package com.example.admin.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        final EditText firstNum=(EditText)findViewById(R.id.firstNum);
        final EditText secNum =(EditText)findViewById(R.id.secNum);

        Button plusButton = (Button)findViewById(R.id.plusButton);
        Button minusButton = (Button)findViewById(R.id.minusButton);
        Button mulButton = (Button)findViewById(R.id.mulButton);
        Button divButton = (Button)findViewById(R.id.divButton);

        //TextView theResult = (TextView)findViewById(R.id.theResult);


            plusButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if ((firstNum.getText().toString().isEmpty() || secNum.getText().toString().isEmpty())) {
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText("Missing Fields");
                    }
                    else {

                        if (isNumeric(firstNum.getText().toString()) && isNumeric(secNum.getText().toString())){
                        Double x = Double.parseDouble(firstNum.getText().toString());
                    Double y = Double.parseDouble(secNum.getText().toString());
                    TextView theResult = (TextView)findViewById(R.id.theResult);
                    theResult.setText((x + y) + "");}
                    else {
                            TextView theResult = (TextView)findViewById(R.id.theResult);
                            theResult.setText("Non Numeric Value");
                        }
                        }

                }
            });

            minusButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if ((firstNum.getText().toString().isEmpty() || secNum.getText().toString().isEmpty())) {
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText("Missing Fields");
                    }
                    else {

                        if (isNumeric(firstNum.getText().toString()) && isNumeric(secNum.getText().toString())){
                            Double x = Double.parseDouble(firstNum.getText().toString());
                            Double y = Double.parseDouble(secNum.getText().toString());
                            TextView theResult = (TextView)findViewById(R.id.theResult);
                            theResult.setText((x - y) + "");}
                        else {
                            TextView theResult = (TextView)findViewById(R.id.theResult);
                            theResult.setText("Non Numeric Value");
                        }
                    }

                }
            });

        mulButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if ((firstNum.getText().toString().isEmpty() || secNum.getText().toString().isEmpty())) {
                    TextView theResult = (TextView)findViewById(R.id.theResult);
                    theResult.setText("Missing Fields");
                }
                else {

                    if (isNumeric(firstNum.getText().toString()) && isNumeric(secNum.getText().toString())){
                        Double x = Double.parseDouble(firstNum.getText().toString());
                        Double y = Double.parseDouble(secNum.getText().toString());
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText((x * y) + "");}
                    else {
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText("Non Numeric Value");
                    }
                }

            }
        });


        divButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if ((firstNum.getText().toString().isEmpty() || secNum.getText().toString().isEmpty())) {
                    TextView theResult = (TextView)findViewById(R.id.theResult);
                    theResult.setText("Missing Fields");
                }
                else {

                    if (isNumeric(firstNum.getText().toString()) && isNumeric(secNum.getText().toString())){
                        Double x = Double.parseDouble(firstNum.getText().toString());
                        Double y = Double.parseDouble(secNum.getText().toString());
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText((x / y) + "");}
                    else {
                        TextView theResult = (TextView)findViewById(R.id.theResult);
                        theResult.setText("Non Numeric Value");
                    }
                }

            }
        });

    }


    public static boolean isNumeric(String strNum) {
        try {
            double d = Double.parseDouble(strNum);
        } catch (NumberFormatException | NullPointerException nfe) {
            return false;
        }
        return true;
    }



}