/*
 * 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.jose.jws;

import org.junit.Before;
import org.junit.Test;
import org.springframework.security.crypto.keys.KeyManager;
import org.springframework.security.crypto.keys.ManagedKey;
import org.springframework.security.crypto.keys.TestManagedKeys;
import org.springframework.security.oauth2.jose.JoseHeader;
import org.springframework.security.oauth2.jose.JoseHeaderNames;
import org.springframework.security.oauth2.jose.TestJoseHeaders;
import org.springframework.security.oauth2.jwt.Jwt;
import org.springframework.security.oauth2.jwt.JwtClaimsSet;
import org.springframework.security.oauth2.jwt.JwtEncodingException;
import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
import org.springframework.security.oauth2.jwt.TestJwtClaimsSets;

import java.security.interfaces.RSAPublicKey;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.Collections;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

/**
 * Tests for {@link NimbusJwsEncoder}.
 *
 * @author Joe Grandja
 */
public class NimbusJwsEncoderTests {
	private KeyManager keyManager;
	private NimbusJwsEncoder jwtEncoder;

	@Before
	public void setUp() {
		this.keyManager = mock(KeyManager.class);
		this.jwtEncoder = new NimbusJwsEncoder(this.keyManager);
	}

	@Test
	public void constructorWhenKeyManagerNullThenThrowIllegalArgumentException() {
		assertThatThrownBy(() -> new NimbusJwsEncoder(null))
				.isInstanceOf(IllegalArgumentException.class)
				.hasMessage("keyManager cannot be null");
	}

	@Test
	public void encodeWhenHeadersNullThenThrowIllegalArgumentException() {
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		assertThatThrownBy(() -> this.jwtEncoder.encode(null, jwtClaimsSet))
				.isInstanceOf(IllegalArgumentException.class)
				.hasMessage("headers cannot be null");
	}

	@Test
	public void encodeWhenClaimsNullThenThrowIllegalArgumentException() {
		JoseHeader joseHeader = TestJoseHeaders.joseHeader().build();

		assertThatThrownBy(() -> this.jwtEncoder.encode(joseHeader, null))
				.isInstanceOf(IllegalArgumentException.class)
				.hasMessage("claims cannot be null");
	}

	@Test
	public void encodeWhenUnsupportedKeyThenThrowJwtEncodingException() {
		JoseHeader joseHeader = TestJoseHeaders.joseHeader().build();
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		assertThatThrownBy(() -> this.jwtEncoder.encode(joseHeader, jwtClaimsSet))
				.isInstanceOf(JwtEncodingException.class)
				.hasMessageContaining("Unsupported key for algorithm 'RS256'");
	}

	@Test
	public void encodeWhenUnsupportedKeyAlgorithmThenThrowJwtEncodingException() {
		JoseHeader joseHeader = TestJoseHeaders.joseHeader(SignatureAlgorithm.ES256).build();
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		assertThatThrownBy(() -> this.jwtEncoder.encode(joseHeader, jwtClaimsSet))
				.isInstanceOf(JwtEncodingException.class)
				.hasMessageContaining("Unsupported key for algorithm 'ES256'");
	}

	@Test
	public void encodeWhenUnsupportedKeyTypeThenThrowJwtEncodingException() {
		ManagedKey managedKey = TestManagedKeys.ecManagedKey().build();
		when(this.keyManager.findByAlgorithm(any())).thenReturn(Collections.singleton(managedKey));

		JoseHeader joseHeader = TestJoseHeaders.joseHeader(SignatureAlgorithm.ES256).build();
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		assertThatThrownBy(() -> this.jwtEncoder.encode(joseHeader, jwtClaimsSet))
				.isInstanceOf(JwtEncodingException.class)
				.hasMessageContaining("Unsupported key type 'EC'");
	}

	@Test
	public void encodeWhenSuccessThenDecodes() {
		ManagedKey managedKey = TestManagedKeys.rsaManagedKey().build();
		when(this.keyManager.findByAlgorithm(any())).thenReturn(Collections.singleton(managedKey));

		JoseHeader joseHeader = TestJoseHeaders.joseHeader()
				.headers(headers -> headers.remove(JoseHeaderNames.CRIT))
				.build();
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		Jwt jws = this.jwtEncoder.encode(joseHeader, jwtClaimsSet);

		NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withPublicKey((RSAPublicKey) managedKey.getPublicKey()).build();
		jwtDecoder.decode(jws.getTokenValue());
	}

	@Test
	public void encodeWhenMultipleActiveKeysThenUseMostRecent() {
		ManagedKey managedKeyActivated2DaysAgo = TestManagedKeys.rsaManagedKey()
				.activatedOn(Instant.now().minus(2, ChronoUnit.DAYS))
				.build();
		ManagedKey managedKeyActivated1DayAgo = TestManagedKeys.rsaManagedKey()
				.activatedOn(Instant.now().minus(1, ChronoUnit.DAYS))
				.build();
		ManagedKey managedKeyActivatedToday = TestManagedKeys.rsaManagedKey()
				.activatedOn(Instant.now())
				.build();

		when(this.keyManager.findByAlgorithm(any())).thenReturn(
				Stream.of(managedKeyActivated2DaysAgo, managedKeyActivated1DayAgo, managedKeyActivatedToday)
						.collect(Collectors.toSet()));

		JoseHeader joseHeader = TestJoseHeaders.joseHeader()
				.headers(headers -> headers.remove(JoseHeaderNames.CRIT))
				.build();
		JwtClaimsSet jwtClaimsSet = TestJwtClaimsSets.jwtClaimsSet().build();

		Jwt jws = this.jwtEncoder.encode(joseHeader, jwtClaimsSet);

		NimbusJwtDecoder jwtDecoder = NimbusJwtDecoder.withPublicKey((RSAPublicKey) managedKeyActivatedToday.getPublicKey()).build();
		jwtDecoder.decode(jws.getTokenValue());
	}
}