refactor: isolate playback and upload use cases

services/api/internal/library/scans.go

@@ -0,0 +1,69 @@
+package library
+
+import (
+	"context"
+	"errors"
+	"net/http"
+
+	"github.com/google/uuid"
+
+	"pipu/api/internal/auth"
+	"pipu/api/internal/platform/apperr"
+)
+
+type ScanStore interface {
+	GetSource(context.Context, uuid.UUID) (Source, error)
+	RetryFailedAnalysis(context.Context) (int, error)
+}
+type ScanStarter interface {
+	Start(Source, string, bool) error
+}
+
+// ScanService owns explicit and scheduled scan starts.
+type ScanService struct {
+	store   ScanStore
+	scanner ScanStarter
+	board   *ProgressBoard
+	root    func(Source) (string, error)
+}
+
+// StartScan запускает скан источника в фоне.
+// RetryAnalysis возвращает в очередь треки, которые анализатор не смог обработать (например, пока диск
+// не был смонтирован).
+func (s *ScanService) RetryAnalysis(ctx context.Context) (int, error) {
+	if err := requirePerm(ctx, auth.PermManageLibrary); err != nil {
+		return 0, err
+	}
+	return s.store.RetryFailedAnalysis(ctx)
+}
+
+func (s *ScanService) StartScan(ctx context.Context, id uuid.UUID, full bool) (Progress, error) {
+	if err := requirePerm(ctx, auth.PermManageLibrary); err != nil {
+		return Progress{}, err
+	}
+	src, err := s.store.GetSource(ctx, id)
+	if err != nil {
+		return Progress{}, notFound(err)
+	}
+	if err := s.startScan(src, full); err != nil {
+		return Progress{}, err
+	}
+	p, _ := s.board.Get(id)
+	return p, nil
+}
+
+func (s *ScanService) startScan(src Source, full bool) error {
+	if src.Status != "mounted" {
+		return apperr.New(http.StatusConflict, CodeSourceOffline, "source is not connected")
+	}
+	root, err := s.root(src)
+	if err != nil {
+		return err
+	}
+	if err := s.scanner.Start(src, root, full); errors.Is(err, ErrScanRunning) {
+		return apperr.Conflict(CodeScanRunning, "scan is already running")
+	} else if err != nil {
+		return err
+	}
+	return nil
+}