/*
 * Copyright 2020 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.web;

import org.junit.Test;
import org.springframework.http.HttpHeaders;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.security.core.Authentication;
import org.springframework.security.oauth2.core.AuthorizationGrantType;
import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
import org.springframework.security.oauth2.core.OAuth2ErrorCodes;
import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
import org.springframework.security.oauth2.core.endpoint.PkceParameterNames;
import org.springframework.security.oauth2.server.authorization.authentication.OAuth2ClientAuthenticationToken;

import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.assertj.core.api.Assertions.entry;

/**
 * Tests for {@link ClientSecretBasicAuthenticationConverter}.
 *
 * @author Patryk Kostrzewa
 * @author Joe Grandja
 */
public class ClientSecretBasicAuthenticationConverterTests {
	private ClientSecretBasicAuthenticationConverter converter = new ClientSecretBasicAuthenticationConverter();

	@Test
	public void convertWhenAuthorizationHeaderEmptyThenReturnNull() {
		MockHttpServletRequest request = new MockHttpServletRequest();
		Authentication authentication = this.converter.convert(request);
		assertThat(authentication).isNull();
	}

	@Test
	public void convertWhenAuthorizationHeaderNotBasicThenReturnNull() {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Bearer token");
		Authentication authentication = this.converter.convert(request);
		assertThat(authentication).isNull();
	}

	@Test
	public void convertWhenAuthorizationHeaderBasicWithMissingCredentialsThenThrowOAuth2AuthenticationException() {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Basic ");
		assertThatThrownBy(() -> this.converter.convert(request))
				.isInstanceOf(OAuth2AuthenticationException.class)
				.extracting(ex -> ((OAuth2AuthenticationException) ex).getError())
				.extracting("errorCode")
				.isEqualTo(OAuth2ErrorCodes.INVALID_REQUEST);
	}

	@Test
	public void convertWhenAuthorizationHeaderBasicWithInvalidBase64ThenThrowOAuth2AuthenticationException() {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Basic clientId:secret");
		assertThatThrownBy(() -> this.converter.convert(request))
				.isInstanceOf(OAuth2AuthenticationException.class)
				.extracting(ex -> ((OAuth2AuthenticationException) ex).getError())
				.extracting("errorCode")
				.isEqualTo(OAuth2ErrorCodes.INVALID_REQUEST);
	}

	@Test
	public void convertWhenAuthorizationHeaderBasicWithMissingSecretThenThrowOAuth2AuthenticationException() throws Exception {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Basic " + encodeBasicAuth("clientId", ""));
		assertThatThrownBy(() -> this.converter.convert(request))
				.isInstanceOf(OAuth2AuthenticationException.class)
				.extracting(ex -> ((OAuth2AuthenticationException) ex).getError())
				.extracting("errorCode")
				.isEqualTo(OAuth2ErrorCodes.INVALID_REQUEST);
	}

	@Test
	public void convertWhenAuthorizationHeaderBasicWithValidCredentialsThenReturnClientAuthenticationToken() throws Exception {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Basic " + encodeBasicAuth("clientId", "secret"));
		OAuth2ClientAuthenticationToken authentication = (OAuth2ClientAuthenticationToken) this.converter.convert(request);
		assertThat(authentication.getPrincipal()).isEqualTo("clientId");
		assertThat(authentication.getCredentials()).isEqualTo("secret");
	}

	@Test
	public void convertWhenConfidentialClientWithPkceParametersThenAdditionalParametersIncluded() throws Exception {
		MockHttpServletRequest request = createPkceTokenRequest();
		request.addHeader(HttpHeaders.AUTHORIZATION, "Basic " + encodeBasicAuth("clientId", "secret"));
		OAuth2ClientAuthenticationToken authentication = (OAuth2ClientAuthenticationToken) this.converter.convert(request);
		assertThat(authentication.getPrincipal()).isEqualTo("clientId");
		assertThat(authentication.getCredentials()).isEqualTo("secret");
		assertThat(authentication.getAdditionalParameters())
				.containsOnly(
						entry(OAuth2ParameterNames.GRANT_TYPE, AuthorizationGrantType.AUTHORIZATION_CODE.getValue()),
						entry(OAuth2ParameterNames.CODE, "code"),
						entry(PkceParameterNames.CODE_VERIFIER, "code-verifier-1"));
	}

	private static String encodeBasicAuth(String clientId, String secret) throws Exception {
		clientId = URLEncoder.encode(clientId, StandardCharsets.UTF_8.name());
		secret = URLEncoder.encode(secret, StandardCharsets.UTF_8.name());
		String credentialsString = clientId + ":" + secret;
		byte[] encodedBytes = Base64.getEncoder().encode(credentialsString.getBytes(StandardCharsets.UTF_8));
		return new String(encodedBytes, StandardCharsets.UTF_8);
	}

	private static MockHttpServletRequest createPkceTokenRequest() {
		MockHttpServletRequest request = new MockHttpServletRequest();
		request.addParameter(OAuth2ParameterNames.GRANT_TYPE, AuthorizationGrantType.AUTHORIZATION_CODE.getValue());
		request.addParameter(OAuth2ParameterNames.CODE, "code");
		request.addParameter(PkceParameterNames.CODE_VERIFIER, "code-verifier-1");
		return request;
	}
}