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

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#define BONUS_ROUND 6
#define MAX_ROUND 15
#define MAX_DICE_EYES 6

void flush(void);
void scan_data(int *n);
void reset_dice(int *dice_list);
int dice_roll();
void roll_multiple_dices(int dice_list[], int n);
void print_round_name(const char **round_name, int i);
void print_dices(int n, int dice_list[]);
void sum_of_all(int n, int dice_list, int *score);
void sum_of_pair(int n, int dice_list[], int *score);
void sum_of_kind(int kind_size, int dice_list[], int *score);
void sum_of_straight(int start, int dice_list[], int *score);
void sum_of_house(int dice_list[], int *score);
void sum_of_chance(int dice_list[], int *score);
void sum_of_yatzy(int dice_list[], int *score);
void calc_round(int i, int dice_list[], int *points, int *score);
void print_round_points(const int points);
void check_bonus_round(int i, int n, int *score);
void print_score(int *score);

/* prompt user for dice amount, then plays game of yatzy with given dices, repeat until input less than 5*/
int main(void){
    int dices = 0, round = 1, score = 0, points = 0;
    int dice_list[MAX_DICE_EYES + 1]; /* +1 because index 0 is ignored */
    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)); /*  seed random number gen. with time since Jan 1. 1970 */

    do {
        scan_data(&dices);
        for(round = 1; round <= MAX_ROUND && dices >= 5; round++){

            roll_multiple_dices(dice_list, dices);
            print_round_name(round_name, round);
            print_dices(dices, dice_list);
            calc_round(round , dice_list, &points, &score);
            print_round_points(points);
            check_bonus_round(round, dices, &score);

            if(round == MAX_ROUND)
                print_score(&score);
        }
    }while(dices >= 5);
    return 0;
}/* TODO less void functions? */

/* prompts user for input, re-prompt if input is not int. Assigns user input to the var dices  */
void scan_data(int *dices){
    printf("\nInsert number of Dices:(less than 5 to exit): ");

    while(scanf(" %d", dices) != 1){ /* if scanf doesnt return 1, the input didn't contain int */
        printf("\ninvalid input, try again: ");
        flush();
    }
    flush(); /* flush one last time in case multiple valid inputs was given (input: 10 5 14) */
}
/* flushes all non int stored in scanf */
void flush(void){
    char skip;
    do{
        scanf("%c", &skip);
    }while(skip != '\n');
}
/* rolls dices and stores them in the array dice_list */
void roll_multiple_dices(int dice_list[], int n){
    int i;

    reset_dice(dice_list);
    for(i = 1; i < (n + 1); i++) /* rolls as many times as dices given (+1 because index 0 is skipped) */
        dice_list[dice_roll()]++; /* store the amount of rolls for each type (1-6) */
}
/* reset dice values */
void reset_dice(int *dice_list){
    int i;

    for(i = 0; i <= MAX_DICE_EYES+1; i++) /* +1 because 0 index is ignored */
        dice_list[i] = 0;
}
/* generates random num 1-6 */
int dice_roll(){
    return ((rand() % MAX_DICE_EYES) + 1); /* +1 to avoid rolling 0 */
}
/* prints the equivalent string of a given round */
void print_round_name(const char **round_name, int round){
    printf("%-16s ", round_name[round]);
}
/* prints dice rolls */
void print_dices(int n, int dice_list[]){ /* put in main? */
    int dice_face, sum;

    printf("Dices:");
    for(dice_face = 1; dice_face <= MAX_DICE_EYES; dice_face++ ){ /* loops for each dice face 1-6 */
        for(sum = dice_list[dice_face]; sum > 0; sum--) /* dice_list[i] is the number of dices with the face i (1-6) */
            printf(" %d", dice_face);
    }
}
/* decides function to be called for each round and formats function parameters*/
void calc_round(int i, int dice_list[], int *points, int *score){
    *points = 0;
    if(i <= 6)
        sum_of_all(i, dice_list[(i)], points);
    else if(i <= 8)
        sum_of_pair((i-6), dice_list, points); /* i-6 because the parameter is size of pair */
    else if(i <= 10)
        sum_of_kind((i-6), dice_list, points);
    else if(i <= 12)
        sum_of_straight((i-10), dice_list, points);
    else if(i == 13)
        sum_of_house(dice_list, points);
    else if(i == 14)
        sum_of_chance(dice_list, points);
    else if(i == 15)
        sum_of_yatzy(dice_list, points);
    *score += *points;
}
/* calculates sum of all dices with given face (1-6), but max 5 dices */
void sum_of_all(int n, int dice_list, int *score){

    if(dice_list > 5)
        *score = (5 * n);
    else
        *score = (dice_list * n);
}
/* calculates sum of pair of a give size */
void sum_of_pair(int n, int dice_list[], int *score){
    int index, amount = n, points = 0;

    for(index = MAX_DICE_EYES; index > 0 && amount != 0; index--){
        if(dice_list[index] >= 2){
            points += (index * 2);
            amount--;
        }
    }
    if(amount == 0)
        *score += points;
}
/* calculates sum "n" of a kind, n varying on input */
void sum_of_kind(int kind_size, int dice_list[], int *score){
    int index;

    for(index = MAX_DICE_EYES; index > 0; index--){
        if(dice_list[index] >= kind_size){
            *score = (index * kind_size);
            dice_list[index] = 0; /* remove the dice type to prevent it being reused */
            index = 0;
        }
    }
}
/* calculates sum of either small or large straight depending on input */
void sum_of_straight(int start, int dice_list[], int *score){
    int index, end = (start + 5), buffer_score = 0;

    for(index = start; index < end && dice_list[index] > 0; index++ )
        buffer_score += index;

    if(index == end)
        *score = buffer_score;
}
/* calculates sum of full house */
void sum_of_house(int dice_list[], int *score){
    int points1 = 0, points2 = 0;

    sum_of_kind(3, dice_list, &points1);/* once 3 of kind is found, dice_list element is removed to avoid overlap with function below*/
    sum_of_pair(1 ,dice_list, &points2);

    if(points1 > 0 && points2 > 0) /* if both functions found a match */
        *score += points1 + points2;
}
/* calculates sum of 5 largest dices */
void sum_of_chance(int dice_list[], int *score){
    int index, count = 0;

    for(index = MAX_DICE_EYES; dice_list[index]+count <= 5; index--){
        *score += (dice_list[index] * index);
        count += dice_list[index];
    }
    *score += (5-count) * index; /* adds remainder, if count is < 5 and dice_list[index]+count > 5 */
}
/* calculates sum of yatzy using sum_of_kind */
void sum_of_yatzy(int dice_list[], int *score){

    sum_of_kind(5, dice_list, score);

    if(*score > 0)
        *score = 50;
}
/* self containing module, check if round is bonus round, check score and calculate points, prints result*/
void check_bonus_round(int i, int n, int *score){
    int bonus = 0;

    if(i == BONUS_ROUND){
        printf("\n%-16s Score: %-*d","Bonus round", (n*2)-1, *score); /*(n*2)-1, is the length of print_dice function -1 (one is used on left side) */

        if(*score >= 63)
            bonus = 50;

        printf("| Earned %2d points\n\n",bonus);
        *score += bonus;
    }
}
/* prints points scored for current round, used each round */
void print_round_points(const int points){
    printf("| Earned %2d points\n", points);
}
/* print score and reset it once printed, used once per game*/
void print_score(int *score){
    printf("\nFinal score: %d\n", *score);
    *score = 0;
}