facebook

gistfile1.txt

class User {
    constructor(userId, userName) {
        this.userId = userId;
        this.userName = userName;
    }
}

class Post {
    constructor(userId, posts) {
        this.userId = userId;
        this.posts = posts;
    }
}

class Friend {
    constructor(follower, followee) {
        this.follower = follower;
        this.followee = followee;
    }
}

class FacebookSystem {
    constructor() {
        this.users = new Map();
        this.friends = [];
        this.posts = [];
    }

    registerUser(userId, userName) {
        if (!this.users.has(userId)) {
            const newUser = new User(userId, userName);
            this.users.set(userId, newUser);
            return newUser;
        }
        return "User already existed";
    }

    addFriend(userId, friendId) {
        this.friends.push(new Friend(userId, friendId))
        this.friends.push(new Friend(friendId, userId))
        return "Added as friend"

    }

    removeFriend(userId, friendId) {
        this.friends = this.friends.filter(friend => !(friend.followee === userId && friend.follower === friendId));
        this.friends = this.friends.filter(friend => !(friend.followee === friendId && friend.follower === userId));
        return "Unfiended successfully";
    }
    addPost(userId, posts) {
        this.posts.push(new Post(userId, posts));
        return "Added post successfully";
    }
    getFriendPosts(userId) {
        const friendList = this.friends.filter(eachUser => eachUser.follower === userId).map(friend => friend.followee)
        return this.posts.filter(post => friendList.includes(post.userId))
    }
}

const facebookSystem = new FacebookSystem();

facebookSystem.registerUser(1, 'Tanvir');
facebookSystem.registerUser(2, 'Nadim');

facebookSystem.addFriend(1, 2);

facebookSystem.addPost(1, 'Hello, friends!');
facebookSystem.addPost(2, 'Hi, a!');

console.log("friendPost", facebookSystem.getFriendPosts(1));
facebookSystem.removeFriend(1, 2);