refactor local metadata helpers

internal/service/local_metadata_read.go

@@ -0,0 +1,151 @@
+package service
+
+import (
+	"encoding/xml"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// ReadLocalMetadata reads sidecar NFO files for a media path. For TV/anime it
+// merges show-level tvshow.nfo with episode-level sidecar metadata.
+func ReadLocalMetadata(mediaPath, libraryRoot string, seriesLike bool) (*LocalMetadata, error) {
+	if seriesLike {
+		return readSeriesMetadata(mediaPath, libraryRoot)
+	}
+	doc, path, err := findMovieNFO(mediaPath, libraryRoot)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return metadataFromArtwork(mediaPath, ""), nil
+		}
+		return nil, err
+	}
+	meta := metadataFromDoc(doc, filepath.Dir(path), false)
+	mergeArtworkMetadata(meta, mediaPath, filepath.Dir(path))
+	return meta, nil
+}
+
+func findMovieNFO(mediaPath, libraryRoot string) (*nfoDocument, string, error) {
+	mediaDir := filepath.Dir(mediaPath)
+	base := strings.TrimSuffix(filepath.Base(mediaPath), filepath.Ext(mediaPath))
+	adultCode := AdultCodeFromMediaPath(mediaPath)
+	names := []string{
+		base + ".nfo",
+		"movie.nfo",
+		filepath.Base(mediaDir) + ".nfo",
+	}
+	if adultCode != "" {
+		names = append([]string{adultCode + ".nfo", strings.ReplaceAll(adultCode, "-", "") + ".nfo"}, names...)
+	}
+	seen := map[string]struct{}{}
+	for _, name := range names {
+		if name == ".nfo" || name == "" {
+			continue
+		}
+		path := filepath.Join(mediaDir, name)
+		key := strings.ToLower(filepath.Clean(path))
+		if _, ok := seen[key]; ok {
+			continue
+		}
+		seen[key] = struct{}{}
+		if doc, _, err := readNFO(path); err == nil {
+			return doc, path, nil
+		} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+			return nil, "", err
+		}
+	}
+	if libraryRoot == "" || !samePath(mediaDir, filepath.Clean(libraryRoot)) {
+		matches, _ := filepath.Glob(filepath.Join(mediaDir, "*.nfo"))
+		if adultCode != "" {
+			codeKey := strings.ToLower(strings.ReplaceAll(adultCode, "-", ""))
+			for _, match := range matches {
+				baseKey := strings.ToLower(strings.ReplaceAll(strings.TrimSuffix(filepath.Base(match), filepath.Ext(match)), "-", ""))
+				if strings.Contains(baseKey, codeKey) || strings.Contains(codeKey, baseKey) {
+					if doc, _, err := readNFO(match); err == nil {
+						return doc, match, nil
+					} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+						return nil, "", err
+					}
+				}
+			}
+		}
+		if len(matches) == 1 {
+			if doc, _, err := readNFO(matches[0]); err == nil {
+				return doc, matches[0], nil
+			} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+				return nil, "", err
+			}
+		}
+	}
+	return nil, "", os.ErrNotExist
+}
+
+func readSeriesMetadata(mediaPath, libraryRoot string) (*LocalMetadata, error) {
+	var meta *LocalMetadata
+	showBaseDir := ""
+	if showDoc, showPath, err := findShowNFO(mediaPath, libraryRoot); err == nil && showDoc != nil {
+		showBaseDir = filepath.Dir(showPath)
+		meta = metadataFromDoc(showDoc, showBaseDir, true)
+	} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+
+	if episodeDoc, episodePath, err := readNFO(nfoPath(mediaPath)); err == nil {
+		episodeMeta := metadataFromDoc(episodeDoc, filepath.Dir(episodePath), true)
+		if meta == nil {
+			meta = &LocalMetadata{}
+		}
+		mergeEpisodeMetadata(meta, episodeMeta, episodeDoc)
+	} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+	if meta == nil {
+		meta = metadataFromArtwork(mediaPath, showBaseDir)
+	} else {
+		mergeArtworkMetadata(meta, mediaPath, showBaseDir)
+	}
+	return meta, nil
+}
+
+func readNFO(path string) (*nfoDocument, string, error) {
+	body, err := os.ReadFile(path) // #nosec G304 -- path is a discovered NFO sidecar under the configured library root.
+	if err != nil {
+		return nil, "", err
+	}
+	var doc nfoDocument
+	if err := xml.Unmarshal(body, &doc); err != nil {
+		return nil, "", err
+	}
+	return &doc, path, nil
+}
+
+func findShowNFO(mediaPath, libraryRoot string) (*nfoDocument, string, error) {
+	dir := filepath.Dir(mediaPath)
+	root := filepath.Clean(libraryRoot)
+	for {
+		names := []string{"tvshow.nfo", "series.nfo"}
+		base := filepath.Base(dir)
+		if _, ok := seasonFromDir(base); ok {
+			parentBase := filepath.Base(filepath.Dir(dir))
+			names = append(names, parentBase+".nfo")
+		}
+		names = append(names, base+".nfo")
+		for _, name := range names {
+			path := filepath.Join(dir, name)
+			if doc, _, err := readNFO(path); err == nil {
+				return doc, path, nil
+			} else if err != nil && !errors.Is(err, os.ErrNotExist) {
+				return nil, "", err
+			}
+		}
+		if samePath(dir, root) {
+			return nil, "", os.ErrNotExist
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			return nil, "", os.ErrNotExist
+		}
+		dir = parent
+	}
+}