/*
  Copyright (c) 2006-2012 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.
*/

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

char *scrub_svc_name = "scrub";

void
glusterd_scrubsvc_build(glusterd_svc_t *svc)
{
    svc->manager = glusterd_scrubsvc_manager;
    svc->start = glusterd_scrubsvc_start;
    svc->stop = glusterd_scrubsvc_stop;
}

int
glusterd_scrubsvc_init(glusterd_svc_t *svc)
{
    return glusterd_svc_init(svc, scrub_svc_name);
}

static int
glusterd_scrubsvc_create_volfile()
{
    char filepath[PATH_MAX] = {
        0,
    };
    int ret = -1;
    glusterd_conf_t *conf = NULL;
    xlator_t *this = NULL;

    this = THIS;
    conf = this->private;
    GF_ASSERT(conf);

    glusterd_svc_build_volfile_path(scrub_svc_name, conf->workdir, filepath,
                                    sizeof(filepath));

    ret = glusterd_create_global_volfile(build_scrub_graph, filepath, NULL);
    if (ret) {
        gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_VOLFILE_CREATE_FAIL,
               "Failed to create volfile");
        goto out;
    }

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

    return ret;
}

int
glusterd_scrubsvc_manager(glusterd_svc_t *svc, void *data, int flags)
{
    int ret = -EINVAL;

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

    if (glusterd_should_i_stop_bitd()) {
        ret = svc->stop(svc, SIGTERM);
    } else {
        ret = glusterd_scrubsvc_create_volfile();
        if (ret)
            goto out;

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

        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;
}

int
glusterd_scrubsvc_start(glusterd_svc_t *svc, int flags)
{
    int ret = -1;
    dict_t *cmdict = NULL;

    cmdict = dict_new();
    if (!cmdict)
        goto error_return;

    ret = dict_set_str(cmdict, "cmdarg0", "--global-timer-wheel");
    if (ret)
        goto dealloc_dict;

    ret = glusterd_svc_start(svc, flags, cmdict);

dealloc_dict:
    dict_unref(cmdict);
error_return:
    return ret;
}

int
glusterd_scrubsvc_stop(glusterd_svc_t *svc, int sig)
{
    return glusterd_svc_stop(svc, sig);
}

int
glusterd_scrubsvc_reconfigure()
{
    int ret = -1;
    xlator_t *this = NULL;
    glusterd_conf_t *priv = NULL;
    gf_boolean_t identical = _gf_false;

    this = THIS;
    GF_VALIDATE_OR_GOTO("glusterd", this, out);

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

    if (glusterd_should_i_stop_bitd())
        goto manager;

    /*
     * 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->scrub_svc.name,
                                               build_scrub_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->scrub_svc.name,
                                                build_scrub_graph, &identical);
    if (ret)
        goto out;

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

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

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