/*
 * 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.
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package org.apache.spark.sql.hudi.command.procedures

import org.apache.hudi.common.table.timeline.{HoodieActiveTimeline, HoodieInstant, HoodieTimeline}

import org.apache.spark.sql.Row
import org.apache.spark.sql.types.{DataTypes, Metadata, StructField, StructType}

import java.util
import java.util.function.Supplier
import java.util.stream.Collectors

class ShowSavepointsProcedure extends BaseProcedure with ProcedureBuilder {
  private val PARAMETERS = Array[ProcedureParameter](
    ProcedureParameter.optional(0, "table", DataTypes.StringType),
    ProcedureParameter.optional(1, "path", DataTypes.StringType)
  )

  private val OUTPUT_TYPE = new StructType(Array[StructField](
    StructField("savepoint_time", DataTypes.StringType, nullable = true, Metadata.empty))
  )

  def parameters: Array[ProcedureParameter] = PARAMETERS

  def outputType: StructType = OUTPUT_TYPE

  override def call(args: ProcedureArgs): Seq[Row] = {
    super.checkArgs(PARAMETERS, args)

    val tableName = getArgValueOrDefault(args, PARAMETERS(0))
    val tablePath = getArgValueOrDefault(args, PARAMETERS(1))

    val basePath: String = getBasePath(tableName, tablePath)
    val metaClient = createMetaClient(jsc, basePath)

    val activeTimeline: HoodieActiveTimeline = metaClient.getActiveTimeline
    val timeline: HoodieTimeline = activeTimeline.getSavePointTimeline.filterCompletedInstants
    val commits: util.List[HoodieInstant] = timeline.getReverseOrderedInstants.collect(Collectors.toList[HoodieInstant])

    if (commits.isEmpty) Seq.empty[Row] else {
      commits.toArray.map(instant => instant.asInstanceOf[HoodieInstant].getTimestamp).map(p => Row(p)).toSeq
    }
  }

  override def build: Procedure = new ShowSavepointsProcedure()
}

object ShowSavepointsProcedure {
  val NAME: String = "show_savepoints"

  def builder: Supplier[ProcedureBuilder] = new Supplier[ProcedureBuilder] {
    override def get(): ShowSavepointsProcedure = new ShowSavepointsProcedure()
  }
}
