#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
#include <time.h>
#include <conio.h>

#define PYTHON_MAX_SIZE 100

void ConsoleGoXY(int x, int y);
void HideCursor(void);
void RemoveCharacters(int PythonPosition[][2]);
void PutCharacters(int PythonPosition[][2]);
int PlaceFood(int FoodCoord[2], int PythonPosition[][2]);

int main()
{
    srand(time(NULL));

    int PythonPosition[PYTHON_MAX_SIZE][2];
    for(int i=0;i<PYTHON_MAX_SIZE;i++) {
        PythonPosition[i][0] = -1;
        PythonPosition[i][1] = -1;
    }
    char PythonDirection = 3;
    PythonPosition[0][0] = 40;
    PythonPosition[0][1] = 12;
    PythonPosition[1][0] = 41;
    PythonPosition[1][1] = 12;
    PythonPosition[2][0] = 42;
    PythonPosition[2][1] = 12;

    HideCursor();
    PutCharacters(PythonPosition);

    char KeyBuf;
    int HaveFood = 0;
    int FoodCoord[2];

    while(1) {
        if(kbhit()) {
            KeyBuf = getch();

            switch(KeyBuf) {
            case 72:
                if(PythonDirection != 2)
                    PythonDirection = 0;
                break;
            case 80:
                if(PythonDirection != 0)
                    PythonDirection = 2;
                break;
            case 75:
                if(PythonDirection != 1)
                    PythonDirection = 3;
                break;
            case 77:
                if(PythonDirection != 3)
                    PythonDirection = 1;
                break;
            case 27:
                exit(0);
            }
        }
        if(!HaveFood)
            HaveFood = PlaceFood(FoodCoord, PythonPosition);
        RemoveCharacters(PythonPosition);

        {
            int i;
            for(i=0;PythonPosition[i+1][0]!= -1;i++)
                ;
            for(;i>0;i--) {
                PythonPosition[i][0] = PythonPosition[i-1][0];
                PythonPosition[i][1] = PythonPosition[i-1][1];
            }
        }

        switch(PythonDirection) {
        case 0:
            PythonPosition[0][1] -= 1;
            break;
        case 1:
            PythonPosition[0][0] += 1;
            break;
        case 2:
            PythonPosition[0][1] += 1;
            break;
        case 3:
            PythonPosition[0][0] -= 1;
            break;
        }
        for(int i=1;PythonPosition[i][0] != -1;i++)
                if((PythonPosition[0][1] == PythonPosition[i][1]) && (PythonPosition[0][0] == PythonPosition[i][0])) {
                    ConsoleGoXY(20,12);
                    printf("Eat yourself");
                    system("pause\n");
                    exit(0);
                }
        if(PythonPosition[0][1] == FoodCoord[1] && PythonPosition[0][0] == FoodCoord[0]) {
            int i;
            for(i=0;PythonPosition[i][0] != -1;i++)
                ;
            if(PythonPosition[i-1][0] == PythonPosition[i-2][0]) {
                if(PythonPosition[i-1][1] > PythonPosition[i-2][1]) {
                    PythonPosition[i][0] = PythonPosition[i-1][0];
                    PythonPosition[i][1] = PythonPosition[i-1][1] - 1;
            }
                else {
                    PythonPosition[i][0] = PythonPosition[i-1][0];
                    PythonPosition[i][1] = PythonPosition[i-1][1] = 1;
                }
            }
            if(PythonPosition[i-1][1] == PythonPosition[i-2][1]) {
                if(PythonPosition[i-1][0] > PythonPosition[i-2][0]) {
                    PythonPosition[i][1] = PythonPosition[i-1][1] + 1;
                    PythonPosition[i][0] = PythonPosition[i-1][0];
            }
                else {
                    PythonPosition[i][1] = PythonPosition[i-1][1] - 1;
                    PythonPosition[i][0] = PythonPosition[i-1][0];
                }
            }
            HaveFood = 0;
        }
        if(PythonPosition[0][0] <= 0 || PythonPosition[0][0] >= 80 || PythonPosition[0][1] <= 0 || PythonPosition[0][1] >= 25) {
            ConsoleGoXY(20,12);
            printf("Out of border\n");
            system("pause");
            exit(0);
        }


        PutCharacters(PythonPosition);
        Sleep(80);
    }



    return 0;
}

void RemoveCharacters(int PythonPosition[][2])
{
    for(int i=0;i<PYTHON_MAX_SIZE;i++) {
        if(PythonPosition[i][0] != -1) {
            ConsoleGoXY(PythonPosition[i][0], PythonPosition[i][1]);
            putchar(' ');
        }
        else break;
    }
}

void PutCharacters(int PythonPosition[][2])
{
    for(int i=0;i<PYTHON_MAX_SIZE;i++) {
        if(PythonPosition[i][0] != -1) {
            ConsoleGoXY(PythonPosition[i][0], PythonPosition[i][1]);
            putchar('@');
        }
        else break;
    }
}

int PlaceFood(int FoodCoord[2], int PythonPosition[][2])
{
    int Normal;
    while(1) {
        Normal = 1;
        FoodCoord[0] = rand() % 80;
        FoodCoord[1] = rand() % 25;
        for(int i=0;PythonPosition[i][0] != -1;i++)
            if(FoodCoord[0] == PythonPosition[i][0] && FoodCoord[1] == PythonPosition[i][1]) {
                Normal = 0;
                break;
            }
        if(Normal == 1) {
            ConsoleGoXY(FoodCoord[0], FoodCoord[1]);
            putchar('*');
            return 1;
        }
    }
}

void ConsoleGoXY(int x, int y)
{
    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD place = {x,y};
    SetConsoleCursorPosition(hConsole, place);
}

void HideCursor(void)
{
    CONSOLE_CURSOR_INFO CCI;
    CCI.bVisible = FALSE;
    CCI.dwSize= 1 ;
    SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE),&CCI);
}