/*
 * Copyright 2002-2022 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.client.web;

import java.lang.reflect.Constructor;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.mock.web.MockHttpServletResponse;
import org.springframework.security.oauth2.client.ClientAuthorizationRequiredException;
import org.springframework.security.oauth2.client.registration.ClientRegistration;
import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
import org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository;
import org.springframework.security.oauth2.client.registration.TestClientRegistrations;
import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationRequest;
import org.springframework.security.web.RedirectStrategy;
import org.springframework.security.web.savedrequest.RequestCache;
import org.springframework.util.ClassUtils;
import org.springframework.web.util.UriComponentsBuilder;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.BDDMockito.given;
import static org.mockito.BDDMockito.willAnswer;
import static org.mockito.BDDMockito.willThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;

/**
 * Tests for {@link OAuth2AuthorizationRequestRedirectFilter}.
 *
 * @author Joe Grandja
 */
public class OAuth2AuthorizationRequestRedirectFilterTests {

	private ClientRegistration registration1;

	private ClientRegistration registration2;

	private ClientRegistrationRepository clientRegistrationRepository;

	private OAuth2AuthorizationRequestRedirectFilter filter;

	private RequestCache requestCache;

	@BeforeEach
	public void setUp() {
		this.registration1 = TestClientRegistrations.clientRegistration().build();
		this.registration2 = TestClientRegistrations.clientRegistration2().build();
		this.clientRegistrationRepository = new InMemoryClientRegistrationRepository(this.registration1,
				this.registration2);
		this.filter = new OAuth2AuthorizationRequestRedirectFilter(this.clientRegistrationRepository);
		this.requestCache = mock(RequestCache.class);
		this.filter.setRequestCache(this.requestCache);
	}

	@Test
	public void constructorWhenClientRegistrationRepositoryIsNullThenThrowIllegalArgumentException() {
		Constructor<OAuth2AuthorizationRequestRedirectFilter> constructor = ClassUtils.getConstructorIfAvailable(
				OAuth2AuthorizationRequestRedirectFilter.class, ClientRegistrationRepository.class);
		assertThatIllegalArgumentException().isThrownBy(() -> constructor.newInstance(null));
	}

	@Test
	public void constructorWhenAuthorizationRequestBaseUriIsNullThenThrowIllegalArgumentException() {
		assertThatIllegalArgumentException().isThrownBy(
				() -> new OAuth2AuthorizationRequestRedirectFilter(this.clientRegistrationRepository, null));
	}

	@Test
	public void constructorWhenAuthorizationRequestResolverIsNullThenThrowIllegalArgumentException() {
		Constructor<OAuth2AuthorizationRequestRedirectFilter> constructor = ClassUtils.getConstructorIfAvailable(
				OAuth2AuthorizationRequestRedirectFilter.class, OAuth2AuthorizationRequestResolver.class);
		assertThatIllegalArgumentException().isThrownBy(() -> constructor.newInstance(null));
	}

	@Test
	public void setAuthorizationRequestRepositoryWhenAuthorizationRequestRepositoryIsNullThenThrowIllegalArgumentException() {
		assertThatIllegalArgumentException().isThrownBy(() -> this.filter.setAuthorizationRequestRepository(null));
	}

	@Test
	public void setAuthorizationRedirectStrategyWhenAuthorizationRedirectStrategyIsNullThenThrowIllegalArgumentException() {
		assertThatIllegalArgumentException().isThrownBy(() -> this.filter.setAuthorizationRedirectStrategy(null));
	}

	@Test
	public void setRequestCacheWhenRequestCacheIsNullThenThrowIllegalArgumentException() {
		assertThatIllegalArgumentException().isThrownBy(() -> this.filter.setRequestCache(null));
	}

	@Test
	public void doFilterWhenNotAuthorizationRequestThenNextFilter() throws Exception {
		String requestUri = "/path";
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		this.filter.doFilter(request, response, filterChain);
		verify(filterChain).doFilter(any(HttpServletRequest.class), any(HttpServletResponse.class));
	}

	@Test
	public void doFilterWhenAuthorizationRequestWithInvalidClientThenStatusInternalServerError() throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration1.getRegistrationId() + "-invalid";
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		this.filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getStatus()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR.value());
		assertThat(response.getErrorMessage()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase());
	}

	@Test
	public void doFilterWhenAuthorizationRequestOAuth2LoginThenRedirectForAuthorization() throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration1.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		this.filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getRedirectedUrl()).matches("https://example.com/login/oauth/authorize\\?"
				+ "response_type=code&client_id=client-id&" + "scope=read:user&state=.{15,}&"
				+ "redirect_uri=http://localhost/login/oauth2/code/registration-id");
	}

