implementing CSV will be fun they said

1-Adapter/src/main/java/persistence/csv/CSVSerializable.java

@@ -3,8 +3,11 @@ package persistence.csv;
 public interface CSVSerializable {
 
 	static String seperator = ",";
+	static String listSeperator = "-";
+	static String memberSeperator = "#";
 
 	String[] getHeaders();
 
 	String toCSVString();
+
 }

1-Adapter/src/main/java/persistence/errors/PersistenceError.java

@@ -0,0 +1,5 @@
+package persistence.errors;
+
+public class PersistenceError extends RuntimeException {
+
+}

1-Adapter/src/main/java/persistence/link/CSVLinkPersistenceAdapter.java

@@ -0,0 +1,32 @@
+package persistence.link;
+
+import abstraction.PersistenceAdapter;
+import link.Link;
+import persistence.GenericDAO;
+
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class CSVLinkPersistenceAdapter implements PersistenceAdapter<Link> {
+
+	private final GenericDAO<LinkEntity> linkDAO;
+
+	public CSVLinkPersistenceAdapter(GenericDAO<LinkEntity> linkDAO) {
+		this.linkDAO = linkDAO;
+	}
+
+	@Override
+	public Set<Link> getAll() {
+		return linkDAO.getALl().stream().map(LinkEntity::toLink).collect(Collectors.toSet());
+	}
+
+	@Override
+	public void add(Link value) {
+
+	}
+
+	@Override
+	public void remove(Link value) {
+
+	}
+}

1-Adapter/src/main/java/persistence/link/LinkEntity.java

@@ -0,0 +1,103 @@
+package persistence.link;
+
+import category.CategoryId;
+import link.Link;
+import link.LinkId;
+import link.LinkUrl;
+import persistence.csv.CSVSerializable;
+import persistence.tag.TagEntity;
+import user.Username;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class LinkEntity implements CSVSerializable {
+
+	private final Integer id;
+	private final String creator;
+	private final String url;
+	private final Set<Integer> categoryIds;
+	private final Set<TagEntity> tags;
+
+	public LinkEntity(Integer id, String creator, String url, Set<Integer> categoryIds, Set<TagEntity> tags) {
+		this.id = id;
+		this.creator = creator;
+		this.url = url;
+		this.categoryIds = categoryIds;
+		this.tags = tags;
+	}
+
+	public LinkEntity(String[] fields) {
+		this.id = Integer.parseInt(fields[0]);
+		this.creator = fields[1];
+		this.url = fields[2];
+		this.categoryIds =
+				(Arrays.stream(fields[3].split(CSVSerializable.listSeperator)).map(Integer::parseInt)).collect(
+						Collectors.toSet());
+
+		this.tags = (Arrays
+				.stream(fields[4].split(CSVSerializable.listSeperator))
+				.map(TagEntity::new)).collect(Collectors.toSet());
+	}
+
+	public LinkEntity(Link link) {
+		this.id = link.getId().id();
+		this.creator = link.getCreator().username();
+		this.url = link.getUrl().toString();
+		this.categoryIds = link.getCategoryIds().stream().map(CategoryId::id).collect(Collectors.toSet());
+		this.tags = link.getTags().stream().map(TagEntity::new).collect(Collectors.toSet());
+	}
+
+	public Link toLink() {
+		return new Link(new LinkId(id),
+		                new Username(creator),
+		                new LinkUrl(url),
+		                categoryIds.stream().map(CategoryId::new).collect(Collectors.toSet()),
+		                tags.stream().map(TagEntity::toTag).collect(Collectors.toSet()));
+	}
+
+	@Override
+	public String[] getHeaders() {
+		return new String[]{"id", "creator", "url", "categoryIds", "tagIds"};
+	}
+
+	@Override
+	public String toCSVString() {
+		return Integer.toString(id) + CSVSerializable.seperator + creator + CSVSerializable.seperator + url + CSVSerializable.seperator + String.join(
+				CSVSerializable.listSeperator,
+				categoryIds
+						.stream()
+						.map(Object::toString)
+						.collect(Collectors.toSet())) + CSVSerializable.seperator + String.join(CSVSerializable.listSeperator,
+		                                                                                        tags
+				                                                                                        .stream()
+				                                                                                        .map(TagEntity::toCSVString)
+				                                                                                        .collect(
+						                                                                                        Collectors.toSet()));
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+
+		LinkEntity that = (LinkEntity) o;
+
+		if (id != null ? !id.equals(that.id) : that.id != null) return false;
+		if (creator != null ? !creator.equals(that.creator) : that.creator != null) return false;
+		if (url != null ? !url.equals(that.url) : that.url != null) return false;
+		if (categoryIds != null ? !categoryIds.equals(that.categoryIds) : that.categoryIds != null) return false;
+		return tags != null ? tags.equals(that.tags) : that.tags == null;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = id != null ? id.hashCode() : 0;
+		result = 31 * result + (creator != null ? creator.hashCode() : 0);
+		result = 31 * result + (url != null ? url.hashCode() : 0);
+		result = 31 * result + (categoryIds != null ? categoryIds.hashCode() : 0);
+		result = 31 * result + (tags != null ? tags.hashCode() : 0);
+		return result;
+	}
+}

