/*
   Copyright (c) 2013 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 <regex.h>
//#include <stdlib.h>
#include <string.h>

#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif

#include "call-stub.h"
#include "defaults.h"
#include "xlator.h"
#include "api/src/glfs.h"
#include "api/src/glfs-internal.h"

#ifndef NSR_SIM_ETCD
#include "etcd-api.h"
#endif
#include "nsr-internal.h"
#include "../../nsr-recon/src/recon_driver.h"
#include "../../nsr-recon/src/recon_xlator.h"

#define NSR_KEY         "xyzzy"
#define NSR_TTL         5

static void
nsr_set_leader (xlator_t *this, etcd_session etcd)
{
        long            term = 0;
        etcd_result     res;
        nsr_private_t   *priv   = this->private;
        char            *term_key = priv->term_uuid;
        char             n_t[sizeof(long)+1];
        char            *text   = NULL;

        gf_log (this->name, GF_LOG_INFO, "Just became leader");

        text = etcd_get(etcd, priv->term_uuid);
        if(text == NULL) {
                term = 0;
        } else {
                term = strtol(text, NULL, 10);
        }
        sprintf(n_t,"%ld",term+1);
        res = etcd_set(etcd, term_key,n_t,text,0);
        if(res != ETCD_OK) {
		gf_log (this->name, GF_LOG_ERROR, "failed to set term");
		return;
	}
        priv->leader = _gf_true;

        priv->current_term = term + 1;

        if (priv->nsr_recon_start == _gf_false) {
                atomic_fetch_and(&(priv->fence_io), 0);
                return;
        }

        // Move this inside recon notify???
        atomic_fetch_or(&(priv->fence_io), 1);

        nsr_recon_notify_event_set_leader(priv);

        return;
}

void *
nsr_leader_thread (void *arg)
{
        xlator_t        *this           = (xlator_t *) arg;
        nsr_private_t   *priv           = this->private;
        etcd_result     res;
        char            *index_in       = NULL;
        char            *index_out      = NULL;

        gf_log (this->name, GF_LOG_INFO,
                "calling glfs_open_str on servers %s", priv->etcd_servers);

        priv->etcd = etcd_open_str(priv->etcd_servers);
        if (!(priv->etcd)) {
                gf_log (this->name, GF_LOG_ERROR,
                        "failed to open etcd session\n");
                return NULL;
        }

        priv->leader_inited = 1;

        for (;;) {
                /* Not leader yet.  Try to become leader. */
                for (;;) {
                        res = etcd_lock (priv->etcd, NSR_KEY, NSR_TTL,
                                         index_in, &index_out);
                        if (res == ETCD_OK) {
                                break;
                        }
                        gf_log (this->name, GF_LOG_WARNING,
                                "etcd_lock failed (%d)", res);
                        sleep(1);
                }
                /* We're there.  Notify other parts of the code. */
                nsr_set_leader(this,priv->etcd);
                /* Try to retain leadership. */
                for (;;) {
                        index_in = index_out;
                        index_out = NULL;
                        res = etcd_lock (priv->etcd, NSR_KEY, NSR_TTL,
                                         index_in, &index_out);
                        if (index_in && (index_in != index_out)) {
                                free(index_in);
                        }
                        if (res != ETCD_OK) {
                                gf_log (this->name, GF_LOG_WARNING,
                                        "lost leadership (%d)", res);
                                if (index_out) {
                                        free(index_out);
                                }
                                break;
                        }
                        sleep(1);
                }
        }

        etcd_close_str(priv->etcd);
        return NULL;
}