# $Hg: pretxnkw.py,v$

from mercurial.i18n import gettext as _
from mercurial.demandload import demandload
demandload(globals(), 'hgkw:kwutil mercurial:util os.path re')

kwencodefilter = 'hgkwencode'

def pretxnkw(ui=None, repo=None, hooktype='', **args):
    '''Important: returns False on success, True on failure.'''

    node = args['node'][0:12]

    if not ui or not repo or not node or hooktype != 'pretxncommit':
        # bail out with error
        return True

    modified, added = repo.status()[1:3]
    candidates = modified + added

    files = []
    for pat, cmd in repo.ui.configitems('encode'):
        if cmd.endswith(kwencodefilter):
            mf = util.matcher(repo.root, '', [pat], [], [])[1]
            for candidate in candidates:
                if mf(candidate):
                    files.append(candidate)

    if not files: # nothing to do
        return False

    re_kw = kwutil.rekw()
    kword = kwutil.mkkw(repo, tip=True, node=node)

    re_kwcheck = re.compile(r'[$]Hg: (.*?),v.*?\$')

    for filename in files:

        data = repo.wopener(filename, 'rb').read()
        bn = os.path.basename(filename)

        # check for keywords with incorrect basename
        # eg. if you forgot to update basename manually after "hg mv"
        failures = [m for m in map(str, re_kwcheck.findall(data)) if m != bn]
        if failures:
            failures = ['%sHg: %s,v$' % ('$', nobn) for nobn in failures]
            ui.warn(_('%d incorrect basenames in file %s:\n'
                '%s\nplease correct to %sHg: %s,v$\n'
                % (len(failures), filename, ', '.join(failures), '$', bn)))
            return True

        # substitute <Dollar>(Hg|Id): <basename>,v.*<Dollar>
        data, kwct = re_kw.subn(kword, data)

        if kwct:
            # backup file and write with expanded keyword
            ui.note(_('expanding keywords in %s\n' % filename))
            util.copyfile(filename, filename+'~')
            repo.wopener(filename, 'wb').write(data)

    return False