def auth_paid_promo(thing, user, pay_id, bid):
    """
    promotes a promotion from 'unpaid' to 'unseen'.  
    
    In the case that bid already exists on the current promotion, the
    previous transaction is voided and repalced with the new bid.
    """
    if thing.promote_status == STATUS.finished:
        return
    elif (thing.promote_status > STATUS.unpaid and
          thing.promote_trans_id):
        # void the existing transaction
        authorize.void_transaction(user, thing.promote_trans_id)

    # create a new transaction and update the bid
    trans_id = authorize.auth_transaction(bid, user, pay_id, thing)
    thing.promote_bid = bid
    
    if trans_id is not None:
        # we won't reset to unseen if already approved and the payment went ok
        promotion_log(thing, "updated payment and/or bid: SUCCESS")
        if trans_id < 0:
            promotion_log(thing, "FREEBIE")
        thing.promote_status = max(thing.promote_status, STATUS.unseen)
        thing.promote_trans_id = trans_id
    else:
        # something bad happend.  
        promotion_log(thing, "updated payment and/or bid: FAILED")    
        thing.promore_status = STATUS.unpaid
        thing.promote_trans_id = 0
    PromoteDates.update_bid(thing)
    # commit last to guarantee consistency
    thing._commit()
    emailer.promo_bid(thing)
    return bool(trans_id)

def void_campaign(link, campaign):
    transactions = get_transactions(link, [campaign])
    bid_record = transactions.get(campaign._id)
    if bid_record:
        a = Account._byID(link.author_id)
        authorize.void_transaction(a, bid_record.transaction, campaign._id)
    hooks.get_hook('campaign.void').call(link=link, campaign=campaign)

def void_campaign(link, index, user):
    campaigns = getattr(link, "campaigns", {}).copy()
    if index in campaigns:
        sd, ed, bid, sr, trans_id = campaigns[index]
        transactions = get_transactions(link)
        if transactions.get(index):
            # void the existing transaction
            a = Account._byID(link.author_id)
            authorize.void_transaction(a, trans_id, index)

def void_campaign(link, campaign):
    transactions = get_transactions(link, [campaign])
    bid_record = transactions.get(campaign._id)
    if bid_record:
        a = Account._byID(link.author_id)
        authorize.void_transaction(a, bid_record.transaction, campaign._id)
        campaign.trans_id = NO_TRANSACTION
        campaign._commit()
        text = "voided transaction for %s: (trans_id: %d)" % (campaign, bid_record.transaction)
        PromotionLog.add(link, text)

def delete_promo(thing):
    """
    deleted promotions have to be specially dealt with.  Reject the
    promo and void any associated transactions.
    """
    thing.promoted = False
    thing._deleted = True
    reject_promo(thing, reason = "The promotion was deleted by the user")
    if thing.promote_trans_id > 0:
        user = Account._byID(thing.author_id)
        authorize.void_transaction(user, thing.promote_trans_id)

def void_campaign(link, campaign, reason):
    transactions = get_transactions(link, [campaign])
    bid_record = transactions.get(campaign._id)
    if bid_record:
        a = Account._byID(link.author_id)
        authorize.void_transaction(a, bid_record.transaction, campaign._id)
        campaign.trans_id = NO_TRANSACTION
        campaign._commit()
        text = "voided transaction for %s: (trans_id: %d)" % (campaign, bid_record.transaction)
        PromotionLog.add(link, text)

        if bid_record.transaction > 0:
            # notify the user that the transaction was voided if it was not
            # a freebie
            emailer.void_payment(link, campaign, reason)

def void_campaign(link, campaign_id):
    transactions = get_transactions(link)
    bid_record = transactions.get(campaign_id)
    if bid_record:
        a = Account._byID(link.author_id)
        authorize.void_transaction(a, bid_record.transaction, campaign_id)