feat: complete task 2 - update FilterReleaseGroups to use centralized filter helper

internal/musicbrainz/filter.go

@@ -0,0 +1,73 @@
+package musicbrainz
+
+import (
+	"naviwatcher/internal/database"
+)
+
+// FilterOptions holds per-artist type filtering preferences.
+type FilterOptions struct {
+	IgnoreSingles      bool
+	IgnoreCompilations bool
+}
+
+// hasSliceType reports whether the slice contains any of the wanted values.
+func hasSliceType(types []string, wanted ...string) bool {
+	for _, s := range types {
+		for _, w := range wanted {
+			if s == w {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// ApplyTypeToggles filters releases based on the IgnoreSingles and IgnoreCompilations flags.
+// Implements canonical filtering logic:
+//   IgnoreSingles filters: Type == "Single" OR Type == "EP" OR SecondaryTypes contains "Single" OR "EP"
+//   IgnoreCompilations filters: Type == "Compilation" OR SecondaryTypes contains "Compilation"
+func ApplyTypeToggles(releases []database.ExternalRelease, opts FilterOptions) []database.ExternalRelease {
+	var result []database.ExternalRelease
+	for _, release := range releases {
+		// Apply IgnoreSingles filtering: filter out if Type is Single/EP OR SecondaryTypes contains Single/EP
+		if opts.IgnoreSingles {
+			if release.Type == "Single" || release.Type == "EP" || hasSliceType(release.SecondaryTypes, "Single", "EP") {
+				continue
+			}
+		}
+
+		// Apply IgnoreCompilations filtering: filter out if Type is Compilation OR SecondaryTypes contains Compilation
+		if opts.IgnoreCompilations {
+			if release.Type == "Compilation" || hasSliceType(release.SecondaryTypes, "Compilation") {
+				continue
+			}
+		}
+
+		result = append(result, release)
+	}
+	return result
+}
+
+// ApplyTypeTogglesToReleaseGroups applies the same IgnoreSingles/IgnoreCompinators filtering logic
+// to a slice of ReleaseGroup objects.
+func ApplyTypeTogglesToReleaseGroups(groups []ReleaseGroup, opts FilterOptions) []ReleaseGroup {
+	var result []ReleaseGroup
+	for _, rg := range groups {
+		// Apply IgnoreSingles filtering: filter out if Type is Single/EP OR SecondaryTypes contains Single/EP
+		if opts.IgnoreSingles {
+			if rg.Type == "Single" || rg.Type == "EP" || hasSliceType(rg.SecondaryTypes, "Single", "EP") {
+				continue
+			}
+		}
+
+		// Apply IgnoreCompilations filtering: filter out if Type is Compilation OR SecondaryTypes contains Compilation
+		if opts.IgnoreCompilations {
+			if rg.Type == "Compilation" || hasSliceType(rg.SecondaryTypes, "Compilation") {
+				continue
+			}
+		}
+
+		result = append(result, rg)
+	}
+	return result
+}