/*
    *    Copyright 2009-2021 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 java.util.function.Supplier;
  
  import org.apache.ibatis.io.Resources;
  import org.apache.ibatis.session.Configuration;
  
  /**
   * @author Clinton Begin
   */
  public class UnknownTypeHandler extends BaseTypeHandler<Object> {
  
    private static final ObjectTypeHandler OBJECT_TYPE_HANDLER = new ObjectTypeHandler();
    // TODO Rename to 'configuration' after removing the 'configuration' property(deprecated property) on parent class
    private final Configuration config;
    private final Supplier<TypeHandlerRegistry> typeHandlerRegistrySupplier;
  
    /**
     * The constructor that pass a MyBatis configuration.
     *
     * @param configuration a MyBatis configuration
     * @since 3.5.4
     */
    public UnknownTypeHandler(Configuration configuration) {
      this.config = configuration;
      this.typeHandlerRegistrySupplier = configuration::getTypeHandlerRegistry;
    }
  
    /**
     * The constructor that pass the type handler registry.
     *
     * @param typeHandlerRegistry a type handler registry
     * @deprecated Since 3.5.4, please use the {@link #UnknownTypeHandler(Configuration)}.
     */
    @Deprecated
    public UnknownTypeHandler(TypeHandlerRegistry typeHandlerRegistry) {
      this.config = new Configuration();
      this.typeHandlerRegistrySupplier = () -> 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<?> resolveTypeHandler(Object parameter, JdbcType jdbcType) {
      TypeHandler<?> handler;
      if (parameter == null) {
        handler = OBJECT_TYPE_HANDLER;
      } else {
        handler = typeHandlerRegistrySupplier.get().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<>();
       ResultSetMetaData rsmd = rs.getMetaData();
       int count = rsmd.getColumnCount();
       boolean useColumnLabel = config.isUseColumnLabel();
       for (int i = 1; i <= count; i++) {
         String name = useColumnLabel ? rsmd.getColumnLabel(i) : 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) {
     TypeHandler<?> handler = null;
     JdbcType jdbcType = safeGetJdbcTypeForColumn(rsmd, columnIndex);
     Class<?> javaType = safeGetClassForColumn(rsmd, columnIndex);
     if (javaType != null && jdbcType != null) {
       handler = typeHandlerRegistrySupplier.get().getTypeHandler(javaType, jdbcType);
     } else if (javaType != null) {
       handler = typeHandlerRegistrySupplier.get().getTypeHandler(javaType);
     } else if (jdbcType != null) {
       handler = typeHandlerRegistrySupplier.get().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;
     }
   }
 }