/*
 * 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.flink.table.plan.nodes.calcite

import org.apache.calcite.plan.{RelOptCluster, RelTraitSet}
import org.apache.calcite.rel.`type`.{RelDataType, RelDataTypeField, RelDataTypeFieldImpl, RelRecordType}
import org.apache.calcite.rel.{RelNode, RelWriter, SingleRel}
import org.apache.flink.table.calcite.FlinkTypeFactory

import scala.collection.JavaConversions._

abstract class WatermarkAssigner(
    cluster: RelOptCluster,
    traits: RelTraitSet,
    inputNode: RelNode,
    val rowtimeField: String,
    val watermarkOffset: Long)
  extends SingleRel(cluster, traits, inputNode) {

  override def deriveRowType(): RelDataType = {
    val inputRowType = inputNode.getRowType.asInstanceOf[RelRecordType]
    val fieldList = inputRowType.getFieldList.map {
      case f: RelDataTypeField if f.getName.equals(rowtimeField) =>
        new RelDataTypeFieldImpl(
          rowtimeField,
          f.getIndex,
          cluster.getTypeFactory.asInstanceOf[FlinkTypeFactory].createRowtimeIndicatorType())
      case f: RelDataTypeField => f
    }
    val typeFactory = getCluster.getTypeFactory.asInstanceOf[FlinkTypeFactory]
    val builder = typeFactory.builder
    builder.addAll(fieldList)
    builder.build()
  }

  override def explainTerms(pw: RelWriter): RelWriter = {
    super.explainTerms(pw)
      .item("fields", getRowType.getFieldNames)
      .item("rowtimeField", rowtimeField)
      .item("watermarkOffset", watermarkOffset)
  }
}