from django.core.files import File
from django.utils import timezone
from shop.pdf import generate_pdf_letter
from shop.email import send_invoice_email, send_creditnote_email
from shop.models import Order, CustomOrder, Invoice, CreditNote
from decimal import Decimal
import logging, importlib
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger('bornhack.%s' % __name__)


def do_work():
    """
        The invoice worker creates Invoice objects for shop orders and
        for custom orders. It also generates PDF files for Invoice objects
        that have no PDF. It also emails invoices for shop orders.
    """

    ###############################################################
    # check if we need to generate any invoices for shop orders
    for order in Order.objects.filter(paid=True, invoice__isnull=True):
        # generate invoice for this Order
        Invoice.objects.create(order=order)
        logger.info('Generated Invoice object for %s' % order)


    ###############################################################
    # check if we need to generate any invoices for custom orders
    for customorder in CustomOrder.objects.filter(invoice__isnull=True):
        # generate invoice for this CustomOrder
        Invoice.objects.create(customorder=customorder)
        logger.info('Generated Invoice object for %s' % customorder)


    ###############################################################
    # check if we need to generate any pdf invoices
    for invoice in Invoice.objects.filter(pdf=''):
        # generate the pdf
        try:
            if invoice.customorder:
                template='pdf/custominvoice.html'
            else:
                template='pdf/invoice.html'
            pdffile = generate_pdf_letter(
                filename=invoice.filename,
                template=template,
                formatdict={
                    'invoice': invoice,
                },
            )
            logger.info('Generated pdf for invoice %s' % invoice)
        except Exception as E:
            logger.exception('Unable to generate PDF file for invoice #%s. Error: %s' % (invoice.pk, E))
            continue

        # update invoice object with the file
        invoice.pdf.save(invoice.filename, File(pdffile))
        invoice.save()


    ###############################################################
    # check if we need to send out any invoices (only for shop orders, and only where pdf has been generated)
    for invoice in Invoice.objects.filter(order__isnull=False, sent_to_customer=False).exclude(pdf=''):
        logger.info("found unmailed Invoice object: %s" % invoice)
        # send the email
        if send_invoice_email(invoice=invoice):
            invoice.sent_to_customer=True
            invoice.save()
            logger.info('OK: Invoice email sent to %s' % invoice.order.user.email)
        else:
            logger.error('Unable to send invoice email for order %s to %s' % (invoice.order.pk, invoice.order.user.email))


    ###############################################################
    # check if we need to generate any pdf creditnotes?
    for creditnote in CreditNote.objects.filter(pdf=''):
        # generate the pdf
        try:
            pdffile = generate_pdf_letter(
                filename=creditnote.filename,
                template='pdf/creditnote.html',
                formatdict={
                    'creditnote': creditnote,
                },
            )
            logger.info('Generated pdf for creditnote %s' % creditnote)
        except Exception as E:
            logger.exception('Unable to generate PDF file for creditnote #%s. Error: %s' % (creditnote.pk, E))
            continue

        # update creditnote object with the file
        creditnote.pdf.save(creditnote.filename, File(pdffile))
        creditnote.save()


    ###############################################################
    # check if we need to send out any creditnotes (only where pdf has been generated)
    for creditnote in CreditNote.objects.filter(sent_to_customer=False).exclude(pdf=''):
        # send the email
        if send_creditnote_email(creditnote=creditnote):
            logger.info('OK: Creditnote email sent to %s' % creditnote.user.email)
            creditnote.sent_to_customer=True
            creditnote.save()
        else:
            logger.error('Unable to send creditnote email for creditnote %s to %s' % (creditnote.pk, creditnote.user.email))