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

#define TEMP_MATS (*(temp_row+row_number))
#define MATS_IN_ROW (*(row+row_number))
void initializetemp();
int checkrow(int, int);
int countfours();
int counttwos();
int countones();
int is_win();
void display();
void winning_move(int);
void losing_move(int);
int player();
int computer();

int row[4] = {7,5,3,1};
int temp_row[4];
int counter;
main()
{
    printf("\n\n  O))       O))               O))            O))                      O))     "
           "\n  O) O))   O)))       O)      O))            O))                      O))     "
           "\n  O)) O)) O O))               O))  O))       O))         O))          O))  O))"
           "\n  O))  O))  O))      O))      O)) O))        O))       O))  O))       O)) O)) "
           "\n  O))   O)  O))      O))      O)O))          O))      O))   O))       O)O))   "
           "\n  O))       O))      O))      O)) O))        O))      O))   O))       O)) O)) "
           "\n  O))       O))      O))      O))  O))      O)))        O)) O)))      O))  O))");
    printf("\n\n                          Welcome to my nim game");

    printf("\n                                  The rules:"
           "\n                      1. Matches are laid out like this:\n"
           "\n                                | | | | | | |"
           "\n                                  | | | | |"
           "\n                                    | | |"
           "\n                                      |\n"
           "\n                     2. Players take matches in turns"
           "\n                         3. As many as they want"
           "\n                    4. But only from one row at a time"
           "\n                    5. Whoever takes the last one loses");


    char flag;
    do
    {
        printf("\n\n           Press 'y' if you want computer to make the first move... ");
        flag = (char)getchar();

        if(flag == 'Y' || flag == 'y')
        {
            if(computer())
                printf("\n\n                                 YOU WIN!\n\n");
            else
                printf("\n\n                                 YOU LOSE!\n\n");
        }
        else
        {
            display();

            if(player())
                printf("\n\n                                 YOU WIN!\n\n");
            else
                printf("\n\n                                 YOU LOSE!\n\n");
        }

        printf("                       Press 'y' to play again... ");
        scanf("%1s",&flag);

    }while(flag=='y' || flag=='Y');
}

int player()
{

    int row_number;
    int how_many;

    printf("\n       Your turn. Chose the row and the number of matches you want to take.\n");

    do
    {
        do
        {
            printf("\n                                   Row: ");
            scanf("%d",&row_number);
            if(row_number < 1 || row_number > 4)
            {
                printf("\n                  ERROR: invalid row number. Please try again.");
                display();
            }
        }while(row_number < 1 || row_number > 4);

            printf("                                 Matches: ");
            scanf("%d",&how_many);

        if(how_many > *(row+row_number-1) || how_many < 1)
        {
            printf("\n               ERROR: invalid number of matches. Please try again.");
            display();
        }
    }while(how_many > *(row+row_number-1) || how_many < 1);

    *(row+row_number-1)-= how_many;

    display();

    return computer();
}

int computer()
{
    int random;
    srand(time(NULL));
    random = rand() % 4;

    if(is_win()==0)
        winning_move(random);
    else
        losing_move(random);

    display();

    if(is_win() == 2)
        return 1;
    else if(is_win() == 3)
        return 0;
    else
        return player();
}

int is_win()
{

    initializetemp();

    int fours = countfours();
    int twos = counttwos();
    int ones = countones();

    if(fours==0 && twos==0)
    {
        if(ones == 0)
            return 2;
        else if(ones == 1)
            return 3;
        else if(ones == 3)
            return 1;
        else
            return 0;
    }
    else if(fours%2 || twos%2 || ones%2)
        return 0;
    else
        return 1;
}

void initializetemp()
{
    for(int i=0;i<4;i++)
        *(temp_row+i) = *(row+i);

}

int countfours()
{
    int fours = 0;

    for(int i=0;i<4;i++)
    {   counter = 0;
        fours += checkrow(i,4);
    }
    return fours;
}

int counttwos()
{
    int twos = 0;

    for(int i=0;i<4;i++)
    {counter=0;
        twos += checkrow(i,2);
    }

    return twos;
}

int countones()
{
    int ones = 0;

    for(int i=0;i<4;i++)
    {counter=0;
        ones += checkrow(i,1);
    }
    return ones;
}

int checkrow(int row_number, int matches)
{
    if(TEMP_MATS>=matches)
    {
        TEMP_MATS-= matches;
        counter++;
        return checkrow(row_number, matches);
    }
    else
        return counter;
}

void winning_move(int row_number)
{
    int matches_taken = 0;

    while(MATS_IN_ROW && is_win() == 0)
    {
        MATS_IN_ROW--;
        matches_taken++;
    }

    if(is_win() == 0)
    {
        MATS_IN_ROW = matches_taken;
        winning_move((row_number+1) % 4);
    }
    else
        printf("\n                     Computer takes %d match(es) from row %d",matches_taken,row_number+1);
}
void losing_move(int row_number)
{
    if(MATS_IN_ROW)
    {
        MATS_IN_ROW--;
        printf("\n                     Computer takes 1 match(es) from row %d",row_number+1);
    }
    else
        losing_move((row_number+1) % 4);
}

void display()
{
    printf("\n");
    for(int i=0;i<4;i++)
    {
        printf("\n                        Row %d:  ",i+1);
        for(int j=0;j<i;j++)
                printf("  ");
        for(int j=0;j<*(row+i);j++)
            printf("| ");
    }
    printf("\n");
}