/*
 * Copyright 2020-2023 the original author or authors.
 *
 * 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
 *
 *      https://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 org.springframework.security.oauth2.server.authorization.oidc.web.authentication;

import java.util.Map;

import jakarta.servlet.http.HttpServletRequest;

import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;

/**
 * Utility methods for the OAuth 2.0 Protocol Endpoints.
 *
 * @author Joe Grandja
 * @author Greg Li
 * @since 1.1.4
 */
final class OAuth2EndpointUtils {

	private OAuth2EndpointUtils() {
	}

	static MultiValueMap<String, String> getFormParameters(HttpServletRequest request) {
		Map<String, String[]> parameterMap = request.getParameterMap();
		MultiValueMap<String, String> parameters = new LinkedMultiValueMap<>();
		parameterMap.forEach((key, values) -> {
			String queryString = StringUtils.hasText(request.getQueryString()) ? request.getQueryString() : "";
			// If not query parameter then it's a form parameter
			if (!queryString.contains(key) && values.length > 0) {
				for (String value : values) {
					parameters.add(key, value);
				}
			}
		});
		return parameters;
	}

	static MultiValueMap<String, String> getQueryParameters(HttpServletRequest request) {
		Map<String, String[]> parameterMap = request.getParameterMap();
		MultiValueMap<String, String> parameters = new LinkedMultiValueMap<>();
		parameterMap.forEach((key, values) -> {
			String queryString = StringUtils.hasText(request.getQueryString()) ? request.getQueryString() : "";
			if (queryString.contains(key) && values.length > 0) {
				for (String value : values) {
					parameters.add(key, value);
				}
			}
		});
		return parameters;
	}

}
