/*
  Copyright (c) 2008-2011 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 "glusterfs.h"
#include "xlator.h"
#include "dht-common.h"


int
dht_frame_return (call_frame_t *frame)
{
        dht_local_t *local = NULL;
        int          this_call_cnt = -1;

        if (!frame)
                return -1;

        local = frame->local;

        LOCK (&frame->lock);
        {
                this_call_cnt = --local->call_cnt;
        }
        UNLOCK (&frame->lock);

        return this_call_cnt;
}


int
dht_itransform (xlator_t *this, xlator_t *subvol, uint64_t x, uint64_t *y_p)
{
        dht_conf_t *conf = NULL;
        int         cnt = 0;
        int         max = 0;
        uint64_t    y = 0;

        if (x == ((uint64_t) -1)) {
                y = (uint64_t) -1;
                goto out;
        }

        conf = this->private;
        if (!conf)
                goto out;

        max = conf->subvolume_cnt;
        cnt = dht_subvol_cnt (this, subvol);

        y = ((x * max) + cnt);

out:
        if (y_p)
                *y_p = y;

        return 0;
}

int
dht_filter_loc_subvol_key (xlator_t *this, loc_t *loc, loc_t *new_loc,
                           xlator_t **subvol)
{
        char          *new_name  = NULL;
        char          *new_path  = NULL;
        xlator_list_t *trav      = NULL;
        char           key[1024] = {0,};
        int            ret       = 0; /* not found */

        /* Why do other tasks if first required 'char' itself is not there */
        if (loc->name && !strchr (loc->name, '@'))
                goto out;

        trav = this->children;
        while (trav) {
                snprintf (key, 1024, "*@%s:%s", this->name, trav->xlator->name);
                if (fnmatch (key, loc->name, FNM_NOESCAPE) == 0) {
                        new_name = GF_CALLOC(strlen (loc->name),
                                             sizeof (char),
                                             gf_common_mt_char);
                        if (!new_name)
                                goto out;
                        if (fnmatch (key, loc->path, FNM_NOESCAPE) == 0) {
                                new_path = GF_CALLOC(strlen (loc->path),
                                                     sizeof (char),
                                                     gf_common_mt_char);
                                if (!new_path)
                                        goto out;
                                strncpy (new_path, loc->path, (strlen (loc->path) -
                                                               strlen (key) + 1));
                        }
                        strncpy (new_name, loc->name, (strlen (loc->name) -
                                                       strlen (key) + 1));

                        if (new_loc) {
                                new_loc->path   = ((new_path) ? new_path:
                                                   gf_strdup (loc->path));
                                new_loc->name   = new_name;
                                new_loc->ino    = loc->ino;
                                new_loc->inode  = inode_ref (loc->inode);
                                new_loc->parent = inode_ref (loc->parent);
                        }
                        *subvol         = trav->xlator;
                        ret = 1;  /* success */
                        goto out;
                }
                trav = trav->next;
        }
out:
        if (!ret) {
                /* !success */
                if (new_path)
                        GF_FREE (new_path);
                if (new_name)
                        GF_FREE (new_name);
        }
        return ret;
}

int
dht_deitransform (xlator_t *this, uint64_t y, xlator_t **subvol_p,
                  uint64_t *x_p)
{
        dht_conf_t *conf = NULL;
        int         cnt = 0;
        int         max = 0;
        uint64_t    x = 0;
        xlator_t   *subvol = 0;

        if (!this->private)
                goto out;

        conf = this->private;
        max = conf->subvolume_cnt;

        cnt = y % max;
        x   = y / max;

        subvol = conf->subvolumes[cnt];

        if (subvol_p)
                *subvol_p = subvol;

        if (x_p)
                *x_p = x;

out:
        return 0;
}


void
dht_local_wipe (xlator_t *this, dht_local_t *local)
{
        if (!local)
                return;

        loc_wipe (&local->loc);
        loc_wipe (&local->loc2);

        if (local->xattr)
                dict_unref (local->xattr);

        if (local->inode)
                inode_unref (local->inode);

        if (local->layout) {
                dht_layout_unref (this, local->layout);
                local->layout = NULL;
        }

        loc_wipe (&local->linkfile.loc);

        if (local->linkfile.xattr)
                dict_unref (local->linkfile.xattr);

        if (local->linkfile.inode)
                inode_unref (local->linkfile.inode);

        if (local->fd) {
                fd_unref (local->fd);
                local->fd = NULL;
        }

        if (local->params) {
                dict_unref (local->params);
                local->params = NULL;
        }

        if (local->xattr_req)
                dict_unref (local->xattr_req);

        if (local->selfheal.layout) {
                dht_layout_unref (this, local->selfheal.layout);
                local->selfheal.layout = NULL;
        }

        if (local->newpath) {
                GF_FREE (local->newpath);
        }

        if (local->key) {
                GF_FREE (local->key);
        }

        GF_FREE (local);
}


dht_local_t *
dht_local_init (call_frame_t *frame)
{
        dht_local_t *local = NULL;

        /* TODO: use mem-pool */
        local = GF_CALLOC (1, sizeof (*local),
                           gf_dht_mt_dht_local_t);

        if (!local)
                return NULL;

        local->op_ret = -1;
        local->op_errno = EUCLEAN;

        frame->local = local;

        return local;
}


char *
basestr (const char *str)
{
        char *basestr = NULL;

        basestr = strrchr (str, '/');
        if (basestr)
                basestr ++;

        return basestr;
}


xlator_t *
dht_first_up_subvol (xlator_t *this)
{
        dht_conf_t *conf = NULL;
        xlator_t   *child = NULL;
        int         i = 0;
        time_t      time = 0;

        conf = this->private;
        if (!conf)
                goto out;

