#
# Copyright 2015 ClusterHQ
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

"""
Helper routines for converting ``errno`` style error codes from C functions
to Python exceptions defined by `libzfs_core` API.

The conversion heavily depends on the context of the error: the attempted
operation and the input parameters.  For this reason, there is a conversion
routine for each `libzfs_core` interface function. The conversion routines
have the return code as a parameter as well as all the parameters of the
corresponding interface functions.

The parameters and exceptions are documented in the `libzfs_core` interfaces.
"""
from __future__ import absolute_import, division, print_function

import errno
import re
import string
from . import exceptions as lzc_exc
from ._constants import (
    ECHRNG,
    ECKSUM,
    ETIME,
    MAXNAMELEN,
    ZFS_ERR_CHECKPOINT_EXISTS,
    ZFS_ERR_DISCARDING_CHECKPOINT,
    ZFS_ERR_NO_CHECKPOINT,
    ZFS_ERR_DEVRM_IN_PROGRESS,
    ZFS_ERR_VDEV_TOO_BIG,
    ZFS_ERR_WRONG_PARENT,
    zfs_errno
)


def lzc_create_translate_error(ret, name, ds_type, props):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.PropertyInvalid(name)
    if ret == errno.EEXIST:
        raise lzc_exc.FilesystemExists(name)
    if ret == errno.ENOENT:
        raise lzc_exc.ParentNotFound(name)
    if ret == ZFS_ERR_WRONG_PARENT:
        raise lzc_exc.WrongParent(_fs_name(name))
    if ret == zfs_errno.ZFS_ERR_BADPROP:
        raise lzc_exc.PropertyInvalid(name)
    raise _generic_exception(ret, name, "Failed to create filesystem")


def lzc_clone_translate_error(ret, name, origin, props):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        _validate_snap_name(origin)
        raise lzc_exc.PropertyInvalid(name)
    if ret == errno.EXDEV:
        raise lzc_exc.PoolsDiffer(name)
    if ret == errno.EEXIST:
        raise lzc_exc.FilesystemExists(name)
    if ret == errno.ENOENT:
        if not _is_valid_snap_name(origin):
            raise lzc_exc.SnapshotNameInvalid(origin)
        raise lzc_exc.DatasetNotFound(name)
    raise _generic_exception(ret, name, "Failed to create clone")


def lzc_rollback_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.ESRCH:
        raise lzc_exc.SnapshotNotFound(name)
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.NameInvalid(name)
    if ret == errno.ENOENT:
        if not _is_valid_fs_name(name):
            raise lzc_exc.NameInvalid(name)
        else:
            raise lzc_exc.FilesystemNotFound(name)
    raise _generic_exception(ret, name, "Failed to rollback")


def lzc_rollback_to_translate_error(ret, name, snap):
    if ret == errno.EEXIST:
        raise lzc_exc.SnapshotNotLatest(snap)
    else:
        lzc_rollback_translate_error(ret, name)


def lzc_snapshot_translate_errors(ret, errlist, snaps, props):
    if ret == 0:
        return

    def _map(ret, name):
        if ret == errno.EXDEV:
            pool_names = iter(map(_pool_name, snaps))
            pool_name = next(pool_names, None)
            same_pool = all(x == pool_name for x in pool_names)
            if same_pool:
                return lzc_exc.DuplicateSnapshots(name)
            else:
                return lzc_exc.PoolsDiffer(name)
        elif ret == errno.EINVAL:
            if any(not _is_valid_snap_name(s) for s in snaps):
                return lzc_exc.NameInvalid(name)
            elif any(len(s) > MAXNAMELEN for s in snaps):
                return lzc_exc.NameTooLong(name)
            else:
                return lzc_exc.PropertyInvalid(name)

        if ret == errno.EEXIST:
            return lzc_exc.SnapshotExists(name)
        if ret == errno.ENOENT:
            return lzc_exc.FilesystemNotFound(name)
        return _generic_exception(ret, name, "Failed to create snapshot")

