/**
    *    Copyright 2009-2015 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
    *
    *       http://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.apache.ibatis.type;
  
  import java.sql.CallableStatement;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.sql.ResultSetMetaData;
  import java.sql.SQLException;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.ibatis.io.Resources;
  
  /**
   * @author Clinton Begin
   */
  public class UnknownTypeHandler extends BaseTypeHandler<Object> {
  
    private static final ObjectTypeHandler OBJECT_TYPE_HANDLER = new ObjectTypeHandler();
  
    private TypeHandlerRegistry typeHandlerRegistry;
  
    public UnknownTypeHandler(TypeHandlerRegistry typeHandlerRegistry) {
      this.typeHandlerRegistry = typeHandlerRegistry;
    }
  
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, Object parameter, JdbcType jdbcType)
        throws SQLException {
      TypeHandler handler = resolveTypeHandler(parameter, jdbcType);
      handler.setParameter(ps, i, parameter, jdbcType);
    }
  
    @Override
    public Object getNullableResult(ResultSet rs, String columnName)
        throws SQLException {
      TypeHandler<?> handler = resolveTypeHandler(rs, columnName);
      return handler.getResult(rs, columnName);
    }
  
    @Override
    public Object getNullableResult(ResultSet rs, int columnIndex)
        throws SQLException {
      TypeHandler<?> handler = resolveTypeHandler(rs.getMetaData(), columnIndex);
      if (handler == null || handler instanceof UnknownTypeHandler) {
        handler = OBJECT_TYPE_HANDLER;
      }
      return handler.getResult(rs, columnIndex);
    }
  
    @Override
    public Object getNullableResult(CallableStatement cs, int columnIndex)
        throws SQLException {
      return cs.getObject(columnIndex);
    }
  
    private TypeHandler<? extends Object> resolveTypeHandler(Object parameter, JdbcType jdbcType) {
      TypeHandler<? extends Object> handler;
      if (parameter == null) {
        handler = OBJECT_TYPE_HANDLER;
      } else {
        handler = typeHandlerRegistry.getTypeHandler(parameter.getClass(), jdbcType);
        // check if handler is null (issue #270)
        if (handler == null || handler instanceof UnknownTypeHandler) {
          handler = OBJECT_TYPE_HANDLER;
        }
      }
      return handler;
    }
  
    private TypeHandler<?> resolveTypeHandler(ResultSet rs, String column) {
      try {
        Map<String,Integer> columnIndexLookup;
        columnIndexLookup = new HashMap<String,Integer>();
        ResultSetMetaData rsmd = rs.getMetaData();
        int count = rsmd.getColumnCount();
        for (int i=1; i <= count; i++) {
          String name = rsmd.getColumnName(i);
          columnIndexLookup.put(name,i);
        }
        Integer columnIndex = columnIndexLookup.get(column);
        TypeHandler<?> handler = null;
        if (columnIndex != null) {
          handler = resolveTypeHandler(rsmd, columnIndex);
        }
       if (handler == null || handler instanceof UnknownTypeHandler) {
         handler = OBJECT_TYPE_HANDLER;
       }
       return handler;
     } catch (SQLException e) {
       throw new TypeException("Error determining JDBC type for column " + column + ".  Cause: " + e, e);
     }
   }
 
   private TypeHandler<?> resolveTypeHandler(ResultSetMetaData rsmd, Integer columnIndex) throws SQLException {
     TypeHandler<?> handler = null;
     JdbcType jdbcType = safeGetJdbcTypeForColumn(rsmd, columnIndex);
     Class<?> javaType = safeGetClassForColumn(rsmd, columnIndex);
     if (javaType != null && jdbcType != null) {
       handler = typeHandlerRegistry.getTypeHandler(javaType, jdbcType);
     } else if (javaType != null) {
       handler = typeHandlerRegistry.getTypeHandler(javaType);
     } else if (jdbcType != null) {
       handler = typeHandlerRegistry.getTypeHandler(jdbcType);
     }
     return handler;
   }
 
   private JdbcType safeGetJdbcTypeForColumn(ResultSetMetaData rsmd, Integer columnIndex) {
     try {
       return JdbcType.forCode(rsmd.getColumnType(columnIndex));
     } catch (Exception e) {
       return null;
     }
   }
 
   private Class<?> safeGetClassForColumn(ResultSetMetaData rsmd, Integer columnIndex) {
     try {
       return Resources.classForName(rsmd.getColumnClassName(columnIndex));
     } catch (Exception e) {
       return null;
     }
   }
 }