import java.util.function.DoubleToLongFunction;

import javafx.application.Application;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.GridPane;
import javafx.stage.Stage;

public class Digitron extends Application{
    private Label l1 = new Label("Prvi broj");
    private Label l2 = new Label("drugi broj");
    private Label l3 = new Label("operacija");
    private Label l4 = new Label("rezultaj");
    private Label rez = new Label("");
    private TextField b1 = new TextField();
    private TextField b2 = new TextField();
    private Button racunaj = new Button("izracunaj");
    private Button ocisti = new Button("ocisti");
    private ComboBox<String> operacija = new ComboBox<>();
    @Override
    public void start(Stage primaryStage) throws Exception {

        l1.setPadding(new Insets(15));
        l2.setPadding(new Insets(15));
        l3.setPadding(new Insets(15));
        l4.setPadding(new Insets(15));
        rez.setPadding(new Insets(15));
        racunaj.setPadding(new Insets(5));
        ObservableList<String> lista = operacija.getItems();
        lista.add("+");
        lista.add("-");
        lista.add("*");
        lista.add("/");
        operacija.getSelectionModel().select(0);
        GridPane matrica = new GridPane();
        matrica.add(l1, 0, 0);
        matrica.add(b1, 1, 0);
        matrica.add(l2, 0, 1);
        matrica.add(b2, 1, 1);
        matrica.add(l3, 0, 2);
        matrica.add(operacija, 1, 2);
        matrica.add(l4, 0, 3);
        matrica.add(rez, 1, 3);
        FlowPane dole = new FlowPane();
        dole.getChildren().add(racunaj);
        dole.getChildren().add(ocisti);
        racunaj.setOnAction(this::racunaj);
        ocisti.setOnAction(this::reset);
        BorderPane kontejner = new BorderPane();
        kontejner.setCenter(matrica);
        kontejner.setBottom(dole);
        Scene scena = new Scene(kontejner,300,300);
        primaryStage.setScene(scena);
        primaryStage.show();

    }

    public void racunaj(ActionEvent e) {
        double br1 = Double.parseDouble(b1.getText());
        double br2 = Double.parseDouble(b2.getText());
        int op = operacija.getSelectionModel().getSelectedIndex();
        double rez1 = 0;
        if(op==4 && br2==0) {
            new Alert(AlertType.INFORMATION,"deljenje sa 0").showAndWait();
            return;
        }
        switch (op) {
        case 0:
            rez1 = br1+br2;
            break;
        case 1:
            rez1 = br1-br2;
            break;
        case 2:
            rez1= br1*br2;
            break;
        case 3:
            rez1 = br1/br2;
        }
        rez.setText(rez1+"");
    }
    public void reset(ActionEvent e) {
        b1.setText("");
        b2.setText("");
        rez.setText("");
    }

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

    }

}