Main.java

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.text.Font;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.control.ListView;
import javafx.scene.control.Label;
import javafx.scene.control.Alert;
import javafx.scene.control.ButtonType;
import java.util.Optional;
import javafx.scene.image.Image;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;

public class Main extends Application {
    private BorderPane root;
    private Flashcards currentSet;
    // Default flashcard set
    ArrayList<String> default_terms = new ArrayList<>(Arrays.asList("CPU", "RAM", "SSD", "GPU"));
    ArrayList<String> default_definitions = new ArrayList<>(Arrays.asList("Central Processing Unit", "Random Access Memory", "Solid State Drive", "Graphics Processing Unit"));
    Flashcards flashcards = new Flashcards(default_terms, default_definitions);
    private EXPBarUI expBar;
    Image appIcon = null;
    Font honk;

    @Override
    public void start(Stage stage) {
        // font loading
        String[] fonts = {"microwave", "honk"};
        for (String fontName : fonts) {
            java.net.URL fontUrl = getClass().getResource("/fonts/" + fontName + ".ttf");
            if (fontUrl != null) {
                Font.loadFont(fontUrl.toExternalForm(), 10);
            }
        }
        
        stage.setTitle("FlashQuiz");
        // load application icon (try classpath first, then local file)
        try {
            java.net.URL iconUrl = getClass().getResource("/icon.png");
            if (iconUrl != null) {
                appIcon = new Image(iconUrl.toExternalForm());
            } else {
                File f = new File("icon.png");
                if (f.exists()) appIcon = new Image(f.toURI().toString());
            }
            if (appIcon != null) stage.getIcons().add(appIcon);
        } catch (Exception ignored) {}
        flashcards.addFlashcardSet(flashcards);
        if (!Flashcards.IDs.isEmpty()) {
            Flashcards.titles.set(Flashcards.IDs.size()-1, "Default Set");
        }

        VBox menu = new VBox(10);
        menu.setPadding(new Insets(12));
        Button homeBtn = new Button("Home");
        Button setsBtn = new Button("Sets");
        Button learnBtn = new Button("Learn");
        Button matchingBtn = new Button("Matching");
        Button bossBtn = new Button("Boss Battle");
        Button accuracyBtn = new Button("Accuracy");

        homeBtn.getStyleClass().addAll("nav-button", "primary");
        setsBtn.getStyleClass().addAll("nav-button", "danger");
        learnBtn.getStyleClass().addAll("nav-button", "accent");
        matchingBtn.getStyleClass().addAll("nav-button", "accent");
        bossBtn.getStyleClass().addAll("nav-button", "accent");
        accuracyBtn.getStyleClass().addAll("nav-button", "accent");

        // add hover animations to nav buttons
        Animations.applyButtonHover(homeBtn);
        Animations.applyButtonHover(setsBtn);
        Animations.applyButtonHover(learnBtn);
        Animations.applyButtonHover(matchingBtn);
        Animations.applyButtonHover(accuracyBtn);
        Animations.applyButtonHover(bossBtn);

        menu.getChildren().addAll(homeBtn, setsBtn, learnBtn, matchingBtn, accuracyBtn, bossBtn);
        root = new BorderPane();
        root.getStyleClass().add("root");
        
        expBar = EXPBarUI.getInstance();
        root.setTop(expBar);

        root.setLeft(menu);
        root.setCenter(buildHomeScreen());
        homeBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildHomeScreen());
            }
        });
        learnBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildLearnScreen());
            }
        });
        matchingBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildMatchingScreen());
            }
        });
        bossBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildBossScreen());
            }
        });
        accuracyBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildAccuracyScreen());
            }
        });
        setsBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(buildSetsScreen());
            }
        });
        Scene scene = new Scene(root, 900, 650);
        try {
            java.net.URL cssUrl = getClass().getResource("/styles.css");
            if (cssUrl != null) {
                scene.getStylesheets().add(cssUrl.toExternalForm());
            } else {
                java.io.File css = new java.io.File("styles.css");
                java.io.File cssApp = new java.io.File("app/styles.css");
                if (css.exists()) {
                    scene.getStylesheets().add(css.toURI().toString());
                } else if (cssApp.exists()) {
                    scene.getStylesheets().add(cssApp.toURI().toString());
                }
            }
        } catch (Exception ignored) {
        }
        stage.setScene(scene);
        stage.show();
    }

