#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <glusterfs/api/glfs.h>
#include <glusterfs/api/glfs-handles.h>

#define LOG_ERR(func, ret)                                                     \
    do {                                                                       \
        if (ret != 0) {                                                        \
            fprintf(stderr, "%s : returned error %d (%s)\n", func, ret,        \
                    strerror(errno));                                          \
            goto out;                                                          \
        } else {                                                               \
            fprintf(stderr, "%s : returned %d\n", func, ret);                  \
        }                                                                      \
    } while (0)

int
main(int argc, char *argv[])
{
    glfs_t *fs = NULL;
    glfs_t *fs2 = NULL;
    glfs_t *fs_tmp = NULL;
    glfs_t *fs_tmp2 = NULL;
    int ret = 0, i;
    glfs_fd_t *fd = NULL;
    glfs_fd_t *fd2 = NULL;
    glfs_fd_t *fd_tmp = NULL;
    glfs_fd_t *fd_tmp2 = NULL;
    char readbuf[32];
    char *filename = "file_tmp";
    char *writebuf = NULL;
    char *vol_id = NULL;
    unsigned int cnt = 1;
    struct glfs_upcall *cbk = NULL;
    char *logfile = NULL;
    char *volname = NULL;
    char *hostname = NULL;

    if (argc != 4) {
        fprintf(stderr, "Invalid argument\n");
        exit(1);
    }

    hostname = argv[1];
    volname = argv[2];
    logfile = argv[3];

    fs = glfs_new(volname);
    if (!fs) {
        fprintf(stderr, "glfs_new: returned NULL\n");
        return -1;
    }

    ret = glfs_set_volfile_server(fs, "tcp", hostname, 24007);
    LOG_ERR("glfs_set_volfile_server", ret);

    ret = glfs_set_logging(fs, logfile, 7);
    LOG_ERR("glfs_set_logging", ret);

    ret = glfs_init(fs);
    LOG_ERR("glfs_init", ret);

    /* This does not block, but enables caching of events. Real
     * applications like NFS-Ganesha run this in a thread before activity
     * on the fs (through this instance) happens. */
    ret = glfs_h_poll_upcall(fs_tmp, &cbk);
    LOG_ERR("glfs_h_poll_upcall", ret);

    fs2 = glfs_new(volname);
    if (!fs2) {
        fprintf(stderr, "glfs_new fs2: returned NULL\n");
        return 1;
    }

    ret = glfs_set_volfile_server(fs2, "tcp", hostname, 24007);
    LOG_ERR("glfs_set_volfile_server-fs2", ret);

    ret = glfs_set_logging(fs2, logfile, 7);
    LOG_ERR("glfs_set_logging-fs2", ret);

    ret = glfs_init(fs2);
    LOG_ERR("glfs_init-fs2", ret);

    fd = glfs_creat(fs, filename, O_RDWR | O_SYNC, 0644);
    if (fd <= 0) {
        ret = -1;
        LOG_ERR("glfs_creat", ret);
    }
    fprintf(stderr, "glfs-create fd - %d\n", fd);

    fd2 = glfs_open(fs2, filename, O_SYNC | O_RDWR | O_CREAT);
    if (fd2 <= 0) {
        ret = -1;
        LOG_ERR("glfs_open-fs2", ret);
    }
    fprintf(stderr, "glfs-open fd2 - %d\n", fd2);

    do {
        if (cnt % 2) {
            fd_tmp = fd;
            fs_tmp = fs;
            fd_tmp2 = fd2;
            fs_tmp2 = fs2;
        } else {
            fd_tmp = fd2;
            fs_tmp = fs2;
            fd_tmp2 = fd;
            fs_tmp2 = fs;
        }

        /* WRITE on fd_tmp */
        writebuf = malloc(10);
        if (writebuf) {
            memcpy(writebuf, "abcd", 4);
            ret = glfs_write(fd_tmp, writebuf, 4, 0);
            if (ret <= 0) {
                ret = -1;
                LOG_ERR("glfs_write", ret);
            } else {
                fprintf(stderr, "glfs_write succeeded\n");
            }
            free(writebuf);
        } else {
            fprintf(stderr, "Could not allocate writebuf\n");
            return -1;
        }

        /* READ on fd_tmp2 */
        ret = glfs_lseek(fd_tmp2, 0, SEEK_SET);
        LOG_ERR("glfs_lseek", ret);

        memset(readbuf, 0, sizeof(readbuf));
        ret = glfs_pread(fd_tmp2, readbuf, 4, 0, 0, NULL);

        if (ret <= 0) {
            ret = -1;
            LOG_ERR("glfs_pread", ret);
        } else {
            fprintf(stderr, "glfs_read: %s\n", readbuf);
        }

        /* Open() fops seem to be not performed on server side until
         * there are I/Os on that fd
         */
        if (cnt > 2) {
            struct glfs_upcall_inode *in_arg = NULL;
            enum glfs_upcall_reason reason = 0;
            struct glfs_object *object = NULL;
            uint64_t flags = 0;
            uint64_t expire = 0;

            ret = glfs_h_poll_upcall(fs_tmp, &cbk);
            LOG_ERR("glfs_h_poll_upcall", ret);

            reason = glfs_upcall_get_reason(cbk);

            /* Expect 'GLFS_INODE_INVALIDATE' upcall event. */
            if (reason == GLFS_UPCALL_INODE_INVALIDATE) {
                in_arg = glfs_upcall_get_event(cbk);

                object = glfs_upcall_inode_get_object(in_arg);
                flags = glfs_upcall_inode_get_flags(in_arg);
                expire = glfs_upcall_inode_get_expire(in_arg);

                fprintf(stderr,
                        " upcall event type - %d,"
                        " object(%p), flags(%d), "
                        " expire_time_attr(%d)\n",
                        reason, object, flags, expire);
            } else {
                fprintf(stderr, "Didn't receive upcall notify event");
                ret = -1;
                goto err;
            }

            glfs_free(cbk);
        }

        sleep(5);
    } while (++cnt < 5);

err:
    glfs_close(fd);
    LOG_ERR("glfs_close", ret);

    glfs_close(fd2);
    LOG_ERR("glfs_close-fd2", ret);

out:
    if (fs) {
        ret = glfs_fini(fs);
        fprintf(stderr, "glfs_fini(fs) returned %d \n", ret);
    }

    if (fs2) {
        ret = glfs_fini(fs2);
        fprintf(stderr, "glfs_fini(fs2) returned %d \n", ret);
    }

    if (ret)
        exit(1);
    exit(0);
}