/*
  Copyright (c) 2006-2011 Gluster, Inc. <http://www.gluster.com>
  This file is part of GlusterFS.

  GlusterFS is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published
  by the Free Software Foundation; either version 3 of the License,
  or (at your option) any later version.

  GlusterFS is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see
  <http://www.gnu.org/licenses/>.
*/


#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <sys/uio.h>
#include <sys/resource.h>

#include <libgen.h>
#include "uuid.h"

#include "fnmatch.h"
#include "xlator.h"
#include "protocol-common.h"
#include "glusterd.h"
#include "call-stub.h"
#include "defaults.h"
#include "list.h"
#include "dict.h"
#include "compat.h"
#include "compat-errno.h"
#include "statedump.h"
#include "glusterd-sm.h"
#include "glusterd-op-sm.h"
#include "glusterd-utils.h"
#include "glusterd-store.h"

static struct list_head gd_friend_sm_queue;

static  char *glusterd_friend_sm_state_names[] = {
        "Establishing Connection",
        "Probe Sent to Peer",
        "Probe Received from Peer",
        "Peer in Cluster",
        "Accepted peer request",
        "Sent and Received peer request",
        "Peer Rejected",
        "Peer detach in progress",
        "Probe Received from peer",
        "Connected to Peer",
        "Peer is connected and Accepted",
        "Invalid State"
};

static char *glusterd_friend_sm_event_names[] = {
        "GD_FRIEND_EVENT_NONE",
        "GD_FRIEND_EVENT_PROBE",
        "GD_FRIEND_EVENT_INIT_FRIEND_REQ",
        "GD_FRIEND_EVENT_RCVD_ACC",
        "GD_FRIEND_EVENT_LOCAL_ACC",
        "GD_FRIEND_EVENT_RCVD_RJT",
        "GD_FRIEND_EVENT_LOCAL_RJT",
        "GD_FRIEND_EVENT_RCVD_FRIEND_REQ",
        "GD_FRIEND_EVENT_INIT_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_RCVD_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_REMOVE_FRIEND",
        "GD_FRIEND_EVENT_CONNECTED",
        "GD_FRIEND_EVENT_MAX"
};

char*
glusterd_friend_sm_state_name_get (int state)
{
        if (state < 0 || state >= GD_FRIEND_STATE_MAX)
                return glusterd_friend_sm_state_names[GD_FRIEND_STATE_MAX];
        return glusterd_friend_sm_state_names[state];
}

char*
glusterd_friend_sm_event_name_get (int event)
{
        if (event < 0 || event >= GD_FRIEND_EVENT_MAX)
                return glusterd_friend_sm_event_names[GD_FRIEND_EVENT_MAX];
        return glusterd_friend_sm_event_names[event];
}

void
glusterd_destroy_probe_ctx (glusterd_probe_ctx_t *ctx)
{
        if (!ctx)
                return;

        if (ctx->hostname)
                GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

void
glusterd_destroy_friend_req_ctx (glusterd_friend_req_ctx_t *ctx)
{
        if (!ctx)
                return;

        if (ctx->vols)
                dict_unref (ctx->vols);
        if (ctx->hostname)
                GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

void
glusterd_destroy_friend_update_ctx (glusterd_friend_update_ctx_t *ctx)
{
        if (!ctx)
                return;
        if (ctx->hostname)
                GF_FREE (ctx->hostname);
        GF_FREE (ctx);
}

int
glusterd_broadcast_friend_delete (char *hostname, uuid_t uuid)
{
        int                             ret = 0;
        rpc_clnt_procedure_t            *proc = NULL;
        xlator_t                        *this = NULL;
        glusterd_friend_update_ctx_t    ctx = {{0},};
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_conf_t                 *priv = NULL;
        dict_t                          *friends = NULL;
        char                            key[100] = {0,};
        int32_t                         count = 0;

        this = THIS;
        priv = this->private;

        GF_ASSERT (priv);

        ctx.hostname = hostname;
        ctx.op = GD_FRIEND_UPDATE_DEL;

        friends = dict_new ();
        if (!friends)
                goto out;

        snprintf (key, sizeof (key), "op");
        ret = dict_set_int32 (friends, key, ctx.op);
        if (ret)
                goto out;

        snprintf (key, sizeof (key), "hostname");
        ret = dict_set_str (friends, key, hostname);
        if (ret)
                goto out;

        ret = dict_set_int32 (friends, "count", count);
        if (ret)
                goto out;

        list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
                if (!peerinfo->connected || !peerinfo->peer)
                        continue;

                ret = dict_set_static_ptr (friends, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto out;
                }

                proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_UPDATE];
                if (proc->fn) {
                        ret = proc->fn (NULL, this, friends);
                }
        }