    private Node buildHomeScreen() {
        // temp button functionality test;
        // File soundFile = new File("sounds/vineBoom.mp3");
        // Button playSoundBtn = new Button("Play Sound");
        // String uri = soundFile.toURI().toString();
        // Media media = new Media(uri);
        // MediaPlayer mediaPlayer = new MediaPlayer(media);
        // playSoundBtn.setOnAction(new EventHandler<ActionEvent>() {
        //     @Override
        //     public void handle(ActionEvent e) {
        //         mediaPlayer.stop();
        //         mediaPlayer.seek(Duration.ZERO);
        //         mediaPlayer.play();
        //     }
        // });
        // box.getChildren().add(playSoundBtn);
        // end temp button functionality test
        Label title = new Label("FlashQuiz");
        Label subtitle = new Label("Selected Set");
        honk = Font.loadFont("file:fonts/honk.ttf", 48);
        // Label warning = new Label("WARNING: The XP bar will reset every time you close the Program.");
        VBox box = new VBox(12);
        box.getStyleClass().add("app-container");
        title.getStyleClass().add("app-header");
        title.setFont(honk);
        subtitle.getStyleClass().add("sub-title");
        box.setPadding(new Insets(16));
        FlowPane wrap = new FlowPane();
        wrap.getStyleClass().add("card-grid");
        wrap.setHgap(12);
        wrap.setVgap(12);

        int selectedIndex = 0;
        if (currentSet != null) {
            int idx = Flashcards.IDs.indexOf(currentSet);
            if (idx >= 0) selectedIndex = idx;
        }

        for (int i = 0; i < Flashcards.IDs.size(); i++) {
            Flashcards fc = Flashcards.IDs.get(i);
            int index = i;
            int count = 0;
            try {
                var s = fc.getFlashcardSet();
                if (s != null && s.size() >= 2 && s.get(0) != null) {
                    count = s.get(0).size();
                }
            } catch (Exception ignored) {}
            String name = (index < Flashcards.titles.size()) ? Flashcards.titles.get(index) : ("Set " + (index + 1));
            Button card = new Button(name + " - " + count + " cards");
            card.getStyleClass().add("set-card");
            Animations.applyCardHover(card);
            Animations.applyButtonHover(card);
            if (index == selectedIndex) {
                card.getStyleClass().add("selected");
            }
            card.setOnAction(new EventHandler<ActionEvent>() {
                @Override
                public void handle(ActionEvent e) {
                    currentSet = fc;
                    for (Node n : wrap.getChildren()) {
                        n.getStyleClass().remove("selected");
                    }
                    card.getStyleClass().add("selected");
                }
            });
            wrap.getChildren().add(card);
        }

        if (!wrap.getChildren().isEmpty()) {
            if (currentSet == null) {
                currentSet = Flashcards.IDs.get(selectedIndex);
            }
            int idx = Flashcards.IDs.indexOf(currentSet);
            if (idx < 0) idx = selectedIndex;
        }
        // warning.getStyleClass().add("levels-warning");
        // box.getChildren().addAll(title, subtitle, wrap, warning);
        box.getChildren().addAll(title, subtitle, wrap);
        Animations.fadeIn(box);
        return box;
    }

    private Node buildLearnScreen() {
        VBox box = new VBox(10);
        box.setPadding(new Insets(16));
        box.getStyleClass().add("app-container");
        Label title = new Label("Learn");
        title.getStyleClass().add("app-header");

        if (currentSet == null || currentSet.getFlashcardSet() == null || currentSet.getFlashcardSet().size() < 2) {
            box.getChildren().addAll(title, new Label("Pick a set on Home first."));
            return box;
        }

        ArrayList<ArrayList<String>> cs = currentSet.getFlashcardSet();
        ArrayList<String> terms = cs.get(0);
        ArrayList<String> definitions = cs.get(1);
        ArrayList<Double> weights = currentSet.getWeights();
        Learn learnView = new Learn(terms, weights, definitions, expBar);
        return learnView;
    }

        private Node buildMatchingScreen() {
            VBox box = new VBox(10);
            box.setPadding(new Insets(16));
            box.getStyleClass().add("app-container");
            Label title = new Label("Matching");
            title.getStyleClass().add("app-header");
        if (currentSet == null || currentSet.getFlashcardSet() == null || currentSet.getFlashcardSet().size() < 2) {
            return box;
        }
        int count = 0;
        try {
            ArrayList<ArrayList<String>> s = currentSet.getFlashcardSet();
            if (s != null && s.size() >= 2 && s.get(0) != null) {
                count = s.get(0).size();
            }
        } catch (Exception ignored) {}
        ArrayList<ArrayList<String>> cs = currentSet.getFlashcardSet(); 
        Matching matchview = new Matching(cs.get(0), cs.get(1), expBar);
        return matchview;
    }

    private Node buildBossScreen() {
        VBox box = new VBox(10);
        box.setPadding(new Insets(16));
        Label title = new Label("Boss Battle");
        if (currentSet == null || currentSet.getFlashcardSet() == null || currentSet.getFlashcardSet().size() < 2) {
            box.getChildren().addAll(title, new Label("Pick a set on Home first."));
            return box;
        }
        int count = 0;
        try {
            ArrayList<ArrayList<String>> s = currentSet.getFlashcardSet();
            if (s != null && s.size() >= 2 && s.get(0) != null) {
                count = s.get(0).size();
            }
        } catch (Exception ignored) {}
        ArrayList<ArrayList<String>> cs = currentSet.getFlashcardSet();
        ArrayList<String> terms = cs.get(0);
        ArrayList<String> definitions = cs.get(1);
        ArrayList<Double> weights = currentSet.getWeights();
        boolean isMCQ = false; // placeholder mode selection
        Boss bossview = new Boss(terms, definitions, weights, expBar);
        return bossview;
    }

