.clean up the code

backend/artist_format.go

@@ -1,90 +0,0 @@
-package backend
-
-import "strings"
-
-func normalizeArtistSeparator(separator string) string {
-	separator = strings.TrimSpace(separator)
-	if separator == "," || separator == ";" {
-		return separator
-	}
-	return ""
-}
-
-func splitArtistSegment(segment string, separator string) []string {
-	segment = strings.TrimSpace(segment)
-	if segment == "" {
-		return nil
-	}
-
-	if strings.Contains(segment, "|||SEP|||") {
-		return strings.Split(segment, "|||SEP|||")
-	}
-
-	parts := []string{segment}
-
-	if separator = normalizeArtistSeparator(separator); separator != "" {
-		var separated []string
-		for _, part := range parts {
-			for _, item := range strings.Split(part, separator) {
-				separated = append(separated, item)
-			}
-		}
-		parts = separated
-	} else if strings.Contains(segment, ";") {
-		var separated []string
-		for _, part := range parts {
-			for _, item := range strings.Split(part, ";") {
-				separated = append(separated, item)
-			}
-		}
-		parts = separated
-	}
-
-	return parts
-}
-
-func SplitArtistCredits(artistStr, separator string) []string {
-	rawParts := splitArtistSegment(artistStr, separator)
-	if len(rawParts) == 0 {
-		return nil
-	}
-
-	seen := make(map[string]struct{}, len(rawParts))
-	result := make([]string, 0, len(rawParts))
-	for _, part := range rawParts {
-		part = strings.TrimSpace(part)
-		if part == "" {
-			continue
-		}
-		if _, exists := seen[part]; exists {
-			continue
-		}
-		seen[part] = struct{}{}
-		result = append(result, part)
-	}
-
-	return result
-}
-
-func SplitMetadataValues(value, separator string) []string {
-	rawParts := splitArtistSegment(value, separator)
-	if len(rawParts) == 0 {
-		return nil
-	}
-
-	seen := make(map[string]struct{}, len(rawParts))
-	result := make([]string, 0, len(rawParts))
-	for _, part := range rawParts {
-		part = strings.TrimSpace(part)
-		if part == "" {
-			continue
-		}
-		if _, exists := seen[part]; exists {
-			continue
-		}
-		seen[part] = struct{}{}
-		result = append(result, part)
-	}
-
-	return result
-}