# diffutil.py - utility functions related to diff and patch

#

# Copyright 2006 Brendan Cully <brendan@kublai.com>

# Copyright 2007 Chris Mason <chris.mason@oracle.com>

# Copyright 2018 Octobus <octobus@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.

import typing

from typing import (

    Any,

    Dict,

    Optional,

)

from .i18n import _

from .node import nullrev

from . import (

    mdiff,

    pycompat,

)

if typing.TYPE_CHECKING:

    from . import ui as uimod

# TODO: narrow the value after the config module is typed

_Opts = Dict[bytes, Any]

def diffallopts(

    ui: "uimod.ui",

    opts: Optional[_Opts] = None,

    untrusted: bool = False,

    section: bytes = b'diff',

    configprefix: bytes = b'',

) -> mdiff.diffopts:

    '''return diffopts with all features supported and parsed'''

    return difffeatureopts(

        ui,

        opts=opts,

        untrusted=untrusted,

        section=section,

        git=True,

        whitespace=True,

        formatchanging=True,

        configprefix=configprefix,

    )

def difffeatureopts(

    ui: "uimod.ui",

    opts: Optional[_Opts] = None,

    untrusted: bool = False,

    section: bytes = b'diff',

    git: bool = False,

    whitespace: bool = False,

    formatchanging: bool = False,

    configprefix: bytes = b'',

) -> mdiff.diffopts:

    """return diffopts with only opted-in features parsed

    Features:

    - git: git-style diffs

    - whitespace: whitespace options like ignoreblanklines and ignorews

    - formatchanging: options that will likely break or cause correctness issues

      with most diff parsers

    """

    def get(

        key: bytes,

        name: Optional[bytes] = None,

        getter=ui.configbool,

        forceplain: Optional[bool] = None,

    ) -> Any:

        if opts:

            v = opts.get(key)

            # diffopts flags are either None-default (which is passed

            # through unchanged, so we can identify unset values), or

            # some other falsey default (eg --unified, which defaults

            # to an empty string). We only want to override the config

            # entries from hgrc with command line values if they

            # appear to have been set, which is any truthy value,

            # True, or False.

            if v or isinstance(v, bool):

                return v

        if forceplain is not None and ui.plain():

            return forceplain

        return getter(

            section, configprefix + (name or key), untrusted=untrusted

        )

    # core options, expected to be understood by every diff parser

    buildopts = {

        b'nodates': get(b'nodates'),

        b'showfunc': get(b'show_function', b'showfunc'),

        b'context': get(b'unified', getter=ui.config),

    }

    buildopts[b'xdiff'] = ui.configbool(b'experimental', b'xdiff')

    if git:

        buildopts[b'git'] = get(b'git')

        # since this is in the experimental section, we need to call

        # ui.configbool directory

        buildopts[b'showsimilarity'] = ui.configbool(

            b'experimental', b'extendedheader.similarity'

        )

        # need to inspect the ui object instead of using get() since we want to

        # test for an int

        hconf = ui.config(b'experimental', b'extendedheader.index')

        if hconf is not None:

            hlen = None

            try:

                # the hash config could be an integer (for length of hash) or a

                # word (e.g. short, full, none)

                hlen = int(hconf)

                if hlen < 0 or hlen > 40:

                    msg = _(b"invalid length for extendedheader.index: '%d'\n")

                    ui.warn(msg % hlen)

            except ValueError:

                # default value

                if hconf == b'short' or hconf == b'':

                    hlen = 12

                elif hconf == b'full':

                    hlen = 40

                elif hconf != b'none':

                    msg = _(b"invalid value for extendedheader.index: '%s'\n")

                    ui.warn(msg % hconf)

            finally:

                buildopts[b'index'] = hlen

    if whitespace:

        buildopts[b'ignorews'] = get(b'ignore_all_space', b'ignorews')

        buildopts[b'ignorewsamount'] = get(

            b'ignore_space_change', b'ignorewsamount'

        )

        buildopts[b'ignoreblanklines'] = get(

            b'ignore_blank_lines', b'ignoreblanklines'

        )

        buildopts[b'ignorewseol'] = get(b'ignore_space_at_eol', b'ignorewseol')

    if formatchanging:

        buildopts[b'text'] = None if opts is None else opts.get(b'text')

        binary = None if opts is None else opts.get(b'binary')

        buildopts[b'nobinary'] = (

            not binary

            if binary is not None

            else get(b'nobinary', forceplain=False)

        )

        buildopts[b'noprefix'] = get(b'noprefix', forceplain=False)

        buildopts[b'worddiff'] = get(

            b'word_diff', b'word-diff', forceplain=False

        )

    return mdiff.diffopts(**pycompat.strkwargs(buildopts))

def diff_parent(ctx):

    """get the context object to use as parent when diffing

    If diff.merge is enabled, an overlayworkingctx of the auto-merged parents will be returned.

    """

    repo = ctx.repo()

    if repo.ui.configbool(b"diff", b"merge") and ctx.p2().rev() != nullrev:

        # avoid circular import

        from . import (

            context,

            merge,

        )

        wctx = context.overlayworkingctx(repo)

        wctx.setbase(ctx.p1())

        with repo.ui.configoverride(

            {

                (

                    b"ui",

                    b"forcemerge",

                ): b"internal:merge3-lie-about-conflicts",

            },

            b"merge-diff",

        ):

            with repo.ui.silent():

                merge.merge(ctx.p2(), wc=wctx)

        return wctx

    else:

        return ctx.p1()