/**
 * 糖果机 状态接口
 * @author huangy on 2019-06-08
 */
public interface State {

    /**
     * 投币
     */
    void insertQuarter();

    /**
     * 退钱
     */
    void ejectQuarter();

    /**
     * 试着转动曲柄
     */
    void turnCrank();

    /**
     * 发放糖果
     */
    void dispense();
}

/**
 * @author huangy on 2019-06-08
 */
public class HasQuarterState implements State {

    GumballMachine gumballMachine;

    public HasQuarterState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("HasQuarterState insertQuarter");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("HasQuarterState ejectQuarter");
    }

    @Override
    public void turnCrank() {
        System.out.println("HasQuarterState turnCrank");
        // 状态里面可以改变状态
        gumballMachine.setState(gumballMachine.soldState);
    }

    @Override
    public void dispense() {
        System.out.println("HasQuarterState dispense");
    }
}

/**
 * @author huangy on 2019-06-08
 */
public class NoQuarterState implements State {

    GumballMachine gumballMachine;

    public NoQuarterState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("NoQuarterState insertQuarter");
        gumballMachine.setState(gumballMachine.hasQuqrterState);
    }

    @Override
    public void ejectQuarter() {
        System.out.println("NoQuarterState ejectQuarter");
    }

    @Override
    public void turnCrank() {
        System.out.println("NoQuarterState turnCrank");
    }

    @Override
    public void dispense() {
        System.out.println("NoQuarterState dispense");
    }
}

/**
 * @author huangy on 2019-06-08
 */
public class SoldOutState implements State {

    GumballMachine gumballMachine;

    public SoldOutState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("SoldOutState insertQuarter");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("SoldOutState ejectQuarter");
    }

    @Override
    public void turnCrank() {
        System.out.println("SoldOutState turnCrank");
    }

    @Override
    public void dispense() {
        System.out.println("SoldOutState dispense");
    }
}

/**
 * @author huangy on 2019-06-08
 */
public class SoldState implements State {

    GumballMachine gumballMachine;

    public SoldState(GumballMachine gumballMachine) {
        this.gumballMachine = gumballMachine;
    }

    @Override
    public void insertQuarter() {
        System.out.println("SoldState insertQuarter");
    }

    @Override
    public void ejectQuarter() {
        System.out.println("SoldState ejectQuarter");
    }

    @Override
    public void turnCrank() {
        System.out.println("SoldState turnCrank");
    }

    @Override
    public void dispense() {
        System.out.println("SoldState dispense");
    }
}

/**
 * 糖果机  （Context）
 * @author huangy on 2019-06-08
 */
public class GumballMachine {

    /**
     * 糖果机的状态
     */
    State soldOutState;

    State noQuqrterState;

    State hasQuqrterState;

    State soldState;

    // 当前状态
    State state = soldOutState;

    // 糖果数目
    int count = 0;

    public GumballMachine(int count) {
        this.count = count;
        soldOutState = new SoldOutState(this);
        noQuqrterState = new NoQuarterState(this);
        hasQuqrterState = new HasQuarterState(this);
        soldState = new SoldState(this);

        if (count > 0) {
            // Context里面可以改变状态
            state = noQuqrterState;
        }
    }

    public void insertQuarter() {
        state.insertQuarter();
    }

    public void ejectQuarter() {
        state.ejectQuarter();
    }

    public void turnCrank() {
        state.turnCrank();
        state.dispense();
    }

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

    public void releaseBall() {
        System.out.println("releaseBall");

        if (count != 0) {
            count--;
        }
    }

    @Override
    public String toString() {
        return "GumballMachine{" +
                "state=" + state +
                ", count=" + count +
                '}';
    }
}

public class DemoTest {

    public static void main(String[] args) {
        GumballMachine gumballMachine = new GumballMachine(5);

        System.out.println(gumballMachine);

        gumballMachine.insertQuarter();
        gumballMachine.turnCrank();


        System.out.println(gumballMachine);
    }

}