/*
  Copyright (c) 2015 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 "thin-arbiter.h"
#include "thin-arbiter-messages.h"
#include "thin-arbiter-mem-types.h"
#include <glusterfs/glusterfs.h>
#include <glusterfs/xlator.h>
#include <glusterfs/logging.h>
#include <glusterfs/byte-order.h>
#include <glusterfs/common-utils.h>

int
ta_set_incoming_values(dict_t *dict, char *key, data_t *value, void *data)
{
    int32_t ret = 0;
    ta_fop_t *fop = (ta_fop_t *)data;
    int32_t *pending = NULL;

    pending = GF_CALLOC(1, value->len, gf_ta_mt_char);
    if (!pending) {
        ret = -ENOMEM;
        goto out;
    }
    ret = dict_set_bin(fop->brick_xattr, key, pending, value->len);
out:
    return ret;
}

int
ta_get_incoming_and_brick_values(dict_t *dict, char *key, data_t *value,
                                 void *data)
{
    ta_fop_t *fop = data;
    char *source = NULL;
    char *in_coming = NULL;
    int32_t len = 0, ret = 0;

    source = GF_CALLOC(1, value->len, gf_ta_mt_char);
    if (!source) {
        ret = -ENOMEM;
        goto out;
    }

    ret = dict_get_ptr_and_len(fop->dict, key, (void **)&in_coming, &len);

    if (!in_coming || value->len != len) {
        ret = -EINVAL;
        goto out;
    }

    if (!memcmp(value->data, source, value->len) &&
        (!memcmp(in_coming, source, len))) {
        fop->on_disk[fop->idx] = 0;
    } else {
        fop->on_disk[fop->idx] = 1;
    }

    fop->idx++;
out:
    GF_FREE(source);
    return ret;
}

void
ta_release_fop(ta_fop_t *fop)
{
    if (!fop) {
        return;
    }
    if (fop->fd) {
        fd_unref(fop->fd);
    }
    loc_wipe(&fop->loc);
    if (fop->dict) {
        dict_unref(fop->dict);
    }
    if (fop->brick_xattr) {
        dict_unref(fop->brick_xattr);
    }

    GF_FREE(fop);
    return;
}

int32_t
ta_set_xattrop_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno, dict_t *dict,
                   dict_t *xdata)
{
    TA_STACK_UNWIND(xattrop, frame, op_ret, op_errno, dict, xdata);
    return 0;
}

/*
case 1 - If brick value is 0 and incoming value is also 0, fine
case 2 - If brick value is 0 and incoming value is non 0, fine
case 3 - If brick value is non 0 and incoming value is also 0, fine
case 4 - If brick value is non 0 and incoming value is non 0, fine
case 5 - If incoming value is non zero on both brick, it is wrong
case 6 - If incoming value is non zero but brick value for other
brick is also non zero, wrong
*/

int32_t
ta_verify_on_disk_source(ta_fop_t *fop, dict_t *dict)
{
    int ret = 0;

    if (!fop) {
        return -EINVAL;
    }

    ret = dict_foreach(dict, ta_get_incoming_and_brick_values, (void *)fop);
    if (ret < 0) {
        return ret;
    }
    if (fop->on_disk[0] && fop->on_disk[1]) {
        return -EINVAL;
    }
    return 0;
}

int32_t
ta_get_xattrop_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno, dict_t *dict,
                   dict_t *xdata)
{
    ta_fop_t *fop = NULL;
    int ret = 0;

    fop = frame->local;
    if (op_ret) {
        goto unwind;
    }

    ret = ta_verify_on_disk_source(fop, dict);
    if (ret < 0) {
        op_errno = -ret;
        goto unwind;
    }

    if (fop->fd) {
        STACK_WIND(frame, ta_set_xattrop_cbk, FIRST_CHILD(this),
                   FIRST_CHILD(this)->fops->fxattrop, fop->fd,
                   fop->xattrop_flags, fop->dict, NULL);
    } else {
        STACK_WIND(frame, ta_set_xattrop_cbk, FIRST_CHILD(this),
                   FIRST_CHILD(this)->fops->xattrop, &fop->loc,
                   fop->xattrop_flags, fop->dict, NULL);
    }
    return 0;

unwind:

