DiscussionBoard.java

//Aly Sibak
//1276226
//to compile:
//cd lab3
//javac User.java Post.java TextPost.java PollPost.java DiscussionBoard.java
//to run:
//java discussionboard cis2430
import java.util.ArrayList;
import java.util.Scanner;
import java.io.*;

public class DiscussionBoard {
    private ArrayList<User> users = new ArrayList<>();
    private ArrayList<Post> posts = new ArrayList<>();

    // Method to ensure input is not blank
    private String getNonBlankInput(Scanner scanner, String prompt) {
        String input;
        do {
                    
            System.out.println(prompt);
            input = scanner.nextLine().trim();
            if (input.isBlank()) {
                System.out.println("Input cannot be blank. Please try again.");
            }
        } while (input.isBlank());
        return input;
    }

    // Create a new user
    public void createUser(Scanner scanner) {
        String fullName = getNonBlankInput(scanner, "Enter full name:");
        System.out.println("Enter username (optional):");
        String username = scanner.nextLine().trim();

        if (username.isBlank()) {
            username = fullName.split(" ")[0].toLowerCase();
        }

        for (User user : users) {
            if (user.getUsername().equalsIgnoreCase(username)) {
                System.out.println("Error: Username already exists.");
                return;
            }
        }

        User newUser = new User(fullName, username);
        users.add(newUser);
        System.out.println("User created successfully.");
    }

    // Code to create a new post, either text or poll
    public void createPost(Scanner scanner) {
        String username = getNonBlankInput(scanner, "Enter username:").toLowerCase();
        User user = null;

        for (User u : users) {
            if (u.getUsername().equals(username)) {
                user = u;
                break;
            }
        }

        if (user == null) {
            System.out.println("Error: User not registered.");
            return;
        }

        String postType;
        do {
            postType = getNonBlankInput(scanner, "Enter the post type ('text', 'poll'):");
            if (!postType.equalsIgnoreCase("text") && !postType.equalsIgnoreCase("poll")) {
                System.out.println("Invalid post type. Please enter 'text' or 'poll'.");
            }
        } while (!postType.equalsIgnoreCase("text") && !postType.equalsIgnoreCase("poll"));

        String title = getNonBlankInput(scanner, "Enter title:");

        if (postType.equalsIgnoreCase("text")) {
            String content = getNonBlankInput(scanner, "Enter content:");
            TextPost newPost = new TextPost(title, content, user);
            posts.add(newPost);
            System.out.println("Text post created successfully by user: " + user.getUsername());
        } else if (postType.equalsIgnoreCase("poll")) {
            String options = getNonBlankInput(scanner, "Enter poll options separated by semicolons:");
            PollPost newPost = new PollPost(title, options, user);
            posts.add(newPost);
            System.out.println("Poll post created successfully by user: " + user.getUsername());
        }
    }

    // View all posts that have been created or not created yet
    public void viewAllPosts() {
        if (posts.isEmpty()) {
            System.out.println("No posts available.");
        } else {
            for (Post post : posts) {
                post.display();
            }
        }
    }

    // Vote in a poll
 // Vote in a poll
public void voteInPoll(Scanner scanner) {
    String input = getNonBlankInput(scanner, "Enter the post ID to vote in:");

    // Declare postId
    int postId;
    
    // Check if the input is a valid number
    try {
        postId = Integer.parseInt(input);
    } catch (NumberFormatException e) {
        System.out.println("Invalid input: Post ID must be a number.");
        return;
    }

    // Adjust postId to match the list index (subtract 1 for zero-based index)
    if (postId < 1 || postId > posts.size()) {
        System.out.println("Error: Invalid post ID.");
        return;
    }

    Post post = posts.get(postId - 1); // Subtract 1 for zero-based indexing

    if (!(post instanceof PollPost)) {
        System.out.println("Error: Post not found or not a poll.");
        return;
    }

    PollPost pollPost = (PollPost) post;
    String[] options = pollPost.getOptions();
    for (int i = 0; i < options.length; i++) {
        System.out.println((i + 1) + ") " + options[i]);
    }

    int choice = Integer.parseInt(getNonBlankInput(scanner, "Enter your choice:")) - 1;
    if (choice < 0 || choice >= options.length) {
        System.out.println("Invalid choice.");
    } else {
        pollPost.vote(choice);
        System.out.println("Vote cast successfully.");
    }
}

    // Save discussion board to file
    public void saveToFile(String filename) throws IOException {
        try (PrintWriter writer = new PrintWriter(new FileWriter(filename))) {
            for (Post post : posts) {
                if (post instanceof TextPost) {
                    writer.println("TEXT|" + post.getId() + "|" + post.getUser().getUsername() + "|" + post.getTitle()
                            + "|" + ((TextPost) post).getContent());
                } else if (post instanceof PollPost) {
                    writer.println("POLL|" + post.getId() + "|" + post.getUser().getUsername() + "|" + post.getTitle()
                            + "|" + String.join(";", ((PollPost) post).getOptions()));
                }
            }
        }
    }

