From a06c74b711b1be3f16eaba97fdf02274917fdb6e Mon Sep 17 00:00:00 2001 From: 100yo Date: Sat, 2 Nov 2024 01:12:04 +0200 Subject: [PATCH] Add Lab 04 assignment --- 04-collections-clean-code/lab/README.md | 333 ++++++++++++++++++++++++ 1 file changed, 333 insertions(+) create mode 100644 04-collections-clean-code/lab/README.md diff --git a/04-collections-clean-code/lab/README.md b/04-collections-clean-code/lab/README.md new file mode 100644 index 00000000..9d6885e4 --- /dev/null +++ b/04-collections-clean-code/lab/README.md @@ -0,0 +1,333 @@ +# Social Network :speech_balloon: + +Тази седмица ще запретнем ръкави и създадем проста социална мрежа, която ще моделира потребители, мрежи от приятелства, постове и реакции. + +### Social Network + +В пакета `bg.sofia.uni.fmi.mjt.socialnetwork` създайте публичен клас `SocialNetworkImpl`, който има публичен конструктор по подразбиране и имплементира интерфейса `SocialNetwork`: + +```java +package bg.sofia.uni.fmi.mjt.socialnetwork; + +import bg.sofia.uni.fmi.mjt.socialnetwork.exception.UserRegistrationException; +import bg.sofia.uni.fmi.mjt.socialnetwork.post.Post; +import bg.sofia.uni.fmi.mjt.socialnetwork.profile.UserProfile; + +import java.util.Collection; +import java.util.Set; +import java.util.SortedSet; + +public interface SocialNetwork { + + /** + * Registers a user in the social network. + * + * @param userProfile the user profile to register + * @throws IllegalArgumentException if the user profile is null + * @throws UserRegistrationException if the user profile is already registered + */ + void registerUser(UserProfile userProfile) throws UserRegistrationException; + + /** + * Returns all the registered users in the social network. + * + * @return unmodifiable set of all registered users (empty one if there are none). + */ + Set getAllUsers(); + + /** + * Posts a new post in the social network. + * + * @param userProfile the user profile that posts the content + * @param content the content of the post + * @return the created post + * @throws UserRegistrationException if the user profile is not registered + * @throws IllegalArgumentException if the user profile is null + * @throws IllegalArgumentException if the content is null or empty + */ + Post post(UserProfile userProfile, String content) throws UserRegistrationException; + + /** + * Returns all posts in the social network. + * + * @return unmodifiable collection of all posts (empty one if there are none). + */ + Collection getPosts(); + + /** + * Returns a collection of unique user profiles that can see the specified post in their feed. A + * user can view a post if both of the following conditions are met: + *
    + *
  1. The user has at least one common interest with the author of the post.
    2. + *
  2. The user has the author of the post in their network of friends.
    3. + *
+ *

+ * Two users are considered to be in the same network of friends if they are directly connected + * (i.e., they are friends) or if there exists a chain of friends connecting them. + *

+ * + * @param post The post for which visibility is being determined + * @return A set of user profiles that meet the visibility criteria (empty one if there are none). + * @throws IllegalArgumentException if the post is null. + */ + Set getReachedUsers(Post post); + + /** + * Returns a set of all mutual friends between the two users. + * + * @param userProfile1 the first user profile + * @param userProfile2 the second user profile + * @return a set of all mutual friends between the two users or an empty set if there are no + * mutual friends + * @throws UserRegistrationException if any of the user profiles is not registered + * @throws IllegalArgumentException if any of the user profiles is null + */ + Set getMutualFriends(UserProfile userProfile1, UserProfile userProfile2) + throws UserRegistrationException; + + /** + * Returns a sorted set of all user profiles ordered by the number of friends they have in + * descending order. + * + * @return a sorted set of all user profiles ordered by the number of friends they have in + * descending order + */ + SortedSet getAllProfilesSortedByFriendsCount(); + +} +``` + +### User Profile + +В пакетa `bg.sofia.uni.fmi.mjt.socialnetwork.profile` създайте публичен клас `DefaultUserProfile`, чрез който ще моделираме потребителите на социалната мрежа. Той трябва да има конструктор + +```java +public DefaultUserProfile(String username) +``` + +и да имплементира интерфейса `UserProfile`: + +```java +package bg.sofia.uni.fmi.mjt.socialnetwork.profile; + +import java.util.Collection; + +public interface UserProfile { + + /** + * Returns the username of the user. + * Each user is guaranteed to have a unique username. + * + * @return the username of the user + */ + String getUsername(); + + /** + * Returns an unmodifiable view of the user's interests. + * + * @return an unmodifiable view of the user's interests + */ + Collection getInterests(); + + /** + * Adds an interest to the user's profile. + * + * @param interest the interest to be added + * @return true if the interest is newly added, false if the interest is already present + * @throws IllegalArgumentException if the interest is null + */ + boolean addInterest(Interest interest); + + /** + * Removes an interest from the user's profile. + * + * @param interest the interest to be removed + * @return true if the interest is removed, false if the interest is not present + * @throws IllegalArgumentException if the interest is null + */ + boolean removeInterest(Interest interest); + + /** + * Return unmodifiable view of the user's friends. + * + * @return an unmodifiable view of the user's friends + */ + Collection getFriends(); + + /** + * Adds a user to the user's friends. + * + * @param userProfile the user to be added as a friend + * @return true if the user is added, false if the user is already a friend + * @throws IllegalArgumentException if the user is trying to add themselves as a friend, or if the user is null + */ + boolean addFriend(UserProfile userProfile); + + /** + * Removes a user from the user's friends. + * + * @param userProfile the user to be removed + * @return true if the user is removed, false if the user is not a friend + * @throws IllegalArgumentException if the user is null + */ + boolean unfriend(UserProfile userProfile); + + /** + * Checks if a user is already a friend. + * + * @param userProfile the user to be checked + * @return true if the user is a friend, false if the user is not a friend + * @throws IllegalArgumentException if the user is null + */ + boolean isFriend(UserProfile userProfile); +} +``` + +Обърнете внимание, че приятелството в нашата социална мрежа е симетрична релация. + +Интересите на даден потребител се моделират от следния enum: + +```java +package bg.sofia.uni.fmi.mjt.socialnetwork.profile; + +public enum Interest { + SPORTS, BOOKS, TRAVEL, MUSIC, MOVIES, GAMES, FOOD +} +``` + +### Post + +Пост в социалнта мрежа се моделира от класа `SocialFeedPost` в пакета `bg.sofia.uni.fmi.mjt.socialnetwork.post`. Класът трябва да има конструктор + +```java +public SocialFeedPost(UserProfile author, String content) +``` +и да имплементира интерфейса + +```java +package bg.sofia.uni.fmi.mjt.socialnetwork.post; + +import bg.sofia.uni.fmi.mjt.socialnetwork.profile.UserProfile; + +import java.time.LocalDateTime; +import java.util.Map; +import java.util.Set; + +public interface Post { + + /** + * Returns the unique id of the post. + * Each post is guaranteed to have a unique id. + * + * @return the unique id of the post + */ + String getUniqueId(); + + /** + * Returns the author of the post. + * + * @return the author of the post + */ + UserProfile getAuthor(); + + /** + * Returns the date and time when the post was published. + * A post is published once it is created. + * + * @return the date and time when the post was published + */ + LocalDateTime getPublishedOn(); + + /** + * Returns the content of the post. + * + * @return the content of the post + */ + String getContent(); + + /** + * Adds a reaction to the post. + * If the profile has already reacted to the post, the reaction is updated to the latest one. + * An author of a post can react to their own post. + * + * @param userProfile the profile that adds the reaction + * @param reactionType the type of the reaction + * @return true if the reaction is added, false if the reaction is updated + * @throws IllegalArgumentException if the profile is null + * @throws IllegalArgumentException if the reactionType is null + */ + boolean addReaction(UserProfile userProfile, ReactionType reactionType); + + /** + * Removes a reaction from the post. + * + * @param userProfile the profile that removes the reaction + * @return true if the reaction is removed, false if the reaction is not present + * @throws IllegalArgumentException if the profile is null + */ + boolean removeReaction(UserProfile userProfile); + + /** + * Returns all reactions to the post. + * The returned map is unmodifiable. + * + * @return an unmodifiable view of all reactions to the post + */ + Map> getAllReactions(); + + /** + * Returns the count of a specific reaction type to the post. + * + * @param reactionType the type of the reaction + * @return the count of reactions of the specified type + * @throws IllegalArgumentException if the reactionType is null + */ + int getReactionCount(ReactionType reactionType); + + /** + * Returns the total count of all reactions to the post. + * + * @return the total count of all reactions to the post + */ + int totalReactionsCount(); +} +``` + +Реакциите се моделират от следния enum: + +```java +package bg.sofia.uni.fmi.mjt.socialnetwork.post; + +public enum ReactionType { + LIKE, LOVE, ANGRY, LAUGH, SAD +} +``` + +### Пакети + +Спазвайте имената на пакетите на всички по-горе описани типове, тъй като в противен случай, решението ви няма да може да бъде автоматично тествано. + +``` +src +└── bg.sofia.uni.fmi.mjt.socialnetwork + ├── exception + │ └── UserRegistrationException.java + ├── post + │ ├── Post.java + │ ├── ReactionType.java + │ ├── SocialFeedPost.java + │ └── (...) + ├── profile + │ ├── DefaultUserProfile.java + │ ├── Interest.java + │ ├── UserProfile.java + │ └── (...) + ├── SocialNetwork.java + ├── SocialNetworkImpl.java + └── (...) +``` + +### :warning: Забележки + +- Не променяйте по никакъв начин интерфейсите, дадени в условието. +- Използването на [Java Stream API](https://docs.oracle.com/en/java/javase/23/docs/api/java.base/java/util/stream/package-summary.html) и/или [lambdas](https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html) **не е разрешено**. Задачата трябва да се реши с помощта на знанията от курса до момента.