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

#include "util.h"

struct timespec timespec_diff(struct timespec a, struct timespec b)
{
    bool over = (b.tv_nsec - a.tv_nsec) < 0;
    struct timespec diff = {
        .tv_sec = b.tv_sec - a.tv_sec - over,
        .tv_nsec = b.tv_nsec - a.tv_nsec + over * 1000000000ul,
    };
    return diff;
}

bool timespec_greater(struct timespec a, struct timespec b)
{
    return a.tv_sec > b.tv_sec
        || (a.tv_sec == b.tv_sec && a.tv_nsec > b.tv_nsec);
}

void timespec_print(struct timespec *ts)
{
    printf("%ld.%.9ld", ts->tv_sec, ts->tv_nsec);
}

bool check_rect(int px, int py, int x, int y, int w, int h)
{
    return px >= x && px <= x + w && py >= y && py <= y + h;
}

bool check_circle(int px, int py, int x, int y, int r)
{
    int dx = x - px;
    int dy = y - py;
    return (dx * dx + dy * dy) <= r * r;
}

bool check_capsule(int px, int py, int x, int y, int w, int h)
{
    assert(w >= h);
    int radius = h / 2;

    // Trivial case
    if (w == h)
        return check_circle(px, py, x + radius, y + radius, radius);

    // General case
    return check_circle(px, py, x + radius, y + radius, radius)
        || check_circle(px, py, x + w - radius, y + radius, radius)
        || check_rect(px, py, x + radius, y, w - 2 * radius, h);
}