#include <stdlib.h>
#include <sys/epoll.h>

#include "eventloop.h"
#include "util.h"
#include "constant.h"

struct eventLoop *eventLoopNew()
{
    int epollfd = epoll_create1(0);
    if (epollfd == -1)
        return NULL;

    struct eventLoop *eventLoop = malloc(sizeof(*eventLoop));
    eventLoop->epollfd = epollfd;
    eventLoop->size = EVENT_LOOP_MAX_EVENTS;

    return eventLoop;
}

int eventLoopWait(struct eventLoop *el, int timeout)
{
    return epoll_wait(el->epollfd, el->events, el->size, timeout);
}

struct tsocket *eventLoopGetSocket(struct eventLoop *el, int index)
{
    return (struct tsocket *)el->events[index].data.ptr;
}

int eventLoopAdd(struct eventLoop *el, struct event *ev, int flag)
{
    struct epoll_event epev;
    epev.events = flag;
    epev.data.ptr = ev;

    return epoll_ctl(el->epollfd, EPOLL_CTL_ADD, ev->fd, &epev);
}

struct event *eventLoopGet(struct eventLoop *el, int index)
{
    return (struct event *)el->events[index].data.ptr;
}

void eventLoopLoop(struct eventLoop *el)
{
    int nevents;
    struct event *ev;

    for (;;) {
        nevents = eventLoopWait(el, -1);
        if (nevents == -1)
            panic("eventloop wait");

        for (int i = 0; i < nevents; i++) {
            ev = eventLoopGet(el, i);
            if (ev->handle(ev->data) == -1)
                eventLoopDel(el, ev);
        }
    }
}

int eventLoopDel(struct eventLoop *el, struct event *ev)
{
    if (epoll_ctl(el->epollfd, EPOLL_CTL_DEL, ev->fd, NULL) == -1)
        return ERROR;

    if (ev->delete)
        ev->delete(ev->data);
    free(ev);

    return OK;
}

struct event *eventNew(void *data, int fd, void (*handle), void (*delete))
{
    struct event *ev = malloc(sizeof(*ev));
    ev->data = data;
    ev->handle = handle;
    ev->fd = fd;
    ev->delete = delete;

    return ev;
}