Communication: Allow user to save messages for later

src/main/java/de/tum/cit/aet/artemis/communication/domain/AnswerPost.java

@@ -10,14 +10,18 @@
 import jakarta.persistence.ManyToOne;
 import jakarta.persistence.OneToMany;
 import jakarta.persistence.Table;
+import jakarta.persistence.Transient;
 
 import org.hibernate.annotations.Cache;
 import org.hibernate.annotations.CacheConcurrencyStrategy;
+import org.hibernate.annotations.SQLRestriction;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonIncludeProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import de.tum.cit.aet.artemis.communication.domain.conversation.Conversation;
 import de.tum.cit.aet.artemis.core.domain.Course;
 
 /**
@@ -35,10 +39,20 @@ public class AnswerPost extends Posting {
     @OneToMany(mappedBy = "answerPost", cascade = CascadeType.REMOVE, orphanRemoval = true, fetch = FetchType.EAGER)
     private Set<Reaction> reactions = new HashSet<>();
 
+    /***
+     * The value 1 represents an answer post, given by the enum {{@link PostingType}}
+     */
+    @OneToMany(mappedBy = "postId", cascade = CascadeType.REMOVE, orphanRemoval = true, fetch = FetchType.LAZY)
+    @SQLRestriction("post_type = 1")
+    private Set<SavedPost> savedPosts = new HashSet<>();
+
     @ManyToOne
     @JsonIncludeProperties({ "id", "exercise", "lecture", "course", "courseWideContext", "conversation", "author" })
     private Post post;
 
+    @Transient
+    private boolean isSaved = false;
+
     @JsonProperty("resolvesPost")
     public Boolean doesResolvePost() {
         return resolvesPost;
@@ -76,6 +90,25 @@ public void setPost(Post post) {
         this.post = post;
     }
 
+    @JsonIgnore
+    public Set<SavedPost> getSavedPosts() {
+        return savedPosts;
+    }
+
+    @JsonProperty("isSaved")
+    public boolean getIsSaved() {
+        return isSaved;
+    }
+
+    public void setIsSaved(boolean isSaved) {
+        this.isSaved = isSaved;
+    }
+
+    @JsonIgnore
+    public Conversation getConversation() {
+        return getPost().getConversation();
+    }
+
     /**
      * Helper method to extract the course an AnswerPost belongs to, which is found in different locations based on the parent Post's context
      *

src/main/java/de/tum/cit/aet/artemis/communication/domain/Post.java

@@ -16,14 +16,17 @@
 import jakarta.persistence.OneToMany;
 import jakarta.persistence.OneToOne;
 import jakarta.persistence.Table;
+import jakarta.persistence.Transient;
 import jakarta.validation.constraints.Size;
 
 import org.hibernate.annotations.Cache;
 import org.hibernate.annotations.CacheConcurrencyStrategy;
+import org.hibernate.annotations.SQLRestriction;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonIncludeProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
 
 import de.tum.cit.aet.artemis.communication.domain.conversation.Conversation;
 import de.tum.cit.aet.artemis.core.domain.Course;
@@ -54,6 +57,13 @@ public class Post extends Posting {
     @OneToMany(mappedBy = "post", cascade = CascadeType.REMOVE, orphanRemoval = true, fetch = FetchType.EAGER)
     private Set<AnswerPost> answers = new HashSet<>();
 
+    /***
+     * The value 0 represents a post, given by the enum {{@link PostingType}}
+     */
+    @OneToMany(mappedBy = "postId", cascade = CascadeType.REMOVE, orphanRemoval = true, fetch = FetchType.LAZY)
+    @SQLRestriction("post_type = 0")
+    private Set<SavedPost> savedPosts = new HashSet<>();
+
     @ElementCollection(fetch = FetchType.EAGER)
     @CollectionTable(name = "post_tag", joinColumns = @JoinColumn(name = "post_id"))
     @Column(name = "text")
@@ -96,6 +106,9 @@ public class Post extends Posting {
     @Column(name = "vote_count")
     private int voteCount;
 
+    @Transient
+    private boolean isSaved = false;
+
     public Post() {
     }
 
@@ -222,6 +235,20 @@ public void setVoteCount(Integer voteCount) {
         this.voteCount = voteCount != null ? voteCount : 0;
     }
 
