#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define INPUT_FILE ("../input.txt")
#define ARR_LEN (1000)

typedef enum direction
{
	DIR_FORWARD = 0,
	DIR_UP = 1,
	DIR_DOWN = 2
}direction;

// this is just direction + amount
typedef struct action_t
{
	direction dir;
	int amount;
}action_t;

int main(int argc, char** argv)
{
	int horizontal_pos = 0;
	int depth = 0;
	int aim = 0;

	FILE* fp = fopen(INPUT_FILE, "r");
	if(fp == NULL)
	{
		printf("Failed to open file for reading...\n");
		exit(-1);
	}

	size_t len = 0;
	ssize_t rc = 0;
	char* line = NULL;
	char action[12];

	action_t action_bank[ARR_LEN];
	memset(action_bank, 0, sizeof(action_t) * ARR_LEN);
	int ct = 0;
	while((rc = getline(&line, &len, fp)) > 0)
	{
		memset(action, '\0', 12);
		int amount = 0;
		sscanf(line, "%s %d", action, &amount);
		action_bank[ct].amount = amount;
		if(strcmp(action, "forward") == 0)
		{
			action_bank[ct].dir = DIR_FORWARD;
			horizontal_pos += amount;
		}
		else if(strcmp(action, "up") == 0)
		{
			action_bank[ct].dir = DIR_UP;
			depth -= amount;
		}
		else if(strcmp(action, "down") == 0)
		{
			action_bank[ct].dir = DIR_DOWN;
			depth += amount;
		}
		else
		{
			printf("action didn't match any known actions -- action: %s\n", action);
			exit(-1);
		}
		ct++;
	}
	printf("Part 1\n");
	printf("Horizontal Position: %d\n", horizontal_pos);
	printf("Depth: %d\n", depth);
	printf("calculated course: %d\n", depth * horizontal_pos);

	// part 2
	horizontal_pos = 0;
	depth = 0;
	for(int ind = 0; ind < ARR_LEN; ind++)
	{
		/* printf(">>>ACTION: %s\tAMOUNT: %d\n", */
		/* 	   action_bank[ind].dir == DIR_FORWARD ? "FORWARD" : */
		/* 	   action_bank[ind].dir == DIR_UP ? "UP" : */
		/* 	   action_bank[ind].dir == DIR_DOWN ? "DOWN" : "UNKNOWN", */
		/* 	   action_bank[ind].amount); */
		if(action_bank[ind].dir == DIR_FORWARD)
		{
			horizontal_pos += action_bank[ind].amount;
			depth += (aim * action_bank[ind].amount);
		}
		else if(action_bank[ind].dir == DIR_UP)
		{
			aim -= action_bank[ind].amount;
		}
		else if(action_bank[ind].dir == DIR_DOWN)
		{
			aim += action_bank[ind].amount;
		}
		else
		{
			printf("Error, dir unknown\n");
			exit(-1);
		}

	}
	printf("Part 2\n");
	printf("Horizontal Position: %d\n"
		   "Depth: %d\n"
		   "Aim: %d\n", horizontal_pos, depth, aim);

	printf("Final Position: %d\n", horizontal_pos * depth);
	return 0;
}