First implementation of fetching collections of book managed by user

internal/adapter/adapter.go

@@ -6,9 +6,41 @@ import (
 	"git.artlef.fr/bibliomane/internal/appcontext"
 	"git.artlef.fr/bibliomane/internal/dto"
 	"git.artlef.fr/bibliomane/internal/model"
+	"git.artlef.fr/bibliomane/internal/query"
 	"gorm.io/gorm"
 )
 
+func CollectionQueryToDto(collectionsQueryResult []query.CollectionsQueryResult) []dto.CollectionItemGet {
+	var collections []dto.CollectionItemGet
+	for _, collectionDb := range collectionsQueryResult {
+		i := findIdInCollection(collections, collectionDb.ID)
+		if i == -1 {
+			collections = append(collections, dto.CollectionItemGet{
+				ID:   collectionDb.ID,
+				Name: collectionDb.Name,
+			})
+			//current collection is the last element
+			i = len(collections) - 1
+		}
+		collections[i].Books = append(collections[i].Books, dto.CollectionBookItemGet{
+			ID:        collectionDb.BookId,
+			Title:     collectionDb.BookTitle,
+			CoverPath: collectionDb.CoverPath,
+		})
+	}
+	return collections
+}
+
+// returns the position in collections, -1 if not found
+func findIdInCollection(collections []dto.CollectionItemGet, collectionId uint) int {
+	for i, collection := range collections {
+		if collection.ID == collectionId {
+			return i
+		}
+	}
+	return -1
+}
+
 func FillBookDbFromFields(ac appcontext.AppContext, fields *dto.BookFields, book *model.Book) error {
 	if fields.Title != nil {
 		book.Title = *fields.Title