    _handle_err_list(ret, errlist, snaps, lzc_exc.SnapshotFailure, _map)


def lzc_destroy_snaps_translate_errors(ret, errlist, snaps, defer):
    if ret == 0:
        return

    def _map(ret, name):
        if ret == errno.EEXIST:
            return lzc_exc.SnapshotIsCloned(name)
        if ret == errno.ENOENT:
            return lzc_exc.PoolNotFound(name)
        if ret == errno.EBUSY:
            return lzc_exc.SnapshotIsHeld(name)
        return _generic_exception(ret, name, "Failed to destroy snapshot")

    _handle_err_list(
        ret, errlist, snaps, lzc_exc.SnapshotDestructionFailure, _map)


def lzc_bookmark_translate_errors(ret, errlist, bookmarks):

    if ret == 0:
        return

    def _map(ret, name):
        source = bookmarks[name]
        if ret == errno.EINVAL:
            if name:
                pool_names = map(_pool_name, bookmarks.keys())

                # use _validate* functions for MAXNAMELEN check
                try:
                    _validate_bmark_name(name)
                except lzc_exc.ZFSError as e:
                    return e

                try:
                    _validate_snap_name(source)
                    source_is_snap = True
                except lzc_exc.ZFSError:
                    source_is_snap = False
                try:
                    _validate_bmark_name(source)
                    source_is_bmark = True
                except lzc_exc.ZFSError:
                    source_is_bmark = False
                if not source_is_snap and not source_is_bmark:
                    return lzc_exc.BookmarkSourceInvalid(source)

                if any(x != _pool_name(name) for x in pool_names):
                    return lzc_exc.PoolsDiffer(name)
            else:
                invalid_names = [
                    b for b in bookmarks.keys() if not _is_valid_bmark_name(b)]
                if invalid_names:
                    return lzc_exc.BookmarkNameInvalid(invalid_names[0])
        if ret == errno.EEXIST:
            return lzc_exc.BookmarkExists(name)
        if ret == errno.ENOENT:
            return lzc_exc.SnapshotNotFound(name)
        if ret == errno.ENOTSUP:
            return lzc_exc.BookmarkNotSupported(name)
        if ret == zfs_errno.ZFS_ERR_BOOKMARK_SOURCE_NOT_ANCESTOR:
            return lzc_exc.BookmarkMismatch(source)
        return _generic_exception(ret, name, "Failed to create bookmark")

    _handle_err_list(
        ret, errlist, bookmarks.keys(), lzc_exc.BookmarkFailure, _map)


def lzc_get_bookmarks_translate_error(ret, fsname, props):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(fsname)
    raise _generic_exception(ret, fsname, "Failed to list bookmarks")


def lzc_destroy_bookmarks_translate_errors(ret, errlist, bookmarks):
    if ret == 0:
        return

    def _map(ret, name):
        if ret == errno.EINVAL:
            return lzc_exc.NameInvalid(name)
        return _generic_exception(ret, name, "Failed to destroy bookmark")

    _handle_err_list(
        ret, errlist, bookmarks, lzc_exc.BookmarkDestructionFailure, _map)


def lzc_snaprange_space_translate_error(ret, firstsnap, lastsnap):
    if ret == 0:
        return
    if ret == errno.EXDEV and firstsnap is not None:
        if _pool_name(firstsnap) != _pool_name(lastsnap):
            raise lzc_exc.PoolsDiffer(lastsnap)
        else:
            raise lzc_exc.SnapshotMismatch(lastsnap)
    if ret == errno.EINVAL:
        if not _is_valid_snap_name(firstsnap):
            raise lzc_exc.NameInvalid(firstsnap)
        elif not _is_valid_snap_name(lastsnap):
            raise lzc_exc.NameInvalid(lastsnap)
        elif len(firstsnap) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(firstsnap)
        elif len(lastsnap) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(lastsnap)
        elif _pool_name(firstsnap) != _pool_name(lastsnap):
            raise lzc_exc.PoolsDiffer(lastsnap)
        else:
            raise lzc_exc.SnapshotMismatch(lastsnap)
    if ret == errno.ENOENT:
        raise lzc_exc.SnapshotNotFound(lastsnap)
    raise _generic_exception(
        ret, lastsnap, "Failed to calculate space used by range of snapshots")


