#include <stdlib.h>
#include <stdint.h>
#include "timer_list.h"
#include "tick.h"

struct timer_list {
    struct timer_list *next;
    unsigned int timeout;
    uint64_t millis;
    void (*callback)(struct timer_list *, void *user);
    void *user;
};

static struct timer_list *head = NULL, **tail = &head;

struct timer_list *timer_list_create(void (*f)(struct timer_list *, void *user), void *user)
{
    struct timer_list *it;

    it = malloc(sizeof *it);
    if (it) {
        it->next = NULL;
        it->millis = 0;
        it->timeout = 0;
        it->callback = f;
        it->user = user;
    }
    return (it);
}

struct timer_list *timer_list_match(int (*match)(void *user, void *arg), void *arg, void **r)
{
    struct timer_list *it = head;

    while (it) {
        if (match(it->user, arg)) {
            if (r) {
                *r = it->user;
            }
            return it;
        }
        it = it->next;
    }
    return (NULL);
}

void timer_list_activate(struct timer_list *it, unsigned int ms)
{
    it->next = NULL;
    it->timeout = ms;
    it->millis = millis();

    *tail = it;
    tail = &it->next;
}

void timer_list_deactive(struct timer_list *it)
{
    struct timer_list **next;

    next = &head;
    while ((*next) != NULL) {
        if ((*next) == it) {
            *next = it->next;
            if (head == NULL) {
                tail = &head;
            }
            break;
        }
        next = &(*next)->next;
    }
}

void timer_list_destroy(struct timer_list *it)
{
    free(it);
}

void timer_list_dispatch()
{
    struct timer_list *it;
    uint64_t c = millis();

    it = head;
    while (it) {
        if ((it->millis + it->timeout) <= c) {
            it->callback(it, it->user);
            it->millis = c;
        }
        it = it->next;
    }
}