package org.neo4j.driver;
   
   import org.neo4j.driver.v1.Config;
   
   import java.io.File;
   import java.io.IOException;
   import java.io.InputStream;
   import java.util.HashMap;
   import java.util.Map;
  import java.util.Properties;
  import java.util.concurrent.TimeUnit;
  
  /**
   * Read and construct the Neo4j driver configuration.
   */
  public class Configuration {
  
      /**
       * Map with key/value found into properties files.
       */
      private Map<String, Object> config = new HashMap<>();
  
      /**
       * Construction that parses property files.
       */
      public Configuration() {
          // Loading neo4j-driver.properties
          Properties prop = new Properties();
  
          try (InputStream stream = this.getClass().getClassLoader().getResourceAsStream("neo4j-driver.properties")) {
              prop.load(stream);
              for (final String name : prop.stringPropertyNames()) {
                  this.config.put(name, prop.getProperty(name));
              }
          } catch (IOException e) {
              throw new RuntimeException("File neo4j-driver.properties not found !!!");
          }
  
          // Loading neo4j-driver-ext.properties to override default config
          Properties propExt = new Properties();
  
          try (InputStream streamExt = this.getClass().getClassLoader().getResourceAsStream("neo4j-driver-ext.properties")) {
              propExt.load(streamExt);
              for (final String name : propExt.stringPropertyNames()) {
                  this.config.put(name, propExt.getProperty(name));
              }
          } catch (Exception e) {
              // silent exception, we don't care
          }
      }
  
      /**
       * Convert this instance to a Neo4j driver config class.
       *
       * @return A Neo4j Config objects
       */
      public Config toDriverConfig() {
          Config.ConfigBuilder cb = Config.build();
  
          if (this.config.containsKey("neo4j.maxIdleConnectionPoolSize")) {
              cb.withMaxIdleSessions(Integer.valueOf((String) this.config.get("neo4j.maxIdleConnectionPoolSize")));
          }
  
          if (this.config.containsKey("neo4j.idleTimeBeforeConnectionTest")) {
              cb.withConnectionLivenessCheckTimeout(Long.valueOf((String) this.config.get("neo4j.idleTimeBeforeConnectionTest")), TimeUnit.SECONDS);
          }
  
          if (this.config.containsKey("neo4j.logLeakedSessions")) {
              if (Boolean.valueOf((String) this.config.get("neo4j.logLeakedSessions"))) {
                  cb.withLeakedSessionsLogging();
              }
          }
  
          if (this.config.containsKey("neo4j.encrypted")) {
              if (Boolean.valueOf((String) this.config.get("neo4j.encrypted"))) {
                  cb.withEncryption();
              } else {
                  cb.withoutEncryption();
              }
          }
  
          if (this.config.containsKey("neo4j.connectionTimeoutMillis")) {
              cb.withConnectionTimeout(Long.valueOf((String) this.config.get("neo4j.connectionTimeoutMillis")), TimeUnit.MILLISECONDS);
          }
  
          if (this.config.containsKey("neo4j.trustStrategy")) {
              switch (this.getStringOrDefault("neo4j.trustStrategy", "").toUpperCase()) {
                  case "ALL":
                      cb.withTrustStrategy(Config.TrustStrategy.trustAllCertificates());
                      break;
                  case "SYSTEM":
                      cb.withTrustStrategy(Config.TrustStrategy.trustSystemCertificates());
                      break;
                  default:
                      File cert = new File(this.getStringOrDefault("neo4j.trustStrategy", ""));
                      if (cert.exists()) {
                          cb.withTrustStrategy(Config.TrustStrategy.trustCustomCertificateSignedBy(cert));
                      } else {
                          throw new RuntimeException("Certificate not found");
                     }
                     break;
             }
         }
 
         return cb.toConfig();
     }
 
     /**
      * Search a value by its key into {@link #config} and transform it as a String.
      *
      * @param key   Key to search.
      * @param value Default value if nkeyis not found.
      * @return The desired value as a string.
      */
     public String getStringOrDefault(String key, String value) {
         return (String) this.config.getOrDefault(key, value);
     }
 }