import imghdr
from wsgiref.util import FileWrapper

import requests
from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.exceptions import PermissionDenied
from django.http import HttpResponse, StreamingHttpResponse
from django.http.request import HttpRequest
from django.http.response import HttpResponseRedirect
from django.shortcuts import get_object_or_404
from django.shortcuts import render
from django.utils.decorators import method_decorator
from django.views.decorators.cache import cache_control
from django.views.decorators.csrf import ensure_csrf_cookie
from graphene_django.views import GraphQLView
from graphql import get_operation_ast, parse
from sentry_sdk.api import start_transaction
from wagtail.admin.views.pages import listing
from wagtail.images import get_image_model
from wagtail.images.exceptions import InvalidFilterSpecError
from wagtail.images.models import Image
from wagtail.images.models import SourceImageIOError
from wagtail.images.utils import verify_signature
from wagtail.images.views.serve import ServeView

from core.logger import get_logger

logger = get_logger(__name__)


# For sentry perfomance monitoring
# taken from https://jerrynsh.com/how-to-monitor-python-graphql-api-with-sentry/
class SentryGraphQLView(GraphQLView):
    def execute_graphql_request(
        self,
        request: HttpRequest,
        data,
        query,
        variables,
        operation_name,
        show_graphiql,
    ):
        """
        adapted to use the new GraphQL 3.0 syntax, still need to get the operation type,
        but the code to do this changed significantly, so the above link only explains
        the 'what' and 'why', but no longer the 'how'
        """
        document = parse(query)
        operation_type = get_operation_ast(document, operation_name).operation
        with start_transaction(op=str(operation_type), name=operation_name):
            return super().execute_graphql_request(
                request, data, query, variables, operation_name, show_graphiql
            )


class PrivateGraphQLView(LoginRequiredMixin, SentryGraphQLView):
    pass


@ensure_csrf_cookie
def home(request):
    if settings.SERVE_VIA_WEBPACK:
        try:
            res = requests.get(
                "http://localhost:8080{}".format(request.get_full_path())
            )
            headers = res.headers
            content_type = headers.get("content-type", "text/html")
            return HttpResponse(res.text, content_type=content_type)
        except Exception as e:
            print("Can not connect to dev server at http://localhost:8080:", e)

    return render(request, "index.html", {})


def override_wagtailadmin_explore_default_ordering(request, parent_page_id):
    """
    Wrap Wagtail's explore view to change the default ordering
    """
    if request.method == "GET" and "ordering" not in request.GET:
        # Display reordering handles by default for children of all Page types.
        return HttpResponseRedirect(request.path_info + "?ordering=ord")

    return listing.IndexView.as_view()(request, parent_page_id)

class CustomImageServeView(ServeView):
    ''' Taken from wagtail.images.views.serve.ServeView the only change is that we use original for the filter_spec_for_signature'''
    model = get_image_model()
    action = "serve"
    key = None

    @method_decorator(cache_control(max_age=3600, public=True))
    def get(self, request, signature, image_id, filter_spec, filename=None):
        # This variable is the only change to the wagtail implementation
        filter_spec_for_signature = 'original'

        if not verify_signature(
            signature.encode(), image_id, filter_spec_for_signature, key=self.key
        ):
            raise PermissionDenied

        image = get_object_or_404(self.model, id=image_id)

        # Get/generate the rendition
        try:
            rendition = image.get_rendition(filter_spec)
        except SourceImageIOError:
            return HttpResponse(
                "Source image file not found", content_type="text/plain", status=410
            )
        except InvalidFilterSpecError:
            return HttpResponse(
                "Invalid filter spec: " + filter_spec,
                content_type="text/plain",
                status=400,
            )

        return getattr(self, self.action)(rendition)