def lzc_hold_translate_errors(ret, errlist, holds, fd):
    if ret == 0:
        return

    def _map(ret, name):
        if ret == errno.EXDEV:
            return lzc_exc.PoolsDiffer(name)
        elif ret == errno.EINVAL:
            if name:
                pool_names = map(_pool_name, holds.keys())
                if not _is_valid_snap_name(name):
                    return lzc_exc.NameInvalid(name)
                elif len(name) > MAXNAMELEN:
                    return lzc_exc.NameTooLong(name)
                elif any(x != _pool_name(name) for x in pool_names):
                    return lzc_exc.PoolsDiffer(name)
            else:
                invalid_names = [
                    b for b in holds.keys() if not _is_valid_snap_name(b)]
                if invalid_names:
                    return lzc_exc.NameInvalid(invalid_names[0])
        fs_name = None
        hold_name = None
        pool_name = None
        if name is not None:
            fs_name = _fs_name(name)
            pool_name = _pool_name(name)
            hold_name = holds[name]
        if ret == errno.ENOENT:
            return lzc_exc.FilesystemNotFound(fs_name)
        if ret == errno.EEXIST:
            return lzc_exc.HoldExists(name)
        if ret == errno.E2BIG:
            return lzc_exc.NameTooLong(hold_name)
        if ret == errno.ENOTSUP:
            return lzc_exc.FeatureNotSupported(pool_name)
        return _generic_exception(ret, name, "Failed to hold snapshot")

    if ret == errno.EBADF:
        raise lzc_exc.BadHoldCleanupFD()
    _handle_err_list(ret, errlist, holds.keys(), lzc_exc.HoldFailure, _map)


def lzc_release_translate_errors(ret, errlist, holds):
    if ret == 0:
        return
    for snap in holds:
        hold_list = holds[snap]
        if not isinstance(hold_list, list):
            raise lzc_exc.TypeError('holds must be in a list')

    def _map(ret, name):
        if ret == errno.EXDEV:
            return lzc_exc.PoolsDiffer(name)
        elif ret == errno.EINVAL:
            if name:
                pool_names = map(_pool_name, holds.keys())
                if not _is_valid_snap_name(name):
                    return lzc_exc.NameInvalid(name)
                elif len(name) > MAXNAMELEN:
                    return lzc_exc.NameTooLong(name)
                elif any(x != _pool_name(name) for x in pool_names):
                    return lzc_exc.PoolsDiffer(name)
            else:
                invalid_names = [
                    b for b in holds.keys() if not _is_valid_snap_name(b)]
                if invalid_names:
                    return lzc_exc.NameInvalid(invalid_names[0])
        elif ret == errno.ENOENT:
            return lzc_exc.HoldNotFound(name)
        elif ret == errno.E2BIG:
            tag_list = holds[name]
            too_long_tags = [t for t in tag_list if len(t) > MAXNAMELEN]
            return lzc_exc.NameTooLong(too_long_tags[0])
        elif ret == errno.ENOTSUP:
            pool_name = None
            if name is not None:
                pool_name = _pool_name(name)
            return lzc_exc.FeatureNotSupported(pool_name)
        else:
            return _generic_exception(
                ret, name, "Failed to release snapshot hold")

    _handle_err_list(
        ret, errlist, holds.keys(), lzc_exc.HoldReleaseFailure, _map)


def lzc_get_holds_translate_error(ret, snapname):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_snap_name(snapname)
    if ret == errno.ENOENT:
        raise lzc_exc.SnapshotNotFound(snapname)
    if ret == errno.ENOTSUP:
        raise lzc_exc.FeatureNotSupported(_pool_name(snapname))
    raise _generic_exception(ret, snapname, "Failed to get holds on snapshot")


