# sparse.py - functionality for sparse checkouts

#

# Copyright 2014 Facebook, Inc.

#

# 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 absolute_import

from .i18n import _

from .node import nullid

from . import (

    error,

)

# Whether sparse features are enabled. This variable is intended to be

# temporary to facilitate porting sparse to core. It should eventually be

# a per-repo option, possibly a repo requirement.

enabled = False

def parseconfig(ui, raw):

    """Parse sparse config file content.

    Returns a tuple of includes, excludes, and profiles.

    """

    includes = set()

    excludes = set()

    current = includes

    profiles = []

    for line in raw.split('\n'):

        line = line.strip()

        if not line or line.startswith('#'):

            # empty or comment line, skip

            continue

        elif line.startswith('%include '):

            line = line[9:].strip()

            if line:

                profiles.append(line)

        elif line == '[include]':

            if current != includes:

                # TODO pass filename into this API so we can report it.

                raise error.Abort(_('sparse config cannot have includes ' +

                                    'after excludes'))

            continue

        elif line == '[exclude]':

            current = excludes

        elif line:

            if line.strip().startswith('/'):

                ui.warn(_('warning: sparse profile cannot use' +

                          ' paths starting with /, ignoring %s\n') % line)

                continue

            current.add(line)

    return includes, excludes, profiles

# Exists as separate function to facilitate monkeypatching.

def readprofile(repo, profile, changeid):

    """Resolve the raw content of a sparse profile file."""

    # TODO add some kind of cache here because this incurs a manifest

    # resolve and can be slow.

    return repo.filectx(profile, changeid=changeid).data()

def patternsforrev(repo, rev):

    """Obtain sparse checkout patterns for the given rev.

    Returns a tuple of iterables representing includes, excludes, and

    patterns.

    """

    # Feature isn't enabled. No-op.

    if not enabled:

        return set(), set(), []

    raw = repo.vfs.tryread('sparse')

    if not raw:

        return set(), set(), []

    if rev is None:

        raise error.Abort(_('cannot parse sparse patterns from working '

                            'directory'))

    includes, excludes, profiles = parseconfig(repo.ui, raw)

    ctx = repo[rev]

    if profiles:

        visited = set()

        while profiles:

            profile = profiles.pop()

            if profile in visited:

                continue

            visited.add(profile)

            try:

                raw = readprofile(repo, profile, rev)

            except error.ManifestLookupError:

                msg = (

                    "warning: sparse profile '%s' not found "

                    "in rev %s - ignoring it\n" % (profile, ctx))

                # experimental config: sparse.missingwarning

                if repo.ui.configbool(

                        'sparse', 'missingwarning', True):

                    repo.ui.warn(msg)

                else:

                    repo.ui.debug(msg)

                continue

            pincludes, pexcludes, subprofs = parseconfig(repo.ui, raw)

            includes.update(pincludes)

            excludes.update(pexcludes)

            for subprofile in subprofs:

                profiles.append(subprofile)

        profiles = visited

    if includes:

        includes.add('.hg*')

    return includes, excludes, profiles

def activeprofiles(repo):

    revs = [repo.changelog.rev(node) for node in

            repo.dirstate.parents() if node != nullid]

    profiles = set()

    for rev in revs:

        profiles.update(patternsforrev(repo, rev)[2])

    return profiles