1-Adapter/src/main/java/persistence/tag/TagEntity.java

@@ -0,0 +1,73 @@
+package persistence.tag;
+
+import persistence.csv.CSVSerializable;
+import persistence.errors.PersistenceError;
+import tag.Tag;
+import tag.TagName;
+
+import java.util.Optional;
+
+public class TagEntity {
+
+	private final String name;
+	private Optional<String> additionalData = Optional.empty();
+
+	public TagEntity(String name, Optional<String> additionalData) {
+		this.name = name;
+		this.additionalData = additionalData;
+	}
+
+
+	public TagEntity(String name, String additionalData) {
+		this.name = name;
+		this.additionalData = Optional.of(additionalData);
+	}
+
+	public TagEntity(String csvString) {
+		var splittedString = csvString.split(CSVSerializable.memberSeperator);
+
+		if (splittedString.length == 0 || splittedString.length > 2) {
+			throw new PersistenceError();
+		}
+
+		this.name = splittedString[0];
+
+		if (splittedString.length == 2) {
+			this.additionalData = Optional.of(splittedString[1]);
+		}
+	}
+
+	public TagEntity(Tag tag) {
+		this.name = tag.getName().name();
+		this.additionalData = tag.getAdditionalData();
+
+	}
+
+	public String toCSVString() {
+		return name + CSVSerializable.memberSeperator + additionalData.orElse("");
+	}
+
+	public Tag toTag(){
+		return new Tag(new TagName(name),additionalData);
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+
+		TagEntity tagEntity = (TagEntity) o;
+
+		if (name != null ? !name.equals(tagEntity.name) : tagEntity.name != null) return false;
+		return additionalData != null
+		       ? additionalData.equals(tagEntity.additionalData)
+		       : tagEntity.additionalData == null;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = name != null ? name.hashCode() : 0;
+		result = 31 * result + (additionalData != null ? additionalData.hashCode() : 0);
+		return result;
+	}
+}

1-Adapter/src/test/java/persistence/link/LinkEntityTest.java

@@ -0,0 +1,45 @@
+package persistence.link;
+
+import org.junit.jupiter.api.Test;
+import persistence.csv.CSVSerializable;
+import persistence.tag.TagEntity;
+
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class LinkEntityTest {
+
+	@Test
+	void toCSVString() {
+
+		var expected =
+				"21" + CSVSerializable.seperator + "hans" + CSVSerializable.seperator + "https://tea.filefighter.de" +
+						CSVSerializable.seperator + "1" + CSVSerializable.listSeperator + "2" +
+						CSVSerializable.listSeperator + "3" + CSVSerializable.seperator + "name" + CSVSerializable.memberSeperator + "hallo";
+
+		TagEntity tagEntity = new TagEntity("name", "hallo");
+		Set<Integer> categoryIds = Set.of(1, 2, 3);
+		Set<TagEntity> tags = Set.of(tagEntity);
+		var actual = new LinkEntity(21, "hans", "https://tea.filefighter.de", categoryIds, tags).toCSVString();
+
+		assertEquals(expected, actual);
+
+	}
+
+	@Test
+	void fromCSVString() {
+
+		var input =
+				"21" + CSVSerializable.seperator + "hans" + CSVSerializable.seperator + "https://tea.filefighter.de" +
+						CSVSerializable.seperator + "1" + CSVSerializable.listSeperator + "2" +
+						CSVSerializable.listSeperator + "3" + CSVSerializable.seperator + "name" + CSVSerializable.memberSeperator + "hallo";
+
+		TagEntity tagEntity = new TagEntity("name", "hallo");
+		Set<Integer> categoryIds = Set.of(1, 2, 3);
+		Set<TagEntity> tags = Set.of(tagEntity);
+		var expected = new LinkEntity(21, "hans", "https://tea.filefighter.de", categoryIds, tags);
+
+		assertEquals(expected, new LinkEntity(input.split(CSVSerializable.seperator)));
+	}
+}

3-Domain/src/main/java/tag/Tag.java

@@ -11,12 +11,25 @@ public class Tag {
 		this.name = name;
 	}
 
+	public Tag(TagName name, String additionalData) {
+		this.name = name;
+		this.additionalData = Optional.ofNullable(additionalData);
+	}
+
 	public Tag(TagName name, Optional<String> additionalData) {
 		this.name = name;
 		this.additionalData = additionalData;
 	}
 
+	public TagName getName() {
+		return name;
+	}
+
+	public Optional<String> getAdditionalData() {
+		return additionalData;
+	}
+
 	public Tag addAdditionalData(String additionalData) {
-		return new Tag(this.name, Optional.of(additionalData));
+		return new Tag(this.name, additionalData);
 	}
 }