/*
 * 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
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 */

package org.apache.gearpump.streaming

import org.apache.gearpump.streaming.partitioner.PartitionerDescription
import org.apache.gearpump.streaming.task.TaskId
import org.apache.gearpump.util.Graph
import org.apache.gearpump.util.Graph.Node
import org.scalacheck.Gen
import org.scalatest.prop.PropertyChecks
import org.scalatest.{Matchers, PropSpec}

class DAGSpec extends PropSpec with PropertyChecks with Matchers {

  val parallelismGen = Gen.chooseNum[Int](1, 100)

  property("DAG should be built correctly for a single task") {
    forAll(parallelismGen) { (parallelism: Int) =>
      val task = ProcessorDescription(id = 0, taskClass = "task", parallelism = parallelism)
      val graph = Graph[ProcessorDescription, PartitionerDescription](task)
      val dag = DAG(graph)
      dag.processors.size shouldBe 1
      assert(dag.taskCount == parallelism)
      dag.tasks.sortBy(_.index) shouldBe (0 until parallelism).map(index => TaskId(0, index))
      dag.graph.edges shouldBe empty
    }
  }
}