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

out:
        if (friends)
                dict_unref (friends);

        return ret;
}


static int
glusterd_ac_none (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_error (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_ERROR, "Received event %d ", event->event);

        return ret;
}

static int
glusterd_ac_reverse_probe_begin (glusterd_friend_sm_event_t *event, void *ctx)
{
        int ret = 0;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_probe_ctx_t            *new_ev_ctx = NULL;

        GF_ASSERT (event);
        GF_ASSERT (ctx);

        peerinfo = event->peerinfo;
        ret = glusterd_friend_sm_new_event
                (GD_FRIEND_EVENT_PROBE, &new_event);

        if (ret) {
                gf_log ("glusterd", GF_LOG_ERROR, "Unable to get new new_event");
                ret = -1;
                goto out;
        }

        new_ev_ctx = GF_CALLOC (1, sizeof(*new_ev_ctx), gf_gld_mt_probe_ctx_t);

        if (!new_ev_ctx) {
                ret = -1;
                goto out;
        }

        new_ev_ctx->hostname = gf_strdup (peerinfo->hostname);
        new_ev_ctx->port = peerinfo->port;
        new_ev_ctx->req = NULL;

        new_event->peerinfo = peerinfo;
        new_event->ctx = new_ev_ctx;

        ret = glusterd_friend_sm_inject_event (new_event);

        if (ret) {
                gf_log ("glusterd", GF_LOG_ERROR, "Unable to inject new_event %d, "
                                "ret = %d", new_event->event, ret);
        }

out:
        if (ret) {
                if (new_event)
                        GF_FREE (new_event);
                if (new_ev_ctx->hostname)
                        GF_FREE (new_ev_ctx->hostname);
                if (new_ev_ctx)
                        GF_FREE (new_ev_ctx);
        }
        gf_log ("", GF_LOG_DEBUG, "returning with %d", ret);
        return ret;
}

static int
glusterd_ac_friend_add (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                     ret = 0;
        glusterd_peerinfo_t     *peerinfo = NULL;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;

        GF_ASSERT (event);
        peerinfo = event->peerinfo;

        this = THIS;
        conf = this->private;

        GF_ASSERT (conf);

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_ADD];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = ctx;
                ret = proc->fn (frame, this, event);
        }

out:
        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_friend_probe (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                     ret = -1;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;
        glusterd_probe_ctx_t    *probe_ctx = NULL;
        glusterd_peerinfo_t     *peerinfo = NULL;
        dict_t                  *dict = NULL;

        GF_ASSERT (ctx);

        probe_ctx = ctx;

        this = THIS;

        GF_ASSERT (this);

        conf = this->private;

        GF_ASSERT (conf);

        ret = glusterd_friend_find (NULL, probe_ctx->hostname, &peerinfo);
        if (ret) {
                //We should not reach this state ideally
                GF_ASSERT (0);
                goto out;
        }

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_PROBE_QUERY];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = ctx;
                dict = dict_new ();
                if (!dict)
                        goto out;
                ret = dict_set_str (dict, "hostname", probe_ctx->hostname);
                if (ret)
                        goto out;

                ret = dict_set_int32 (dict, "port", probe_ctx->port);
                if (ret)
                        goto out;

                ret = dict_set_static_ptr (dict, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto out;
                }

                ret = proc->fn (frame, this, dict);
                if (ret)
                        goto out;

        }


out:
        if (dict)
                dict_unref (dict);
        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_send_friend_remove_req (glusterd_friend_sm_event_t *event,
                                    void *data)
{
        int                     ret = 0;
        glusterd_peerinfo_t     *peerinfo = NULL;
        rpc_clnt_procedure_t    *proc = NULL;
        call_frame_t            *frame = NULL;
        glusterd_conf_t         *conf = NULL;
        xlator_t                *this = NULL;
        glusterd_friend_sm_event_type_t event_type = GD_FRIEND_EVENT_NONE;
        glusterd_probe_ctx_t            *ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;

        GF_ASSERT (event);
        peerinfo = event->peerinfo;

        this = THIS;
        conf = this->private;