    TA_STACK_UNWIND(xattrop, frame, -1, op_errno, NULL, NULL);
    return -1;
}

ta_fop_t *
ta_prepare_fop(call_frame_t *frame, xlator_t *this, loc_t *loc, fd_t *fd,
               gf_xattrop_flags_t flags, dict_t *dict, dict_t *xdata)
{
    ta_fop_t *fop = NULL;
    int ret = 0;

    fop = GF_CALLOC(1, sizeof(*fop), gf_ta_mt_local_t);
    if (!fop) {
        goto out;
    }

    if (loc) {
        loc_copy(&fop->loc, loc);
    }

    if (fd) {
        fop->fd = fd_ref(fd);
    }

    fop->xattrop_flags = flags;
    fop->idx = 0;

    if (dict != NULL) {
        fop->dict = dict_ref(dict);
    }
    fop->brick_xattr = dict_new();
    if (fop->brick_xattr == NULL) {
        goto out;
    }
    ret = dict_foreach(dict, ta_set_incoming_values, (void *)fop);
    if (ret < 0) {
        goto out;
    }
    frame->local = fop;
    return fop;

out:
    ta_release_fop(fop);
    return NULL;
}

int32_t
ta_fxattrop(call_frame_t *frame, xlator_t *this, fd_t *fd,
            gf_xattrop_flags_t flags, dict_t *dict, dict_t *xdata)
{
    int ret = 0;
    ta_fop_t *fop = NULL;

    fop = ta_prepare_fop(frame, this, NULL, fd, flags, dict, xdata);
    if (!fop) {
        ret = -ENOMEM;
        goto unwind;
    }

    STACK_WIND(frame, ta_get_xattrop_cbk, FIRST_CHILD(this),
               FIRST_CHILD(this)->fops->fxattrop, fd, flags, fop->brick_xattr,
               xdata);
    return 0;

unwind:

    TA_STACK_UNWIND(xattrop, frame, -1, -ret, NULL, NULL);
    return 0;
}

int32_t
ta_xattrop(call_frame_t *frame, xlator_t *this, loc_t *loc,
           gf_xattrop_flags_t flags, dict_t *dict, dict_t *xdata)
{
    int ret = 0;
    ta_fop_t *fop = NULL;

    fop = ta_prepare_fop(frame, this, loc, NULL, flags, dict, xdata);
    if (!fop) {
        ret = -ENOMEM;
        goto unwind;
    }

    STACK_WIND(frame, ta_get_xattrop_cbk, FIRST_CHILD(this),
               FIRST_CHILD(this)->fops->xattrop, loc, flags, fop->brick_xattr,
               xdata);
    return 0;

unwind:

    TA_STACK_UNWIND(xattrop, frame, -1, -ret, NULL, NULL);
    return 0;
}

int32_t
ta_writev(call_frame_t *frame, xlator_t *this, fd_t *fd, struct iovec *vector,
          int32_t count, off_t off, uint32_t flags, struct iobref *iobref,
          dict_t *xdata)
{
    TA_FAILED_FOP(writev, frame, EINVAL);
    return 0;
}

int32_t
ta_fsetxattr(call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *dict,
             int32_t flags, dict_t *xdata)
{
    TA_FAILED_FOP(fsetxattr, frame, EINVAL);
    return 0;
}

int32_t
ta_setxattr(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *dict,
            int32_t flags, dict_t *xdata)
{
    TA_FAILED_FOP(setxattr, frame, EINVAL);
    return 0;
}

int32_t
ta_fallocate(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t keep_size,
             off_t offset, size_t len, dict_t *xdata)
{
    TA_FAILED_FOP(fallocate, frame, EINVAL);
    return 0;
}

int32_t
ta_access(call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t mask,
          dict_t *xdata)
{
    TA_FAILED_FOP(access, frame, EINVAL);
    return 0;
}

int32_t
ta_discard(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
           size_t len, dict_t *xdata)
{
    TA_FAILED_FOP(discard, frame, EINVAL);
    return 0;
}

int32_t
ta_entrylk(call_frame_t *frame, xlator_t *this, const char *volume, loc_t *loc,
           const char *basename, entrylk_cmd cmd, entrylk_type type,
           dict_t *xdata)
{
    TA_FAILED_FOP(entrylk, frame, EINVAL);
    return 0;
}

int32_t
ta_fentrylk(call_frame_t *frame, xlator_t *this, const char *volume, fd_t *fd,
            const char *basename, entrylk_cmd cmd, entrylk_type type,
            dict_t *xdata)
{
    TA_FAILED_FOP(fentrylk, frame, EINVAL);
    return 0;
}

int32_t
ta_flush(call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
{
    TA_FAILED_FOP(flush, frame, EINVAL);
    return 0;
}

