#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <ucore/utils.h>
#include <ucore/utils.h>
#include <ucore/iomux.h>
#include <ucore/wqueue.h>
#include <ucore/fd_utils.h>


int stdout_read(struct IOMux *mux, struct UCWQueue *wqueue)
{
    return 1;
}
void stdin_read_cb(struct IOMux *mux, struct IOMuxFD *fd, unsigned int event)
{
    struct MBuf *mbuf = uc_mbuf_new(65);
    uint8_t *buf = uc_mbuf_head(mbuf);
    struct UCWQueue *wqueue = fd->cookie_ptr;

    ssize_t len = read(fd->fd, buf, 65);
    
    printf("Read %d bytes\n", len);
    if (len <= 0) {
        uc_mbuf_free(mbuf);
        iomux_unregister_fd(mux, &wqueue->fd);
        uc_wqueue_clear(wqueue);
        iomux_unregister_fd(mux, fd);

        return;
    }
    uc_mbuf_put(mbuf, len);
    
    uc_wqueue_enqueue(wqueue, mbuf);
    struct MBuf *mbuf2 = uc_mbuf_copy_data(mbuf);
    uc_wqueue_enqueue(wqueue, mbuf2);
}

struct IOMuxFD stdin_fd = {
    .fd = 0,
    .what = MUX_EV_READ,
    .callback = stdin_read_cb,

};

int stdout_write(struct IOMux *mux, struct UCWQueue *wqueue, struct MBuf *mbuf)
{
    uint32_t len;
    ssize_t wlen;
    uint8_t *data;

    len = uc_mbuf_len(mbuf);
    data = uc_mbuf_pull(mbuf, len);
    wlen = write(wqueue->fd.fd, data, len);

    if (wlen < 0) {
        if (errno != EWOULDBLOCK) {
            perror("write");
        }
        return UC_WQ_ABORT;
    }

    if (wlen == len) {
        return UC_WQ_DONE;
    }

    return UC_WQ_PARTIAL;
}

struct UCWQueue stdout_queue;

int main(int argc, char *argv[])
{
    //struct IOMux *mux = iomux_create(IOMUX_TYPE_SELECT);
    struct IOMux *mux = iomux_create(IOMUX_TYPE_EPOLL);
    uc_wqueue_init(&stdout_queue, mux);
    stdin_fd.cookie_ptr = &stdout_queue;
    stdout_queue.fd.fd = 1;
    stdout_queue.write_cb = stdout_write;
//    stdout_queue.read_cb = stdout_read; //we should not get read events here.

    uc_set_nonblocking(1); 

    iomux_register_fd(mux, &stdin_fd);
    iomux_register_fd(mux, &stdout_queue.fd);
    iomux_run(mux);

    return 0;
}