        GF_ASSERT (conf);

        ctx = event->ctx;

        if (!peerinfo->connected) {
                event_type = GD_FRIEND_EVENT_REMOVE_FRIEND;

                ret = glusterd_friend_sm_new_event (event_type, &new_event);

                if (!ret) {
                        new_event->peerinfo = peerinfo;
                        ret = glusterd_friend_sm_inject_event (new_event);
                } else {
                        gf_log ("glusterd", GF_LOG_ERROR,
                                 "Unable to get event");
                }

                if (ctx)
                        ret = glusterd_xfer_cli_deprobe_resp (ctx->req, ret, 0,
                                                              ctx->hostname);
                glusterd_friend_sm ();
                glusterd_op_sm ();

                if (ctx) {
                        glusterd_broadcast_friend_delete (ctx->hostname, NULL);
                        glusterd_destroy_probe_ctx (ctx);
                }
                goto out;
        }

        if (!peerinfo->peer)
                goto out;
        proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_REMOVE];
        if (proc->fn) {
                frame = create_frame (this, this->ctx->pool);
                if (!frame) {
                        goto out;
                }
                frame->local = data;
                ret = proc->fn (frame, this, event);
        }

out:
        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static gf_boolean_t
glusterd_should_update_peer (glusterd_peerinfo_t *peerinfo,
                             glusterd_peerinfo_t *cur_peerinfo)
{
        gf_boolean_t is_valid = _gf_false;

        if ((peerinfo == cur_peerinfo) ||
            (peerinfo->state.state == GD_FRIEND_STATE_BEFRIENDED))
                is_valid = _gf_true;

        return is_valid;
}

static int
glusterd_ac_send_friend_update (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                           ret               = 0;
        glusterd_peerinfo_t          *cur_peerinfo      = NULL;
        glusterd_peerinfo_t          *peerinfo          = NULL;
        rpc_clnt_procedure_t         *proc              = NULL;
        xlator_t                     *this              = NULL;
        glusterd_friend_update_ctx_t  ev_ctx            = {{0}};
        glusterd_conf_t              *priv              = NULL;
        dict_t                       *friends           = NULL;
        char                          key[100]          = {0,};
        char                         *dup_buf           = NULL;
        int32_t                       count             = 0;

        GF_ASSERT (event);
        cur_peerinfo = event->peerinfo;

        this = THIS;
        priv = this->private;

        GF_ASSERT (priv);

        ev_ctx.op = GD_FRIEND_UPDATE_ADD;

        friends = dict_new ();
        if (!friends)
                goto out;

        snprintf (key, sizeof (key), "op");
        ret = dict_set_int32 (friends, key, ev_ctx.op);
        if (ret)
                goto out;

        list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
                if (!glusterd_should_update_peer (peerinfo, cur_peerinfo))
                        continue;

                count++;
                snprintf (key, sizeof (key), "friend%d.uuid", count);
                dup_buf = gf_strdup (uuid_utoa (peerinfo->uuid));
                ret = dict_set_dynstr (friends, key, dup_buf);
                if (ret)
                        goto out;
                snprintf (key, sizeof (key), "friend%d.hostname", count);
                ret = dict_set_str (friends, key, peerinfo->hostname);
                if (ret)
                        goto out;
                gf_log ("", GF_LOG_INFO, "Added uuid: %s, host: %s",
                        dup_buf, peerinfo->hostname);
        }

        ret = dict_set_int32 (friends, "count", count);
        if (ret)
                goto out;

        list_for_each_entry (peerinfo, &priv->peers, uuid_list) {
                if (!peerinfo->connected || !peerinfo->peer)
                        continue;

                if (!glusterd_should_update_peer (peerinfo, cur_peerinfo))
                        continue;

                ret = dict_set_static_ptr (friends, "peerinfo", peerinfo);
                if (ret) {
                        gf_log ("", GF_LOG_ERROR, "failed to set peerinfo");
                        goto out;
                }

                proc = &peerinfo->peer->proctable[GLUSTERD_FRIEND_UPDATE];
                if (proc->fn) {
                        ret = proc->fn (NULL, this, friends);
                }
        }

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

out:
        if (friends)
                dict_unref (friends);

        return ret;
}

static int
glusterd_peer_detach_cleanup (glusterd_conf_t *priv)
{
        int                     ret = -1;
        glusterd_volinfo_t      *volinfo = NULL;
        glusterd_volinfo_t      *tmp_volinfo = NULL;

