package com.monitorjbl.json;

public class JsonResult {
	private static final JsonResult instance = new JsonResult();
	private static final ThreadLocal<JsonView> current = new ThreadLocal<>();

	private JsonResult() {
	}

	/**
	 * Use the provided {@code JsonView} object to serialize the return value.
	 *
	 * @param view
	 *            JsonView used to render JSON
	 * @param <E>
	 *            Type of object being rendered
	 * @return ResultWrapper to provide return value
	 */
	@SuppressWarnings("unchecked")
	public <E> ResultWrapper<E> use(JsonView<E> view) {
		current.set(view);
		return new ResultWrapper<>(view);
	}

	public static JsonResult instance() {
		return instance;
	}

	static JsonView get() {
		return current.get();
	}

	static void unset() {
		current.remove();
	}

	public static class ResultWrapper<T> {
		private JsonView<T> obj;

		private ResultWrapper(JsonView<T> obj) {
			this.obj = obj;
		}

		/**
		 * Returns the object being serialized
		 *
		 * @return the object
		 */
		public T returnValue() {
			return obj.getValue();
		}
	}
}