from decimal import Decimal

from django.urls import resolve, reverse
from django.dispatch import receiver
from django.http import HttpRequest
from django.utils.translation import gettext_lazy as _, gettext, get_language
from pretix.base.decimal import round_decimal
from pretix.base.models import Event, Order, TaxRule
from pretix.base.models.orders import OrderFee
from pretix.base.settings import settings_hierarkey
from pretix.base.signals import order_fee_calculation
from pretix.base.templatetags.money import money_filter
from pretix.control.signals import nav_event_settings
from pretix.presale.signals import fee_calculation_for_cart, front_page_top, order_meta_from_request
from pretix.presale.views import get_cart
from pretix.presale.views.cart import cart_session


@receiver(nav_event_settings, dispatch_uid='service_fee_nav_settings')
def navbar_settings(sender, request, **kwargs):
    url = resolve(request.path_info)
    return [{
        'label': _('Service Fee'),
        'url': reverse('plugins:pretix_servicefees:settings', kwargs={
            'event': request.event.slug,
            'organizer': request.organizer.slug,
        }),
        'active': url.namespace == 'plugins:pretix_servicefees' and url.url_name.startswith('settings'),
    }]


def get_fees(event, total, invoice_address, mod='', request=None, positions=[], gift_cards=None):
    if request is not None and not positions:
        positions = get_cart(request)
    positions = [pos for pos in positions if not pos.addon_to_id and pos.price != Decimal('0.00')]

    skip_non_admission = event.settings.get('service_fee_skip_non_admission', as_type=bool)
    if skip_non_admission:
        positions = [pos for pos in positions if pos.item.admission]

    fee_per_ticket = event.settings.get('service_fee_per_ticket' + mod, as_type=Decimal)
    if mod and fee_per_ticket is None:
        fee_per_ticket = event.settings.get('service_fee_per_ticket', as_type=Decimal)

    fee_abs = event.settings.get('service_fee_abs' + mod, as_type=Decimal)
    if mod and fee_abs is None:
        fee_abs = event.settings.get('service_fee_abs', as_type=Decimal)

    fee_percent = event.settings.get('service_fee_percent' + mod, as_type=Decimal)
    if mod and fee_percent is None:
        fee_percent = event.settings.get('service_fee_percent', as_type=Decimal)

    fee_per_ticket = Decimal("0") if fee_per_ticket is None else fee_per_ticket
    fee_abs = Decimal("0") if fee_abs is None else fee_abs
    fee_percent = Decimal("0") if fee_percent is None else fee_percent

    if event.settings.get('service_fee_skip_if_gift_card', as_type=bool):
        gift_cards = gift_cards or []
        if request:
            cs = cart_session(request)
            if cs.get('gift_cards'):
                gift_cards = event.organizer.accepted_gift_cards.filter(pk__in=cs.get('gift_cards'), currency=event.currency)
        summed = 0
        for gc in gift_cards:
            fval = Decimal(gc.value)  # TODO: don't require an extra query
            fval = min(fval, total - summed)
            if fval > 0:
                total -= fval
                summed += fval

    if (fee_per_ticket or fee_abs or fee_percent) and total != Decimal('0.00'):
        fee = round_decimal(fee_abs + total * (fee_percent / 100) + len(positions) * fee_per_ticket, event.currency)
        tax_rule = event.settings.tax_rate_default or TaxRule.zero()
        tax = tax_rule.tax(fee, invoice_address=invoice_address, base_price_is='gross')
        return [OrderFee(
            fee_type=OrderFee.FEE_TYPE_SERVICE,
            internal_type='',
            value=fee,
            tax_rate=tax.rate,
            tax_value=tax.tax,
            tax_rule=tax_rule
        )]
    return []


@receiver(fee_calculation_for_cart, dispatch_uid="service_fee_calc_cart")
def cart_fee(sender: Event, request: HttpRequest, invoice_address, total, **kwargs):
    mod = ''
    try:
        from pretix_resellers.utils import ResellerException, get_reseller_and_user
    except ImportError:
        pass
    else:
        try:
            reseller, user = get_reseller_and_user(request)
            config = reseller.configs.get(organizer_id=sender.organizer_id)
            if config.skip_default_service_fees:
                return []
        except ResellerException:
            pass
        else:
            mod = '_resellers'
    return get_fees(sender, total, invoice_address, mod, request)


@receiver(order_fee_calculation, dispatch_uid="service_fee_calc_order")
def order_fee(sender: Event, positions, invoice_address, total, meta_info, gift_cards, **kwargs):
    mod = ''
    if meta_info.get('servicefees_reseller_id'):
        mod = '_resellers'
        try:
            from pretix_resellers.models import Reseller
        except ImportError:
            pass
        else:
            r = Reseller.objects.get(pk=meta_info.get('servicefees_reseller_id'))
            config = r.configs.get(organizer_id=sender.organizer_id)
            if config.skip_default_service_fees:
                return []

    return get_fees(sender, total, invoice_address, mod, positions=positions, gift_cards=gift_cards)


@receiver(front_page_top, dispatch_uid="service_fee_front_page_top")
def front_page_top_recv(sender: Event, **kwargs):
    fees = []
    fee_per_ticket = sender.settings.get('service_fee_per_ticket', as_type=Decimal)
    if fee_per_ticket:
        fees = fees + ["{} {}".format(money_filter(fee_per_ticket, sender.currency), gettext('per ticket'))]

    fee_abs = sender.settings.get('service_fee_abs', as_type=Decimal)
    if fee_abs:
        fees = fees + ["{} {}".format(money_filter(fee_abs, sender.currency), gettext('per order'))]

    fee_percent = sender.settings.get('service_fee_percent', as_type=Decimal)
    if fee_percent:
        fees = fees + ['{} % {}'.format(fee_percent, gettext('per order'))]

    if fee_per_ticket or fee_abs or fee_percent:
        return '<p>%s</p>' % gettext('A service fee of {} will be added on top of each order.').format(
            ' {} '.format(gettext('plus')).join(fees)
        )


@receiver(order_meta_from_request, dispatch_uid="servicefees_order_meta")
def order_meta_signal(sender: Event, request: HttpRequest, **kwargs):
    meta = {}
    try:
        from pretix_resellers.utils import ResellerException, get_reseller_and_user
    except ImportError:
        pass
    else:
        try:
            reseller, user = get_reseller_and_user(request)
            meta['servicefees_reseller_id'] = reseller.pk
        except ResellerException:
            pass
    return meta