def inject(assembler, chain_definition, chain_items):
    if not chain_items:
        return

    ksampler_name = chain_definition.get('ksampler_node', 'ksampler')
    if ksampler_name not in assembler.node_map:
        print(f"Warning: Target node '{ksampler_name}' for ControlNet chain not found. Skipping chain injection.")
        return
        
    ksampler_id = assembler.node_map[ksampler_name]

    if 'positive' not in assembler.workflow[ksampler_id]['inputs'] or \
       'negative' not in assembler.workflow[ksampler_id]['inputs']:
        print(f"Warning: KSampler node '{ksampler_name}' is missing 'positive' or 'negative' inputs. Skipping ControlNet chain.")
        return
        
    current_positive_connection = assembler.workflow[ksampler_id]['inputs']['positive']
    current_negative_connection = assembler.workflow[ksampler_id]['inputs']['negative']
    
    for item_data in chain_items:
        cn_loader_id = assembler._get_unique_id()
        cn_loader_node = assembler._get_node_template("ControlNetLoader")
        cn_loader_node['inputs']['control_net_name'] = item_data['control_net_name']
        assembler.workflow[cn_loader_id] = cn_loader_node

        image_loader_id = assembler._get_unique_id()
        image_loader_node = assembler._get_node_template("LoadImage")
        image_loader_node['inputs']['image'] = item_data['image']
        assembler.workflow[image_loader_id] = image_loader_node

        apply_cn_id = assembler._get_unique_id()
        apply_cn_node = assembler._get_node_template(chain_definition['template'])
        
        apply_cn_node['inputs']['strength'] = item_data['strength']
        
        apply_cn_node['inputs']['positive'] = current_positive_connection
        apply_cn_node['inputs']['negative'] = current_negative_connection
        apply_cn_node['inputs']['control_net'] = [cn_loader_id, 0]
        apply_cn_node['inputs']['image'] = [image_loader_id, 0]
        
        assembler.workflow[apply_cn_id] = apply_cn_node

        current_positive_connection = [apply_cn_id, 0]
        current_negative_connection = [apply_cn_id, 1]

    assembler.workflow[ksampler_id]['inputs']['positive'] = current_positive_connection
    assembler.workflow[ksampler_id]['inputs']['negative'] = current_negative_connection
    
    print(f"ControlNet injector applied. KSampler inputs redirected through {len(chain_items)} ControlNet nodes.")