package org.maxur.perfmodel.backend.service.impl;
   
   import com.typesafe.config.Config;
   import com.typesafe.config.ConfigException;
   import com.typesafe.config.ConfigFactory;
   import org.jvnet.hk2.annotations.Service;
   import org.maxur.perfmodel.backend.service.PropertiesService;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
  
  import javax.annotation.PostConstruct;
  import java.net.URI;
  import java.util.function.Function;
  
  /**
   * @author Maxim Yunusov
   * @version 1.0
   * @since <pre>9/2/2015</pre>
   */
  @Service
  public class PropertiesServiceHoconImpl implements PropertiesService {
  
      private static final Logger LOGGER = LoggerFactory.getLogger(PropertiesServiceHoconImpl.class);
  
      private Config defaultConfig;
  
      private Config userConfig;
  
      @PostConstruct
      public void init() {
          defaultConfig = ConfigFactory.load().getConfig("DEFAULTS");
          userConfig = ConfigFactory.load().getConfig("PMC");
      }
  
      @Override
      public URI asURI(final String key) {
          return URI.create(asString(key));
      }
  
      @Override
      public String asString(final String key) {
          return getValue(key, this::getString);
      }
  
      @Override
      public Integer asInteger(final String key) {
          return getValue(key, this::getInt);
      }
  
      private <T> T getValue(final String key, final Function<String, T> method) {
          try {
              final T value = method.apply(key);
              LOGGER.info("Configuration parameter {} = '{}'", key, value);
              return value;
          } catch (ConfigException.Missing e) {
              LOGGER.error("Configuration parameter '{}' is not found.", key);
              throw e;
          }
      }
  
      private String getString(final String key) {
          try {
              return userConfig.getString(key);
          } catch (ConfigException.Missing e) {
              return defaultConfig.getString(key);
          }
      }
  
      private Integer getInt(final String key) {
          try {
              return userConfig.getInt(key);
          } catch (ConfigException.Missing e) {
              return defaultConfig.getInt(key);
          }
      }
  }