def lzc_send_translate_error(ret, snapname, fromsnap, fd, flags):
    if ret == 0:
        return
    if ret == errno.EXDEV and fromsnap is not None:
        if _pool_name(fromsnap) != _pool_name(snapname):
            raise lzc_exc.PoolsDiffer(snapname)
        else:
            raise lzc_exc.SnapshotMismatch(snapname)
    elif ret == errno.EINVAL:
        if (fromsnap is not None and not _is_valid_snap_name(fromsnap) and
                not _is_valid_bmark_name(fromsnap)):
            raise lzc_exc.NameInvalid(fromsnap)
        elif (not _is_valid_snap_name(snapname) and
                not _is_valid_fs_name(snapname)):
            raise lzc_exc.NameInvalid(snapname)
        elif fromsnap is not None and len(fromsnap) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(fromsnap)
        elif len(snapname) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(snapname)
        elif (fromsnap is not None and
                _pool_name(fromsnap) != _pool_name(snapname)):
            raise lzc_exc.PoolsDiffer(snapname)
    elif ret == errno.ENOENT:
        if (fromsnap is not None and not _is_valid_snap_name(fromsnap) and
                not _is_valid_bmark_name(fromsnap)):
            raise lzc_exc.NameInvalid(fromsnap)
        raise lzc_exc.SnapshotNotFound(snapname)
    elif ret == errno.ENAMETOOLONG:
        if fromsnap is not None and len(fromsnap) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(fromsnap)
        else:
            raise lzc_exc.NameTooLong(snapname)
    raise lzc_exc.StreamIOError(ret)


def lzc_send_space_translate_error(ret, snapname, fromsnap):
    if ret == 0:
        return
    if ret == errno.EXDEV and fromsnap is not None:
        if _pool_name(fromsnap) != _pool_name(snapname):
            raise lzc_exc.PoolsDiffer(snapname)
        else:
            raise lzc_exc.SnapshotMismatch(snapname)
    elif ret == errno.EINVAL:
        if fromsnap is not None and not _is_valid_snap_name(fromsnap):
            raise lzc_exc.NameInvalid(fromsnap)
        elif not _is_valid_snap_name(snapname):
            raise lzc_exc.NameInvalid(snapname)
        elif fromsnap is not None and len(fromsnap) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(fromsnap)
        elif len(snapname) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(snapname)
        elif (fromsnap is not None and
                _pool_name(fromsnap) != _pool_name(snapname)):
            raise lzc_exc.PoolsDiffer(snapname)
    elif ret == errno.ENOENT and fromsnap is not None:
        if not _is_valid_snap_name(fromsnap):
            raise lzc_exc.NameInvalid(fromsnap)
    if ret == errno.ENOENT:
        raise lzc_exc.SnapshotNotFound(snapname)
    raise _generic_exception(
        ret, snapname, "Failed to estimate backup stream size")