int32_t
ta_fsync(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t datasync,
         dict_t *xdata)
{
    TA_FAILED_FOP(fsync, frame, EINVAL);
    return 0;
}
int32_t
ta_fsyncdir(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t datasync,
            dict_t *xdata)
{
    TA_FAILED_FOP(fsyncdir, frame, EINVAL);
    return 0;
}

int32_t
ta_getxattr(call_frame_t *frame, xlator_t *this, loc_t *loc, const char *name,
            dict_t *xdata)
{
    TA_FAILED_FOP(getxattr, frame, EINVAL);
    return 0;
}

int32_t
ta_fgetxattr(call_frame_t *frame, xlator_t *this, fd_t *fd, const char *name,
             dict_t *xdata)
{
    TA_FAILED_FOP(fgetxattr, frame, EINVAL);
    return 0;
}

int32_t
ta_link(call_frame_t *frame, xlator_t *this, loc_t *oldloc, loc_t *newloc,
        dict_t *xdata)
{
    TA_FAILED_FOP(link, frame, EINVAL);
    return 0;
}

int32_t
ta_lk(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t cmd,
      struct gf_flock *flock, dict_t *xdata)
{
    TA_FAILED_FOP(lk, frame, EINVAL);
    return 0;
}

int32_t
ta_mkdir(call_frame_t *frame, xlator_t *this, loc_t *loc, mode_t mode,
         mode_t umask, dict_t *xdata)
{
    TA_FAILED_FOP(mkdir, frame, EINVAL);
    return 0;
}

int32_t
ta_mknod(call_frame_t *frame, xlator_t *this, loc_t *loc, mode_t mode,
         dev_t rdev, mode_t umask, dict_t *xdata)
{
    TA_FAILED_FOP(mknod, frame, EINVAL);
    return 0;
}

int32_t
ta_open(call_frame_t *frame, xlator_t *this, loc_t *loc, int32_t flags,
        fd_t *fd, dict_t *xdata)
{
    TA_FAILED_FOP(open, frame, EINVAL);
    return 0;
}

int32_t
ta_opendir(call_frame_t *frame, xlator_t *this, loc_t *loc, fd_t *fd,
           dict_t *xdata)
{
    TA_FAILED_FOP(opendir, frame, EINVAL);
    return 0;
}

int32_t
ta_readdir(call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
           off_t offset, dict_t *xdata)
{
    TA_FAILED_FOP(readdir, frame, EINVAL);
    return 0;
}

int32_t
ta_readdirp(call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
            off_t offset, dict_t *xdata)
{
    TA_FAILED_FOP(readdirp, frame, EINVAL);
    return 0;
}

int32_t
ta_readlink(call_frame_t *frame, xlator_t *this, loc_t *loc, size_t size,
            dict_t *xdata)
{
    TA_FAILED_FOP(readlink, frame, EINVAL);
    return 0;
}

int32_t
ta_readv(call_frame_t *frame, xlator_t *this, fd_t *fd, size_t size,
         off_t offset, uint32_t flags, dict_t *xdata)
{
    TA_FAILED_FOP(readv, frame, EINVAL);
    return 0;
}

int32_t
ta_removexattr(call_frame_t *frame, xlator_t *this, loc_t *loc,
               const char *name, dict_t *xdata)
{
    TA_FAILED_FOP(removexattr, frame, EINVAL);
    return 0;
}

int32_t
ta_fremovexattr(call_frame_t *frame, xlator_t *this, fd_t *fd, const char *name,
                dict_t *xdata)
{
    TA_FAILED_FOP(fremovexattr, frame, EINVAL);
    return 0;
}

int32_t
ta_rename(call_frame_t *frame, xlator_t *this, loc_t *oldloc, loc_t *newloc,
          dict_t *xdata)
{
    TA_FAILED_FOP(rename, frame, EINVAL);
    return 0;
}

int32_t
ta_rmdir(call_frame_t *frame, xlator_t *this, loc_t *loc, int xflags,
         dict_t *xdata)
{
    TA_FAILED_FOP(rmdir, frame, EINVAL);
    return 0;
}

int32_t
ta_setattr(call_frame_t *frame, xlator_t *this, loc_t *loc, struct iatt *stbuf,
           int32_t valid, dict_t *xdata)
{
    TA_FAILED_FOP(setattr, frame, EINVAL);
    return 0;
}

int32_t
ta_fsetattr(call_frame_t *frame, xlator_t *this, fd_t *fd, struct iatt *stbuf,
            int32_t valid, dict_t *xdata)
{
    TA_FAILED_FOP(fsetattr, frame, EINVAL);
    return 0;
}

int32_t
ta_stat(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata)
{
    TA_FAILED_FOP(stat, frame, EINVAL);
    return 0;
}

