/*
    * Licensed under the GPL License. You may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *   https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
    *
    * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
    * WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
    * PURPOSE.
   */
  package psiprobe.beans.accessors;
  
  import java.sql.SQLException;
  import java.util.List;
  
  import psiprobe.model.DataSourceInfo;
  
  /**
   * Datasource accessor for Flexy Pool wrappers.
   */
  public class FlexyPoolDatasourceAccessor implements DatasourceAccessor {
  
    /** The Constant flexyPoolDataSourceClassName. */
    private static final String FLEXY_POOL_DATASOURCE_CLASS_NAME =
        "com.vladmihalcea.flexypool.FlexyPoolDataSource";
  
    /** The Constant delegateAccessorClassNames. */
    private static final List<String> DELEGATE_ACCESSOR_CLASS_NAMES =
        List.of("psiprobe.beans.accessors.C3P0DatasourceAccessor",
            "psiprobe.beans.accessors.Dbcp2DatasourceAccessor",
            "psiprobe.beans.accessors.HikariCpDatasourceAccessor",
            "psiprobe.beans.accessors.OracleDatasourceAccessor",
            "psiprobe.beans.accessors.OracleUcpDatasourceAccessor",
            "psiprobe.beans.accessors.OpenEjbBasicDatasourceAccessor",
            "psiprobe.beans.accessors.OpenEjbManagedDatasourceAccessor",
            "psiprobe.beans.accessors.Tomcat10DbcpDatasourceAccessor",
            "psiprobe.beans.accessors.Tomcat11DbcpDatasourceAccessor",
            "psiprobe.beans.accessors.TomcatJdbcPoolDatasourceAccessor",
            "psiprobe.beans.accessors.TomEeJdbcPoolDatasourceAccessor",
            "psiprobe.beans.accessors.ViburCpDatasourceAccessor");
  
    /** The Constant DELEGATE_ACCESSORS. */
    private static final List<DatasourceAccessor> DELEGATE_ACCESSORS =
        DELEGATE_ACCESSOR_CLASS_NAMES.stream().map(FlexyPoolDatasourceAccessor::newAccessor).toList();
  
    @Override
    public DataSourceInfo getInfo(Object resource) throws SQLException {
      Object targetDataSource = getTargetDataSource(resource);
      if (targetDataSource == null) {
        return null;
      }
  
      for (DatasourceAccessor accessor : DELEGATE_ACCESSORS) {
        if (accessor.canMap(targetDataSource)) {
          return accessor.getInfo(targetDataSource);
        }
      }
  
      return null;
    }
  
    @Override
    public boolean reset(Object resource) throws SQLException {
      Object targetDataSource = getTargetDataSource(resource);
      if (targetDataSource == null) {
        return false;
      }
  
      for (DatasourceAccessor accessor : DELEGATE_ACCESSORS) {
        if (accessor.canMap(targetDataSource)) {
          return accessor.reset(targetDataSource);
        }
      }
  
      return false;
    }
  
    @Override
    public boolean canMap(Object resource) {
      return resource != null
          && FLEXY_POOL_DATASOURCE_CLASS_NAME.equals(resource.getClass().getName());
    }
  
    /**
     * Gets the target datasource from a Flexy Pool wrapper.
     *
     * @param resource the resource
     * @return the target datasource
     */
    private Object getTargetDataSource(Object resource) {
      if (!canMap(resource)) {
        return null;
      }
  
      try {
        return resource.getClass().getMethod("getTargetDataSource").invoke(resource);
      } catch (ReflectiveOperationException e) {
        return null;
      }
   }
 
   /**
    * Creates a datasource accessor.
    *
    * @param accessorClassName the accessor class name
    * @return the datasource accessor
    */
   private static DatasourceAccessor newAccessor(String accessorClassName) {
     try {
       return Class.forName(accessorClassName).asSubclass(DatasourceAccessor.class)
           .getDeclaredConstructor().newInstance();
     } catch (ReflectiveOperationException e) {
       return new UnsupportedDatasourceAccessor();
     }
   }
 
   /**
    * Unsupported datasource accessor.
    */
   private static final class UnsupportedDatasourceAccessor implements DatasourceAccessor {
 
     @Override
     public DataSourceInfo getInfo(Object resource) {
       return null;
     }
 
     @Override
     public boolean reset(Object resource) {
       return false;
     }
 
     @Override
     public boolean canMap(Object resource) {
       return false;
     }
   }
 }