Fix billing records RLS

Author: lovable-dev[bot]

supabase/migrations/20250905163600_8f8c4e57-c744-4010-9c9b-b71392d1ded9.sql

@@ -0,0 +1,79 @@
+-- Drop the overly broad existing policy
+DROP POLICY IF EXISTS "Users can view their billing records" ON public.billing_records;
+
+-- Create more granular and secure RLS policies for billing_records
+CREATE POLICY "Users can view their own billing records"
+ON public.billing_records
+FOR SELECT
+TO authenticated
+USING (auth.uid() = user_id);
+
+-- System can create billing records (for automated processing)
+CREATE POLICY "System can create billing records"
+ON public.billing_records
+FOR INSERT
+TO authenticated
+WITH CHECK (auth.uid() = user_id);
+
+-- Only allow updates to specific non-sensitive fields and only by record owner
+CREATE POLICY "Users can update limited billing record fields"
+ON public.billing_records
+FOR UPDATE
+TO authenticated
+USING (auth.uid() = user_id)
+WITH CHECK (
+  auth.uid() = user_id AND
+  -- Prevent modification of critical financial data
+  OLD.total_revenue = NEW.total_revenue AND
+  OLD.commission_amount = NEW.commission_amount AND
+  OLD.fee_amount = NEW.fee_amount AND
+  OLD.stripe_charge_id = NEW.stripe_charge_id AND
+  OLD.campaign_id = NEW.campaign_id AND
+  OLD.created_at = NEW.created_at
+);
+
+-- No deletion of billing records for audit trail integrity
+CREATE POLICY "Billing records cannot be deleted"
+ON public.billing_records
+FOR DELETE
+TO authenticated
+USING (false);
+
+-- Create security audit function for billing record access
+CREATE OR REPLACE FUNCTION public.log_billing_access(record_id uuid, access_type text)
+RETURNS void
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path = public
+AS $$
+BEGIN
+  -- Log financial data access for security monitoring
+  PERFORM public.log_security_event(
+    'billing_record_access', 
+    auth.uid(), 
+    jsonb_build_object(
+      'record_id', record_id,
+      'access_type', access_type,
+      'timestamp', now()
+    )
+  );
+END;
+$$;
+
+-- Create function to validate billing record ownership before sensitive operations
+CREATE OR REPLACE FUNCTION public.validate_billing_record_ownership(record_id uuid)
+RETURNS boolean
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path = public
+AS $$
+DECLARE
+  record_owner uuid;
+BEGIN
+  SELECT user_id INTO record_owner 
+  FROM billing_records 
+  WHERE id = record_id;
+  
+  RETURN (record_owner = auth.uid());
+END;
+$$;