from mercurial import (
    cmdutil,
    context,
    error,
)
from mercurial.i18n import _

cmdtable = {}
command = cmdutil.command(cmdtable)

@command('debugcommitmessage', [], _('FORM'))
def debugcommitmessage(ui, repo, *args):
    form = None
    if len(args) > 1:
        raise error.Abort(_('provide at most one form'))
    elif len(args) > 0:
        form = args[0]

    status = repo.status()
    text = ''
    user = None
    date = None
    extra = None

    ctx = context.workingcommitctx(repo, status, text, user, date, extra)

    subs = []
    editform = form or 'commit.normal.normal'
    extramsg = _('Leave message empty to abort commit.')

    forms = [e for e in editform.split('.') if e]
    forms.insert(0, 'changeset')
    while forms:
        tmpl = repo.ui.config('committemplate', '.'.join(forms))
        if tmpl:
            committext = cmdutil.buildcommittemplate(
                    repo, ctx, subs, extramsg, tmpl)
            break
        forms.pop()
    else:
        committext = cmdutil.buildcommittext(repo, ctx, subs, extramsg)

    ui.status(committext)