refactor: split modules and harden scraping workflows

internal/service/scanner_prune.go

@@ -0,0 +1,128 @@
+package service
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+)
+
+// RemovePath deletes the media row for a path that has disappeared from disk
+// (incremental delete used by the watcher on Remove/Rename events).
+func (s *ScannerService) RemovePath(ctx context.Context, path string) (int64, error) {
+	if _, err := os.Stat(path); err == nil {
+		return 0, nil // still exists; nothing to remove
+	}
+	res := s.repo.DB.WithContext(ctx).
+		Where("path = ?", path).
+		Delete(&model.Media{})
+	if res.Error == nil && res.RowsAffected > 0 {
+		s.invalidateMediaCache(ctx)
+	}
+	return res.RowsAffected, res.Error
+}
+
+func (s *ScannerService) pruneMissingMedia(ctx context.Context, libraryID string, seen map[string]struct{}) (int64, error) {
+	// 只取 id/path，并把删除按批提交：此前整表载入完整 Media 结构体、
+	// 每行一条 DELETE，大库 prune 既费内存又长期占用写锁。
+	var rows []struct {
+		ID   string
+		Path string
+	}
+	if err := s.repo.DB.WithContext(ctx).
+		Model(&model.Media{}).
+		Select("id, path").
+		Where("library_id = ?", libraryID).
+		Find(&rows).Error; err != nil {
+		return 0, err
+	}
+	stale := make([]string, 0)
+	for _, row := range rows {
+		if row.Path == "" {
+			continue
+		}
+		if _, ok := seen[filepath.Clean(row.Path)]; ok {
+			continue
+		}
+		if _, err := os.Stat(row.Path); err == nil {
+			continue
+		} else if !os.IsNotExist(err) {
+			continue
+		}
+		stale = append(stale, row.ID)
+	}
+	return s.deleteMediaByIDs(ctx, stale, false)
+}
+
+// deleteMediaByIDs removes media rows in fixed-size batches so each write
+// transaction stays short and the global write gate is released frequently.
+func (s *ScannerService) deleteMediaByIDs(ctx context.Context, ids []string, hard bool) (int64, error) {
+	const batch = 500
+	var removed int64
+	for i := 0; i < len(ids); i += batch {
+		end := i + batch
+		if end > len(ids) {
+			end = len(ids)
+		}
+		q := s.repo.DB.WithContext(ctx)
+		if hard {
+			q = q.Unscoped()
+		}
+		res := q.Where("id IN ?", ids[i:end]).Delete(&model.Media{})
+		if res.Error != nil {
+			return removed, res.Error
+		}
+		removed += res.RowsAffected
+	}
+	return removed, nil
+}
+
+func (s *ScannerService) pruneMissingCloudMedia(ctx context.Context, libraryID string, seen map[string]struct{}) (int64, error) {
+	return s.pruneMissingCloudMediaForLibraries(ctx, []string{libraryID}, seen)
+}
+
+func (s *ScannerService) pruneMissingCloudMediaForLibraries(ctx context.Context, libraryIDs []string, seen map[string]struct{}) (int64, error) {
+	if len(libraryIDs) == 0 {
+		return 0, nil
+	}
+	var rows []struct {
+		ID   string
+		Path string
+	}
+	if err := s.repo.DB.WithContext(ctx).
+		Model(&model.Media{}).
+		Select("id, path").
+		Where("library_id IN ? AND path LIKE ?", libraryIDs, "cloud://%").
+		Find(&rows).Error; err != nil {
+		return 0, err
+	}
+	stale := make([]string, 0)
+	for _, row := range rows {
+		if _, ok := seen[row.Path]; ok {
+			continue
+		}
+		stale = append(stale, row.ID)
+	}
+	return s.deleteMediaByIDs(ctx, stale, true)
+}
+
+func (s *ScannerService) autoScrapeEnabled(ctx context.Context) bool {
+	if s.repo == nil || s.repo.Setting == nil {
+		return false
+	}
+	value, err := s.repo.Setting.Get(ctx, "scrape.auto_on_scan")
+	if err != nil {
+		s.log.Warn("read scrape.auto_on_scan failed", zap.Error(err))
+		return false
+	}
+	switch strings.ToLower(strings.TrimSpace(value)) {
+	case "1", "true", "yes", "on", "enabled":
+		return true
+	default:
+		return false
+	}
+}