Head-First-Design-Pattern-CPP-Examples/State/gumball/GumballMachine.h at master · TimurIskahov/Head-First-Design-Pattern-CPP-Examples · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
#ifndef GUMBALL_MACHINE_H
#define GUMBALL_MACHINE_H

#include <iostream>

class GumballMachine {
	friend std::ostream& operator<<(std::ostream &, GumballMachine &);
	public:
	GumballMachine(int c) : count(c) { if (count > 0) state = NO_QUARTER; }
	void insertQuarter();
	void ejectQuarter();
	void turnCrank();
	void dispense();
	void refill(int numberOfGumballs);
	private:
	static constexpr int SOLD_OUT = 0;
	static constexpr int NO_QUARTER = 1;
	static constexpr int HAS_QUARTER = 2;
	static constexpr int SOLD = 3;
	int state = SOLD_OUT;
	int count = 0;
};

inline
void
GumballMachine::insertQuarter()
{
	if (state == HAS_QUARTER)
		std::cout << "You can't insert another quarter\n";
	else if (state == NO_QUARTER) {
		state = HAS_QUARTER;
		std::cout << "you inserted a quarter\n";
	} else if (state == SOLD_OUT)
		std::cout << "You can't insert a quarter, the machine is sold out\n";
	else if (state == SOLD)
		std::cout << "Please wait, we're already giving you a gumball\n";
}

inline
void
GumballMachine::ejectQuarter()
{
	if (state == HAS_QUARTER) {
		std::cout<< "Quarter returned\n";
		state = NO_QUARTER;
	} else if (state == NO_QUARTER) {
		std::cout<< "You haven't inserted a quarter\n";
	} else if (state == SOLD) {
		std::cout<< "Sorry, you already turned the crank\n";
	} else if (state == SOLD_OUT) {
		std::cout<< "You can't eject, you haven't inserted a quarter yet\n";
	}
}

inline
void
GumballMachine::turnCrank()
{
	if (state == SOLD) {
		std::cout << "Turning twice doesn't get you another gumball!\n";
	} else if (state == NO_QUARTER) {
		std::cout << "You turned but there's no quarter\n";
	} else if (state == SOLD_OUT) {
		std::cout << "You turned, but there are no gumballs\n";
	} else if (state == HAS_QUARTER) {
		std::cout << "You turned...\n";
		state = SOLD;
		dispense();
	}
}

inline
void
GumballMachine::dispense()
{
	if (state == SOLD) {
		std::cout << "A gumball comes rolling out the slot\n";
		count = count - 1;
		if (count == 0) {
			std::cout << "Oops, out of gumballs!\n";
			state = SOLD_OUT;
		} else {
			state = NO_QUARTER;
		}
	} else if (state == NO_QUARTER) {
		std::cout << "You need to pay first\n";
	} else if (state == SOLD_OUT) {
		std::cout << "No gumball dispensed\n";
	} else if (state == HAS_QUARTER) {
		std::cout << "No gumball dispensed\n";
	}
}

inline
std::ostream&
operator<<(std::ostream& os, GumballMachine &gumballMachine)
{
	os << "\nMighty Gumball, Inc.";
	os << "\nJava-enabled Standing Gumball Model #2004\n";
	os << "Inventory: " << gumballMachine.count << " gumball";
	if (gumballMachine.count != 1) {
		os << "s";
	}
	os << "\nMachine is ";
	if (gumballMachine.state == GumballMachine::SOLD_OUT) {
		os << "sold out";
	} else if (gumballMachine.state == GumballMachine::NO_QUARTER) {
		os << "waiting for quarter";
	} else if (gumballMachine.state == GumballMachine::HAS_QUARTER) {
		os << "waiting for turn of crank";
	} else if (gumballMachine.state == GumballMachine::SOLD) {
		os << "delivering a gumball";
	}
	os << "\n";
	return os;
}

#endif /* GUMBALL_MACHINE_H */