#include <stdlib.h>
#include <stdio.h>
#include <err.h>
#include <string.h>
#include "input.h"

#define INPUT "input/03.txt"
#define EXPECTED1 7446L
#define EXPECTED2 2646L

void part1(struct input_str* input) {
	long priority_sum = 0;
	char duplicate_item;
	for(size_t i = 0; i < input->line_count; i++) {
		int rucksack_size = strlen(input->lines[i]);
		int compartment_size = rucksack_size / 2;
		for(int j = 0; j < compartment_size; j++) {
			for(int k = compartment_size; k <= rucksack_size; k++) {
				if(input->lines[i][j] == input->lines[i][k]) {
					duplicate_item = input->lines[i][j];
					goto found_duplicate;
				}
			}
		}
		err(2, "rucksack %ld: no duplicate found", i);

found_duplicate:
	if(duplicate_item > 'a')
		priority_sum += duplicate_item - 'a' + 1;
	else
		priority_sum += duplicate_item - 'A' + 27;
	}

	CHECK(priority_sum, EXPECTED1)
}

void part2(struct input_str* input) {
	long priority_sum = 0;
	char badge;
	// loop on groups of elves
	for(size_t i = 0; i < input->line_count; i += 3) {
		// loop on first rucksack content
		for(size_t j = 0; j <= strlen(input->lines[i]); j++) {
			// second rucksack
			for(size_t k = 0; k <= strlen(input->lines[i+1]); k++) {
				// third rucksack
				for(size_t l = 0; l <= strlen(input->lines[i+2]); l++) {
					if(input->lines[i][j] == input->lines[i+1][k] && input->lines[i][j] == input->lines[i+2][l]) {
						badge = input->lines[i][j];
						goto found_bagde;
					}
				}
			}
		}
		err(2, "rucksack %ld: no badge found", i);

found_bagde:
	if(badge > 'a')
		priority_sum += badge - 'a' + 1;
	else
		priority_sum += badge - 'A' + 27;
	}

	CHECK(priority_sum, EXPECTED2)
}

int main() {
	// read input
	struct input_str input;
	input_str_read(&input, INPUT);

	// do stuff
	part1(&input);
	part2(&input);

	// cleanup & exit
	input_str_free(&input);
	return 0;
}