#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "01_hashtable.c"

house **process_next_house(house **hash_table, uint32_t *table_size, int32_t *x, int32_t *y, uint32_t *hcount) {
	//first check to see if we need to enlarge the hash table
	if (hash(*x, *y) > *table_size - 1) {
		*table_size = *table_size * 2;
		hash_table = ht_resize(hash_table, *table_size / 2, *table_size);
	}

	//process next house
	house *loc = ht_lookup(hash_table, *x, *y);
	if (loc == NULL) {
		(*hcount)++;
		ht_insert(hash_table, *x, *y, 1);
	} else {
		(loc->p)++;
	} 

	return hash_table;
}

int main() {
	FILE *file = fopen("input", "r");
	if (file == NULL) {
		perror("main: error opening file.");
		return 1;
	}

	uint32_t table_size = 25;
	house **hash_table = ht_init(table_size);

	int32_t x = 0;
	int32_t y = 0;
	ht_insert(hash_table, x, y, 1);		//initial house at (0, 0).
	uint32_t hcount = 1;

	int32_t c;
	while ((c = fgetc(file)) != EOF) {
		if(c == '^') {
			y++;
			hash_table = process_next_house(hash_table, &table_size, &x, &y, &hcount);
		} else if (c == 'v') {
			y--;
			hash_table = process_next_house(hash_table, &table_size, &x, &y, &hcount);
		} else if (c == '>') {
			x++;
			hash_table = process_next_house(hash_table, &table_size, &x, &y, &hcount);
		} else if (c == '<') {
			x--;
			hash_table = process_next_house(hash_table, &table_size, &x, &y, &hcount);
		} 
	}
	if (ferror(file)) {
		perror("main: error reading from file.");
		return -1;
	}
	fclose(file);

	printf("unique houses: %u\n", hcount);

	for (uint32_t i = 0; i < table_size; i++) {
		free(hash_table[i]);
	}
	free(hash_table);
	return 0;
}