refactor tmdb provider by responsibility

internal/service/tmdb_helpers.go

@@ -0,0 +1,46 @@
+package service
+
+import (
+	"fmt"
+	"strings"
+)
+
+// deduplicate removes duplicates from a string slice.
+func deduplicate(s []string) []string {
+	if len(s) == 0 {
+		return s
+	}
+	seen := make(map[string]bool, len(s))
+	out := make([]string, 0, len(s))
+	for _, v := range s {
+		if !seen[v] {
+			seen[v] = true
+			out = append(out, v)
+		}
+	}
+	return out
+}
+
+func nonEmptyStrings(values ...string) []string {
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		value = strings.TrimSpace(value)
+		if value != "" {
+			out = append(out, value)
+		}
+	}
+	return out
+}
+
+func genreIDStrings(ids []int) []string {
+	if len(ids) == 0 {
+		return nil
+	}
+	out := make([]string, 0, len(ids))
+	for _, id := range ids {
+		if id > 0 {
+			out = append(out, fmt.Sprint(id))
+		}
+	}
+	return out
+}