"""
Place this file at the root of scurri and then from the console you can:
from get_labels_for_upis import get_pdfs

get_pdfs('optional_output_path')

The UPIs must be an array:
['UPI000001',
 'UPI000002',
...
 'UPIXXXXXX'
]

TOTAL_UPIS must have the number of expected UPIs as a check that the data
is right

At the end a file with a PDF will be created at the specified output path.
Defaults to /tmp
"""
from __future__ import absolute_import, division, unicode_literals

from datetime import date
import logging
import sys

from django.template import Context
from django.utils import timezone

from sculib.pdf.merge import merge_pdfs
from scurri.carriers.labels import MultiDocumentLabel
from scurri.core.text import wrap_text
from scurri.postmanifest import models

logger = logging.getLogger(__name__)

UPIS = []
TOTAL_UPIS = 0


class ParcelNotFound(Exception):  # Used internally
    pass


def _find_parcels_by_upi(upi, carrier=None, user=None):
    for Parcel in models.PARCEL_MODELS.itervalues():
        qs = Parcel.objects
        if carrier:
            qs = qs.filter(consignment__carrier=carrier)
        elif user:
            qs = qs.filter(consignment__carrier__members=user)

        parcels = (
            qs.filter(consignment__consignment_number=upi).select_related(
                'consignment',
                'consignment__carrier',
                'consignment__recipient'))

        for parcel in parcels:
            yield parcel


def _make_label(parcels):
    context = _get_context(parcels)

    label = MultiDocumentLabel(
        template='postmanifest/labels/fastway.html', context=context)
    return label


def _get_context(parcels):

    try:
        # We might have >1 parcels with same barcode
        # In this case, we need to warn the user
        parcel = parcels[0]

    except IndexError:
        raise ParcelNotFound()

    consignment = parcel.consignment
    recipient = consignment.recipient
    retailer = consignment.retailer

    if parcel.state.diverted:
        carrier_name = 'ParcelConnect'
    else:
        # todo: include service name?
        carrier_name = 'Fastway'

    now = timezone.now()
    edd = _get_expected_delivery_date(parcel, now=now)
    return Context({
        'carrier_name': carrier_name,

        # 'comments': ['No Comments', 'to display'],
        'consignment_number': consignment.order_number,

        # FIXME: return correct data in the datamatrix
        # FIXME: Use 4W1C barcode + length specifier to allow newlines
        'datamatrix_data': _format_datamatrix(parcel),

        # Fixme: each row should be 30 char. max length
        'delivery_address': _format_address(recipient),
        'delivery_country': recipient.country,

        'delivery_mobile_phone': recipient.mobile,
        'delivery_phone_number': recipient.phone,
        # 'delivery_state': 'STATE',  # TODO: what needs to go here?
        'delivery_date': now,
        'expected_delivery_date': edd,
        'recipient_name': recipient.name,
        # 'service_name': 'SERVICE',  # TODO: how to get this? do we need it?  # noqa
        'tracking_number': parcel.tracking_number,
        'warehouse_address': _format_address(
            retailer, with_country=True),
        'warehouse_phone_number': '',  # TODO: how to get this?
        'weight': parcel.weight,
        'weight_unit': 'kg',

        'item_id': parcel.index,
        'item_total': consignment.parcels.count(),
    })


def _format_address(addr, with_country=False):
    address = ', '.join(filter(None, [
        addr.address1,
        addr.address2,
        addr.address3,
        addr.address4,
        addr.postcode,
        addr.country if with_country else None,
    ]))
    return wrap_text(address, max_line_width=30, number_of_lines=4)


def _get_expected_delivery_date(parcel, now=None):
    from scurri.postmanifest.io.targets.fastway import get_expected_delivery_date  # noqa

    try:
        return get_expected_delivery_date(parcel=parcel, scan_date=now)
    except Exception:
        logger.exception('Failure calculating expected delivery date')
        return None


def _format_datamatrix(parcel):
    # todo: do we want pipes as a separator, or we just need to use
    #       a different DPL code to support newlines?
    recipient = parcel.consignment.recipient
    return ' | '.join((
        recipient.name or '',
        '',  # intentionally left blank - Building Name should go here
        recipient.address1 or '',
        recipient.address2 or '',
        recipient.address3 or '',
        recipient.address4 or '',
        recipient.postcode or '',
        recipient.phone or '',
        '',
        recipient.name or '',
    ))


def _make_pdf(parcels):
    label = _make_label(parcels)
    return label


def get_pdfs(output_path='/tmp'):
    if TOTAL_UPIS <= 0:
        raise Exception('Amend the UPIS and TOTAL_UPIS, please')

    carrier = models.Carrier.objects.get(name='Fastway')
    pdfs = []

    assert len(UPIS) == TOTAL_UPIS  # Check that numbers are valid

    for upi in UPIS:
        parcels = list(_find_parcels_by_upi(upi, carrier=carrier))
        pdfs.append(_make_pdf(parcels))

    total_pdfs = len(pdfs)
    output_filename = '/'.join([output_path,
                                date.today().isoformat() + '-' + 'labels.pdf'])

    sys.stdout.write('{} labels generated and stored in {}'.format(
        total_pdfs, output_filename))

    pdfs = merge_pdfs(pdfs)

    with open(output_filename, b'wb') as f:
        f.writelines(pdfs.getvalue())