	@Test
	public void doFilterWhenAuthorizationRequestOAuth2LoginThenAuthorizationRequestSaved() throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration2.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		AuthorizationRequestRepository<OAuth2AuthorizationRequest> authorizationRequestRepository = mock(
				AuthorizationRequestRepository.class);
		this.filter.setAuthorizationRequestRepository(authorizationRequestRepository);
		this.filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		verify(authorizationRequestRepository).saveAuthorizationRequest(any(OAuth2AuthorizationRequest.class),
				any(HttpServletRequest.class), any(HttpServletResponse.class));
	}

	@Test
	public void doFilterWhenCustomAuthorizationRequestBaseUriThenRedirectForAuthorization() throws Exception {
		String authorizationRequestBaseUri = "/custom/authorization";
		this.filter = new OAuth2AuthorizationRequestRedirectFilter(this.clientRegistrationRepository,
				authorizationRequestBaseUri);
		String requestUri = authorizationRequestBaseUri + "/" + this.registration1.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		this.filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getRedirectedUrl()).matches("https://example.com/login/oauth/authorize\\?"
				+ "response_type=code&client_id=client-id&" + "scope=read:user&state=.{15,}&"
				+ "redirect_uri=http://localhost/login/oauth2/code/registration-id");
	}

	@Test
	public void doFilterWhenNotAuthorizationRequestAndClientAuthorizationRequiredExceptionThrownThenRedirectForAuthorization()
			throws Exception {
		String requestUri = "/path";
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		willThrow(new ClientAuthorizationRequiredException(this.registration1.getRegistrationId())).given(filterChain)
				.doFilter(any(ServletRequest.class), any(ServletResponse.class));
		this.filter.doFilter(request, response, filterChain);
		verify(filterChain).doFilter(any(HttpServletRequest.class), any(HttpServletResponse.class));
		assertThat(response.getRedirectedUrl()).matches("https://example.com/login/oauth/authorize\\?"
				+ "response_type=code&client_id=client-id&" + "scope=read:user&state=.{15,}&"
				+ "redirect_uri=http://localhost/authorize/oauth2/code/registration-id");
		verify(this.requestCache).saveRequest(any(HttpServletRequest.class), any(HttpServletResponse.class));
	}

	@Test
	public void doFilterWhenNotAuthorizationRequestAndClientAuthorizationRequiredExceptionThrownButAuthorizationRequestNotResolvedThenStatusInternalServerError()
			throws Exception {
		String requestUri = "/path";
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		willThrow(new ClientAuthorizationRequiredException(this.registration1.getRegistrationId())).given(filterChain)
				.doFilter(any(ServletRequest.class), any(ServletResponse.class));
		OAuth2AuthorizationRequestResolver resolver = mock(OAuth2AuthorizationRequestResolver.class);
		OAuth2AuthorizationRequestRedirectFilter filter = new OAuth2AuthorizationRequestRedirectFilter(resolver);
		filter.doFilter(request, response, filterChain);
		verify(filterChain).doFilter(any(HttpServletRequest.class), any(HttpServletResponse.class));
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getStatus()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR.value());
		assertThat(response.getErrorMessage()).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase());
	}

	// gh-4911
	@Test
	public void doFilterWhenAuthorizationRequestAndAdditionalParametersProvidedThenAuthorizationRequestIncludesAdditionalParameters()
			throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration1.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		request.addParameter("idp", "https://other.provider.com");
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		OAuth2AuthorizationRequestResolver defaultAuthorizationRequestResolver = new DefaultOAuth2AuthorizationRequestResolver(
				this.clientRegistrationRepository,
				OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI);
		OAuth2AuthorizationRequestResolver resolver = mock(OAuth2AuthorizationRequestResolver.class);
		OAuth2AuthorizationRequest result = OAuth2AuthorizationRequest
				.from(defaultAuthorizationRequestResolver.resolve(request))
				.additionalParameters(Collections.singletonMap("idp", request.getParameter("idp"))).build();
		given(resolver.resolve(any())).willReturn(result);
		OAuth2AuthorizationRequestRedirectFilter filter = new OAuth2AuthorizationRequestRedirectFilter(resolver);
		filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getRedirectedUrl()).matches("https://example.com/login/oauth/authorize\\?"
				+ "response_type=code&client_id=client-id&" + "scope=read:user&state=.{15,}&"
				+ "redirect_uri=http://localhost/login/oauth2/code/registration-id&"
				+ "idp=https://other.provider.com");
	}

