"""
Extension functions to discard all moderated messages in a SourceForge-based
mailman queue.

(Currently there is no way to do this without manually selecting 'discard'
for each and every message.)
"""

import twill, twill.utils
import re

# export:
__all__ = ['discard_all_messages',
           'exit_if_empty'
           ]

def exit_if_empty():
    """
    >> exit_if_empty

    Exit the script currently running, if there are no deferred messages
    on the current page.
    """
    state = twill.get_browser()
    form = state.get_form("1")
    if not form:
        print "No messages; exiting."
        raise SystemExit
    
def discard_all_messages():
    """
    >> discard_all_messages

    Set all buttons to "discard".
    """
    _formvalue_by_regexp_setall("1", "^\d+$", "3")

### utility functions

def _formvalue_by_regexp_setall(formname, fieldname, value):
    state = twill.get_browser()
    
    form = state.get_form(formname)
    if not form:
        print 'no such form', formname
        return

    regexp = re.compile(fieldname)

    matches = [ ctl for ctl in form.controls if regexp.search(str(ctl.name)) ]

    if matches:
        print '-- matches %d' % (len(matches),)

        n = 0
        for control in matches:
            state.clicked(form, control)
            if control.readonly:
                continue

            n += 1
            twill.utils.set_form_control_value(control, value)

        print 'set %d values total' % (n,)