""" This extension provides direct access

It is the ability to refer and access hidden sha in commands provided that you 

know their value.

For example hg log -r xxx where xxx is a commit has should work whether xxx is

hidden or not as we assume that the user knows what he is doing when referring

to xxx.

"""

from mercurial import extensions

from mercurial import cmdutil

from mercurial import repoview

from mercurial import branchmap

from mercurial import revset

from mercurial import error

from mercurial import commands

from mercurial import hg

from mercurial import util

from mercurial.i18n import _

cmdtable = {}

command = cmdutil.command(cmdtable)

# By default, all the commands have directaccess with warnings

# List of commands that have no directaccess and directaccess with no warning

directaccesslevel = [

    # Format:

    # ('nowarning', 'evolve', 'prune'),

    # means: no directaccess warning, for the command in evolve named prune

    #

    # ('error', None, 'serve'),

    # means: no directaccess for the command in core named serve

    #

    # The list is ordered alphabetically by command names, starting with all

    # the commands in core then all the commands in the extensions

    #

    # The general guideline is:

    # - remove directaccess warnings for read only commands

    # - no direct access for commands with consequences outside of the repo

    # - leave directaccess warnings for all the other commands

    #

    ('nowarning', None, 'annotate'),

    ('nowarning', None, 'archive'),

    ('nowarning', None, 'bisect'),

    ('nowarning', None, 'bookmarks'),

    ('nowarning', None, 'bundle'),

    ('nowarning', None, 'cat'),

    ('nowarning', None, 'diff'),

    ('nowarning', None, 'export'),

    ('nowarning', None, 'identify'),

    ('nowarning', None, 'incoming'),

    ('nowarning', None, 'log'),

    ('nowarning', None, 'manifest'),

    ('error', None, 'outgoing'), # confusing if push errors and not outgoing

    ('error', None, 'push'), # destructive

    ('nowarning', None, 'revert'),

    ('error', None, 'serve'),

    ('nowarning', None, 'tags'),

    ('nowarning', None, 'unbundle'),

    ('nowarning', None, 'update'),

]

def reposetup(ui, repo):

    repo._explicitaccess = set()

def _computehidden(repo):

    hidden = repoview.filterrevs(repo, 'visible')

    cl = repo.changelog

    dynamic = hidden & repo._explicitaccess

    if dynamic:

        blocked = cl.ancestors(dynamic, inclusive=True)

        hidden = frozenset(r for r in hidden if r not in blocked)

    return hidden

def setupdirectaccess():

    """ Add two new filtername that behave like visible to provide direct access

    and direct access with warning. Wraps the commands to setup direct access """

    repoview.filtertable.update({'visible-directaccess-nowarn': _computehidden})

    repoview.filtertable.update({'visible-directaccess-warn': _computehidden})

    branchmap.subsettable['visible-directaccess-nowarn'] = 'visible'

    branchmap.subsettable['visible-directaccess-warn'] = 'visible'

    for warn, ext, cmd in directaccesslevel:

        try:

            cmdtable = extensions.find(ext).cmdtable if ext else commands.table

            wrapper = wrapwitherror if warn == 'error' else wrapwithoutwarning

            extensions.wrapcommand(cmdtable, cmd, wrapper)

        except (error.UnknownCommand, KeyError):

            pass

def wrapwitherror(orig, ui, repo, *args, **kwargs):

    if repo and repo.filtername == 'visible-directaccess-warn':

        repo = repo.filtered('visible')

    return orig(ui, repo, *args, **kwargs)

def wrapwithoutwarning(orig, ui, repo, *args, **kwargs):

    if repo and repo.filtername == 'visible-directaccess-warn':

        repo = repo.filtered("visible-directaccess-nowarn")

    return orig(ui, repo, *args, **kwargs)

def uisetup(ui):

    """ Change ordering of extensions to ensure that directaccess extsetup comes

    after the one of the extensions in the loadsafter list """

    loadsafter = ui.configlist('directaccess','loadsafter')

    order = list(extensions._order)

    directaccesidx = order.index('directaccess')

    # The min idx for directaccess to load after all the extensions in loadafter

    minidxdirectaccess = directaccesidx

    for ext in loadsafter:

        try:

            minidxdirectaccess = max(minidxdirectaccess, order.index(ext))

        except ValueError:

            pass # extension not loaded

    if minidxdirectaccess > directaccesidx:

        order.insert(minidxdirectaccess + 1, 'directaccess')

        order.remove('directaccess')

        extensions._order = order

def _repository(orig, *args, **kwargs):

    """Make visible-directaccess-warn the default filter for new repos"""

    repo = orig(*args, **kwargs)

    return repo.filtered("visible-directaccess-warn")

def extsetup(ui):

    extensions.wrapfunction(revset, 'posttreebuilthook', _posttreebuilthook)

    extensions.wrapfunction(hg, 'repository', _repository)

    setupdirectaccess()

hashre = util.re.compile('[0-9a-fA-F]{1,40}')

_listtuple = ('symbol', '_list')

def gethashsymbols(tree, maxrev):

    # Returns the list of symbols of the tree that look like hashes

    # for example for the revset 3::abe3ff it will return ('abe3ff')

    if not tree:

        return []

    if len(tree) == 2 and tree[0] == "symbol":

        try:

            n = int(tree[1])

            # This isn't necessarily a rev number, could be a hash prefix

            if n > maxrev:

                return [tree[1]]

            else:

                return []

        except ValueError as e:

            if hashre.match(tree[1]):

                return [tree[1]]

            return []

    elif tree[0] == "func" and tree[1] == _listtuple:

        # the optimiser will group sequence of hash request

        result = []

        for entry in tree[2][1].split('\0'):

            if hashre.match(entry):

                result.append(entry)

        return result

    elif len(tree) >= 3:

        results = []

        for subtree in tree[1:]:

            results += gethashsymbols(subtree, maxrev)

        return results

    else:

        return []

def _posttreebuilthook(orig, tree, repo):

    # This is use to enabled direct hash access

    # We extract the symbols that look like hashes and add them to the

    # explicitaccess set

    orig(tree, repo)

    filternm = ""

    if repo is not None:

        filternm = repo.filtername

    if filternm is not None and filternm.startswith('visible-directaccess'):

        prelength = len(repo._explicitaccess)

        accessbefore = set(repo._explicitaccess)

        cl = repo.unfiltered().changelog

        repo.symbols = gethashsymbols(tree, len(cl))

        for node in repo.symbols:

            try:

                node = cl._partialmatch(node)

            except error.LookupError:

                node = None

            if node is not None:

                rev = cl.rev(node)

                if rev not in repo.changelog:

                    repo._explicitaccess.add(rev)

        if prelength != len(repo._explicitaccess):

            if repo.filtername != 'visible-directaccess-nowarn':

                unhiddencommits = repo._explicitaccess - accessbefore

                repo.ui.warn( _("Warning: accessing hidden changesets %s " 

                                "for write operation\n") % 

                                (",".join([str(repo.unfiltered()[l]) 

                                    for l in unhiddencommits])))

            repo.invalidatevolatilesets()