#include <bits/stdc++.h>
#include <iostream>
#include <conio.h>
#include <windows.h>

using namespace std;

bool gameOver;
const int width = 40;
const int height = 20;
int x, y, fruitX, fruitY, score;
int tailX[100], tailY[100];
int ntail;
enum eDirection { STOP = 0, LEFT, RIGHT, UP, DOWN };
eDirection dir;

void setup() {
    gameOver = false;
    dir = STOP;
    x = width / 2;
    y = height / 2;
    fruitX = rand() % width;
    fruitY = rand() % height;
    score = 0;
}

void draw() {
    SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), {0,0});
    for(int i = 0; i < width + 2; i++) cout << "#";
    cout << "\n";
    for(int i = 0; i < height; i++) {
        for(int j = 0; j < width; j++ ) {
            if(j == 0) cout << "#";
            if(i == y && j == x) cout << "O";
            else if(i == fruitY && j == fruitX) cout << "F";
            else {
                bool print = false;
                for (int k = 0; k < ntail; k++) {
                    if (tailX[k] == j && tailY[k] == i) {
                        cout << "o";
                        print = true;
                    }
                }
                if(!print) cout << " ";
            }
            if(j == width - 1) cout << "#";
        }
        cout << "\n";
    }
    for(int i = 0; i < width + 2; i++) cout << "#";
    cout << "\n";
    cout << "score:" << score << "\n";

}

void input() {
    if(kbhit()) {
        char userInput = getch();
        switch(toupper(userInput)) {
            case 'A':
            case 75:
                dir = LEFT;
                break;
            case 'D':
            case 77:
                dir = RIGHT;
                break;
            case 'W':
            case 72:
                dir = UP;
                break;
            case 'S':
            case 80:
                dir = DOWN;
                break;
            case 27:
                break;

        }
    }
}

void logic() {

    int prevX = tailX[0];
    int prevY = tailY[0];
    int prev2X, prev2Y;
    tailX[0] = x;
    tailY[0] = y;
    for(int i = 1; i < ntail; i++) {
        prev2X = tailX[i];
        prev2Y = tailY[i];
        tailX[i] = prevX;
        tailY[i] = prevY;
        prevX = prev2X;
        prevY = prev2Y; 
    }

    switch(dir){
        case LEFT:
            x--;
            break;
        case RIGHT:
            x++;
            break;
        case UP:
            y--;
            break;
        case DOWN:
            y++;
            break;
    }

    if(x >= width) x = 0;
    else if(x < 0) x = width - 1;
    if(y >= height) y = 0;
    else if(y < 0) y = height - 1;
    for(int i = 0; i < ntail; i++)
        if(tailX[i] == x && tailY[i] == y)
            gameOver = true;
    if(x == fruitX && y == fruitY) {
        score += 10;
        fruitX = rand() % width;
        fruitY = rand() % height;
        ntail++;
    }

}

int main() {
    system("cls");
    setup();
    while(!gameOver){
        draw();
        input();
        logic();
        Sleep(100);
    }
    return 0;
}