/*
    * Copyright 2017 LINE Corporation
    *
    * LINE Corporation 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:
    *
    *   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 com.linecorp.centraldogma.client.spring;
  
  import java.net.UnknownHostException;
  import java.util.List;
  import java.util.Optional;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
  import org.springframework.boot.context.properties.EnableConfigurationProperties;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.core.env.Environment;
  
  import com.google.common.net.HostAndPort;
  
  import com.linecorp.armeria.client.ClientFactory;
  import com.linecorp.armeria.client.ClientFactoryBuilder;
  import com.linecorp.centraldogma.client.CentralDogma;
  import com.linecorp.centraldogma.client.armeria.ArmeriaCentralDogmaBuilder;
  import com.linecorp.centraldogma.client.armeria.ArmeriaClientConfigurator;
  import com.linecorp.centraldogma.client.armeria.DnsAddressEndpointGroupConfigurator;
  
  /**
   * Spring bean configuration for {@link CentralDogma} client.
   */
  @Configuration
  @ConditionalOnMissingBean(CentralDogma.class)
  @EnableConfigurationProperties(CentralDogmaSettings.class)
  public class CentralDogmaClientAutoConfiguration {
  
      private static final Logger logger = LoggerFactory.getLogger(CentralDogmaClientAutoConfiguration.class);
  
      static final long DEFAULT_INITIALIZATION_TIMEOUT_MILLIS = 15000;
  
      /**
       * Returns a newly created {@link CentralDogma} client.
       */
      @Bean
      public CentralDogma dogmaClient(
              Environment env,
              CentralDogmaSettings settings,
              Optional<List<CentralDogmaClientFactoryConfigurator>> factoryConfigurators,
              Optional<ArmeriaClientConfigurator> armeriaClientConfigurator,
              Optional<DnsAddressEndpointGroupConfigurator> dnsAddressEndpointGroupConfigurator)
              throws UnknownHostException {
  
          final ArmeriaCentralDogmaBuilder builder = new ArmeriaCentralDogmaBuilder();
  
          if (factoryConfigurators.isPresent()) {
              final ClientFactoryBuilder clientFactoryBuilder = ClientFactory.builder();
              factoryConfigurators.get().forEach(configurator -> configurator.configure(clientFactoryBuilder));
              builder.clientFactory(clientFactoryBuilder.build());
          }
  
          builder.clientConfigurator(cb -> armeriaClientConfigurator.ifPresent(
                  configurator -> configurator.configure(cb)));
          dnsAddressEndpointGroupConfigurator.ifPresent(builder::dnsAddressEndpointGroupConfigurator);
  
          // Set health check interval.
          final Long healthCheckIntervalMillis = settings.getHealthCheckIntervalMillis();
          if (healthCheckIntervalMillis != null) {
              builder.healthCheckIntervalMillis(healthCheckIntervalMillis);
          }
  
          // Enable or disable TLS.
          final Boolean useTls = settings.getUseTls();
          if (useTls != null) {
              builder.useTls(useTls);
          }
  
          // Set access token.
          final String accessToken = settings.getAccessToken();
          if (accessToken != null) {
              builder.accessToken(accessToken);
          }
  
          // Set profile or hosts.
          final String profile = settings.getProfile();
          final List<String> hosts = settings.getHosts();
          if (profile != null) {
             if (hosts != null) {
                 throw new IllegalStateException(
                         "'hosts' and 'profile' are mutually exclusive. Do not set both of them.");
             }
             builder.profile(CentralDogmaClientAutoConfiguration.class.getClassLoader(), profile);
         } else if (hosts != null) {
             for (String h : hosts) {
                 final HostAndPort hostAndPort = HostAndPort.fromString(h);
                 if (hostAndPort.hasPort()) {
                     builder.host(hostAndPort.getHost(), hostAndPort.getPort());
                 } else {
                     builder.host(hostAndPort.getHost());
                 }
             }
         } else {
             // Use the currently active Spring Boot profiles if neither profile nor hosts was specified.
             final String[] springBootProfiles = env.getActiveProfiles();
             logger.info("Using the Spring Boot profiles as the source of the Central Dogma client profile: {}",
                         springBootProfiles);
             builder.profile(springBootProfiles);
         }
 
         // Replication lag tolerance settings.
         final Integer maxNumRetriesOnReplicationLag = settings.getMaxNumRetriesOnReplicationLag();
         if (maxNumRetriesOnReplicationLag != null) {
             builder.maxNumRetriesOnReplicationLag(maxNumRetriesOnReplicationLag);
         }
 
         final Long retryIntervalOnReplicationLagMillis = settings.getRetryIntervalOnReplicationLagMillis();
         if (retryIntervalOnReplicationLagMillis != null) {
             builder.retryIntervalOnReplicationLagMillis(retryIntervalOnReplicationLagMillis);
         }
 
         final CentralDogma centralDogma = builder.build();
         Long initializationTimeoutMillis = settings.initializationTimeoutMillis();
         if (initializationTimeoutMillis == null) {
             initializationTimeoutMillis = DEFAULT_INITIALIZATION_TIMEOUT_MILLIS;
         }
         if (initializationTimeoutMillis > 0) {
             try {
                 centralDogma.whenEndpointReady().get(initializationTimeoutMillis, TimeUnit.MILLISECONDS);
             } catch (InterruptedException | ExecutionException | TimeoutException e) {
                 throw new IllegalStateException(
                         "Failed to initialize the endpoints of " + centralDogma + " in " +
                         initializationTimeoutMillis + " milliseconds", e);
             }
         }
         return centralDogma;
     }
 }