/*
    * 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.db.protocol.postgresql.packet.command.query.extended.bind;
  
  import lombok.Getter;
  import org.apache.shardingsphere.db.protocol.postgresql.constant.PostgreSQLValueFormat;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.command.PostgreSQLCommandPacket;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.command.PostgreSQLCommandPacketType;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.extended.PostgreSQLColumnType;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.extended.bind.protocol.PostgreSQLBinaryProtocolValue;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.command.query.extended.bind.protocol.PostgreSQLBinaryProtocolValueFactory;
  import org.apache.shardingsphere.db.protocol.postgresql.packet.identifier.PostgreSQLIdentifierTag;
  import org.apache.shardingsphere.db.protocol.postgresql.payload.PostgreSQLPacketPayload;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * Command bind packet for PostgreSQL.
   */
  public final class PostgreSQLComBindPacket extends PostgreSQLCommandPacket {
      
      private final PostgreSQLPacketPayload payload;
      
      @Getter
      private final String portal;
      
      @Getter
      private final String statementId;
      
      public PostgreSQLComBindPacket(final PostgreSQLPacketPayload payload) {
          this.payload = payload;
          payload.readInt4();
          portal = payload.readStringNul();
          statementId = payload.readStringNul();
      }
      
      /**
       * Read parameters from bind message.
       *
       * @param paramTypes parameter types
       * @return values of parameter
       */
      public List<Object> readParameters(final List<PostgreSQLColumnType> paramTypes) {
          List<Integer> paramFormats = getParameterFormats();
          int parameterCount = payload.readInt2();
          List<Object> result = new ArrayList<>(parameterCount);
          for (int paramIndex = 0; paramIndex < parameterCount; paramIndex++) {
              int parameterValueLength = payload.readInt4();
              if (-1 == parameterValueLength) {
                  result.add(null);
                  continue;
              }
              Object paramValue = isTextParameterValue(paramFormats, paramIndex)
                      ? getTextParameterValue(payload, parameterValueLength, paramTypes.get(paramIndex))
                      : getBinaryParameterValue(payload, parameterValueLength, paramTypes.get(paramIndex));
              result.add(paramValue);
          }
          return result;
      }
      
      private List<Integer> getParameterFormats() {
          int parameterFormatCount = payload.readInt2();
          List<Integer> result = new ArrayList<>(parameterFormatCount);
          for (int i = 0; i < parameterFormatCount; i++) {
              result.add(payload.readInt2());
          }
          return result;
      }
      
      private boolean isTextParameterValue(final List<Integer> paramFormats, final int paramIndex) {
          if (paramFormats.isEmpty()) {
              return true;
          }
          return PostgreSQLValueFormat.TEXT.getCode() == paramFormats.get(1 == paramFormats.size() ? 0 : paramIndex);
      }
      
      private Object getTextParameterValue(final PostgreSQLPacketPayload payload, final int paramValueLength, final PostgreSQLColumnType paramType) {
          String value = payload.getByteBuf().readCharSequence(paramValueLength, payload.getCharset()).toString();
          return paramType.getTextValueParser().parse(value);
      }
      
      private Object getBinaryParameterValue(final PostgreSQLPacketPayload payload, final int paramValueLength, final PostgreSQLColumnType paramType) {
         PostgreSQLBinaryProtocolValue binaryProtocolValue = PostgreSQLBinaryProtocolValueFactory.getBinaryProtocolValue(paramType);
         return binaryProtocolValue.read(payload, paramValueLength);
     }
     
     /**
      * Read result formats from bind message.
      *
      * @return formats of value
      */
     public List<PostgreSQLValueFormat> readResultFormats() {
         int resultFormatsLength = payload.readInt2();
         if (0 == resultFormatsLength) {
             return Collections.emptyList();
         }
         if (1 == resultFormatsLength) {
             return Collections.singletonList(PostgreSQLValueFormat.valueOf(payload.readInt2()));
         }
         List<PostgreSQLValueFormat> result = new ArrayList<>(resultFormatsLength);
         for (int i = 0; i < resultFormatsLength; i++) {
             result.add(PostgreSQLValueFormat.valueOf(payload.readInt2()));
         }
         return result;
     }
     
     @Override
     protected void write(final PostgreSQLPacketPayload payload) {
     }
     
     @Override
     public PostgreSQLIdentifierTag getIdentifier() {
         return PostgreSQLCommandPacketType.BIND_COMMAND;
     }
 }