        GF_ASSERT (priv);

        list_for_each_entry_safe (volinfo,tmp_volinfo,
                                  &priv->volumes, vol_list) {
                if (!glusterd_friend_contains_vol_bricks (volinfo,
                                                          priv->uuid)) {
                        gf_log (THIS->name, GF_LOG_INFO,
                                "Deleting stale volume %s", volinfo->volname);
                        ret = glusterd_delete_volume (volinfo);
                        if (ret) {
                                gf_log (THIS->name, GF_LOG_ERROR,
                                        "Error deleting stale volume");
                                goto out;
                        }
                }
        }
        ret = 0;
out:
        gf_log (THIS->name, GF_LOG_DEBUG, "Returning %d", ret);
        return ret;
}

static int
glusterd_ac_handle_friend_remove_req (glusterd_friend_sm_event_t *event,
                                      void *ctx)
{
        int                             ret = 0;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_req_ctx_t       *ev_ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_conf_t                 *priv = NULL;

        GF_ASSERT (ctx);
        ev_ctx = ctx;
        peerinfo = event->peerinfo;
        GF_ASSERT (peerinfo);

        priv = THIS->private;
        GF_ASSERT (priv);

        ret = glusterd_xfer_friend_remove_resp (ev_ctx->req, ev_ctx->hostname,
                                                ev_ctx->port);

        list_for_each_entry (peerinfo, &priv->peers, uuid_list) {

                ret = glusterd_friend_sm_new_event (GD_FRIEND_EVENT_REMOVE_FRIEND,
                                                    &new_event);
                if (ret)
                        goto out;

                new_event->peerinfo = peerinfo;

                ret = glusterd_friend_sm_inject_event (new_event);
                if (ret)
                        goto out;
        }
        ret = glusterd_peer_detach_cleanup (priv);
        if (ret) {
                gf_log (THIS->name, GF_LOG_WARNING,
                        "Peer detach cleanup was not successful");
                ret = 0;
        }
out:
        gf_log (THIS->name, GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_ac_friend_remove (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                     ret = -1;

        ret = glusterd_friend_remove_cleanup_vols (event->peerinfo->uuid);
        if (ret)
                gf_log (THIS->name, GF_LOG_WARNING, "Volumes cleanup failed");

        ret = glusterd_friend_cleanup (event->peerinfo);
        if (ret) {
                gf_log (THIS->name, GF_LOG_ERROR, "Cleanup returned: %d", ret);
        }

        return 0;
}

/*static int
glusterd_ac_none (void *ctx)
{
        int ret = 0;

        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}*/

static int
glusterd_ac_handle_friend_add_req (glusterd_friend_sm_event_t *event, void *ctx)
{
        int                             ret = 0;
        uuid_t                          uuid;
        glusterd_peerinfo_t             *peerinfo = NULL;
        glusterd_friend_req_ctx_t       *ev_ctx = NULL;
        glusterd_friend_update_ctx_t    *new_ev_ctx = NULL;
        glusterd_friend_sm_event_t      *new_event = NULL;
        glusterd_friend_sm_event_type_t event_type = GD_FRIEND_EVENT_NONE;
        int                             status = 0;
        int32_t                         op_ret = -1;
        int32_t                         op_errno = 0;

        GF_ASSERT (ctx);
        ev_ctx = ctx;
        uuid_copy (uuid, ev_ctx->uuid);
        peerinfo = event->peerinfo;
        GF_ASSERT (peerinfo);
        uuid_copy (peerinfo->uuid, ev_ctx->uuid);

        //Build comparison logic here.
        ret = glusterd_compare_friend_data (ev_ctx->vols, &status);
        if (ret)
                goto out;

        if (GLUSTERD_VOL_COMP_RJT != status) {
                event_type = GD_FRIEND_EVENT_LOCAL_ACC;
                op_ret = 0;
        } else {
                event_type = GD_FRIEND_EVENT_LOCAL_RJT;
                op_errno = GF_PROBE_VOLUME_CONFLICT;
                op_ret = -1;
        }

        ret = glusterd_friend_sm_new_event (event_type, &new_event);

        if (ret) {
                gf_log ("", GF_LOG_ERROR, "Out of Memory");
        }

        new_event->peerinfo = peerinfo;

