from __future__ import absolute_import

from mercurial import (
    commands,
    error,
    exchange,
    extensions,
    node,
    phases,
    util,
)

from mercurial.i18n import _

def enforcesinglehead(repo, tr):
    for name, heads in repo.filtered('visible').branchmap().iteritems():
        if len(heads) > 1:
            hexs = [node.short(n) for n in heads]
            raise error.Abort(_('%d heads on "%s"') % (len(heads), name),
                              hint=(', '.join(hexs)))

def publishbarebranch(repo, tr):
    """Publish changeset without topic"""
    if 'node' not in tr.hookargs: # no new node
        return
    startnode = node.bin(tr.hookargs['node'])
    topublish = repo.revs('not public() and (%n:) - hidden() - topic()', startnode)
    if topublish:
        cl = repo.changelog
        nodes = [cl.node(r) for r in topublish]
        repo._phasecache.advanceboundary(repo, tr, phases.public, nodes)

def wrappush(orig, repo, remote, *args, **kwargs):
    """interpret the --publish flag and pass it to the push operation"""
    newargs = kwargs.copy()
    if kwargs.pop('publish', False):
        opargs = kwargs.get('opargs')
        if opargs is None:
            opargs = {}
        newargs['opargs'] = opargs.copy()
        newargs['opargs']['publish'] = True
    return orig(repo, remote, *args, **newargs)

def extendpushoperation(orig, *args, **kwargs):
    publish = kwargs.pop('publish', False)
    op = orig(*args, **kwargs)
    op.publish = publish
    return op

def wrapphasediscovery(orig, pushop):
    orig(pushop)
    if pushop.publish:
        if not util.safehasattr(pushop, 'remotephases'):
            msg = _('--publish flag only supported from Mercurial 4.4 and higher')
            raise error.Abort(msg)
        if not pushop.remotephases.publishing:
            unfi = pushop.repo.unfiltered()
            droots = pushop.remotephases.draftroots
            revset = '%ln and (not public() or %ln::)'
            future = list(unfi.set(revset, pushop.futureheads, droots))
            pushop.outdatedphases = future

def installpushflag(ui):
    entry = extensions.wrapcommand(commands.table, 'push', wrappush)
    entry[1].append(('', 'publish', False,
                    _('push the changeset as public')))
    extensions.wrapfunction(exchange, 'pushoperation', extendpushoperation)
    extensions.wrapfunction(exchange, '_pushdiscoveryphase', wrapphasediscovery)
    exchange.pushdiscoverymapping['phase'] = exchange._pushdiscoveryphase