from django.urls import re_path
from django.contrib.auth.decorators import permission_required
from rest_framework import routers, viewsets
from rest_framework.decorators import api_view, permission_classes
from rest_framework.response import Response
from rest_framework.permissions import IsAuthenticated

from inventory.models import Event, Container, Item
from inventory.serializers import EventSerializer, ContainerSerializer, ItemSerializer, SearchResultSerializer

from base64 import b64decode


class EventViewSet(viewsets.ModelViewSet):
    serializer_class = EventSerializer
    queryset = Event.objects.all()
    permission_classes = []


class ContainerViewSet(viewsets.ModelViewSet):
    serializer_class = ContainerSerializer
    queryset = Container.objects.all()


def filter_items(items, query):
    query_tokens = query.split(' ')
    for item in items:
        value = 0
        for token in query_tokens:
            if token in item.description:
                value += 1
        if value > 0:
            yield {'search_score': value, 'item': item}


@api_view(['GET'])
@permission_classes([IsAuthenticated])
def search_items(request, event_slug, query):
    try:
        event = Event.objects.get(slug=event_slug)
        if not request.user.has_event_perm(event, 'view_item'):
            return Response(status=403)
        items = filter_items(Item.objects.filter(event=event), b64decode(query).decode('utf-8'))
        return Response(SearchResultSerializer(items, many=True).data)
    except Event.DoesNotExist:
        return Response(status=404)


@api_view(['GET', 'POST'])
@permission_classes([IsAuthenticated])
def item(request, event_slug):
    try:
        event = None
        if event_slug != 'none':
            event = Event.objects.get(slug=event_slug)
        if request.method == 'GET':
            if not request.user.has_event_perm(event, 'view_item'):
                return Response(status=403)
            return Response(ItemSerializer(Item.objects.filter(event=event), many=True).data)
        elif request.method == 'POST':
            if not request.user.has_event_perm(event, 'add_item'):
                return Response(status=403)
            validated_data = ItemSerializer(data=request.data)
            if validated_data.is_valid():
                validated_data.save(event=event)
                return Response(validated_data.data, status=201)
            return Response(status=400)
    except Event.DoesNotExist:
        return Response(status=404)
    except KeyError:
        return Response(status=400)


@api_view(['GET', 'PUT', 'DELETE', 'PATCH'])
@permission_classes([IsAuthenticated])
def item_by_id(request, event_slug, id):
    try:
        event = Event.objects.get(slug=event_slug)
        item = Item.objects.get(event=event, id=id)
        if request.method == 'GET':
            if not request.user.has_event_perm(event, 'view_item'):
                return Response(status=403)
            return Response(ItemSerializer(item).data)
        elif request.method == 'PUT':
            if not request.user.has_event_perm(event, 'change_item'):
                return Response(status=403)
            validated_data = ItemSerializer(item, data=request.data)
            if validated_data.is_valid():
                validated_data.save()
                return Response(validated_data.data)
            return Response(validated_data.errors, status=400)
        elif request.method == 'PATCH':
            if not request.user.has_event_perm(event, 'change_item'):
                return Response(status=403)
            validated_data = ItemSerializer(item, data=request.data, partial=True)
            if validated_data.is_valid():
                validated_data.save()
                return Response(validated_data.data)
            return Response(validated_data.errors, status=400)
        elif request.method == 'DELETE':
            if not request.user.has_event_perm(event, 'delete_item'):
                return Response(status=403)
            item.delete()
            return Response(status=204)
    except Item.DoesNotExist:
        return Response(status=404)
    except Event.DoesNotExist:
        return Response(status=404)


router = routers.SimpleRouter()
router.register(r'events', EventViewSet, basename='events')
router.register(r'boxes', ContainerViewSet, basename='boxes')
router.register(r'box', ContainerViewSet, basename='boxes')

urlpatterns = router.urls + [
    # path('<event_slug>/items/', item),
    # path('<event_slug>/items/<query>/', search_items),
    # path('<event_slug>/item/', item),
    # path('<event_slug>/item/<id>/', item_by_id),
    re_path(r'^(?P<event_slug>[\w-]+)/items/$', item, name='item'),
    re_path(r'^(?P<event_slug>[\w-]+)/items/(?P<query>[-A-Za-z0-9+/]*={0,3})/$', search_items, name='search_items'),
    re_path(r'^(?P<event_slug>[\w-]+)/item/$', item, name='item'),
    re_path(r'^(?P<event_slug>[\w-]+)/item/(?P<id>\d+)/$', item_by_id, name='item_by_id'),
]