from collections import namedtuple

import debug                            # pyflakes:ignore

from ietf.doc.models import Document, STATUSCHANGE_RELATIONS
from ietf.doc.utils_search import fill_in_telechat_date
from ietf.iesg.agenda import get_doc_section


TelechatPageCount = namedtuple('TelechatPageCount',['for_approval','for_action','related','ad_pages_left_to_ballot_on'])

def telechat_page_count(date=None, docs=None, ad=None):
    if not date and not docs:
        return TelechatPageCount(0, 0, 0, 0)

    if not docs:
        candidates = Document.objects.filter(docevent__telechatdocevent__telechat_date=date).distinct() 
        fill_in_telechat_date(candidates)
        docs = [ doc for doc in candidates if doc.telechat_date()==date ]

    for_action =[d for d in docs if get_doc_section(d).endswith('.3')]

    for_approval = set(docs)-set(for_action)

    drafts = [d for d in for_approval if d.type_id == 'draft']

    ad_pages_left_to_ballot_on = 0
    pages_for_approval = 0
    
    for draft in drafts:
        pages_for_approval += draft.pages or 0
        if ad:
            ballot = draft.active_ballot()
            if ballot:
                positions = ballot.active_balloter_positions()
                ad_position = positions[ad]
                if ad_position is None or ad_position.pos_id == "norecord":
                    ad_pages_left_to_ballot_on += draft.pages or 0

    pages_for_action = 0
    for d in for_action:
        if d.type_id == 'draft':
            pages_for_action += d.pages or 0
        elif d.type_id == 'statchg':
            for rel in d.related_that_doc(STATUSCHANGE_RELATIONS):
                pages_for_action += rel.pages or 0
        elif d.type_id == 'conflrev':
            for rel in d.related_that_doc('conflrev'):
                pages_for_action += rel.pages or 0
        else:
            pass

    related_pages = 0
    for d in for_approval-set(drafts):
        if d.type_id == 'statchg':
            for rel in d.related_that_doc(STATUSCHANGE_RELATIONS):
                related_pages += rel.pages or 0
        elif d.type_id == 'conflrev':
            for rel in d.related_that_doc('conflrev'):
                related_pages += rel.pages or 0
        else:
            # There's really nothing to rely on to give a reading load estimate for charters
            pass
    
    return TelechatPageCount(for_approval=pages_for_approval,
                             for_action=pages_for_action,
                             related=related_pages,
                             ad_pages_left_to_ballot_on=ad_pages_left_to_ballot_on)