From a03206a8e175d63636d0555bfcf8c8eb19a9ffc4 Mon Sep 17 00:00:00 2001
From: qvalentin <valentin.theodor@web.de>
Date: Tue, 17 May 2022 16:53:32 +0200
Subject: [PATCH] refactor long method

---
 .../src/main/java/link/LinkUseCase.java       | 33 +++++++++++--------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/2-Application/src/main/java/link/LinkUseCase.java b/2-Application/src/main/java/link/LinkUseCase.java
index 01eae21..282c3cf 100644
--- a/2-Application/src/main/java/link/LinkUseCase.java
+++ b/2-Application/src/main/java/link/LinkUseCase.java
@@ -1,5 +1,7 @@
 package link;
 
+import category.Category;
+import category.CategoryId;
 import category.CategoryName;
 import category.CategoryRepository;
 import exeptions.CategroyDoesNotExist;
@@ -8,6 +10,7 @@ import tag.TaggingUseCase;
 import user.Username;
 
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 public class LinkUseCase {
@@ -45,19 +48,21 @@ public class LinkUseCase {
 	}
 
 	public Set<LinkDto> getLinks() {
-		return linkRepository
-				.getAll()
-				.stream()
-				.map(link -> new LinkDto(link.getCreator(),
-				                         link.getUrl(),
-				                         link
-						                         .getCategoryIds()
-						                         .stream()
-						                         .map(categoryRepository::getById)
-						                         .map(optional -> optional.orElseThrow(() -> new CategroyDoesNotExist(
-								                         "A Category for a certain id does not exits. You must create it first.")))
-						                         .collect(Collectors.toSet()),
-				                         link.getTags()))
-				.collect(Collectors.toSet());
+		return linkRepository.getAll().stream().map(convertLink()).collect(Collectors.toSet());
+	}
+
+	private Function<Link, LinkDto> convertLink() {
+		return link -> new LinkDto(link.getCreator(), link.getUrl(), getCategoriesOf(link), link.getTags());
+	}
+
+	private Set<Category> getCategoriesOf(Link link) {
+		return link.getCategoryIds().stream().map(getCategoryForId()).collect(Collectors.toSet());
+	}
+
+	private Function<CategoryId, Category> getCategoryForId() {
+		return id -> categoryRepository
+				.getById(id)
+				.orElseThrow(() -> new CategroyDoesNotExist(
+						"A Category for a certain id does not exits. You must create it first."));
 	}
 }