ivatar/ivatar/middleware.py

# -*- coding: utf-8 -*-
"""
Middleware classes
"""

from django.utils.deprecation import MiddlewareMixin
from django.middleware.locale import LocaleMiddleware


class CustomLocaleMiddleware(LocaleMiddleware):
    """
    Middleware that extends LocaleMiddleware to skip Vary header processing for image URLs
    """

    def process_response(self, request, response):
        # Check if this is an image-related URL
        path = request.path
        if any(
            path.startswith(prefix)
            for prefix in ["/avatar/", "/gravatarproxy/", "/blueskyproxy/"]
        ):
            # Delete Vary from header if exists
            if "Vary" in response:
                del response["Vary"]

            # Extract hash from URL path for ETag
            # URLs are like /avatar/{hash}, /gravatarproxy/{hash}, /blueskyproxy/{hash}
            path_parts = path.strip("/").split("/")
            if len(path_parts) >= 2:
                hash_value = path_parts[1]  # Get the hash part
                response["Etag"] = f'"{hash_value}"'
            else:
                # Fallback to content hash if we can't extract from URL
                response["Etag"] = f'"{hash(response.content)}"'

            # Skip the parent's process_response to avoid adding Accept-Language to Vary
            return response

        # For all other URLs, use the parent's behavior
        return super().process_response(request, response)


class MultipleProxyMiddleware(
    MiddlewareMixin
):  # pylint: disable=too-few-public-methods
    """
    Middleware to rewrite proxy headers for deployments
    with multiple proxies
    """

    def process_request(self, request):  # pylint: disable=no-self-use
        """
        Rewrites the proxy headers so that forwarded server is
        used if available.
        """
        if "HTTP_X_FORWARDED_SERVER" in request.META:
            request.META["HTTP_X_FORWARDED_HOST"] = request.META[
                "HTTP_X_FORWARDED_SERVER"
            ]