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

#define MAX(x, y) (((x) > (y)) ? (x) : (y))
#define MIN(x, y) (((x) < (y)) ? (x) : (y))

#if 0
#define PART_1
#else
#define PART_2
#endif

#if 0
#define FILE_PATH "example.txt"
#define WIDTH  10
#define HEIGHT 10
#else
#define FILE_PATH "input.txt"
#define WIDTH  10000
#define HEIGHT 10000
#endif

int board[WIDTH][HEIGHT] = {0};

void draw_line(int x1, int y1, int x2, int y2)
{
    if(x1 == x2)
    {
        for(int y = MIN(y1, y2); y <= MAX(y1, y2); y++)
            board[x1][y]++;

    }
    else if(y1 == y2)
    {
        for(int x = MIN(x1, x2); x <= MAX(x1, x2); x++)
            board[x][y1]++;
    }
#ifdef PART_2
    else
    {
        int direction_x = (x1 < x2) ? 1 : -1;
        int direction_y = (y1 < y2) ? 1 : -1;

        int y = y1;
        int x = x1;
        while(!((y == y2) && (x == x2)))
        {
            board[x][y]++;
            x+=direction_x;
            y+=direction_y;
        }
    }
#endif
}

void parse()
{
    FILE *fp = fopen(FILE_PATH, "r");
    if(!fp) {
        fprintf(stderr, "ERROR: Could not open file: %s", FILE_PATH);
        exit(EXIT_FAILURE);
    }

    char *vec1, *vec2;
    char line[256];
    while(fgets(line, sizeof(line), fp) != NULL)
    {
        vec1 = strtok(line, " -> ");
        vec2 = strtok(NULL, " -> ");

        int x1, y1, x2, y2;
        x1 = atoi(strtok(vec1, ","));
        y1 = atoi(strtok(NULL, ","));
        x2 = atoi(strtok(vec2, ","));
        y2 = atoi(strtok(NULL, ","));

        draw_line(x1, y1, x2, y2);
    }
}

void print_board()
{
    for(int i = 0; i < HEIGHT; i++)
    {
        for(int j = 0; j < WIDTH; j++)
        {
            if(board[j][i] == 0)
                putc('.', stdout);
            else if(board[j][i] == 1)
                putc('#', stdout);
            else
                putc('@', stdout);
        }
        putc('\n', stdout);
    }
}

int main(void)
{
    parse();

    int count = 0;
    for(int i = 0; i < HEIGHT; i++)
        for(int j = 0; j < WIDTH; j++)
            if(board[j][i] >= 2) count += 1;

    printf("Count is %d\n", count);

    return 0;
}