namespace formgen.ioc
{

	/**
	 */
	type type_field<type_value> = {
		name : string;
		ioc : interface_ioc<type_value>;
		marked : boolean;
	};
	
	
	/**
	 */
	export class class_ioc_group implements interface_ioc<Record<string, any>>
	{

		/**
		 */
		private fields : Array<type_field<any>>;
		

		/**
		 */
		private label : (null | string);
		

		/**
		 */
		private notification : trait_notification<Record<string, any>>;
		
		
		/**
		 */
		public constructor(
			fields : Array<type_field<any>>,
			{
				"label": label = null,
				"handlers": handlers = [],
			}
			:
			{
				label ?: (null | string);
				handlers ?: Array<type_handler<Record<string, any>>>;
			}
			=
			{
			}
		)
		{
			this.fields = fields;
			this.label = label;
			this.notification = new trait_notification(handlers);
		}
		
		
		/**
		 * [implementation]
		 */
		public async setup(
			element_target : Element
		) : Promise<void>
		{
			const element_container : Element = document.createElement("div");
			element_container.classList.add("formgen-ioc");
			element_container.classList.add("formgen-ioc-group");
			// label
			{
				if (this.label === null)
				{
					// do nothing
				}
				else
				{
					const element_label : Element = document.createElement("label");
					element_label.textContent = this.label;
					element_container.appendChild(element_label);
				}
			}
			// fields
			{
				const element_fields : Element = document.createElement("div");
				element_fields.classList.add("formgen-ioc-group-fields");
				for (const field of this.fields)
				{
					const element_field : Element = document.createElement("div");
					element_field.classList.add("formgen-ioc-group-field");
					element_field.classList.toggle("formgen-ioc-group-field-marked", field.marked);
					element_field.setAttribute("rel", field.name);
					await field.ioc.setup(element_field);
					field.ioc.listen(
						async () => {
							const value : Record<string, any> = await this.read();
							await this.notification.notify(value);
						}
					);
					element_fields.appendChild(element_field);
				}
				element_container.appendChild(element_fields);
			}
			element_target.appendChild(element_container);
			return Promise.resolve<void>(undefined);
		}
		
		
		/**
		 * [implementation]
		 */
		public async read(
		) : Promise<Record<string, any>>
		{
			let result : Record<string, any> = {};
			for (const field of this.fields)
			{
				result[field.name] = await field.ioc.read();
			}
			return result;
		}
		
		
		/**
		 * [implementation]
		 */
		public async write(
			value : Record<string, any>
		) : Promise<void>
		{
			for (const field of this.fields)
			{
				await field.ioc.write(value[field.name]);
			}
		}

		
		/**
		 */
		public listen(
			handler : type_handler<Record<string, any>>
		) : void
		{
			this.notification.listen(handler);
		}
		
	}

}