+    @JsonIgnore
+    public Set<SavedPost> getSavedPosts() {
+        return savedPosts;
+    }
+
+    @JsonProperty("isSaved")
+    public boolean getIsSaved() {
+        return isSaved;
+    }
+
+    public void setIsSaved(boolean isSaved) {
+        this.isSaved = isSaved;
+    }
+
     /**
      * Helper method to extract the course a Post belongs to, which is found in different locations based on the Post's context
      *

src/main/java/de/tum/cit/aet/artemis/communication/domain/Posting.java

@@ -18,6 +18,7 @@
 import com.fasterxml.jackson.annotation.JsonIncludeProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import de.tum.cit.aet.artemis.communication.domain.conversation.Conversation;
 import de.tum.cit.aet.artemis.core.domain.Course;
 import de.tum.cit.aet.artemis.core.domain.DomainObject;
 import de.tum.cit.aet.artemis.core.domain.User;
@@ -118,4 +119,6 @@ public void setAuthorRole(UserRole authorRole) {
 
     @Transient
     public abstract Course getCoursePostingBelongsTo();
+
+    public abstract Conversation getConversation();
 }

src/main/java/de/tum/cit/aet/artemis/communication/domain/PostingType.java

@@ -0,0 +1,23 @@
+package de.tum.cit.aet.artemis.communication.domain;
+
+import java.util.Arrays;
+
+public enum PostingType {
+
+    POST((short) 0), ANSWER((short) 1);
+
+    private final short databaseKey;
+
+    PostingType(short databaseKey) {
+        this.databaseKey = databaseKey;
+    }
+
+    public short getDatabaseKey() {
+        return databaseKey;
+    }
+
+    public static PostingType fromDatabaseKey(short databaseKey) {
+        return Arrays.stream(PostingType.values()).filter(type -> type.getDatabaseKey() == databaseKey).findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("Unknown database key: " + databaseKey));
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/domain/SavedPost.java

@@ -0,0 +1,83 @@
+package de.tum.cit.aet.artemis.communication.domain;
+
+import java.time.ZonedDateTime;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+
+import de.tum.cit.aet.artemis.core.domain.DomainObject;
+import de.tum.cit.aet.artemis.core.domain.User;
+
+@Entity
+@Table(name = "saved_post")
+public class SavedPost extends DomainObject {
+
+    @ManyToOne
+    @JoinColumn(name = "user_id", nullable = false)
+    private User user;
+
+    @Column(name = "post_id", nullable = false)
+    private Long postId;
+
+    @Enumerated
+    @Column(name = "post_type", nullable = false)
+    private PostingType postType;
+
+    @Enumerated
+    @Column(name = "status", nullable = false)
+    private SavedPostStatus status;
+
+    @Column(name = "completed_at")
+    private ZonedDateTime completedAt;
+
+    public SavedPost() {
+    }
+
+    public SavedPost(User user, Long postId, PostingType postType, SavedPostStatus status, ZonedDateTime completedAt) {
+        this.user = user;
+        this.postId = postId;
+        this.postType = postType;
+        this.status = status;
+        this.completedAt = completedAt;
+    }
+
+    public Long getPostId() {
+        return postId;
+    }
+
+    public void setPostId(Long postId) {
+        this.postId = postId;
+    }
+
+    public void setStatus(SavedPostStatus status) {
+        this.status = status;
+    }
+
+    public User getUser() {
+        return user;
+    }
+
+    public SavedPostStatus getStatus() {
+        return status;
+    }
+
+    public void setCompletedAt(ZonedDateTime completedAt) {
+        this.completedAt = completedAt;
+    }
+
+    public void setPostType(PostingType postType) {
+        this.postType = postType;
+    }
+
+    public PostingType getPostType() {
+        return postType;
+    }
+
+    public ZonedDateTime getCompletedAt() {
+        return completedAt;
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/domain/SavedPostStatus.java

@@ -0,0 +1,23 @@
+package de.tum.cit.aet.artemis.communication.domain;
+
+import java.util.Arrays;
+
+public enum SavedPostStatus {
+
+    IN_PROGRESS((short) 0), COMPLETED((short) 1), ARCHIVED((short) 2);
+
+    private final short databaseKey;
+
+    SavedPostStatus(short databaseKey) {
+        this.databaseKey = databaseKey;
+    }
+
+    public short getDatabaseKey() {
+        return databaseKey;
+    }
+
+    public static SavedPostStatus fromDatabaseKey(short databaseKey) {
+        return Arrays.stream(SavedPostStatus.values()).filter(type -> type.getDatabaseKey() == databaseKey).findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("Unknown database key: " + databaseKey));
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/dto/AuthorDTO.java

@@ -0,0 +1,13 @@
+package de.tum.cit.aet.artemis.communication.dto;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+import de.tum.cit.aet.artemis.core.domain.User;
+
+@JsonInclude(JsonInclude.Include.NON_EMPTY)
+public record AuthorDTO(Long id, String name, String imageUrl) {
+
+    public AuthorDTO(User user) {
+        this(user.getId(), user.getName(), user.getImageUrl());
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/dto/PostingConversationDTO.java

