/*
   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.
*/
#include "snapview-server.h"
#include "snapview-server-mem-types.h"

#include "xlator.h"
#include "rpc-clnt.h"
#include "xdr-generic.h"
#include "protocol-common.h"
#include <pthread.h>


int
__svs_inode_ctx_set (xlator_t *this, inode_t *inode, svs_inode_t *svs_inode)
{
        uint64_t    value = 0;
        int         ret   = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode, out);
        GF_VALIDATE_OR_GOTO (this->name, svs_inode, out);

        value = (uint64_t)(long) svs_inode;

        ret = __inode_ctx_set (inode, this, &value);

out:
        return ret;
}

svs_inode_t *
__svs_inode_ctx_get (xlator_t *this, inode_t *inode)
{
        svs_inode_t *svs_inode = NULL;
        uint64_t     value     = 0;
        int          ret       = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode, out);

        ret = __inode_ctx_get (inode, this, &value);
        if (ret)
                goto out;

        svs_inode = (svs_inode_t *) ((long) value);

out:
        return svs_inode;
}

svs_inode_t *
svs_inode_ctx_get (xlator_t *this, inode_t *inode)
{
        svs_inode_t *svs_inode = NULL;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode, out);

        LOCK (&inode->lock);
        {
                svs_inode = __svs_inode_ctx_get (this, inode);
        }
        UNLOCK (&inode->lock);

out:
        return svs_inode;
}

int32_t
svs_inode_ctx_set (xlator_t *this, inode_t *inode, svs_inode_t *svs_inode)
{
        int32_t    ret = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode, out);
        GF_VALIDATE_OR_GOTO (this->name, svs_inode, out);

        LOCK (&inode->lock);
        {
                ret = __svs_inode_ctx_set (this, inode, svs_inode);
        }
        UNLOCK (&inode->lock);

out:
        return ret;
}

svs_inode_t *
svs_inode_new (void)
{
        svs_inode_t    *svs_inode = NULL;

        svs_inode = GF_CALLOC (1, sizeof (*svs_inode), gf_svs_mt_svs_inode_t);

        return svs_inode;
}

svs_inode_t *
svs_inode_ctx_get_or_new (xlator_t *this, inode_t *inode)
{
        svs_inode_t   *svs_inode = NULL;
        int            ret       = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode, out);

        LOCK (&inode->lock);
        {
                svs_inode = __svs_inode_ctx_get (this, inode);
                if (!svs_inode) {
                        svs_inode = svs_inode_new ();
                        if (svs_inode) {
                                ret = __svs_inode_ctx_set (this, inode,
                                                           svs_inode);
                                if (ret) {
                                        GF_FREE (svs_inode);
                                        svs_inode = NULL;
                                }
                        }
                }
        }
        UNLOCK (&inode->lock);

out:
        return svs_inode;
}

svs_fd_t *
svs_fd_new (void)
{
        svs_fd_t    *svs_fd = NULL;

        svs_fd = GF_CALLOC (1, sizeof (*svs_fd), gf_svs_mt_svs_fd_t);

        return svs_fd;
}

int
__svs_fd_ctx_set (xlator_t *this, fd_t *fd, svs_fd_t *svs_fd)
{
        uint64_t    value = 0;
        int         ret   = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);
        GF_VALIDATE_OR_GOTO (this->name, svs_fd, out);

        value = (uint64_t)(long) svs_fd;

        ret = __fd_ctx_set (fd, this, value);

out:
        return ret;
}

svs_fd_t *
__svs_fd_ctx_get (xlator_t *this, fd_t *fd)
{
        svs_fd_t *svs_fd = NULL;
        uint64_t  value  = 0;
        int       ret    = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);

        ret = __fd_ctx_get (fd, this, &value);
        if (ret)
                return NULL;

        svs_fd = (svs_fd_t *) ((long) value);

out:
        return svs_fd;
}

svs_fd_t *
svs_fd_ctx_get (xlator_t *this, fd_t *fd)
{
        svs_fd_t *svs_fd = NULL;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);