def lzc_receive_translate_errors(
    ret, snapname, fd, force, raw, resumable, embedded, origin, properrs
):
    if ret == 0:
        if properrs is not None and len(properrs) > 0:
            def _map(ret, name):
                if ret == errno.EINVAL:
                    return lzc_exc.PropertyInvalid(name)
                if ret == zfs_errno.ZFS_ERR_BADPROP:
                    return lzc_exc.PropertyInvalid(name)
                return _generic_exception(ret, name, "Failed to set property")
            _handle_err_list(
                errno.EINVAL, properrs, [snapname],
                lzc_exc.ReceivePropertyFailure, _map)
        else:
            return
    if ret == errno.EINVAL:
        if (not _is_valid_snap_name(snapname) and
                not _is_valid_fs_name(snapname)):
            raise lzc_exc.NameInvalid(snapname)
        elif len(snapname) > MAXNAMELEN:
            raise lzc_exc.NameTooLong(snapname)
        elif origin is not None and not _is_valid_snap_name(origin):
            raise lzc_exc.NameInvalid(origin)
        elif resumable:
            raise lzc_exc.StreamFeatureInvalid()
        elif embedded and not raw:
            raise lzc_exc.StreamFeatureIncompatible()
        else:
            raise lzc_exc.BadStream()
    if ret == errno.ENOENT:
        if not _is_valid_snap_name(snapname):
            raise lzc_exc.NameInvalid(snapname)
        else:
            raise lzc_exc.DatasetNotFound(snapname)
    if ret == errno.EEXIST:
        raise lzc_exc.DatasetExists(snapname)
    if ret == errno.ENOTSUP:
        raise lzc_exc.StreamFeatureNotSupported()
    if ret == errno.ENODEV:
        raise lzc_exc.StreamMismatch(_fs_name(snapname))
    if ret == errno.ETXTBSY:
        raise lzc_exc.DestinationModified(_fs_name(snapname))
    if ret == errno.EBUSY:
        raise lzc_exc.DatasetBusy(_fs_name(snapname))
    if ret == errno.ENOSPC:
        raise lzc_exc.NoSpace(_fs_name(snapname))
    if ret == errno.EDQUOT:
        raise lzc_exc.QuotaExceeded(_fs_name(snapname))
    if ret == errno.ENAMETOOLONG:
        raise lzc_exc.NameTooLong(snapname)
    if ret == errno.EROFS:
        raise lzc_exc.ReadOnlyPool(_pool_name(snapname))
    if ret == errno.EAGAIN:
        raise lzc_exc.SuspendedPool(_pool_name(snapname))
    if ret == ECKSUM:
        raise lzc_exc.BadStream()
    if ret == ZFS_ERR_WRONG_PARENT:
        raise lzc_exc.WrongParent(_fs_name(snapname))
    if ret == zfs_errno.ZFS_ERR_STREAM_TRUNCATED:
        raise lzc_exc.StreamTruncated()
    if ret == zfs_errno.ZFS_ERR_BADPROP:
        raise lzc_exc.PropertyInvalid(snapname)

    raise lzc_exc.StreamIOError(ret)


def lzc_promote_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.NotClone(name)
    if ret == errno.ENOTSOCK:
        raise lzc_exc.NotClone(name)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(name)
    if ret == errno.EEXIST:
        raise lzc_exc.SnapshotExists(name)
    raise _generic_exception(ret, name, "Failed to promote dataset")


def lzc_change_key_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.PropertyInvalid(name)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(name)
    if ret == errno.EACCES:
        raise lzc_exc.EncryptionKeyNotLoaded()
    raise _generic_exception(ret, name, "Failed to change encryption key")


def lzc_load_key_translate_error(ret, name, noop):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.PropertyInvalid(name)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(name)
    if ret == errno.EACCES:
        raise lzc_exc.EncryptionKeyInvalid()
    if ret == errno.EEXIST:
        raise lzc_exc.EncryptionKeyAlreadyLoaded()
    if noop:
        raise _generic_exception(ret, name, "Failed to load encryption key")
    else:
        raise _generic_exception(ret, name, "Failed to verify encryption key")


def lzc_unload_key_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.PropertyInvalid(name)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(name)
    if ret == errno.EACCES:
        raise lzc_exc.EncryptionKeyNotLoaded()
    raise _generic_exception(ret, name, "Failed to unload encryption key")


def lzc_sync_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.PoolNotFound(name)
    raise _generic_exception(ret, name, "Failed to sync pool")


def lzc_reopen_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.PoolNotFound(name)
    raise _generic_exception(ret, name, "Failed to reopen pool")


def lzc_channel_program_translate_error(ret, name, error):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.PoolNotFound(name)
    if ret == ETIME:
        raise lzc_exc.ZCPTimeout()
    if ret == errno.ENOMEM:
        raise lzc_exc.ZCPMemoryError()
    if ret == errno.ENOSPC:
        raise lzc_exc.ZCPSpaceError()
    if ret == errno.EPERM:
        raise lzc_exc.ZCPPermissionError()
    if ret == ECHRNG:
        raise lzc_exc.ZCPRuntimeError(error)
    if ret == errno.EINVAL:
        if error is None:
            raise lzc_exc.ZCPLimitInvalid()
        else:
            raise lzc_exc.ZCPSyntaxError(error)
    raise _generic_exception(ret, name, "Failed to execute channel program")


