#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 suceeded\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,
                                         "Didnt 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);
}