        LOCK (&conf->subvolume_lock);
        {
                for (i = 0; i < conf->subvolume_cnt; i++) {
                        if (conf->subvol_up_time[i]) {
                                if (!time) {
                                        time = conf->subvol_up_time[i];
                                        child = conf->subvolumes[i];
                                } else if (time > conf->subvol_up_time[i]) {
                                        time  = conf->subvol_up_time[i];
                                        child = conf->subvolumes[i];
                                }
                        }
                }
        }
        UNLOCK (&conf->subvolume_lock);

out:
        return child;
}

xlator_t *
dht_last_up_subvol (xlator_t *this)
{
        dht_conf_t *conf = NULL;
        xlator_t   *child = NULL;
        int         i = 0;

        conf = this->private;
        if (!conf)
                goto out;

        LOCK (&conf->subvolume_lock);
        {
                for (i = conf->subvolume_cnt-1; i >= 0; i--) {
                        if (conf->subvolume_status[i]) {
                                child = conf->subvolumes[i];
                                break;
                        }
                }
        }
        UNLOCK (&conf->subvolume_lock);

out:
        return child;
}

xlator_t *
dht_subvol_get_hashed (xlator_t *this, loc_t *loc)
{
        dht_layout_t *layout = NULL;
        xlator_t     *subvol = NULL;

        if (is_fs_root (loc)) {
                subvol = dht_first_up_subvol (this);
                goto out;
        }

        layout = dht_layout_get (this, loc->parent);

        if (!layout) {
                gf_log (this->name, GF_LOG_DEBUG,
                        "layout missing path=%s parent=%"PRId64,
                        loc->path, loc->parent->ino);
                goto out;
        }

        subvol = dht_layout_search (this, layout, loc->name);

        if (!subvol) {
                gf_log (this->name, GF_LOG_DEBUG,
                        "could not find subvolume for path=%s",
                        loc->path);
                goto out;
        }

out:
        if (layout) {
                dht_layout_unref (this, layout);
        }

        return subvol;
}


xlator_t *
dht_subvol_get_cached (xlator_t *this, inode_t *inode)
{
        dht_layout_t *layout = NULL;
        xlator_t     *subvol = NULL;


        layout = dht_layout_get (this, inode);

        if (!layout) {
                goto out;
        }

        subvol = layout->list[0].xlator;

out:
        if (layout) {
                dht_layout_unref (this, layout);
        }

        return subvol;
}


xlator_t *
dht_subvol_next (xlator_t *this, xlator_t *prev)
{
        dht_conf_t *conf = NULL;
        int         i = 0;
        xlator_t   *next = NULL;

        conf = this->private;
        if (!conf)
                goto out;

        for (i = 0; i < conf->subvolume_cnt; i++) {
                if (conf->subvolumes[i] == prev) {
                        if ((i + 1) < conf->subvolume_cnt)
                                next = conf->subvolumes[i + 1];
                        break;
                }
        }

out:
        return next;
}


int
dht_subvol_cnt (xlator_t *this, xlator_t *subvol)
{
        int i = 0;
        int ret = -1;
        dht_conf_t *conf = NULL;

        conf = this->private;
        if (!conf)
                goto out;

        for (i = 0; i < conf->subvolume_cnt; i++) {
                if (subvol == conf->subvolumes[i]) {
                        ret = i;
                        break;
                }
        }

out:
        return ret;
}


#define set_if_greater(a, b) do {               \
                if ((a) < (b))                  \
                        (a) = (b);              \
        } while (0)

int
dht_iatt_merge (xlator_t *this, struct iatt *to,
                struct iatt *from, xlator_t *subvol)
{
        if (!from || !to)
                return 0;

        to->ia_dev      = from->ia_dev;

        uuid_copy (to->ia_gfid, from->ia_gfid);

        to->ia_ino      = from->ia_ino;
        to->ia_prot     = from->ia_prot;
        to->ia_type     = from->ia_type;
        to->ia_nlink    = from->ia_nlink;
        to->ia_rdev     = from->ia_rdev;
        to->ia_size    += from->ia_size;
        to->ia_blksize  = from->ia_blksize;
        to->ia_blocks  += from->ia_blocks;

        set_if_greater (to->ia_uid, from->ia_uid);
        set_if_greater (to->ia_gid, from->ia_gid);

        set_if_greater (to->ia_atime, from->ia_atime);
        set_if_greater (to->ia_mtime, from->ia_mtime);
        set_if_greater (to->ia_ctime, from->ia_ctime);

        return 0;
}

int
dht_build_child_loc (xlator_t *this, loc_t *child, loc_t *parent, char *name)
{
        if (!child) {
                goto err;
        }

        if (strcmp (parent->path, "/") == 0)
                gf_asprintf ((char **)&child->path, "/%s", name);
        else
                gf_asprintf ((char **)&child->path, "%s/%s", parent->path, name);

        if (!child->path) {
                goto err;
        }

        child->name = strrchr (child->path, '/');
        if (child->name)
                child->name++;

        child->parent = inode_ref (parent->inode);
        child->inode = inode_new (parent->inode->table);

        if (!child->inode) {
                goto err;
        }

        return 0;
err:
        loc_wipe (child);
        return -1;
}