/***
 * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * 	http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package br.com.caelum.vraptor.controller;

import java.lang.annotation.Annotation;

import javax.servlet.http.HttpServletRequest;

import br.com.caelum.vraptor.Delete;
import br.com.caelum.vraptor.Get;
import br.com.caelum.vraptor.Head;
import br.com.caelum.vraptor.Options;
import br.com.caelum.vraptor.Patch;
import br.com.caelum.vraptor.Post;
import br.com.caelum.vraptor.Put;
import br.com.caelum.vraptor.Trace;

public enum HttpMethod {
	GET(Get.class), POST(Post.class), PUT(Put.class), DELETE(Delete.class), TRACE(Trace.class), HEAD(Head.class), OPTIONS(Options.class), PATCH(Patch.class);

	private static final String METHOD_PARAMETER = "_method";
	private final Class<? extends Annotation> type;

	HttpMethod(Class<? extends Annotation> type) {
		this.type = type;
	}

	public Class<? extends Annotation> getAnnotation() {
		return type;
	}

	public static HttpMethod of(HttpServletRequest request) {
		String methodName = request.getParameter(METHOD_PARAMETER);
		if (methodName == null) {
			methodName = request.getMethod();
		} else if ("GET".equalsIgnoreCase(request.getMethod())) {
			throw new InvalidInputException("You can't use " + METHOD_PARAMETER +
					" parameter on a GET request. Use POST instead.");
		}
		try {
			return valueOf(methodName.toUpperCase());
		} catch (IllegalArgumentException e) {
			// funny, but we need a better explanation, to support sendError
			throw new IllegalArgumentException("HTTP Method not known: " + methodName, e);
		}
	}
}