    private Node buildAccuracyScreen() {
        VBox box = new VBox(10);
        box.setPadding(new Insets(16));
        box.getStyleClass().add("app-container");
        Label title = new Label("Accuracy Challenge");
        title.getStyleClass().add("app-header");
        if (currentSet == null || currentSet.getFlashcardSet() == null || currentSet.getFlashcardSet().size() < 2) {
            box.getChildren().addAll(title, new Label("Pick a set on Home first."));
            return box;
        }
        ArrayList<ArrayList<String>> cs = currentSet.getFlashcardSet();
        ArrayList<String> terms = cs.get(0);
        ArrayList<String> definitions = cs.get(1);
        ArrayList<Double> weights = currentSet.getWeights();
        Accuracy accuracy = new Accuracy(terms, definitions, weights, expBar);
        return accuracy;
    }

    private Node buildSetsScreen() {
        VBox box = new VBox(10);
        box.setPadding(new Insets(16));

        Label title = new Label("Sets");
        title.getStyleClass().add("app-header");
        ListView<String> list = new ListView<>();
        list.getStyleClass().add("sets-list");

        int index = 1;
        for (Flashcards fc : Flashcards.IDs) {
            int count = 0;
            try {
                var s = fc.getFlashcardSet();
                if (s != null && s.size() >= 2 && s.get(0) != null) {
                    count = s.get(0).size();
                }
            } catch (Exception ignored) {}
            String name = (index-1 < Flashcards.titles.size()) ? Flashcards.titles.get(index-1) : ("Set " + index);
            list.getItems().add(name + " - " + count + " cards");
            index++;
        }

        int curIdx = Flashcards.IDs.indexOf(currentSet);
        if (curIdx >= 0) {
            list.getSelectionModel().select(curIdx);
        }

        list.getSelectionModel().selectedIndexProperty().addListener(new ChangeListener<Number>() {
            @Override
            public void changed(ObservableValue<? extends Number> obs, Number oldVal, Number newVal) {
                int sel = newVal == null ? -1 : newVal.intValue();
                if (sel >= 0 && sel < Flashcards.IDs.size()) {
                    currentSet = Flashcards.IDs.get(sel);
                }
            }
        });

        Button createBtn = new Button("Create Set");
        createBtn.getStyleClass().addAll("nav-button", "accent");
        createBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                root.setCenter(new SetsEditor());
            }
        });

        Button editBtn = new Button("Edit Set");
        editBtn.getStyleClass().addAll("nav-button", "accent");
        editBtn.setOnAction(new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent e) {
                int sel = list.getSelectionModel().getSelectedIndex();
                if (sel >= 0 && sel < Flashcards.IDs.size()) {
                    root.setCenter(new SetsEditor(Flashcards.IDs.get(sel)));
                } else {
                    Alert info = new Alert(Alert.AlertType.INFORMATION);
                    info.setTitle("Edit Set");
                    info.setHeaderText(null);
                    info.setContentText("Please select a set from the list to edit.");
                    info.showAndWait();
                }
            }
        });

        Button deleteSetsBtn = new Button("Delete Set");
        deleteSetsBtn.getStyleClass().addAll("nav-button", "danger");
        deleteSetsBtn.setOnAction(e -> {
            int sel = list.getSelectionModel().getSelectedIndex();
            if (sel < 0 || sel >= Flashcards.IDs.size()) return;

            Alert confirm = new Alert(Alert.AlertType.CONFIRMATION);
            confirm.setTitle("Delete Set");
            confirm.setHeaderText("Delete selected set");
            confirm.setContentText("Are you sure you want to delete the selected set? This cannot be undone.");
            Optional<ButtonType> res = confirm.showAndWait();
            if (res.isPresent() && res.get() == ButtonType.OK) {
                // Remove from model
                Flashcards.IDs.remove(sel);
                if (sel < Flashcards.titles.size()) Flashcards.titles.remove(sel);
                // Remove from view
                list.getItems().remove(sel);

                // Adjust currentSet selection
                if (currentSet != null && !Flashcards.IDs.contains(currentSet)) {
                    if (!Flashcards.IDs.isEmpty()) {
                        int newSel = Math.min(sel, Flashcards.IDs.size() - 1);
                        currentSet = Flashcards.IDs.get(newSel);
                        list.getSelectionModel().select(newSel);
                    } else {
                        currentSet = null;
                    }
                } else {
                    int currentIdx = Flashcards.IDs.indexOf(currentSet);
                    if (currentIdx >= 0) list.getSelectionModel().select(currentIdx);
                }
            }
        });

        HBox hbox = new HBox(8);
        hbox.getChildren().addAll(createBtn, editBtn, deleteSetsBtn);
        box.getChildren().addAll(title, list, hbox);
        Animations.fadeIn(box);
        return box;
    }

    public static void main(String[] args) {
        launch(args);
    }
}