feat: custom content type icons, built-in types, user lookup

internal/infrastructure/useCases/LookupUserNames.go

@@ -0,0 +1,48 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/user"
+	"sort"
+)
+
+type LookupUserNamesUseCase struct {
+	users user.Repository
+}
+
+type UserName struct {
+	ID          uint32
+	DisplayName string
+}
+
+func NewLookupUserNamesUseCase(users user.Repository) *LookupUserNamesUseCase {
+	return &LookupUserNamesUseCase{users}
+}
+
+func (u *LookupUserNamesUseCase) Lookup(ids []uint32) ([]UserName, error) {
+	distinct := distinctIDs(ids)
+	if len(distinct) == 0 || len(distinct) > user.MaxLookupIDs {
+		return nil, user.ErrInvalidLookup
+	}
+	found, err := u.users.FindByIDs(distinct)
+	if err != nil {
+		return nil, err
+	}
+	sort.Slice(found, func(i, j int) bool { return found[i].ID < found[j].ID })
+	names := make([]UserName, 0, len(found))
+	for _, record := range found {
+		names = append(names, UserName{ID: record.ID, DisplayName: record.NameOrUsername()})
+	}
+	return names, nil
+}
+
+func distinctIDs(ids []uint32) []uint32 {
+	seen := make(map[uint32]bool, len(ids))
+	distinct := make([]uint32, 0, len(ids))
+	for _, id := range ids {
+		if !seen[id] {
+			seen[id] = true
+			distinct = append(distinct, id)
+		}
+	}
+	return distinct
+}