        new_ev_ctx = GF_CALLOC (1, sizeof (*new_ev_ctx),
                                gf_gld_mt_friend_update_ctx_t);
        if (!new_ev_ctx) {
                ret = -1;
                goto out;
        }

        uuid_copy (new_ev_ctx->uuid, ev_ctx->uuid);
        new_ev_ctx->hostname = gf_strdup (ev_ctx->hostname);
        new_ev_ctx->op = GD_FRIEND_UPDATE_ADD;

        new_event->ctx = new_ev_ctx;

        glusterd_friend_sm_inject_event (new_event);

        ret = glusterd_xfer_friend_add_resp (ev_ctx->req, ev_ctx->hostname,
                                             ev_ctx->port, op_ret, op_errno);

out:
        gf_log ("", GF_LOG_DEBUG, "Returning with %d", ret);

        return ret;
}

static int
glusterd_friend_sm_transition_state (glusterd_peerinfo_t *peerinfo,
                                     glusterd_sm_t *state,
                                     glusterd_friend_sm_event_type_t event_type)
{

        GF_ASSERT (state);
        GF_ASSERT (peerinfo);

        (void) glusterd_sm_tr_log_transition_add (&peerinfo->sm_log,
                                           peerinfo->state.state,
                                           state[event_type].next_state,
                                           event_type);

        peerinfo->state.state = state[event_type].next_state;
        return 0;
}


glusterd_sm_t glusterd_state_default [] = {
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none},
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_probe},//EV_PROBE
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_friend_add}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_probe}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_probe_rcvd [] = {
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none},
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EV_PROBE
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_PROBE_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_connected_rcvd [] = {
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none},
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EV_PROBE
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_reverse_probe_begin}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t glusterd_state_connected_accepted [] = {
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none},
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_friend_probe}, //EV_PROBE
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_friend_add}, //EV_INIT_FRIEND_REQ
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EV_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_CONNECTED
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_none}, //EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_sent [] = {
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_rcvd [] = {
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_RCVD, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_befriended [] = {
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_friend_add},//EVENT_CONNECTED
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_sent_rcvd [] = {
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND,
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_rejected [] = {
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_friend_probe}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_friend_add}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_friend_add},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_RCVD, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_req_accepted [] = {
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_PROBE,
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_BEFRIENDED, glusterd_ac_send_friend_update}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_REJECTED, glusterd_ac_none}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_handle_friend_add_req}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_REQ_ACCEPTED, glusterd_ac_send_friend_remove_req}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_handle_friend_remove_req}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_CONNECTED_ACCEPTED, glusterd_ac_reverse_probe_begin},//EVENT_CONNECTED
        {GD_FRIEND_STATE_REQ_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t  glusterd_state_unfriend_sent [] = {
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_NONE,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_PROBE,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_INIT_FRIEND_REQ,
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_ACC
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_LOCAL_ACC
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCVD_RJT
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCVD_LOCAL_RJT
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_error}, //EVENT_RCV_FRIEND_REQ
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_INIT_REMOVE_FRIEND
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none}, //EVENT_RCVD_REMOVE_FRIEND
        {GD_FRIEND_STATE_DEFAULT, glusterd_ac_friend_remove}, //EVENT_REMOVE_FRIEND
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none},//EVENT_CONNECTED
        {GD_FRIEND_STATE_UNFRIEND_SENT, glusterd_ac_none},//EVENT_MAX
};

glusterd_sm_t *glusterd_friend_state_table [] = {
        glusterd_state_default,
        glusterd_state_req_sent,
        glusterd_state_req_rcvd,
        glusterd_state_befriended,
        glusterd_state_req_accepted,
        glusterd_state_req_sent_rcvd,
        glusterd_state_rejected,
        glusterd_state_unfriend_sent,
        glusterd_state_probe_rcvd,
        glusterd_state_connected_rcvd,
        glusterd_state_connected_accepted
};

int
glusterd_friend_sm_new_event (glusterd_friend_sm_event_type_t event_type,
                              glusterd_friend_sm_event_t **new_event)
{
        glusterd_friend_sm_event_t      *event = NULL;

        GF_ASSERT (new_event);
        GF_ASSERT (GD_FRIEND_EVENT_NONE <= event_type &&
                        GD_FRIEND_EVENT_MAX > event_type);

        event = GF_CALLOC (1, sizeof (*event), gf_gld_mt_friend_sm_event_t);

        if (!event)
                return -1;

