/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2018 Joyent, Inc.
 * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
 */

#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>

#include "testlib.h"
#include "mevent.h"

static char *cookie = "Shortcake";

static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cv = PTHREAD_COND_INITIALIZER;

static void
callback(int fd, enum ev_type ev, void *arg)
{
        static off_t size = 0;
        struct stat st;

        ASSERT_INT_EQ(("bad event"), ev, EVF_VNODE);
        ASSERT_PTR_EQ(("bad cookie"), arg, cookie);

        if (fstat(fd, &st) != 0)
                FAIL_ERRNO("fstat failed");

        ASSERT_INT64_NEQ(("File size has not changed"), size, st.st_size);
        size = st.st_size;

        pthread_mutex_lock(&mtx);
        pthread_cond_signal(&cv);
        VERBOSE(("wakeup"));
        pthread_mutex_unlock(&mtx);
}

static void
test_fd(int fd, char *tag)
{
        struct mevent *evp;
        int err;

        evp = mevent_add_flags(fd, EVF_VNODE, EVFF_ATTRIB, callback, cookie);
        ASSERT_PTR_NEQ(("%s: mevent_add", tag), evp, NULL);

        for (uint_t i = 0; cookie[i] != '\0'; i++) {
                ssize_t written;

                if (i > 0) {
                        /*
                         * Check that no events are emitted for writes which do
                         * not alter the size.
                         */
                        if (lseek(fd, -1, SEEK_CUR) == -1)
                                FAIL_ERRNO("lseek");
                        if (write(fd, "X", 1) == -1)
                                FAIL_ERRNO("write");
                        /*
                         * Allow time for the callback to fire if it is going
                         * to.
                         */
                        VERBOSE(("Write within"));
                        usleep(100);
                }

                pthread_mutex_lock(&mtx);

                written = write(fd, cookie + i, 1);
                if (written < 0)
                        FAIL_ERRNO("bad write");
                ASSERT_INT64_EQ(("write byte %d of cookie", i), written, 1);
                VERBOSE(("Write extend"));

                /* Wait for the size change to be processed */
                pthread_cond_wait(&cv, &mtx);
                pthread_mutex_unlock(&mtx);
                /*
                 * This is a bit unsatisfactory but we need to allow time
                 * for mevent to re-associate the port or the next write could
                 * be missed.
                 */
                usleep(100);
        }

        err = mevent_disable(evp);
        ASSERT_INT_EQ(("%s: mevent_disable: %s", tag, strerror(err)), err, 0);

        (void) printf("PASS %s - %s\n", testlib_prog, tag);
}

int
main(int argc, const char **argv)
{
        int fd;

        start_test(argv[0], 20);
        set_mevent_file_poll_interval_ms(500);
        start_event_thread();

        /* Test with a temporary file in /tmp */
        char *template = strdup("/tmp/mevent.vnode.XXXXXX");
        ASSERT_PTR_NEQ(("strdup"), template, NULL);
        fd = mkstemp(template);
        if (fd == -1)
                FAIL_ERRNO("Couldn't create temporary file with mkstemp");

        VERBOSE(("Opened temporary file at '%s'", template));

        test_fd(fd, "temporary file");

        /* Test with a file which is unlinked from the filesystem */
        FILE *fp = tmpfile();
        ASSERT_PTR_NEQ(("tmpfile"), fp, NULL);

        fd = fileno(fp);
        if (fd == -1)
                FAIL_ERRNO("Couldn't get file descriptor for temporary file");

        test_fd(fd, "anon file");

        /*
         * Defer to here to avoid generating a new event before the disable has
         * been processed and the port deassociated.
         */
        unlink(template);
        free(template);

        PASS();
}