#include <bits/stdc++.h>
#include <conio.h>
#include <windows.h>
using namespace std;

//Enumeration for direction
enum EDirecton
{
    Stop = 0,
    Left,
    Right,
    Up,
    Down
};
struct Position
{
    int Row;
    int Col;
};
//Declare variables
bool gameOver;
const int width = 40;
const int height = 20;
Position head;
Position food;
int score;
Position snake[200];
int snakeSize;
EDirecton direction;
Position obstacle;

void SetUp()
{
    gameOver = false;
    direction = Stop;
    head.Col = width / 2;
    head.Row = height / 2;
    food.Col = rand() % width;
    food.Row = rand() % height;
    score = 0;
    obstacle.Col = rand() % width;
    obstacle.Row = rand() % height;
}
//Function for changing the cursor coordinates
void SetCursorPointer(int col, int row)
{
    static HANDLE hStdout = NULL;
    COORD coord;

    coord.X = col;
    coord.Y = row;

    if (!hStdout)
    {
        hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
    }

    SetConsoleCursorPosition(hStdout,coord);
}
void Draw()
{
    //Draw upper border
    SetCursorPointer(0, 0);
    for (int col = 0; col < width + 2; col++)
    {
         cout << "#";
    }
    cout << endl;

    //Draw field
    for (int row = 0; row < height; row ++)
    {
        for (int col = 0; col < width; col++)
        {
            if (col == 0)
            {
                cout << "#";
            }
            //Draw snake head
            if (row == head.Row && col == head.Col)
            {
                 cout << "O";
            }
            //Draw food
            else if (row == food.Row && col == food.Col)
            {
                cout << "@";
            }
            //Draw Obstacle
            else if (row == obstacle.Row && col == obstacle.Col)
            {
                cout << "X";
            }
            else
            {
                //Draw snake body
                bool print = false;
                for (int index = 0; index < snakeSize; index++)
                {
                    if (snake[index].Col == col && snake[index].Row == row)
                    {
                        cout << "o";
                        print = true;
                    }
                }
                if (!print)
                {
                    cout << " ";
                }
            }


            if (col == width - 1)
            {
                cout << "#";
            }
        }
        cout << endl;
    }

    //Draw bottom border
    for (int col = 0; col < width + 2; col++)
    {
        cout << "#";
    }
    cout << endl;
    SetCursorPointer(15, 22);
    cout << "Score:" << score << endl;
}
//Function for changing direction
void Input()
{
    //The direction is changed when a key is pressed
    if (_kbhit())
    {
        switch (_getch())
        {
        case 'a':
            direction = Left;
            break;
        case 'd':
            direction = Right;
            break;
        case 'w':
            direction = Up;
            break;
        case 's':
            direction = Down;
            break;
        case 'x':
            gameOver = true;
            break;
        }
    }
}
//Implement thе snake movement
void Logic()
{
    Position previous = snake[0];
    Position next;
    snake[0].Col = head.Col;
    snake[0].Row = head.Row;
    for (int index = 1; index < snakeSize; index++)
    {
        next.Col = snake[index].Col;
        next.Row = snake[index].Row;
        snake[index].Col = previous.Col;
        snake[index].Row = previous.Row;
        previous.Col = next.Col;
        previous.Row = next.Row;
    }
    switch (direction)
    {
        case Left:
            head.Col--;
            break;
        case Right:
            head.Col++;
            break;
        case Up:
            head.Row--;
            break;
        case Down:
            head.Row++;
            break;
        default:
            break;
    }
    //Check if the snake have hit the border
    if (head.Col >= width || head.Col < 0 || head.Row >= height || head.Row < 0)
    {
        gameOver = true;
    }

    //Check if the snake has eaten its body
    for (int index = 0; index < snakeSize; index++)
    {
        if (snake[index].Col == head.Col & snake[index].Row == head.Row)
        {
            gameOver = true;
        }
    }

    //Check if the snake has hit an obstacle
    if (obstacle.Col == head.Col & obstacle.Row == head.Row)
    {
        gameOver = true;
    }

    //Check if the snake has eaten the food
    if (head.Col == food.Col && head.Row == food.Row)
    {
        score += 10;
        food.Col = rand() % width;
        food.Row = rand() % height;
        snakeSize++;
    }
}
//Main function where everything starts
int main()
{
    SetUp();
    while (!gameOver)
    {
        Draw();
        Input();
        Logic();
    }
    return 0;
}