/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.shardingsphere.driver.jdbc.core.resultset;
  
  import com.google.common.base.Preconditions;
  import lombok.RequiredArgsConstructor;
  import org.apache.shardingsphere.driver.jdbc.unsupported.AbstractUnsupportedGeneratedKeysResultSet;
  import org.apache.shardingsphere.infra.annotation.HighFrequencyInvocation;
  
  import java.math.BigDecimal;
  import java.math.RoundingMode;
  import java.nio.charset.StandardCharsets;
  import java.sql.ResultSetMetaData;
  import java.sql.Statement;
  import java.util.Collections;
  import java.util.Iterator;
  
  /**
   * ResultSet for generated keys.
   */
  @HighFrequencyInvocation
  @RequiredArgsConstructor
  public final class GeneratedKeysResultSet extends AbstractUnsupportedGeneratedKeysResultSet {
      
      private final String column;
      
      private final Iterator<Comparable<?>> values;
      
      private final Statement statement;
      
      private Comparable<?> currentValue;
      
      private boolean closed;
      
      public GeneratedKeysResultSet() {
          column = null;
          values = Collections.emptyIterator();
          statement = null;
      }
      
      @Override
      public boolean isClosed() {
          return closed;
      }
      
      @Override
      public boolean next() {
          if (closed || !values.hasNext()) {
              currentValue = null;
              return false;
          }
          currentValue = values.next();
          return true;
      }
      
      @Override
      public void close() {
          closed = true;
      }
      
      @Override
      public ResultSetMetaData getMetaData() {
          checkState();
          return new GeneratedKeysResultSetMetaData(column);
      }
      
      @Override
      public boolean wasNull() {
          checkState();
          return false;
      }
      
      @Override
      public String getString(final int columnIndex) {
          checkStateForGetData();
          return currentValue.toString();
      }
      
      @Override
      public String getString(final String columnLabel) {
          return getString(1);
      }
      
      @Override
     public String getNString(final int columnIndex) {
         return getString(columnIndex);
     }
     
     @Override
     public String getNString(final String columnLabel) {
         return getString(columnLabel);
     }
     
     @Override
     public byte getByte(final int columnIndex) {
         checkStateForGetData();
         return Byte.parseByte(getString(columnIndex));
     }
     
     @Override
     public byte getByte(final String columnLabel) {
         return getByte(1);
     }
     
     @Override
     public short getShort(final int columnIndex) {
         checkStateForGetData();
         return Short.parseShort(getString(columnIndex));
     }
     
     @Override
     public short getShort(final String columnLabel) {
         return getShort(1);
     }
     
     @Override
     public int getInt(final int columnIndex) {
         checkStateForGetData();
         return Integer.parseInt(getString(columnIndex));
     }
     
     @Override
     public int getInt(final String columnLabel) {
         return getInt(1);
     }
     
     @Override
     public long getLong(final int columnIndex) {
         checkStateForGetData();
         return Long.parseLong(getString(columnIndex));
     }
     
     @Override
     public long getLong(final String columnLabel) {
         return getLong(1);
     }
     
     @Override
     public float getFloat(final int columnIndex) {
         checkStateForGetData();
         return Float.parseFloat(getString(columnIndex));
     }
     
     @Override
     public float getFloat(final String columnLabel) {
         return getFloat(1);
     }
     
     @Override
     public double getDouble(final int columnIndex) {
         checkStateForGetData();
         return Double.parseDouble(getString(columnIndex));
     }
     
     @Override
     public double getDouble(final String columnLabel) {
         return getDouble(1);
     }
     
     @Override
     public BigDecimal getBigDecimal(final int columnIndex, final int scale) {
         checkStateForGetData();
         return new BigDecimal(getString(columnIndex)).setScale(scale, RoundingMode.HALF_UP);
     }
     
     @Override
     public BigDecimal getBigDecimal(final String columnLabel, final int scale) {
         return getBigDecimal(1, scale);
     }
     
     @Override
     public BigDecimal getBigDecimal(final int columnIndex) {
         checkStateForGetData();
         return new BigDecimal(getString(columnIndex));
     }
     
     @Override
     public BigDecimal getBigDecimal(final String columnLabel) {
         return getBigDecimal(1);
     }
     
     @Override
     public byte[] getBytes(final int columnIndex) {
         checkStateForGetData();
         return getString(columnIndex).getBytes(StandardCharsets.UTF_8);
     }
     
     @Override
     public byte[] getBytes(final String columnLabel) {
         return getBytes(1);
     }
     
     @Override
     public Object getObject(final int columnIndex) {
         checkStateForGetData();
         return currentValue;
     }
     
     @Override
     public Object getObject(final String columnLabel) {
         return getObject(1);
     }
     
     @Override
     public int findColumn(final String columnLabel) {
         checkState();
         return 1;
     }
     
     @Override
     public int getType() {
         checkState();
         return TYPE_FORWARD_ONLY;
     }
     
     @Override
     public int getConcurrency() {
         checkState();
         return CONCUR_READ_ONLY;
     }
     
     @Override
     public Statement getStatement() {
         checkState();
         return statement;
     }
     
     private void checkStateForGetData() {
         checkState();
         Preconditions.checkNotNull(currentValue, "ResultSet should call next or has no more data.");
     }
     
     private void checkState() {
         Preconditions.checkState(!closed, "ResultSet has closed.");
     }
 }