    // Load discussion board from file
    public void loadFromFile(String filename) throws IOException {
        File file = new File(filename);
        if (!file.exists()) {
            System.out.println("File not found, starting with blank discussion board.");
            return;
        }

        try (BufferedReader reader = new BufferedReader(new FileReader(filename))) {
            String line;
            while ((line = reader.readLine()) != null) {
                String[] parts = line.split("\\|");

                // Check if the line has the minimum number of parts (for post data)
                if (parts.length < 3) {
                    System.out.println("Error: Invalid line format, skipping: " + line);
                    continue;
                }

                String recordType = parts[0];

                if (recordType.equals("USER")) {
                    // Check if there are enough parts for a user
                    if (parts.length < 3) {
                        System.out.println("Error: Invalid user format, skipping: " + line);
                        continue;
                    }
                    String username = parts[1];
                    String fullName = parts[2];
                    users.add(new User(fullName, username));
                } else {
                    String username = parts[2];
                    User user = null;

                    // Try to find the user by username
                    for (User u : users) {
                        if (u.getUsername().equals(username)) {
                            user = u;
                            break;
                        }
                    }

                    // If user is not found, auto-create the user
                    if (user == null) {
                        System.out.println("Auto-creating user for post: " + username);
                        user = new User(username, username); // Placeholder for full name
                        users.add(user);
                    }

                    // Handle text posts
                    if (recordType.equals("TEXT") && parts.length >= 5) {
                        TextPost post = new TextPost(parts[3], parts[4], user);
                        posts.add(post);
                    }
                    // Handle poll posts
                    else if (recordType.equals("POLL") && parts.length >= 5) {
                        PollPost post = new PollPost(parts[3], parts[4], user);
                        posts.add(post);
                    }
                    // Handle invalid post format
                    else {
                        System.out.println("Error: Invalid post format, skipping: " + line);
                    }
                }
            }
        }
    }

    // View posts by username
    public void viewPostsByUsername(Scanner scanner) {
        String username = getNonBlankInput(scanner, "Enter username:").toLowerCase();
        boolean found = false;

        for (Post post : posts) {
            if (post.getUser().getUsername().equalsIgnoreCase(username)) {
                post.display();
                found = true;
            }
        }

        if (!found) {
            System.out.println("No posts found for the given username.");
        }
    }

// View posts by keyword, matching word-by-word and ignoring case
public void viewPostsByKeyword(Scanner scanner) {
    String keyword = getNonBlankInput(scanner, "Enter keyword:").toLowerCase();
    boolean found = false;

    for (Post post : posts) {
        // Tokenize the title into words
        String[] titleWords = post.getTitle().toLowerCase().split("\\s+");

        // Check if any of the words in the title matches the keyword
        for (String word : titleWords) {
            if (word.equals(keyword)) {
                post.display();
                found = true;
                break; // Stop checking this post once a match is found
            }
        }
    }

    if (!found) {
        System.out.println("No posts found containing the exact keyword.");
    }
}


    // Main menu
    public void menu(String filename) throws IOException {
        Scanner scanner = new Scanner(System.in);

        // Try to load the discussion board from the file
        loadFromFile(filename);

        while (true) {
            System.out.println("1) Create new user");
            System.out.println("2) Create new post");
            System.out.println("3) View all posts");
            System.out.println("4) Vote in poll");
            System.out.println("5) View all posts with a given username");
            System.out.println("6) View all posts with a given keyword");
            System.out.println("7) Save Discussion Board");
            System.out.println("8) End Program");

            if (scanner.hasNextInt()) {
                int choice = scanner.nextInt();
                scanner.nextLine(); // Consume the newline character

                switch (choice) {
                    case 1:
                        createUser(scanner);
                        break;
                    case 2:
                        createPost(scanner);
                        break;
                    case 3:
                        viewAllPosts();
                        break;
                    case 4:
                        voteInPoll(scanner);
                        break;
                    case 5:
                        viewPostsByUsername(scanner);
                        break;
                    case 6:
                        viewPostsByKeyword(scanner);
                        break;
                    case 7:
                        saveToFile(filename);
                        System.out.println("Discussion board saved successfully.");
                        break;
                    case 8:
                        System.out.println("Program Ended.");
                        return; // Exit the loop and program
                    default:
                        System.out.println("Invalid option.");
                }
            } else {
                System.out.println("Invalid input. Please enter a number between 1 and 8.");
                scanner.next(); // Consume the invalid input
            }
        }
    }

    // Main method to start the program
    public static void main(String[] args) throws IOException {
        DiscussionBoard db = new DiscussionBoard();

        // Check if a file was provided as a command-line argument
        if (args.length > 0) {
            db.menu("./boards/" + args[0] + ".dboard");
        } else {
            db.menu("./boards/blank.dboard"); // Default to a blank discussion board
        }
    }

}