/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.kafka.common.security.oauthbearer.internals;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.apache.kafka.common.security.auth.SaslExtensions;
import org.junit.jupiter.api.Test;

import javax.security.sasl.SaslException;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class OAuthBearerClientInitialResponseTest {

    /*
        Test how a client would build a response
     */
    @Test
    public void testBuildClientResponseToBytes() throws Exception {
        String expectedMesssage = "n,,\u0001auth=Bearer 123.345.567\u0001nineteen=42\u0001\u0001";

        Map<String, String> extensions = new HashMap<>();
        extensions.put("nineteen", "42");
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse("123.345.567", new SaslExtensions(extensions));

        String message = new String(response.toBytes(), StandardCharsets.UTF_8);

        assertEquals(expectedMesssage, message);
    }

    @Test
    public void testBuildServerResponseToBytes() throws Exception {
        String serverMessage = "n,,\u0001auth=Bearer 123.345.567\u0001nineteen=42\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(serverMessage.getBytes(StandardCharsets.UTF_8));

        String message = new String(response.toBytes(), StandardCharsets.UTF_8);

        assertEquals(serverMessage, message);
    }

    @Test
    public void testThrowsSaslExceptionOnInvalidExtensionKey() throws Exception {
        Map<String, String> extensions = new HashMap<>();
        extensions.put("19", "42"); // keys can only be a-z
        assertThrows(SaslException.class, () -> new OAuthBearerClientInitialResponse("123.345.567", new SaslExtensions(extensions)));
    }

    @Test
    public void testToken() throws Exception {
        String message = "n,,\u0001auth=Bearer 123.345.567\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(message.getBytes(StandardCharsets.UTF_8));
        assertEquals("123.345.567", response.tokenValue());
        assertEquals("", response.authorizationId());
    }

    @Test
    public void testAuthorizationId() throws Exception {
        String message = "n,a=myuser,\u0001auth=Bearer 345\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(message.getBytes(StandardCharsets.UTF_8));
        assertEquals("345", response.tokenValue());
        assertEquals("myuser", response.authorizationId());
    }

    @Test
    public void testExtensions() throws Exception {
        String message = "n,,\u0001propA=valueA1, valueA2\u0001auth=Bearer 567\u0001propB=valueB\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(message.getBytes(StandardCharsets.UTF_8));
        assertEquals("567", response.tokenValue());
        assertEquals("", response.authorizationId());
        assertEquals("valueA1, valueA2", response.extensions().map().get("propA"));
        assertEquals("valueB", response.extensions().map().get("propB"));
    }

    // The example in the RFC uses `vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg==` as the token
    // But since we use Base64Url encoding, padding is omitted. Hence this test verifies without '='.
    @Test
    public void testRfc7688Example() throws Exception {
        String message = "n,a=user@example.com,\u0001host=server.example.com\u0001port=143\u0001" +
                "auth=Bearer vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(message.getBytes(StandardCharsets.UTF_8));
        assertEquals("vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg", response.tokenValue());
        assertEquals("user@example.com", response.authorizationId());
        assertEquals("server.example.com", response.extensions().map().get("host"));
        assertEquals("143", response.extensions().map().get("port"));
    }

    @Test
    public void testNoExtensionsFromByteArray() throws Exception {
        String message = "n,a=user@example.com,\u0001" +
                "auth=Bearer vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg\u0001\u0001";
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse(message.getBytes(StandardCharsets.UTF_8));
        assertEquals("vF9dft4qmTc2Nvb3RlckBhbHRhdmlzdGEuY29tCg", response.tokenValue());
        assertEquals("user@example.com", response.authorizationId());
        assertTrue(response.extensions().map().isEmpty());
    }

    @Test
    public void testNoExtensionsFromTokenAndNullExtensions() throws Exception {
        OAuthBearerClientInitialResponse response = new OAuthBearerClientInitialResponse("token", null);
        assertTrue(response.extensions().map().isEmpty());
    }

    @Test
    public void testValidateNullExtensions() throws Exception {
        OAuthBearerClientInitialResponse.validateExtensions(null);
    }
}
