from django.contrib import admin
from django.contrib.contenttypes.admin import GenericTabularInline
from django.contrib.contenttypes.models import ContentType
from django.db.models import Q
from django.core.urlresolvers import reverse

from services.models import ServiceType
from .models import Payment


class PaymentMixin:
    def get_fields(self, request, obj=None):
        fields = ('amount', 'period', 'payment_method', 'date',)
        if request.user.has_perm('banking.validate_payment'):
            fields += ('validated',)
        return fields

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        if request.user.has_perm('banking.validate_payment'):
            return qs
        # Show only adherent contribution and payment related to a service for which the user is in managment group.
        user_ctype = ContentType.objects.get(app_label='adhesions', model='adherent')
        return qs.filter(Q(reason_type=user_ctype) | Q(service__service_type__group__in=request.user.groups.all()))


class PaymentInline(PaymentMixin, GenericTabularInline):
    model = Payment
    ct_field = 'reason_type'
    ct_fk_field = 'reason_id'
    extra = 1


class ValidatedPaymentInline(PaymentInline):
    extra = 0
    verbose_name_plural = 'Paiements validés'

    def get_readonly_fields(self, request, obj=None):
        if request.user.has_perm('banking.validate_payment'):
            return ()
        else:
            return self.get_fields(request, obj)

    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return request.user.has_perm('banking.validate_payment')

    def get_queryset(self, request):
        return super().get_queryset(request).filter(validated=True)


class PendingOrNewPaymentInline(PaymentInline):
    verbose_name_plural = 'Paiements en attente de validation et nouveaux paiements'

    def get_queryset(self, request):
        return super().get_queryset(request).filter(validated=False)


class PaymentTypeFilter(admin.SimpleListFilter):
    title = 'type de paiement'
    parameter_name = 'type'

    def lookups(self, request, model_admin):
        choices = [
            ('membership', 'Cotisation'),
            ('service', 'Service'),
        ]
        service_types = ServiceType.objects.all()
        if not (request.user.is_superuser or request.user.has_perm('banking.validate_payment')):
            service_types = service_types.filter(group__in=request.user.groups.all())
        for stype in service_types:
            choices.append((stype.pk, 'Service (%s)' % stype.name))
        return choices

    def queryset(self, request, queryset):
        if self.value() == 'membership':
            return queryset.filter(reason_type__app_label='adhesions',
                                   reason_type__model='adherent')
        if self.value() == 'service':
            return queryset.filter(reason_type__app_label='services',
                                   reason_type__model='service')
        try:
            service_type = ServiceType.objects.get(pk=int(self.value()))
        except (ValueError, TypeError, ServiceType.DoesNotExist,):
            return queryset
        else:
            return queryset.filter(service__service_type=service_type)


def validate_payment(payment, request, queryset):
    queryset.update(validated=True)


class PaymentAdmin(PaymentMixin, admin.ModelAdmin):
    list_display_links = None
    list_filter = (PaymentTypeFilter, 'payment_method', 'validated',)

    def get_list_display(self, request):
        list_display = ()
        if request.user.has_perm('auth.change_user'):
            list_display += ('adherent_link',)
        else:
            list_display += ('get_adherent',)
        list_display += ('payment_type_verbose', 'amount',
                        'period', 'payment_method', 'validated',)
        if request.user.has_perm('banking.validate_payment'):
            list_display += ('change',)
        else:
            list_display += ('change_pending',)
        return list_display

    def adherent_link(self, obj):
        adherent = obj.get_adherent()
        url = reverse('admin:adhesions_adherent_change', args=[adherent.pk])
        return '<a href="%s">%s</a>' % (url, adherent)
    adherent_link.short_description = 'Adhérent'
    adherent_link.allow_tags = True

    def change(self, obj):
        url = reverse('admin:banking_payment_change', args=[obj.pk])
        return '<a href="%s" class="changelink">Modifier</a>' % url
    change.short_description = ''
    change.allow_tags = True

    def change_pending(self, obj):
        if obj.validated:
            return '-'
        else:
            return self.change(obj)
    change_pending.short_description = ''
    change_pending.allow_tags = True

    def get_actions(self, request):
        actions = super().get_actions(request)
        if request.user.has_perm('banking.validate_payment'):
            actions['validate'] = (validate_payment, 'validate', 'Valider les paiements sélectionnés')
        return actions

    def has_add_permission(self, request):
        return False

    def has_change_permission(self, request, obj=None):
        if obj and not request.user.has_perm('banking.validate_payment'):
            return not obj.validated
        return True

    def has_delete_permission(self, request, obj=None):
        if obj and not request.user.has_perm('banking.validate_payment'):
            return not obj.validated
        return False


admin.site.register(Payment, PaymentAdmin)