@@ -0,0 +1,34 @@
+package de.tum.cit.aet.artemis.communication.dto;
+
+import de.tum.cit.aet.artemis.communication.domain.ConversationType;
+import de.tum.cit.aet.artemis.communication.domain.conversation.Channel;
+import de.tum.cit.aet.artemis.communication.domain.conversation.Conversation;
+import de.tum.cit.aet.artemis.communication.domain.conversation.GroupChat;
+
+public record PostingConversationDTO(Long id, String title, ConversationType type) {
+
+    public PostingConversationDTO(Conversation conversation) {
+        this(conversation.getId(), determineTitle(conversation), determineType(conversation));
+    }
+
+    private static String determineTitle(Conversation conversation) {
+        if (conversation instanceof Channel) {
+            return ((Channel) conversation).getName();
+        }
+        else if (conversation instanceof GroupChat) {
+            return ((GroupChat) conversation).getName();
+        }
+        else {
+            return "Chat";
+        }
+    }
+
+    private static ConversationType determineType(Conversation conversation) {
+        if (conversation instanceof Channel) {
+            return ConversationType.CHANNEL;
+        }
+        else {
+            return ConversationType.DIRECT;
+        }
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/dto/PostingDTO.java

@@ -0,0 +1,40 @@
+package de.tum.cit.aet.artemis.communication.dto;
+
+import java.time.ZonedDateTime;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+import de.tum.cit.aet.artemis.communication.domain.AnswerPost;
+import de.tum.cit.aet.artemis.communication.domain.Posting;
+import de.tum.cit.aet.artemis.communication.domain.PostingType;
+import de.tum.cit.aet.artemis.communication.domain.UserRole;
+
+@JsonInclude(JsonInclude.Include.NON_EMPTY)
+public record PostingDTO(Long id, AuthorDTO author, UserRole role, ZonedDateTime creationDate, ZonedDateTime updatedDate, String content, boolean isSaved, short savedPostStatus,
+        List<ReactionDTO> reactions, PostingConversationDTO conversation, short postingType, Long referencePostId) {
+
+    public PostingDTO(Posting post, boolean isSaved, short savedPostStatus) {
+        this(post.getId(), new AuthorDTO(post.getAuthor()), post.getAuthorRole(), post.getCreationDate(), post.getUpdatedDate(), post.getContent(), isSaved, savedPostStatus,
+                post.getReactions().stream().map(ReactionDTO::new).toList(), new PostingConversationDTO(post.getConversation()), getSavedPostType(post).getDatabaseKey(),
+                getReferencePostId(post));
+    }
+
+    static PostingType getSavedPostType(Posting posting) {
+        if (posting instanceof AnswerPost) {
+            return PostingType.ANSWER;
+        }
+        else {
+            return PostingType.POST;
+        }
+    }
+
+    static Long getReferencePostId(Posting posting) {
+        if (posting instanceof AnswerPost) {
+            return ((AnswerPost) posting).getPost().getId();
+        }
+        else {
+            return posting.getId();
+        }
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/dto/ReactionDTO.java

@@ -0,0 +1,12 @@
+package de.tum.cit.aet.artemis.communication.dto;
+
+import java.time.ZonedDateTime;
+
+import de.tum.cit.aet.artemis.communication.domain.Reaction;
+
+public record ReactionDTO(Long id, AuthorDTO user, ZonedDateTime creationDate, String emojiId) {
+
+    public ReactionDTO(Reaction reaction) {
+        this(reaction.getId(), new AuthorDTO(reaction.getUser()), reaction.getCreationDate(), reaction.getEmojiId());
+    }
+}

src/main/java/de/tum/cit/aet/artemis/communication/repository/AnswerPostRepository.java

@@ -31,5 +31,12 @@ default AnswerPost findAnswerMessageByIdElseThrow(Long answerPostId) {
         return getValueElseThrow(findById(answerPostId).filter(answerPost -> answerPost.getPost().getConversation() != null), answerPostId);
     }
 
+    @NotNull
+    default AnswerPost findAnswerPostOrMessageByIdElseThrow(Long answerPostId) {
+        return getValueElseThrow(findById(answerPostId), answerPostId);
+    }
+
     long countAnswerPostsByPostIdIn(List<Long> postIds);
+
+    List<AnswerPost> findByIdIn(List<Long> idList);
 }

src/main/java/de/tum/cit/aet/artemis/communication/repository/ConversationMessageRepository.java

@@ -114,6 +114,7 @@ private PageImpl<Post> findPostsWithSpecification(Pageable pageable, Specificati
                 LEFT JOIN FETCH p.conversation
                 LEFT JOIN FETCH p.reactions
                 LEFT JOIN FETCH p.tags
+                LEFT JOIN FETCH p.savedPosts
                 LEFT JOIN FETCH p.answers a
                     LEFT JOIN FETCH a.reactions
                     LEFT JOIN FETCH a.post