"""
Tenant-aware middleware for multi-tenancy
"""

from django.http import HttpResponseRedirect
from django.urls import reverse
from django.utils.deprecation import MiddlewareMixin


class TenantMiddleware(MiddlewareMixin):
    """
    Middleware that sets the current hospital context from the authenticated user.

    This middleware ensures that:
    - authenticated users have their tenant_hospital set from their profile
    - PX admins can switch between hospitals via session
    - PX admins without a selected hospital are redirected to select-hospital
    - Source Users have their source context available
    - All requests have tenant context available
    """

    EXEMPT_PATHS = [
        "/core/select-hospital/",
        "/accounts/logout/",
        "/accounts/password_reset/",
        "/accounts/password_reset/done/",
        "/accounts/reset/",
        "/api/",
        "/health/",
        "/admin/",
        "/__debug__/",
    ]

    def process_request(self, request):
        """Set tenant hospital context on each request."""
        if request.user and request.user.is_authenticated:
            request.user_roles = request.user.get_role_names()

            request.source_user = None
            request.source_user_profile = None
            if request.user.is_source_user():
                profile = request.user.get_source_user_profile_active()
                if profile:
                    request.source_user = profile
                    request.source_user_profile = profile

            if request.user.is_px_admin():
                hospital_id = request.session.get("selected_hospital_id")
                if hospital_id:
                    from apps.organizations.models import Hospital

                    try:
                        request.tenant_hospital = Hospital.objects.get(id=hospital_id)
                    except Hospital.DoesNotExist:
                        request.tenant_hospital = None
                        request.session.pop("selected_hospital_id", None)
                else:
                    request.tenant_hospital = None
            else:
                request.tenant_hospital = request.user.hospital
        else:
            request.tenant_hospital = None
            request.user_roles = []
            request.source_user = None
            request.source_user_profile = None

        return None

    def process_view(self, request, view_func, view_args, view_kwargs):
        """Redirect PX admins without hospital to select-hospital page."""
        if not request.user or not request.user.is_authenticated:
            return None

        if not request.user.is_px_admin():
            return None

        if request.tenant_hospital:
            return None

        path = request.path
        for exempt_path in self.EXEMPT_PATHS:
            if path.startswith(exempt_path):
                return None

        if request.headers.get("x-requested-with") == "XMLHttpRequest":
            return None

        return HttpResponseRedirect(reverse("core:select_hospital"))