良いコード／悪いコードで学ぶ設計入門を見ながら書いたコード

thinkingAbout_6_2.java

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

class Main {
    static final Map<MagicType, Magic> magics = new HashMap<>();
    public static void main(String[] args) {
        final Caster caster = new Caster("アルトリア", 90);
        final Fire fire = new Fire(caster);
        final Thunder thunder = new Thunder(caster);
        final HellFire hellFire = new HellFire(caster);

        magics.put(MagicType.fire, fire);
        magics.put(MagicType.thunder, thunder);
        magics.put(MagicType.hellFire, hellFire);

        magicAttack(MagicType.thunder);
    }

    static void magicAttack(final MagicType magicType) {
        final Magic usingMagic = magics.get(magicType);
        System.out.println(usingMagic.name());
    }
}

enum MagicType {
    fire,
    thunder,
    hellFire
}

class Caster {
    private static int GROWTH_RATE_OF_AGILITY = 5;
    private static int GROWTH_RATE_OF_MAGIC_ATTACK = 15;
    private static int GROWTH_RATE_OF_VITALITY = 2;
    String name;
    int level;
    int agility;
    int magicAttack;
    int vitality;

    Caster(final String name, final int level) {
        this.name = name;
        this.level = level;
        this.agility = level * GROWTH_RATE_OF_AGILITY;
        this.magicAttack = level * GROWTH_RATE_OF_MAGIC_ATTACK;
        this.vitality = level * GROWTH_RATE_OF_VITALITY;
    }
}

class MagicPoint {
    final int value;

    MagicPoint(final int value) {
        this.value = value;
    }
}

class AttackPower {
    final int value;

    AttackPower(final int value) {
        this.value = value;
    }
}

class TechnicalPoint {
    final int value;

    TechnicalPoint(final int value) {
        this.value = value;
    }
}

interface Magic {
    String name();
    MagicPoint costMagicPoint();
    AttackPower attackPower();
    TechnicalPoint costTechnicalPoint();
}

class Fire implements Magic {
    private final Caster caster;

    Fire(final Caster caster) {
        this.caster = caster;
    }

    public String name() {
        return "ファイア";
    }

    public MagicPoint costMagicPoint() {
        return new MagicPoint(2);
    }

    public AttackPower attackPower() {
        final int value = 20 + (int)(caster.level * 0.5);
        return new AttackPower(value);
    }

    public TechnicalPoint costTechnicalPoint() {
        return new TechnicalPoint(0);
    }
}

class Thunder implements Magic {
    private final Caster caster;

    Thunder(final Caster caster) {
        this.caster = caster;
    }

    public String name() {
        return "紫電";
    }

    public MagicPoint costMagicPoint() {
        final int value = 5 + (int)(caster.level * 0.2);
        return new MagicPoint(value);
    }

    public AttackPower attackPower() {
        final int value = 50 + (int)(caster.agility * 1.5);
        return new AttackPower(value);
    }

    public TechnicalPoint costTechnicalPoint() {
        return new TechnicalPoint(5);
    }
}

class HellFire implements Magic {
    private final Caster caster;

    HellFire(final Caster caster) {
        this.caster = caster;
    }

    public String name() {
        return "地獄の業火";
    }

    public MagicPoint costMagicPoint() {
        return new MagicPoint(16);
    }

    public AttackPower attackPower() {
        final int value = 200 + (int)(caster.magicAttack * 0.5 + caster.vitality * 2);
        return new AttackPower(value);
    }

    public TechnicalPoint costTechnicalPoint() {
        final int value = 20 + (int)(caster.level * 0.4);
        return new TechnicalPoint(value);
    }
}