/*
   Copyright (c) 2014 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/

#ifdef BUILD_GNFS

#include <glusterfs/globals.h>
#include <glusterfs/run.h>
#include <glusterfs/syscall.h>
#include "glusterd.h"
#include "glusterd-utils.h"
#include "glusterd-volgen.h"
#include "glusterd-nfs-svc.h"
#include "glusterd-messages.h"
#include "glusterd-svc-helper.h"

static gf_boolean_t
glusterd_nfssvc_need_start()
{
    glusterd_conf_t *priv = NULL;
    gf_boolean_t start = _gf_false;
    glusterd_volinfo_t *volinfo = NULL;

    priv = THIS->private;

    cds_list_for_each_entry(volinfo, &priv->volumes, vol_list)
    {
        if (!glusterd_is_volume_started(volinfo))
            continue;

        if (dict_get_str_boolean(volinfo->dict, NFS_DISABLE_MAP_KEY, 1))
            continue;
        start = _gf_true;
        break;
    }

    return start;
}

static int
glusterd_nfssvc_create_volfile()
{
    char filepath[PATH_MAX] = {
        0,
    };
    glusterd_conf_t *conf = THIS->private;

    glusterd_svc_build_volfile_path(conf->nfs_svc.name, conf->workdir, filepath,
                                    sizeof(filepath));
    return glusterd_create_global_volfile(build_nfs_graph, filepath, NULL);
}

static int
glusterd_nfssvc_manager(glusterd_svc_t *svc, void *data, int flags)
{
    int ret = -1;

    if (!svc->inited) {
        ret = glusterd_svc_init(svc, "nfs");
        if (ret) {
            gf_msg(THIS->name, GF_LOG_ERROR, 0, GD_MSG_FAILED_INIT_NFSSVC,
                   "Failed to init nfs service");
            goto out;
        } else {
            svc->inited = _gf_true;
            gf_msg_debug(THIS->name, 0, "nfs service initialized");
        }
    }

    ret = svc->stop(svc, SIGKILL);
    if (ret)
        goto out;

    /* not an error, or a (very) soft error at best */
    if (sys_access(XLATORDIR "/nfs/server.so", R_OK) != 0) {
        gf_msg(THIS->name, GF_LOG_INFO, 0, GD_MSG_GNFS_XLATOR_NOT_INSTALLED,
               "nfs/server.so xlator is not installed");
        goto out;
    }

    ret = glusterd_nfssvc_create_volfile();
    if (ret)
        goto out;

    if (glusterd_nfssvc_need_start()) {
        ret = svc->start(svc, flags);
        if (ret)
            goto out;

        ret = glusterd_conn_connect(&(svc->conn));
        if (ret)
            goto out;
    }
out:
    if (ret)
        gf_event(EVENT_SVC_MANAGER_FAILED, "svc_name=%s", svc->name);

    gf_msg_debug(THIS->name, 0, "Returning %d", ret);

    return ret;
}

static int
glusterd_nfssvc_start(glusterd_svc_t *svc, int flags)
{
    return glusterd_svc_start(svc, flags, NULL);
}

static int
glusterd_nfssvc_stop(glusterd_svc_t *svc, int sig)
{
    int ret = -1;
    gf_boolean_t deregister = _gf_false;

    if (glusterd_proc_is_running(&(svc->proc)))
        deregister = _gf_true;

    ret = glusterd_svc_stop(svc, sig);
    if (ret)
        goto out;
    if (deregister)
        glusterd_nfs_pmap_deregister();

out:
    gf_msg_debug(THIS->name, 0, "Returning %d", ret);

    return ret;
}

void
glusterd_nfssvc_build(glusterd_svc_t *svc)
{
    svc->manager = glusterd_nfssvc_manager;
    svc->start = glusterd_nfssvc_start;
    svc->stop = glusterd_nfssvc_stop;
}

int
glusterd_nfssvc_reconfigure()
{
    int ret = -1;
    xlator_t *this = THIS;
    glusterd_conf_t *priv = NULL;
    gf_boolean_t identical = _gf_false;
    gf_boolean_t vol_started = _gf_false;
    glusterd_volinfo_t *volinfo = NULL;

    priv = this->private;
    GF_VALIDATE_OR_GOTO(this->name, priv, out);

    /* not an error, or a (very) soft error at best */
    if (sys_access(XLATORDIR "/nfs/server.so", R_OK) != 0) {
        gf_msg(this->name, GF_LOG_INFO, 0, GD_MSG_GNFS_XLATOR_NOT_INSTALLED,
               "nfs/server.so xlator is not installed");
        ret = 0;
        goto out;
    }

    cds_list_for_each_entry(volinfo, &priv->volumes, vol_list)
    {
        if (GLUSTERD_STATUS_STARTED == volinfo->status) {
            vol_started = _gf_true;
            break;
        }
    }
    if (!vol_started) {
        ret = 0;
        goto out;
    }

    /*
     * Check both OLD and NEW volfiles, if they are SAME by size
     * and cksum i.e. "character-by-character". If YES, then
     * NOTHING has been changed, just return.
     */

    ret = glusterd_svc_check_volfile_identical(priv->nfs_svc.name,
                                               build_nfs_graph, &identical);
    if (ret)
        goto out;

    if (identical) {
        ret = 0;
        goto out;
    }

    /*
     * They are not identical. Find out if the topology is changed
     * OR just the volume options. If just the options which got
     * changed, then inform the xlator to reconfigure the options.
     */
    identical = _gf_false; /* RESET the FLAG */
    ret = glusterd_svc_check_topology_identical(priv->nfs_svc.name,
                                                build_nfs_graph, &identical);
    if (ret)
        goto out;

    /* Topology is not changed, but just the options. But write the
     * options to NFS volfile, so that NFS will be reconfigured.
     */
    if (identical) {
        ret = glusterd_nfssvc_create_volfile();
        if (ret == 0) { /* Only if above PASSES */
            ret = glusterd_fetchspec_notify(THIS);
        }
        goto out;
    }

    /*
     * NFS volfile's topology has been changed. NFS server needs
     * to be RESTARTED to ACT on the changed volfile.
     */
    ret = priv->nfs_svc.manager(&(priv->nfs_svc), NULL, PROC_START_NO_WAIT);

out:
    gf_msg_debug(this->name, 0, "Returning %d", ret);
    return ret;
}
#endif