def lzc_pool_checkpoint_translate_error(ret, name, discard=False):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.PoolNotFound(name)
    if ret == ZFS_ERR_CHECKPOINT_EXISTS:
        raise lzc_exc.CheckpointExists()
    if ret == ZFS_ERR_NO_CHECKPOINT:
        raise lzc_exc.CheckpointNotFound()
    if ret == ZFS_ERR_DISCARDING_CHECKPOINT:
        raise lzc_exc.CheckpointDiscarding()
    if ret == ZFS_ERR_DEVRM_IN_PROGRESS:
        raise lzc_exc.DeviceRemovalRunning()
    if ret == ZFS_ERR_VDEV_TOO_BIG:
        raise lzc_exc.DeviceTooBig()
    if discard:
        raise _generic_exception(
            ret, name, "Failed to discard pool checkpoint")
    else:
        raise _generic_exception(ret, name, "Failed to create pool checkpoint")


def lzc_pool_checkpoint_discard_translate_error(ret, name):
    lzc_pool_checkpoint_translate_error(ret, name, discard=True)


def lzc_rename_translate_error(ret, source, target):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(source)
        _validate_fs_name(target)
        if _pool_name(source) != _pool_name(target):
            raise lzc_exc.PoolsDiffer(source)
    if ret == errno.EEXIST:
        raise lzc_exc.FilesystemExists(target)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(source)
    if ret == ZFS_ERR_WRONG_PARENT:
        raise lzc_exc.WrongParent(target)
    raise _generic_exception(ret, source, "Failed to rename dataset")


def lzc_destroy_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
    if ret == errno.ENOENT:
        raise lzc_exc.FilesystemNotFound(name)
    raise _generic_exception(ret, name, "Failed to destroy dataset")


def lzc_inherit_prop_translate_error(ret, name, prop):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
        raise lzc_exc.PropertyInvalid(prop)
    if ret == errno.ENOENT:
        raise lzc_exc.DatasetNotFound(name)
    raise _generic_exception(ret, name, "Failed to inherit a property")


def lzc_set_prop_translate_error(ret, name, prop, val):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_or_snap_name(name)
        raise lzc_exc.PropertyInvalid(prop)
    if ret == errno.ENOENT:
        raise lzc_exc.DatasetNotFound(name)
    raise _generic_exception(ret, name, "Failed to set a property")


def lzc_get_props_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_or_snap_name(name)
    if ret == errno.ENOENT:
        raise lzc_exc.DatasetNotFound(name)
    raise _generic_exception(ret, name, "Failed to get properties")


def lzc_list_children_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
    raise _generic_exception(ret, name, "Error while iterating children")


def lzc_list_snaps_translate_error(ret, name):
    if ret == 0:
        return
    if ret == errno.EINVAL:
        _validate_fs_name(name)
    raise _generic_exception(ret, name, "Error while iterating snapshots")


def lzc_list_translate_error(ret, name, opts):
    if ret == 0:
        return
    if ret == errno.ENOENT:
        raise lzc_exc.DatasetNotFound(name)
    if ret == errno.EINVAL:
        _validate_fs_or_snap_name(name)
    raise _generic_exception(ret, name, "Error obtaining a list")


def _handle_err_list(ret, errlist, names, exception, mapper):
    '''
    Convert one or more errors from an operation into the requested exception.

    :param int ret: the overall return code.
    :param errlist: the dictionary that maps entity names to their specific
        error codes.
    :type errlist: dict of bytes:int
    :param names: the list of all names of the entities on which the operation
        was attempted.
    :param type exception: the type of the exception to raise if an error
        occurred. The exception should be a subclass of
        ``MultipleOperationsFailure``.
    :param function mapper: the function that maps an error code and a name to
        a Python exception.

