"""
Tenant middleware for multi-tenancy support.
"""

from django.http import Http404
from django.shortcuts import get_object_or_404
from .models import Tenant


class TenantMiddleware:
    """
    Middleware to handle tenant resolution and context.
    """
    
    def __init__(self, get_response):
        self.get_response = get_response
    
    def __call__(self, request):
        # Skip tenant resolution for admin and API endpoints
        if request.path.startswith('/admin/') or request.path.startswith('/api/'):
            response = self.get_response(request)
            return response
        
        # Get tenant from subdomain or header
        tenant = self.get_tenant(request)
        
        if tenant:
            request.tenant = tenant
        else:
            # For development, use the first available tenant
            try:
                request.tenant = Tenant.objects.filter(is_active=True).first()
            except Tenant.DoesNotExist:
                request.tenant = None
        
        response = self.get_response(request)
        return response
    
    def get_tenant(self, request):
        """
        Resolve tenant from request.
        """
        # Try to get tenant from subdomain
        host = request.get_host()
        if '.' in host:
            subdomain = host.split('.')[0]
            try:
                return Tenant.objects.get(
                    name__iexact=subdomain,
                    is_active=True
                )
            except Tenant.DoesNotExist:
                pass
        
        # Try to get tenant from header (for API calls)
        tenant_id = request.headers.get('X-Tenant-ID')
        if tenant_id:
            try:
                return Tenant.objects.get(
                    tenant_id=tenant_id,
                    is_active=True
                )
            except Tenant.DoesNotExist:
                pass
        
        return None