        *new_event = event;
        event->event = event_type;
        INIT_LIST_HEAD (&event->list);

        return 0;
}

int
glusterd_friend_sm_inject_event (glusterd_friend_sm_event_t *event)
{
        GF_ASSERT (event);
        gf_log ("glusterd", GF_LOG_DEBUG, "Enqueue event: '%s'",
                glusterd_friend_sm_event_name_get (event->event));
        list_add_tail (&event->list, &gd_friend_sm_queue);

        return 0;
}

void
glusterd_destroy_friend_event_context (glusterd_friend_sm_event_t *event)
{
        if (!event)
                return;

        switch (event->event) {
        case GD_FRIEND_EVENT_RCVD_FRIEND_REQ:
        case GD_FRIEND_EVENT_RCVD_REMOVE_FRIEND:
                glusterd_destroy_friend_req_ctx (event->ctx);
                break;
        case GD_FRIEND_EVENT_LOCAL_ACC:
        case GD_FRIEND_EVENT_LOCAL_RJT:
        case GD_FRIEND_EVENT_RCVD_ACC:
        case GD_FRIEND_EVENT_RCVD_RJT:
                glusterd_destroy_friend_update_ctx (event->ctx);
                break;
        default:
                break;
        }
}

int
glusterd_friend_sm ()
{
        glusterd_friend_sm_event_t      *event      = NULL;
        glusterd_friend_sm_event_t      *tmp        = NULL;
        int                              ret        = -1;
        glusterd_friend_sm_ac_fn         handler    = NULL;
        glusterd_sm_t                   *state      = NULL;
        glusterd_peerinfo_t             *peerinfo   = NULL;
        glusterd_friend_sm_event_type_t  event_type = 0;
        gf_boolean_t                     is_await_conn = _gf_false;

        while (!list_empty (&gd_friend_sm_queue)) {
                list_for_each_entry_safe (event, tmp, &gd_friend_sm_queue, list) {

                        list_del_init (&event->list);
                        event_type = event->event;
                        peerinfo = event->peerinfo;
                        if (!peerinfo) {
                                gf_log ("glusterd", GF_LOG_CRITICAL, "Received"
                                        " event %s with empty peer info",
                                glusterd_friend_sm_event_name_get (event_type));

                                GF_FREE (event);
                                continue;
                        }
                        gf_log ("", GF_LOG_DEBUG, "Dequeued event of type: '%s'",
                                glusterd_friend_sm_event_name_get (event_type));


                        state = glusterd_friend_state_table[peerinfo->state.state];

                        GF_ASSERT (state);

                        handler = state[event_type].handler;
                        GF_ASSERT (handler);

                        ret = handler (event, event->ctx);
                        if (ret == GLUSTERD_CONNECTION_AWAITED) {
                                is_await_conn = _gf_true;
                                ret = 0;
                        }

                        if (ret) {
                                gf_log ("glusterd", GF_LOG_ERROR, "handler returned: "
                                                "%d", ret);
                                glusterd_destroy_friend_event_context (event);
                                GF_FREE (event);
                                continue;
                        }

                        if ((GD_FRIEND_EVENT_REMOVE_FRIEND == event_type) ||
                           (GD_FRIEND_EVENT_INIT_REMOVE_FRIEND == event_type)){
                                glusterd_destroy_friend_event_context (event);
                                GF_FREE (event);
                                continue;
                        }

                        ret = glusterd_friend_sm_transition_state (peerinfo,
                                                            state, event_type);

                        if (ret) {
                                gf_log ("glusterd", GF_LOG_ERROR, "Unable to transition"
                                        " state from '%s' to '%s' for event '%s'",
                        glusterd_friend_sm_state_name_get(peerinfo->state.state),
                        glusterd_friend_sm_state_name_get(state[event_type].next_state),
                                glusterd_friend_sm_event_name_get(event_type));
                                goto out;
                        }

                        ret = glusterd_store_peerinfo (peerinfo);

                        glusterd_destroy_friend_event_context (event);
                        GF_FREE (event);
                        if (is_await_conn)
                                break;
                }
                if (is_await_conn)
                        break;
        }

        ret = 0;
out:
        return ret;
}


int
glusterd_friend_sm_init ()
{
        INIT_LIST_HEAD (&gd_friend_sm_queue);
        return 0;
}