#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);

    /* Santa */
	int32_t x_s = 0;
	int32_t y_s = 0; 
	ht_insert(hash_table, x_s, y_s, 1);	//initial house at (0, 0)
	uint32_t hcount = 1;

	/* Robo-Santa */
	int32_t x_r = 0;
	int32_t y_r = 0;

	enum toggle {
		santa,
		robo_santa
	};
	enum toggle turn = robo_santa;

	int32_t c;
	while ((c = fgetc(file)) != EOF) {
		turn = turn ^ robo_santa;	//toggle turn
		switch(turn) {
			case santa:
				if (c == '^') {
					y_s++;
					hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
				} else if (c == 'v') {
					y_s--;
					hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
				} else if (c == '>') {
					x_s++;
					hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
				} else if (c == '<') {
					x_s--;
					hash_table = process_next_house(hash_table, &table_size, &x_s, &y_s, &hcount);
				}
				break;
			case robo_santa:
                if (c == '^') {
					y_r++;
					hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
				} else if (c == 'v') {
					y_r--;
					hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
				} else if (c == '>') {
					x_r++;
					hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
				} else if (c == '<') {
					x_r--;
					hash_table = process_next_house(hash_table, &table_size, &x_r, &y_r, &hcount);
				}
				break; 
			default:
				perror("main: turn error.");
				return -1;
		}
	}
	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;
}