//
// Created by lennart on 12/6/23.
//

#include <ctype.h>
#include <stdlib.h>
#include "input_handler.h"

typedef struct {
    int countWinningNumbers;
    int winningNumbers[10];
    int countGivenNumbers;
    int givenNumbers[25];
    int copies;
} Card;

#define LIST_NAME CardList
#define LIST_PREFIX clist
#define ELEMENT_TYPE Card
#include "list.h"

CardList* load_cards(const char *file_name);

int main() {
    CardList *cards = load_cards("day_4.txt");

    // Part 1 - Iterate over given numbers and linearly check for matches
    int sum = 0;
    int sum2 = 0; // Part 2
    for(int i = 0; i < cards->length; i++) {
        Card card = cards->data[i];
        int won = 0;

        for(int j = 0; j < card.countGivenNumbers; j++) {
            int given = card.givenNumbers[j];

            for(int k = 0; k < card.countWinningNumbers; k++) {
                if(card.winningNumbers[k] == given) {
                    won += 1;
                    continue;
                }
            }
        }
        sum += (1 << won) >> 1;
        // Part 2 - Begin (register copies won)
        sum2 += card.copies;
        for(int j = 1; j <= won && (i + j) < cards->length; j++) {
            cards->data[i + j].copies += card.copies;
        }
        // Part 2 - End
    }
    printf("Result #1: %i\n", sum);
    printf("Result #2: %i\n", sum2);

    clist_free(cards);
}

CardList* load_cards(const char *file_name) {
    FILE *f = fopen(file_name, "r");
    if(f == NULL) {
        printf("Error! Missing input file");
        exit(1);
    }

    CardList *list = clist_create(16);
    char* buffer = NULL;
    int bufferLen = 0;

    while(!feof(f)) {
        char *line = read_line(f, &buffer, &bufferLen);
        if(strlen(line) < strlen("Game 1: ")) {
            continue;
        }

        line = &line[strlen("Game ")];
        while(*line == ' ') line++;
        int gameId = (int) strtol(line, &line, 10);

        Card card;
        card.countWinningNumbers = 0;
        card.countGivenNumbers = 0;
        card.copies = 1;

        // Find the winning numbers
        line += 2;
        while(*line != '|') {
            if(*line == 0) {
                printf("Error! Unexpected end of line: %s", buffer);
                exit(1);
            }
            if(!isdigit(*line)) {
                line++;
                continue;
            }
            if(card.countWinningNumbers >= 10) {
                printf("Error! Given numbers out of bounds in: %s", buffer);
                exit(1);
            }

            int num = (int) strtol(line, &line, 10);
            card.winningNumbers[card.countWinningNumbers++] = num;
        }

        // Find the given numbers
        line += 2;
        while(*line != 0) {
            if(card.countGivenNumbers >= 25) {
                printf("Error! Given numbers out of bounds in: %s", buffer);
                exit(1);
            }
            if(!isdigit(*line)) {
                line++;
                continue;
            }

            int num = (int) strtol(line, &line, 10);
            card.givenNumbers[card.countGivenNumbers++] = num;
        }

        clist_add(list, card);
    }

    free(buffer);
    return list;
}