# mercurial.revlogutils -- basic utilities for revlog

#

# Copyright 2019 Pierre-Yves David <pierre-yves.david@octobus.net>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

from __future__ import annotations

import typing

from ..thirdparty import attr

# Force pytype to use the non-vendored package

if typing.TYPE_CHECKING:

    # noinspection PyPackageRequirements

    import attr

from ..interfaces import repository

# See mercurial.revlogutils.constants for doc

COMP_MODE_INLINE = 2

RANK_UNKNOWN = -1

def offset_type(offset, type):

    if (type & ~repository.REVISION_FLAGS_KNOWN) != 0:

        raise ValueError(b'unknown revlog index flags: %d' % type)

    return int(int(offset) << 16 | type)

def entry(

    data_offset,

    data_compressed_length,

    data_delta_base,

    link_rev,

    parent_rev_1,

    parent_rev_2,

    node_id,

    flags=0,

    data_uncompressed_length=-1,

    data_compression_mode=COMP_MODE_INLINE,

    sidedata_offset=0,

    sidedata_compressed_length=0,

    sidedata_compression_mode=COMP_MODE_INLINE,

    rank=RANK_UNKNOWN,

):

    """Build one entry from symbolic name

    This is useful to abstract the actual detail of how we build the entry

    tuple for caller who don't care about it.

    This should always be called using keyword arguments. Some arguments have

    default value, this match the value used by index version that does not store such data.

    """

    return (

        offset_type(data_offset, flags),

        data_compressed_length,

        data_uncompressed_length,

        data_delta_base,

        link_rev,

        parent_rev_1,

        parent_rev_2,

        node_id,

        sidedata_offset,

        sidedata_compressed_length,

        data_compression_mode,

        sidedata_compression_mode,

        rank,

    )

@attr.s(slots=True, frozen=True)

class revisioninfo:

    """Information about a revision that allows building its fulltext

    node:       expected hash of the revision

    p1, p2:     parent revs of the revision (as node)

    btext:      built text cache consisting of a one-element list

    cachedelta: (baserev, uncompressed_delta, usage_mode) or None

    flags:      flags associated to the revision storage

    One of btext[0] or cachedelta must be set.

    """

    node = attr.ib()

    p1 = attr.ib()

    p2 = attr.ib()

    btext = attr.ib()

    textlen = attr.ib()

    cachedelta = attr.ib()

    flags = attr.ib()