        LOCK (&fd->lock);
        {
                svs_fd = __svs_fd_ctx_get (this, fd);
        }
        UNLOCK (&fd->lock);

out:
        return svs_fd;
}

int32_t
svs_fd_ctx_set (xlator_t *this, fd_t *fd, svs_fd_t *svs_fd)
{
        int32_t    ret = -1;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);
        GF_VALIDATE_OR_GOTO (this->name, svs_fd, out);

        LOCK (&fd->lock);
        {
                ret = __svs_fd_ctx_set (this, fd, svs_fd);
        }
        UNLOCK (&fd->lock);

out:
        return ret;
}

svs_fd_t *
__svs_fd_ctx_get_or_new (xlator_t *this, fd_t *fd)
{
        svs_fd_t        *svs_fd    = NULL;
        int              ret       = -1;
        glfs_t          *fs        = NULL;
        glfs_object_t   *object    = NULL;
        svs_inode_t     *inode_ctx = NULL;
        glfs_fd_t       *glfd      = NULL;
        inode_t         *inode     = NULL;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);

        inode = fd->inode;
        svs_fd = __svs_fd_ctx_get (this, fd);
        if (svs_fd) {
                ret = 0;
                goto out;
        }

        svs_fd = svs_fd_new ();
        if (!svs_fd) {
                gf_log (this->name, GF_LOG_ERROR, "failed to allocate new fd "
                        "context for gfid %s", uuid_utoa (inode->gfid));
                goto out;
        }

        if (fd_is_anonymous (fd)) {
                inode_ctx = svs_inode_ctx_get (this, inode);
                if (!inode_ctx) {
                        gf_log (this->name, GF_LOG_ERROR, "failed to get inode "
                                "context for %s", uuid_utoa (inode->gfid));
                        goto out;
                }

                fs = inode_ctx->fs;
                object = inode_ctx->object;

                if (inode->ia_type == IA_IFDIR) {
                        glfd = glfs_h_opendir (fs, object);
                        if (!glfd) {
                                gf_log (this->name, GF_LOG_ERROR, "failed to "
                                        "open the directory %s",
                                        uuid_utoa (inode->gfid));
                                goto out;
                        }
                }

                if (inode->ia_type == IA_IFREG) {
                        glfd = glfs_h_open (fs, object, O_RDONLY|O_LARGEFILE);
                        if (!glfd) {
                                gf_log (this->name, GF_LOG_ERROR, "failed to "
                                        "open the file %s",
                                        uuid_utoa (inode->gfid));
                                goto out;
                        }
                }

                svs_fd->fd = glfd;
        }

        ret = __svs_fd_ctx_set (this, fd, svs_fd);
        if (ret) {
                gf_log (this->name, GF_LOG_ERROR, "failed to set fd context "
                        "for gfid %s", uuid_utoa (inode->gfid));
                if (svs_fd->fd) {
                        if (inode->ia_type == IA_IFDIR) {
                                ret = glfs_closedir (svs_fd->fd);
                                if (ret)
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "failed to close the fd for %s",
                                                uuid_utoa (inode->gfid));
                        }
                        if (inode->ia_type == IA_IFREG) {
                                ret = glfs_close (svs_fd->fd);
                                if (ret)
                                        gf_log (this->name, GF_LOG_ERROR,
                                                "failed to close the fd for %s",
                                                uuid_utoa (inode->gfid));
                        }
                }
                ret = -1;
        }

out:
        if (ret) {
                GF_FREE (svs_fd);
                svs_fd = NULL;
        }

        return svs_fd;
}

svs_fd_t *
svs_fd_ctx_get_or_new (xlator_t *this, fd_t *fd)
{
        svs_fd_t  *svs_fd = NULL;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, fd, out);

        LOCK (&fd->lock);
        {
                svs_fd = __svs_fd_ctx_get_or_new (this, fd);
        }
        UNLOCK (&fd->lock);

out:
        return svs_fd;
}

void
svs_uuid_generate (uuid_t gfid, char *snapname, uuid_t origin_gfid)
{
        unsigned char md5_sum[MD5_DIGEST_LENGTH] = {0};
        char          ino_string[NAME_MAX + 32]  = "";