int32_t
ta_fstat(call_frame_t *frame, xlator_t *this, fd_t *fd, dict_t *xdata)
{
    TA_FAILED_FOP(fstat, frame, EINVAL);
    return 0;
}

int32_t
ta_statfs(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata)
{
    TA_FAILED_FOP(statfs, frame, EINVAL);
    return 0;
}

int32_t
ta_symlink(call_frame_t *frame, xlator_t *this, const char *linkname,
           loc_t *loc, mode_t umask, dict_t *xdata)
{
    TA_FAILED_FOP(symlink, frame, EINVAL);
    return 0;
}

int32_t
ta_truncate(call_frame_t *frame, xlator_t *this, loc_t *loc, off_t offset,
            dict_t *xdata)
{
    TA_FAILED_FOP(truncate, frame, EINVAL);
    return 0;
}

int32_t
ta_ftruncate(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
             dict_t *xdata)
{
    TA_FAILED_FOP(ftruncate, frame, EINVAL);
    return 0;
}

int32_t
ta_unlink(call_frame_t *frame, xlator_t *this, loc_t *loc, int xflags,
          dict_t *xdata)
{
    TA_FAILED_FOP(unlink, frame, EINVAL);
    return 0;
}

int32_t
ta_zerofill(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
            off_t len, dict_t *xdata)
{
    TA_FAILED_FOP(zerofill, frame, EINVAL);
    return 0;
}

int32_t
ta_seek(call_frame_t *frame, xlator_t *this, fd_t *fd, off_t offset,
        gf_seek_what_t what, dict_t *xdata)
{
    TA_FAILED_FOP(seek, frame, EINVAL);
    return 0;
}

int32_t
mem_acct_init(xlator_t *this)
{
    int ret = -1;

    ret = xlator_mem_acct_init(this, gf_ta_mt_end + 1);
    if (ret)
        gf_log(this->name, GF_LOG_ERROR,
               "Memory accounting "
               "initialization failed.");
    return ret;
}

int
reconfigure(xlator_t *this, dict_t *options)
{
    return 0;
}

int32_t
init(xlator_t *this)
{
    if (!this->children || this->children->next) {
        gf_log(this->name, GF_LOG_ERROR,
               "'thin_arbiter' not configured with exactly one child");
        return -1;
    }

    if (!this->parents) {
        gf_log(this->name, GF_LOG_ERROR, "dangling volume. check volfile ");
    }
    return 0;
}

void
fini(xlator_t *this)
{
    return;
}

struct xlator_fops fops = {
    /*Passed fop*/
    .xattrop = ta_xattrop,
    .fxattrop = ta_fxattrop,
    /*Failed fop*/
    .writev = ta_writev,
    .stat = ta_stat,
    .fstat = ta_fstat,
    .truncate = ta_truncate,
    .ftruncate = ta_ftruncate,
    .access = ta_access,
    .readlink = ta_readlink,
    .mknod = ta_mknod,
    .mkdir = ta_mkdir,
    .unlink = ta_unlink,
    .rmdir = ta_rmdir,
    .symlink = ta_symlink,
    .rename = ta_rename,
    .link = ta_link,
    .open = ta_open,
    .readv = ta_readv,
    .flush = ta_flush,
    .fsync = ta_fsync,
    .opendir = ta_opendir,
    .readdir = ta_readdir,
    .readdirp = ta_readdirp,
    .fsyncdir = ta_fsyncdir,
    .statfs = ta_statfs,
    .setxattr = ta_setxattr,
    .getxattr = ta_getxattr,
    .fsetxattr = ta_fsetxattr,
    .fgetxattr = ta_fgetxattr,
    .removexattr = ta_removexattr,
    .fremovexattr = ta_fremovexattr,
    .lk = ta_lk,
    .entrylk = ta_entrylk,
    .fentrylk = ta_fentrylk,
    .setattr = ta_setattr,
    .fsetattr = ta_fsetattr,
    .fallocate = ta_fallocate,
    .discard = ta_discard,
    .zerofill = ta_zerofill,
    .seek = ta_seek,
};

struct xlator_cbks cbks = {};

struct volume_options options[] = {
    {.key = {NULL}},
};

xlator_api_t xlator_api = {
    .init = init,
    .fini = fini,
    .reconfigure = reconfigure,
    .mem_acct_init = mem_acct_init,
    .op_version = {GD_OP_VERSION_6_0},
    .fops = &fops,
    .cbks = &cbks,
    .options = options,
    .identifier = "thin-arbiter",
    .category = GF_MAINTAINED,
};