/* Khai Quang Ho, kho19@student.aau.dk, A402, SW1 */

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#define BONUS_ROUND 7

int dice_roll(){
    return ((rand()%6)+1); /* +1 to avoid rolling 0 */
}
    void reset_dice(int *dice_pairs){
    int i;
    for(i = 0; i <= 7; i++) /* reset dice values */
        dice_pairs[i] = 0;
}
void roll_multiple_dices(int *dice_pairs, int num){
    int i;
    reset_dice(dice_pairs);
    for(i = 1; i < num+1; i++) /* rolls as many times as dices given (+1 because index 0 is skipped) */
        dice_pairs[dice_roll()] += 1; /* store the amount of rolls for each type */
}
void sum_of_all(int n, int dice_pairs, int *score){
    if(dice_pairs > 5)
        *score = (5 * (n));
    else
        *score = (dice_pairs * n);
}
void sum_of_pair(int n, int dice_pairs[], int *score){
    int index, amount = n, buff_score = 0;
    for(index = 6; index > 0 && amount != 0; index--){
        if(dice_pairs[index] >= 2){
            buff_score += (index*2);
            amount--;
            if(amount == 0){
                *score += buff_score;
            }
        }
    }
}
void sum_of_kind(int n, int dice_pairs[], int *score){ /* optimize */
    int index;
    for(index = 6; index>0; index--){
        if(dice_pairs[index] >= n){
            *score = (index*n);
            index = 0;
        }
    }
}
void sum_of_straight(int start, int dice_pairs[], int *score){
    int index, end = (start+5), buffer_score = 0;
    for(index = start; index < end && dice_pairs[index] > 0; index++ )
        buffer_score += index;
    if(index == end)
        *score = buffer_score;
}
void sum_of_house(int dice_pairs[], int *score){
    int index, buff_score = 0;
    for(index = 6; index>0; index--){
        if(dice_pairs[index] >= 3){
            *score = (index*3);
            dice_pairs[index] = 0;
            sum_of_pair(1 ,dice_pairs, &buff_score); /* already pointer */
            if(buff_score > 0)
                *score += buff_score;
            else
                *score = 0;
            index = 0;
        }
    }
}
void sum_of_chance(int dice_pairs[], int *score){
    int index, count = 0;
    for(index = 6; index > 0 && count <5; index--){
        if(dice_pairs[index]+count <= 5){
            *score += (dice_pairs[index] * index);
            count += dice_pairs[index];
        }
        else{
            *score += (5-count) * index;
            count = 5;
        }
    }
}
void sum_of_yatzy(int dice_pairs[], int *score){
    sum_of_kind((5), dice_pairs, score);
    if(*score > 0)
        *score = 50;
}
void check_bonus_round(int i, int *score){
    int bonus = 0;
    if(i == BONUS_ROUND){
        if(*score >= 63)
            bonus = 50;
        *score += bonus;
        printf("\nBonus round: Earned %d points, total score: %d\n",bonus, *score);
    }
}
void calc_round(int i, int dice_pairs[], int *buff_score){
    if(i <= 6)
        sum_of_all(i, dice_pairs[(i)], buff_score);
    else if(i <= 8)
        sum_of_pair((i-6), dice_pairs, buff_score);
    else if(i <= 10)
        sum_of_kind((i-6), dice_pairs, buff_score);
    else if(i <= 12)
        sum_of_straight((i-10), dice_pairs, buff_score);
    else if(i == 13)
        sum_of_house(dice_pairs, buff_score);
    else if(i == 14)
        sum_of_chance(dice_pairs, buff_score);
    else if(i == 15)
        sum_of_yatzy(dice_pairs, buff_score);
}
void print_dice(int n, int dice_pairs[]){
    int i, j;
    printf("\nDice:");
    for(i = 1; i <= 6; i++ ){
        for(j = dice_pairs[i]; j > 0; j--)
            printf(" %d", i);
    }
}
void scan_data(int *n){
    char skip;
    printf("\ninsert number of dices (less than 5 to exit): ");
    while( scanf(" %d", n) != 1){
        printf("\ninvalid input, try again: ");
        do{
            scanf("%c", &skip);
        }while(skip != '\n');
    }
}

int main(void){
    int n, i;
    int score = 0, buff_score = 0;
    int dice_pairs[7] ={0, 0, 0, 0, 0, 0, 0};
    const char *round_name[] =
    {"NULL", "ones", "twos", "threes", "fours", "fives", "sixes",
    "one pair", "two pairs", "three of a kind", "four of a kind",
    "small straight", "large straight", "full house", "chance", "yatzy"};
    srand(time(NULL));

    do {
        scan_data(&n);
        score = 0;
        for(i = 1; i <= 15 && n >= 5; i++){

            roll_multiple_dices(dice_pairs, n);
            printf("\nRolling for %s", round_name[i]);
            print_dice(n, dice_pairs);

            calc_round(i , dice_pairs, &buff_score);

            score += buff_score;
            printf(": Earned %2d points, total score: %d\n", buff_score, score);
            buff_score = 0;

            check_bonus_round(i, &score);
        }
    }while(n >= 5);
    return 0;
}