    Unless ``ret`` is zero this function will raise the ``exception``.
    If the ``errlist`` is not empty, then the compound exception will contain
    a list of exceptions corresponding to each individual error code in the
    ``errlist``.
    Otherwise, the ``exception`` will contain a list with a single exception
    corresponding to the ``ret`` value. If the ``names`` list contains only one
    element, that is, the operation was attempted on a single entity, then the
    name of that entity is passed to the ``mapper``.
    If the operation was attempted on multiple entities, but the ``errlist``
    is empty, then we can not know which entity caused the error and, thus,
    ``None`` is used as a name to signify that fact.

    .. note::
        Note that the ``errlist`` can contain a special element with a key of
        "N_MORE_ERRORS".
        That element means that there were too many errors to place on the
        ``errlist``.
        Those errors are suppressed and only their count is provided as a
        value of the special ``N_MORE_ERRORS`` element.
    '''
    if ret == 0:
        return

    if len(errlist) == 0:
        suppressed_count = 0
        names = list(zip(names, range(2)))
        if len(names) == 1:
            name, _ = names[0]
        else:
            name = None
        errors = [mapper(ret, name)]
    else:
        errors = []
        suppressed_count = errlist.pop('N_MORE_ERRORS', 0)
        for name in errlist:
            err = errlist[name]
            errors.append(mapper(err, name))

    raise exception(errors, suppressed_count)


def _pool_name(name):
    '''
    Extract a pool name from the given dataset or bookmark name.

    '/' separates dataset name components.
    '@' separates a snapshot name from the rest of the dataset name.
    '#' separates a bookmark name from the rest of the dataset name.
    '''
    return re.split(b'[/@#]', name, 1)[0]


def _fs_name(name):
    '''
    Extract a dataset name from the given snapshot or bookmark name.

    '@' separates a snapshot name from the rest of the dataset name.
    '#' separates a bookmark name from the rest of the dataset name.
    '''
    return re.split(b'[@#]', name, 1)[0]


def _is_valid_name_component(component):
    allowed = string.ascii_letters + string.digits + u'-_.: '
    return component and all(x in allowed.encode() for x in component)


def _is_valid_fs_name(name):
    return name and all(_is_valid_name_component(c) for c in name.split(b'/'))


def _is_valid_snap_name(name):
    parts = name.split(b'@')
    return (len(parts) == 2 and _is_valid_fs_name(parts[0]) and
            _is_valid_name_component(parts[1]))


def _is_valid_bmark_name(name):
    parts = name.split(b'#')
    return (len(parts) == 2 and _is_valid_fs_name(parts[0]) and
            _is_valid_name_component(parts[1]))


def _validate_fs_name(name):
    if not _is_valid_fs_name(name):
        raise lzc_exc.FilesystemNameInvalid(name)
    elif len(name) > MAXNAMELEN:
        raise lzc_exc.NameTooLong(name)


def _validate_snap_name(name):
    if not _is_valid_snap_name(name):
        raise lzc_exc.SnapshotNameInvalid(name)
    elif len(name) > MAXNAMELEN:
        raise lzc_exc.NameTooLong(name)


def _validate_bmark_name(name):
    if not _is_valid_bmark_name(name):
        raise lzc_exc.BookmarkNameInvalid(name)
    elif len(name) > MAXNAMELEN:
        raise lzc_exc.NameTooLong(name)


def _validate_fs_or_snap_name(name):
    if not _is_valid_fs_name(name) and not _is_valid_snap_name(name):
        raise lzc_exc.NameInvalid(name)
    elif len(name) > MAXNAMELEN:
        raise lzc_exc.NameTooLong(name)


def _generic_exception(err, name, message):
    if err in _error_to_exception:
        return _error_to_exception[err](name)
    else:
        return lzc_exc.ZFSGenericError(err, message, name)


_error_to_exception = {e.errno: e for e in [
    lzc_exc.ZIOError,
    lzc_exc.NoSpace,
    lzc_exc.QuotaExceeded,
    lzc_exc.DatasetBusy,
    lzc_exc.NameTooLong,
    lzc_exc.ReadOnlyPool,
    lzc_exc.SuspendedPool,
    lzc_exc.PoolsDiffer,
    lzc_exc.PropertyNotSupported,
]}


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