""" 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.i18n import _

cmdtable = {}

command = cmdutil.command(cmdtable)

# List of commands where no warning is shown for direct access

directaccesslevel = [

    # warning or not, extension (None if core), command name

    (False, None, 'update'), 

    (False, None, 'export'),

    (True,  'rebase', 'rebase'),

    (False,  'evolve', 'prune'),

]

def reposetup(ui, repo):

    repo._explicitaccess = set()

def _computehidden(repo):

    hidden = repoview.computehidden(repo)

    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 = wrapwithwarning if warn else wrapwithoutwarning

            extensions.wrapcommand(cmdtable, cmd, wrapper)

        except (error.UnknownCommand, KeyError):

            pass

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

    if repo and repo.filtername == 'visible':

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

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

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

    if repo and repo.filtername == 'visible':

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

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

def extsetup(ui):

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

    setupdirectaccess()

def gethashsymbols(tree):

    # 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:

            int(tree[1])

            return []

        except ValueError as e:

            return [tree[1]]

    elif len(tree) == 3:

        return gethashsymbols(tree[1]) + gethashsymbols(tree[2])

    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)

        repo.symbols = gethashsymbols(tree)

        cl = repo.unfiltered().changelog

        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()