Design-Patterns/State/State.cpp at master · HADES-01/Design-Patterns · 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
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/**
 * @cite State Pattern states that state machines are created that facilitates the transitioning of an object from one state to another based on either a change in internal state or triggered by an external event.
 * Aims at promoting loose coupling and Extensible code as the state specific code is divided into separate entities making it easier to add new states and altering previous states.
 *
 * @brief State Pattern can be exemplified by a state machine that denotes the states of interaction of a person on instagram.
 */

#include <iostream>
#include <map>
#include <vector>

// Possible states the person might be currently in or can be in.
enum State
{
    open_instagram,
    stalk_someone,
    doom_scroll,
    comment,
    check_stories,
    like,
    check_posts,
    open_reels,
    close_instagram
};

// Printing the state in textual format.
std::ostream &operator<<(std::ostream &oss, const State &s)
{
    switch (s)
    {
    case open_instagram:
        std::cout << "Home Page...";
        break;
    case stalk_someone:
        std::cout << "Stalk Someone (Be careful)...";
        break;
    case doom_scroll:
        std::cout << "Doom Scroll (Be Careful)...";
        break;
    case check_posts:
        std::cout << "Check New Posts ...";
        break;
    case check_stories:
        std::cout << "Check New Stories ...";
        break;
    case like:
        std::cout << "Like (Be Careful if you're stalking) ... ";
        break;
    case comment:
        std::cout << "Comment (Make it thoughtful) ... ";
        break;
    case open_reels:
        std::cout << "Open Reels (Be Careful of Doom Scrolling) ... ";
        break;
    case close_instagram:
        std::cout << "Close Instagram ... ";
        break;

    default:
        break;
    }
    return oss;
}

int main()
{
    // Facilitates the transition from one state to another state.
    // Connects a state with multiple other states.
    std::map<State, std::vector<State>> states;

    // Connecting States with each other ...
    {
        states[open_instagram].push_back(check_posts);
        states[open_instagram].push_back(check_stories);
        states[open_instagram].push_back(open_reels);
        states[open_instagram].push_back(close_instagram);

        states[check_posts].push_back(stalk_someone);
        states[check_posts].push_back(like);
        states[check_posts].push_back(comment);
        states[check_posts].push_back(open_instagram);
        states[check_posts].push_back(close_instagram);

        states[check_stories].push_back(stalk_someone);
        states[check_stories].push_back(like);
        states[check_stories].push_back(open_instagram);
        states[check_stories].push_back(close_instagram);

        states[stalk_someone].push_back(check_posts);
        states[stalk_someone].push_back(like);
        states[stalk_someone].push_back(open_instagram);
        states[stalk_someone].push_back(close_instagram);

        states[open_reels].push_back(doom_scroll);
        states[open_reels].push_back(open_instagram);
        states[open_reels].push_back(close_instagram);

        states[doom_scroll].push_back(stalk_someone);
        states[doom_scroll].push_back(open_instagram);
        states[doom_scroll].push_back(like);
        states[doom_scroll].push_back(comment);
        // Creates an infinte loop of doom scrolling ...
        states[doom_scroll].push_back(doom_scroll);
        states[doom_scroll].push_back(close_instagram);
    }

    // Setting up intial and exit states ...
    State current_state = State::open_instagram, exit = State::close_instagram;

    // Simulating User Interaction with the app and transitioning based on the interaction...
    while (true)
    {
        std::cout << current_state << "\n";
        int option, i = 1;
        std::cout << "Make Your Choice\n";
        for (auto choice : states[current_state])
        {
            std::cout << "\t" << i++ << ". " << choice << ".\n";
        }
        std::cout << "Enter Your Choice :: ";
        std::cin >> option;
        if (option < 0 || option >= states[current_state].size())
        {
            std::cout << "Wrong Choice...\n";
            continue;
        }

        std::cout << "You choose to " << states[current_state][option] << ".\n";
        if (states[current_state][option] == like || states[current_state][option] == comment)
            continue;
        current_state = states[current_state][option];

        if (current_state == exit)
            break;
    }

    return 0;
}