string) ([]database.GetUserWatchListRow, error) {
+	entries, err := s.db.GetUserWatchList(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch watchlist: %w", err)
+	}
+	return entries, nil
+}
+
+type ExportEntry struct {
+	AnimeID   int64  `json:"anime_id"`
+	Title     string `json:"title"`
+	ImageURL  string `json:"image_url"`
+	Status    string `json:"status"`
+	UpdatedAt string `json:"updated_at"`
+}
+
+type ExportData struct {
+	ExportedAt string        `json:"exported_at"`
+	Entries    []ExportEntry `json:"entries"`
+}
+
+// displayTitle returns the best available title
+func displayTitle(e database.GetUserWatchListRow) string {
+	if e.TitleEnglish.Valid && e.TitleEnglish.String != "" {
+		return e.TitleEnglish.String
+	}
+	if e.TitleJapanese.Valid && e.TitleJapanese.String != "" {
+		return e.TitleJapanese.String
+	}
+	return e.TitleOriginal
+}
+
+func (s *Service) Export(ctx context.Context, userID string) (ExportData, error) {
+	entries, err := s.GetUserWatchlist(ctx, userID)
+	if err != nil {
+		return ExportData{}, err
+	}
+
+	export := ExportData{
+		ExportedAt: time.Now().UTC().Format(time.RFC3339),
+		Entries:    make([]ExportEntry, len(entries)),
+	}
+
+	for i, entry := range entries {
+		export.Entries[i] = ExportEntry{
+			AnimeID:   entry.AnimeID,
+			Title:     displayTitle(entry),
+			ImageURL:  entry.ImageUrl,
+			Status:    entry.Status,
+			UpdatedAt: entry.UpdatedAt.Format(time.RFC3339),
+		}
+	}
+
+	return export, nil
+}
+
+func (s *Service) Import(ctx context.Context, userID string, export ExportData) (int, error) {
+	imported := 0
+	for _, entry := range export.Entries {
+		_, err := s.db.UpsertAnime(ctx, database.UpsertAnimeParams{
+			ID:            entry.AnimeID,
+			TitleOriginal: entry.Title,
+			TitleEnglish:  sql.NullString{},
+			TitleJapanese: sql.NullString{},
+			ImageUrl:      entry.ImageURL,
+		})
+		if err != nil {
+			continue // skip failures and keep going
+		}
+
+		_, err = s.db.UpsertWatchListEntry(ctx, database.UpsertWatchListEntryParams{
+			ID:      uuid.New().String(),
+			UserID:  userID,
+			AnimeID: entry.AnimeID,
+			Status:  entry.Status,
+		})
+		if err != nil {
+			continue
+		}
+		imported++
+	}
+	return imported, nil
+}