Hands On Game Development Patterns with Unity 2019

public interface iCopyable {
    iCopyalbe Copy();
}

public class Enemy: MonoBehaviour, iCopyable {
    public iCopyable Copy() {
        return Instantiate(this);
    }
}

public class Sniper: Enemy {
    public void Shoot() {
        // Implement shooting functionality
    }
}

public class Drone: Enemy {
    public void Fly() {
        // Implement flying functionality
    }
    
    public void Fire() {
        // Implement laser fire functionality.
    }
}

public class EnemySpawner: MonoBehaviour {
    public iCopyable m_Copy;
    
    public Enmey SpawnEnemy(Enemy prototype) {
        m_Copy = prototype.Copy();
        return (Enemy)m_Copy;
    }
}

public class Client: MonoBehaviour {
    public Drone m_Drone;
    public Sniper m_Sniper;
    public EnemySpawner m_Spawner;
    
    private Enemy m_Spawn;
    
    private int m_IncrementorDrone = 0;
    private int m_IncrementorSniper = 0;
    
    public void Update() {
        if (Input.GetKeyDown(KeyCode.D)) {
            m_Spawn = m_Spawner.SpawnEnemy(m_Drone);
            
            m_Spawn.name = "Drone_Clone_" + ++m_IncrementorDrone;
        }
        
        if (Input.GetKeyDown(KeyCode.S)) {
            m_Spawn = m_Spawner.SpawnEnemy(m_Sniper);
            
            m_Spawn.name = "Sniper_Clone_" + ++m_IncrementorSniper;
        }
    }
}

public enum NPCType {
    Farmer,
    Beggar,
    Shopowner
}


public interface INPC {
    void Speak();
}

public class Farmer: INPC {
    public void Speak() {
        Debug.Log("Farmer: You reap what you sow!");
    }
}

public class Beggar: INPC {
    public void Speak() {
        Debug.Log("Beggar: Do you have some change to spare?");
    }
}

public class Shopowner: INPC {
    public void Speak() {
        Debug.Log("Shopowner: Do you wish to purchase something");
    }
}

public class NPCFactory: MonoBehaviour {
    public INPC GetNPC(NPCType type) {
        switch (type) {
            case NPCType.Beggar:
                INPC beggar = new Beggar();
                return beggar;
            case NPCType.Farmer:
                INPC farmer = new Farmer();
                return farmer;
            case NPCType.Shopowner:
                INPC shopowner = new Shopowner();
                return shopowner;
        }
        return null;
    }
}

public class NPCSpanwer: MonoBehaviour {
    public NPCFactory m_Factory;
    
    private INPC m_Farmer;
    private INPC m_Beggar;
    private INPC m_Shopowner;
    
    public void SpawnVillagers() {
        m_Beggar = m_Factory.GetNPC(NPCType.Beggar);
        m_Farmer = m_Factory.GetNPC(NPCType.Farmer);
        m_Shopowner = m_Factory.GetNPC(NPCType.Shopowner);
        
        m_Beggar.Speak();
        m_Farmer.Speak();
        m_Shopowner.Speak();
    }
}

public class Client: MonoBehaviour {
    public NPCSpanwer m_SpawnerNPC;
    
    public void Update() {
        if (Input.GetKeyDown(KeyCode.S)) {
            m_SpawnerNPC.SpawnVillagers();
        }
    }
}