from __future__ import annotations

import secrets

from django.contrib.messages import get_messages

from .consent import ConsentService


class ConsentMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        request.consent = ConsentService.get_consent(request)
        return self.get_response(request)


class SecurityHeadersMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    ADMIN_PREFIXES = ("/cms/", "/django-admin/")

    def __call__(self, request):
        nonce = secrets.token_urlsafe(16)
        request.csp_nonce = nonce
        response = self.get_response(request)
        if request.path.startswith(self.ADMIN_PREFIXES):
            return response
        response["Content-Security-Policy"] = (
            f"default-src 'self'; "
            f"script-src 'self' 'nonce-{nonce}' https://challenges.cloudflare.com; "
            "style-src 'self' https://fonts.googleapis.com; "
            "img-src 'self' data: blob:; "
            "font-src 'self' https://fonts.gstatic.com; "
            "connect-src 'self' https://challenges.cloudflare.com; "
            "frame-src https://challenges.cloudflare.com; "
            "object-src 'none'; "
            "base-uri 'self'; "
            "frame-ancestors 'self'"
        )
        response["Permissions-Policy"] = "camera=(), microphone=(), geolocation=()"
        return response


class AdminMessageGuardMiddleware:
    ADMIN_PREFIXES = ("/cms/", "/django-admin/")

    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        # The public site has no legitimate use of Django's shared flash queue.
        # Drain any stale admin messages before frontend rendering can see them.
        if not request.path.startswith(self.ADMIN_PREFIXES):
            storage = get_messages(request)
            list(storage)
            storage._queued_messages = []
            storage._loaded_data = []
            for sub_storage in getattr(storage, "storages", []):
                sub_storage._queued_messages = []
                sub_storage._loaded_data = []
                sub_storage.used = True
            storage.used = True
        return self.get_response(request)