/*
 * Copyright 2012-present 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.boot.actuate.autoconfigure.env;

import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.junit.jupiter.api.Test;

import org.springframework.boot.actuate.autoconfigure.endpoint.web.documentation.MockMvcEndpointDocumentationTests;
import org.springframework.boot.actuate.endpoint.Show;
import org.springframework.boot.actuate.env.EnvironmentEndpoint;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.AbstractEnvironment;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.EnumerablePropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.http.MediaType;
import org.springframework.restdocs.operation.preprocess.ContentModifyingOperationPreprocessor;
import org.springframework.restdocs.operation.preprocess.OperationPreprocessor;
import org.springframework.restdocs.payload.FieldDescriptor;
import org.springframework.test.context.TestPropertySource;

import static org.assertj.core.api.Assertions.assertThat;
import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.document;
import static org.springframework.restdocs.operation.preprocess.Preprocessors.preprocessResponse;
import static org.springframework.restdocs.operation.preprocess.Preprocessors.replacePattern;
import static org.springframework.restdocs.payload.PayloadDocumentation.fieldWithPath;
import static org.springframework.restdocs.payload.PayloadDocumentation.responseFields;

/**
 * Tests for generating documentation describing the {@link EnvironmentEndpoint}.
 *
 * @author Andy Wilkinson
 */
@TestPropertySource(
		properties = "spring.config.location=classpath:/org/springframework/boot/actuate/autoconfigure/env/")
class EnvironmentEndpointDocumentationTests extends MockMvcEndpointDocumentationTests {

	private static final FieldDescriptor activeProfiles = fieldWithPath("activeProfiles")
		.description("Names of the active profiles, if any.");

	private static final FieldDescriptor defaultProfiles = fieldWithPath("defaultProfiles")
		.description("Names of the default profiles, if any.");

	private static final FieldDescriptor propertySources = fieldWithPath("propertySources")
		.description("Property sources in order of precedence.");

	private static final FieldDescriptor propertySourceName = fieldWithPath("propertySources.[].name")
		.description("Name of the property source.");

	@Test
	void env() {
		assertThat(this.mvc.get().uri("/actuator/env")).hasStatusOk()
			.apply(document("env/all",
					preprocessResponse(
							replacePattern(Pattern.compile(
									"org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/"), ""),
							filterProperties()),
					responseFields(activeProfiles, defaultProfiles, propertySources, propertySourceName,
							fieldWithPath("propertySources.[].properties")
								.description("Properties in the property source keyed by property name."),
							fieldWithPath("propertySources.[].properties.*.value")
								.description("Value of the property."),
							fieldWithPath("propertySources.[].properties.*.origin")
								.description("Origin of the property, if any.")
								.optional())));
	}

	@Test
	void singlePropertyFromEnv() {
		assertThat(this.mvc.get().uri("/actuator/env/com.example.cache.max-size")).hasStatusOk()
			.apply(document("env/single",
					preprocessResponse(replacePattern(Pattern
						.compile("org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/"), "")),
					responseFields(
							fieldWithPath("property").description("Property from the environment, if found.")
								.optional(),
							fieldWithPath("property.source").description("Name of the source of the property."),
							fieldWithPath("property.value").description("Value of the property."), activeProfiles,
							defaultProfiles, propertySources, propertySourceName,
							fieldWithPath("propertySources.[].property")
								.description("Property in the property source, if any.")
								.optional(),
							fieldWithPath("propertySources.[].property.value").description("Value of the property."),
							fieldWithPath("propertySources.[].property.origin")
								.description("Origin of the property, if any.")
								.optional())));
	}

	private OperationPreprocessor filterProperties() {
		return new ContentModifyingOperationPreprocessor(this::filterProperties);
	}

	@SuppressWarnings("unchecked")
	private byte[] filterProperties(byte[] content, MediaType mediaType) {
		ObjectMapper objectMapper = new ObjectMapper().enable(SerializationFeature.INDENT_OUTPUT);
		try {
			Map<String, Object> payload = objectMapper.readValue(content, Map.class);
			List<Map<String, Object>> propertySources = (List<Map<String, Object>>) payload.get("propertySources");
			for (Map<String, Object> propertySource : propertySources) {
				Map<String, String> properties = (Map<String, String>) propertySource.get("properties");
				Set<String> filteredKeys = properties.keySet()
					.stream()
					.filter(this::retainKey)
					.limit(3)
					.collect(Collectors.toSet());
				properties.keySet().retainAll(filteredKeys);
			}
			return objectMapper.writeValueAsBytes(payload);
		}
		catch (IOException ex) {
			throw new IllegalStateException(ex);
		}
	}

	private boolean retainKey(String key) {
		return key.startsWith("java.") || key.equals("JAVA_HOME") || key.startsWith("com.example.");
	}

	@Configuration(proxyBeanMethods = false)
	static class TestConfiguration {

		@Bean
		EnvironmentEndpoint endpoint(ConfigurableEnvironment environment) {
			return new EnvironmentEndpoint(new AbstractEnvironment() {

				@Override
				protected void customizePropertySources(MutablePropertySources propertySources) {
					environment.getPropertySources()
						.stream()
						.filter(this::includedPropertySource)
						.forEach(propertySources::addLast);
				}

				private boolean includedPropertySource(PropertySource<?> propertySource) {
					return propertySource instanceof EnumerablePropertySource
							&& !"Inlined Test Properties".equals(propertySource.getName());
				}

			}, Collections.emptyList(), Show.ALWAYS);
		}

	}

}
