Chen Formula App

ChenCalculator.java

package com.example.chenformula;

import java.util.HashMap;
import java.util.Map;

public class ChenCalculator {

    public static final Map<String, Double> POINTS_BY_CARD = new HashMap<>();

    static {
        POINTS_BY_CARD.put("A", 10.0);
        POINTS_BY_CARD.put("K", 8.0);
        POINTS_BY_CARD.put("Q", 7.0);
        POINTS_BY_CARD.put("J", 6.0);
        POINTS_BY_CARD.put("10", 5.0);
        POINTS_BY_CARD.put("9", 4.5);
        POINTS_BY_CARD.put("8", 4.0);
        POINTS_BY_CARD.put("7", 3.5);
        POINTS_BY_CARD.put("6", 3.0);
        POINTS_BY_CARD.put("5", 2.5);
        POINTS_BY_CARD.put("4", 2.0);
        POINTS_BY_CARD.put("3", 1.5);
        POINTS_BY_CARD.put("2", 1.0);
    }

    public static int calculate(String firstCard, String secondCard, boolean suited) {
        double result = 0.0;

        result += scoreHighestCardOnly(firstCard, secondCard);

        if (isPair(firstCard, secondCard)) {
            // what if less than 5!!
            result = result * 2;
        }

        if (suited) {
            result += 2;
        }

        result = result - pointsIfGapBetweenCards(firstCard, secondCard);

        result += bonusPointIf0or1CardGapAndBothCardsLowerThanQ(firstCard, secondCard);

        return Math.toIntExact(Math.round(result));
    }

    private static double scoreHighestCardOnly(String firstCard, String secondCard) {

        String higherCard = determineHigherCard(firstCard, secondCard);

        return POINTS_BY_CARD.get(higherCard);
    }

    private static String determineHigherCard(String firstCard, String secondCard) {
        String higherCard;
        if (POINTS_BY_CARD.get(firstCard) > POINTS_BY_CARD.get(secondCard)) {
            higherCard = firstCard;
        } else {
            higherCard = secondCard;
        }
        return higherCard;
    }

    private static boolean isPair(String firstCard, String secondCard) {
        return firstCard.equals(secondCard);
    }

    private static int pointsIfGapBetweenCards(String firstCard, String secondCard) {

        int higherCardNumber;
        int lowerCardNumber;
        if (determineHigherCard(firstCard, secondCard).equals(firstCard)) {
            higherCardNumber = getCardValue(firstCard);
            lowerCardNumber = getCardValue(secondCard);
        } else {
            higherCardNumber = getCardValue(secondCard);
            lowerCardNumber = getCardValue(firstCard);
        }
        if (firstCard.equals(secondCard)) {
            return 0;
        }
        int gap = higherCardNumber - lowerCardNumber - 1;
        if (gap == 1) {
            return 1;
        }
        if (gap == 2) {
            return 2;
        }
        if (gap == 3) {
            return 4;
        }
        if (gap >= 4) {
            return 5;
        }
        return gap;
    }

    private static int getCardValue(String card) {
        if ("J".equals(card)) {
            return 11;
        }
        if ("Q".equals(card)) {
            return 12;
        }
        if ("K".equals(card)) {
            return 13;
        }
        if ("A".equals(card)) {
            return 14;
        }
        return Integer.parseInt(card);
    }

    private static int bonusPointIf0or1CardGapAndBothCardsLowerThanQ(String firstCard, String secondCard) {
        if (pointsIfGapBetweenCards(firstCard, secondCard) <= 1
                && getCardValue(firstCard) < 12
                && getCardValue(secondCard) < 12) {
            return 1;
        }
        return 0;
    }
}

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/headline"
        android:textSize="30sp"
        android:layout_margin="10dp"
        android:gravity="center"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_margin="5sp">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:layout_margin="5sp">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/card_1_big"
            android:textSize="25sp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/card_1_small"
            android:textSize="15sp"/>
        </LinearLayout>

        <EditText
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="center"
            android:hint="@string/card_value_hint"
            android:id="@+id/card1"
            android:autofillHints="2...A"/>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_margin="5sp">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:layout_margin="5sp">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/card_2_big"
            android:textSize="25sp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/card_2_small"
            android:textSize="15sp"/>
        </LinearLayout>

        <EditText
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="center"
            android:hint="@string/card_value_hint"
            android:id="@+id/card2"
            android:autofillHints="2...A"/>

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_margin="5sp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/suited"
            android:textSize="25sp"/>

        <CheckBox
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/suitedCheckbox"/>

    </LinearLayout>

    <Button
        android:id="@+id/calculateButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/calculate"
        android:layout_gravity="center"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="5"
        android:id="@+id/result"
        android:textSize="25sp"
        android:layout_margin="10sp"
        android:layout_gravity="center"/>




</LinearLayout>

MainActivity.java

package com.example.chenformula;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

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

        Button button = findViewById(R.id.calculateButton);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                EditText card1EditText = findViewById(R.id.card1);
                String card1Content = card1EditText.getText().toString();

                EditText card2EditText = findViewById(R.id.card2);
                String card2Content = card2EditText.getText().toString();

                List<String> zugelasseneZahlen = createListForValidInputs();

                if (!zugelasseneZahlen.contains(card1Content)) {
                    card1EditText.setError("invalid!!!!");
                    return;
                }
                if (!zugelasseneZahlen.contains(card2Content)) {
                    card2EditText.setError("invalid!!!!");
                    return;
                }

                CheckBox checkbox = findViewById(R.id.suitedCheckbox);
                boolean suited = checkbox.isChecked();

                int result = ChenCalculator.calculate(card1Content, card2Content, suited);

                TextView resultTextView = findViewById(R.id.result);
                resultTextView.setText(String.valueOf(result));
            }
        });
    }

    private List<String> createListForValidInputs() {
        List<String> result = new ArrayList<>();
        result.add("2");
        result.add("3");
        result.add("4");
        result.add("5");
        result.add("6");
        result.add("7");
        result.add("8");
        result.add("9");
        result.add("10");
        result.add("J");
        result.add("Q");
        result.add("K");
        result.add("A");
        return result;
    }
}