import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class GalleryApp extends Application {
    
    public static final int APP_WIDTH  = 500;
    public static final int APP_HEIGHT = 600;
    public static final int N_IMAGES   =   5;
    
    private BorderPane  mainPane;
    private Button      bnPrev, bnNext;
    private Label       lbImage;
    private Image[]     imgArray;
    private ImageView[] ivArray;
    
    private int currentIndex;
    
    @Override
    public void start(Stage stage) {
        
        setupImages();
        setupPane();
        setupXXX();
        
        Scene scene = new Scene(mainPane, APP_WIDTH, APP_HEIGHT);
        
        // stage setup: title, scene, show
        stage.setTitle("CS112 F24 GalleryApp");
        stage.setScene(scene);
        
        stage.show();
    }
    
    private void setupImages() {
        
        imgArray = new Image[N_IMAGES];
        ivArray  = new ImageView[N_IMAGES];
        
        String prefix = "file:f";
        
        for (int i = 0; i < N_IMAGES; ++i) {
            String fname = prefix + (i + 1) + ".png";
            imgArray[i] = new Image(fname);
            ivArray[i]  = new ImageView(imgArray[i]);
        }
    }
    
    private void setupPane() {
        mainPane = new BorderPane();
    }
    
    private void setupXXX() {
        lbImage = new Label(); // Label("Text"); Label(imgView)
        lbImage.setGraphic(ivArray[currentIndex]);
        
        bnPrev = new Button("<");
        bnNext = new Button(">");
        
        bnPrev.setPrefHeight(APP_HEIGHT);
        bnNext.setPrefHeight(APP_HEIGHT);
        
        // action listener
        // TODO: handle wrap-around for prev/next
        bnPrev.setOnAction(e -> {
            
        });
        
        bnNext.setOnAction(e -> {
            ++currentIndex;
            
            // wrap-around
            if (currentIndex == N_IMAGES) {
                currentIndex = 0;
            }
            
            lbImage.setGraphic(ivArray[currentIndex]);
        });
        
        mainPane.setCenter(lbImage);
        mainPane.setLeft(bnPrev);
        mainPane.setRight(bnNext);
    }

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

}