/*
    *    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.SQLException;
  
  /**
   * @author Clinton Begin
   */
  public class EnumOrdinalTypeHandler<E extends Enum<E>> extends BaseTypeHandler<E> {
  
    private final Class<E> type;
    private final E[] enums;
  
    public EnumOrdinalTypeHandler(Class<E> type) {
      if (type == null) {
        throw new IllegalArgumentException("Type argument cannot be null");
      }
      this.type = type;
      this.enums = type.getEnumConstants();
      if (this.enums == null) {
        throw new IllegalArgumentException(type.getSimpleName() + " does not represent an enum type.");
      }
    }
  
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, E parameter, JdbcType jdbcType) throws SQLException {
      ps.setInt(i, parameter.ordinal());
    }
  
    @Override
    public E getNullableResult(ResultSet rs, String columnName) throws SQLException {
      int ordinal = rs.getInt(columnName);
      if (ordinal == 0 && rs.wasNull()) {
        return null;
      }
      return toOrdinalEnum(ordinal);
    }
  
    @Override
    public E getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
      int ordinal = rs.getInt(columnIndex);
      if (ordinal == 0 && rs.wasNull()) {
        return null;
      }
      return toOrdinalEnum(ordinal);
    }
  
    @Override
    public E getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
      int ordinal = cs.getInt(columnIndex);
      if (ordinal == 0 && cs.wasNull()) {
        return null;
      }
      return toOrdinalEnum(ordinal);
    }
  
    private E toOrdinalEnum(int ordinal) {
      try {
        return enums[ordinal];
      } catch (Exception ex) {
        throw new IllegalArgumentException("Cannot convert " + ordinal + " to " + type.getSimpleName() + " by ordinal value.", ex);
      }
    }
  }