	// gh-4911, gh-5244
	@Test
	public void doFilterWhenAuthorizationRequestAndCustomAuthorizationRequestUriSetThenCustomAuthorizationRequestUriUsed()
			throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration1.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		String loginHintParamName = "login_hint";
		request.addParameter(loginHintParamName, "user@provider.com");
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		OAuth2AuthorizationRequestResolver defaultAuthorizationRequestResolver = new DefaultOAuth2AuthorizationRequestResolver(
				this.clientRegistrationRepository,
				OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI);
		OAuth2AuthorizationRequestResolver resolver = mock(OAuth2AuthorizationRequestResolver.class);
		OAuth2AuthorizationRequest defaultAuthorizationRequest = defaultAuthorizationRequestResolver.resolve(request);
		Map<String, Object> additionalParameters = new HashMap<>(defaultAuthorizationRequest.getAdditionalParameters());
		additionalParameters.put(loginHintParamName, request.getParameter(loginHintParamName));
		// @formatter:off
		String customAuthorizationRequestUri = UriComponentsBuilder
				.fromUriString(defaultAuthorizationRequest.getAuthorizationRequestUri())
				.queryParam(loginHintParamName, additionalParameters.get(loginHintParamName))
				.build(true)
				.toUriString();
		OAuth2AuthorizationRequest result = OAuth2AuthorizationRequest
				.from(defaultAuthorizationRequestResolver.resolve(request))
				.additionalParameters(Collections.singletonMap("idp", request.getParameter("idp")))
				.authorizationRequestUri(customAuthorizationRequestUri)
				.build();
		// @formatter:on
		given(resolver.resolve(any())).willReturn(result);
		OAuth2AuthorizationRequestRedirectFilter filter = new OAuth2AuthorizationRequestRedirectFilter(resolver);
		filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getRedirectedUrl()).matches("https://example.com/login/oauth/authorize\\?"
				+ "response_type=code&client_id=client-id&" + "scope=read:user&state=.{15,}&"
				+ "redirect_uri=http://localhost/login/oauth2/code/registration-id&"
				+ "login_hint=user@provider\\.com");
	}

	@Test
	public void doFilterWhenCustomAuthorizationRedirectStrategySetThenCustomAuthorizationRedirectStrategyUsed()
			throws Exception {
		String requestUri = OAuth2AuthorizationRequestRedirectFilter.DEFAULT_AUTHORIZATION_REQUEST_BASE_URI + "/"
				+ this.registration1.getRegistrationId();
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		RedirectStrategy customRedirectStrategy = (httpRequest, httpResponse, url) -> {
			String redirectUrl = httpResponse.encodeRedirectURL(url);
			httpResponse.setStatus(HttpStatus.OK.value());
			httpResponse.setHeader(HttpHeaders.CONTENT_TYPE, MediaType.TEXT_PLAIN_VALUE);
			httpResponse.getWriter().write(redirectUrl);
			httpResponse.getWriter().flush();
		};
		this.filter.setAuthorizationRedirectStrategy(customRedirectStrategy);
		this.filter.doFilter(request, response, filterChain);
		verifyNoMoreInteractions(filterChain);
		assertThat(response.getStatus()).isEqualTo(HttpStatus.OK.value());
		assertThat(response.getContentType()).isEqualTo(MediaType.TEXT_PLAIN_VALUE);
		assertThat(response.getContentAsString(StandardCharsets.UTF_8))
				.matches("https://example.com/login/oauth/authorize\\?" + "response_type=code&client_id=client-id&"
						+ "scope=read:user&state=.{15,}&"
						+ "redirect_uri=http://localhost/login/oauth2/code/registration-id");
	}

	// gh-11602

	@Test
	public void doFilterWhenNotAuthorizationRequestAndClientAuthorizationRequiredExceptionThrownThenSaveRequestBeforeCommitted()
			throws Exception {
		String requestUri = "/path";
		MockHttpServletRequest request = new MockHttpServletRequest("GET", requestUri);
		request.setServletPath(requestUri);
		MockHttpServletResponse response = new MockHttpServletResponse();
		FilterChain filterChain = mock(FilterChain.class);
		willAnswer((invocation) -> assertThat((invocation.<HttpServletResponse>getArgument(1)).isCommitted()).isFalse())
				.given(this.requestCache).saveRequest(any(HttpServletRequest.class), any(HttpServletResponse.class));
		willThrow(new ClientAuthorizationRequiredException(this.registration1.getRegistrationId())).given(filterChain)
				.doFilter(any(ServletRequest.class), any(ServletResponse.class));
		this.filter.doFilter(request, response, filterChain);
		assertThat(response.isCommitted()).isTrue();
	}

}