        GF_ASSERT (snapname);

        (void) snprintf (ino_string, sizeof (ino_string), "%s%s",
                         snapname, uuid_utoa(origin_gfid));
        MD5((unsigned char *)ino_string, strlen(ino_string), md5_sum);
        gf_uuid_copy (gfid, md5_sum);
}

void
svs_fill_ino_from_gfid (struct iatt *buf)
{
        xlator_t *this     = NULL;

        this = THIS;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, buf, out);

        /* consider least significant 8 bytes of value out of gfid */
        if (gf_uuid_is_null (buf->ia_gfid)) {
                buf->ia_ino = -1;
                goto out;
        }

        buf->ia_ino = gfid_to_ino (buf->ia_gfid);
out:
        return;
}

void
svs_iatt_fill (uuid_t gfid, struct iatt *buf)
{
        struct timeval  tv    = {0, };
        xlator_t       *this  = NULL;

        this = THIS;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, buf, out);

        buf->ia_type = IA_IFDIR;
        buf->ia_uid  = 0;
        buf->ia_gid  = 0;
        buf->ia_size = 0;
        buf->ia_nlink = 2;
        buf->ia_blocks = 8;
        buf->ia_size = 4096;

        gf_uuid_copy (buf->ia_gfid, gfid);
        svs_fill_ino_from_gfid (buf);

        buf->ia_prot = ia_prot_from_st_mode (0755);

        gettimeofday (&tv, 0);

        buf->ia_mtime = buf->ia_atime = buf->ia_ctime = tv.tv_sec;
        buf->ia_mtime_nsec = buf->ia_atime_nsec = buf->ia_ctime_nsec =
                (tv.tv_usec * 1000);

out:
        return;
}

/* priv->snaplist_lock should be held before calling this function */
snap_dirent_t *
__svs_get_snap_dirent (xlator_t *this, const char *name)
{
        svs_private_t      *private     = NULL;
        int                 i           = 0;
        snap_dirent_t      *dirents     = NULL;
        snap_dirent_t      *tmp_dirent  = NULL;
        snap_dirent_t      *dirent      = NULL;

        private = this->private;

        dirents = private->dirents;
        if (!dirents) {
                goto out;
        }

        tmp_dirent = dirents;
        for (i = 0; i < private->num_snaps; i++) {
                if (!strcmp (tmp_dirent->name, name)) {
                        dirent = tmp_dirent;
                        break;
                }
                tmp_dirent++;
        }

 out:
        return dirent;
}

glfs_t *
__svs_initialise_snapshot_volume (xlator_t *this, const char *name,
                                  int32_t *op_errno)
{
        svs_private_t      *priv                = NULL;
        int32_t             ret                 = -1;
        int32_t             local_errno         = ESTALE;
        snap_dirent_t      *dirent              = NULL;
        char                volname[PATH_MAX]   = {0, };
        glfs_t             *fs                  = NULL;
        int                 loglevel            = GF_LOG_INFO;
        char                logfile[PATH_MAX]   = {0, };

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, this->private, out);
        GF_VALIDATE_OR_GOTO (this->name, name, out);

        priv = this->private;

        dirent = __svs_get_snap_dirent (this, name);
        if (!dirent) {
                gf_log (this->name, GF_LOG_DEBUG, "snap entry for "
                        "name %s not found", name);
                local_errno = ENOENT;
                goto out;
        }

        if (dirent->fs) {
                ret = 0;
                fs = dirent->fs;
                goto out;
        }

        snprintf (volname, sizeof (volname), "/snaps/%s/%s",
                  dirent->name, dirent->snap_volname);


        fs = glfs_new (volname);
        if (!fs) {
                gf_log (this->name, GF_LOG_ERROR,
                        "glfs instance for snap volume %s "
                        "failed", dirent->name);
                local_errno = ENOMEM;
                goto out;
        }

