patterns/state/gumballmachinestate/gumballmachine.d

module gumballmachine;

import std.stdio : writeln;
import std.conv : to;
import soldoutstate, noquarterstate, hasquarterstate, soldstate, state;

class GumballMachine
{ 
    State soldOutState;
    State noQuarterState;
    State hasQuarterState;
    State soldState;
 
    State state;
    int count = 0;
 
    this(int numberGumballs)
    {
        soldOutState = new SoldOutState(this);
        noQuarterState = new NoQuarterState(this);
        hasQuarterState = new HasQuarterState(this);
        soldState = new SoldState(this);

        this.count = numberGumballs;
        if (numberGumballs > 0)
        {
            state = noQuarterState;
        }
        else
        {
            state = soldOutState;
        }
    }
 
    void insertQuarter()
    {
        state.insertQuarter();
    }
 
    void ejectQuarter()
    {
        state.ejectQuarter();
    }
 
    void turnCrank()
    {
        state.turnCrank();
        state.dispense();
    }
 
    void releaseBall()
    {
        writeln("A gumball comes rolling out the slot...");
        if (count > 0)
        {
            count = count - 1;
        }
    }
 
    int getCount()
    {
        return count;
    }
 
    void refill(int count)
    {
        this.count += count;
        writeln("The gumball machine was just refilled; its new count is: ", this.count);
        state.refill();
    }

    void setState(State state)
    {
        this.state = state;
    }

    State getState()
    {
        return state;
    }

    State getSoldOutState()
    {
        return soldOutState;
    }

    State getNoQuarterState()
    {
        return noQuarterState;
    }

    State getHasQuarterState()
    {
        return hasQuarterState;
    }

    State getSoldState()
    {
        return soldState;
    }
 
    override string toString() const
    {
        string s;
        s ~= "\nMighty Gumball, Inc.";
        s ~= "\nJava-enabled Standing Gumball Model #2004";
        s ~= "\nInventory: " ~ count.to!string ~ " gumball";
        if (count != 1)
        {
            s ~= "s";
        }
        s ~= "\n";
        s ~= "Machine is " ~ state.to!string ~ "\n";
        return s;
    }
}