        ret = glfs_set_volfile_server (fs, "tcp", "localhost",
                                       24007);
        if (ret) {
                gf_log (this->name, GF_LOG_ERROR, "setting the "
                        "volfile server for snap volume %s "
                        "failed", dirent->name);
                goto out;
        }

        snprintf (logfile, sizeof (logfile),
                  DEFAULT_SVD_LOG_FILE_DIRECTORY "/snaps/%s/%s-%s.log",
                  priv->volname, name, dirent->uuid);

        ret = glfs_set_logging(fs, logfile, loglevel);
        if (ret) {
                gf_log (this->name, GF_LOG_ERROR, "failed to set the "
                        "log file path");
                goto out;
        }

        ret = glfs_init (fs);
        if (ret) {
                gf_log (this->name, GF_LOG_ERROR, "initing the "
                        "fs for %s failed", dirent->name);
                goto out;
        }

        ret = 0;

out:
        if (ret) {
                if (op_errno)
                        *op_errno = local_errno;

                if (fs)
                        glfs_fini (fs);
                fs = NULL;
        }

        if (fs) {
                dirent->fs = fs;
        }

        return fs;
}

glfs_t *
svs_initialise_snapshot_volume (xlator_t *this, const char *name,
                                int32_t *op_errno)
{
        glfs_t             *fs   = NULL;
        svs_private_t      *priv = NULL;

        GF_VALIDATE_OR_GOTO ("snapview-server", this, out);
        GF_VALIDATE_OR_GOTO (this->name, this->private, out);
        GF_VALIDATE_OR_GOTO (this->name, name, out);

        priv = this->private;

        LOCK (&priv->snaplist_lock);
        {
                fs = __svs_initialise_snapshot_volume (this, name, op_errno);
        }
        UNLOCK (&priv->snaplist_lock);


out:

        return fs;
}

snap_dirent_t *
svs_get_latest_snap_entry (xlator_t *this)
{
        svs_private_t *priv       = NULL;
        snap_dirent_t *dirents    = NULL;
        snap_dirent_t *dirent     = NULL;

        GF_VALIDATE_OR_GOTO ("svs", this, out);

        priv = this->private;

        LOCK (&priv->snaplist_lock);
        {
                dirents = priv->dirents;
                if (!dirents) {
                        goto unlock;
                }
                if (priv->num_snaps)
                        dirent = &dirents[priv->num_snaps - 1];
        }
unlock:
        UNLOCK (&priv->snaplist_lock);

out:
        return dirent;
}

glfs_t *
svs_get_latest_snapshot (xlator_t *this)
{
        glfs_t        *fs         = NULL;
        snap_dirent_t *dirent     = NULL;
        svs_private_t *priv       = NULL;

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

        dirent = svs_get_latest_snap_entry (this);

        if (dirent) {
                LOCK (&priv->snaplist_lock);
                {
                        fs = dirent->fs;
                }
                UNLOCK (&priv->snaplist_lock);
        }

out:
        return fs;
}

glfs_t *
svs_inode_ctx_glfs_mapping (xlator_t *this, svs_inode_t *inode_ctx)
{
        glfs_t *fs = NULL;

        GF_VALIDATE_OR_GOTO ("svs", this, out);
        GF_VALIDATE_OR_GOTO (this->name, inode_ctx, out);

        fs = inode_ctx->fs;

        SVS_CHECK_VALID_SNAPSHOT_HANDLE (fs, this);

out:
        return fs;
}

glfs_t *
svs_inode_glfs_mapping (xlator_t *this, inode_t *inode)
{
        svs_inode_t *inode_ctx = NULL;
        glfs_t      *fs        = NULL;

        inode_ctx = svs_inode_ctx_get (this, inode);
        if (!inode_ctx) {
                gf_log (this->name, GF_LOG_ERROR, "inode context not found for"
                        " the inode %s", uuid_utoa (inode->gfid));
                goto out;
        }

        fs = svs_inode_ctx_glfs_mapping (this, inode_ctx);

out:
        return fs;
}