/*
 * 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.gearpump.streaming.source

import java.time.Instant

import org.apache.gearpump.Message
import org.apache.gearpump.cluster.UserConfig
import org.apache.gearpump.streaming.MockUtil
import org.apache.gearpump.streaming.dsl.plan.functions.FunctionRunner
import org.apache.gearpump.streaming.dsl.task.TransformTask.Transform
import org.mockito.Mockito._
import org.scalacheck.Gen
import org.scalatest.mock.MockitoSugar
import org.scalatest.{Matchers, PropSpec}
import org.scalatest.prop.PropertyChecks

class DataSourceTaskSpec extends PropSpec with PropertyChecks with Matchers with MockitoSugar {

  private val runnerGen = {
    val runner = mock[FunctionRunner[Any, Any]]
    Gen.oneOf(Some(runner), None)
  }

  property("DataSourceTask should setup data source") {
    forAll(runnerGen, Gen.chooseNum[Long](0L, 1000L).map(Instant.ofEpochMilli)) {
      (runner: Option[FunctionRunner[Any, Any]], startTime: Instant) =>
      val taskContext = MockUtil.mockTaskContext
      implicit val system = MockUtil.system
      val dataSource = mock[DataSource]
      val config = UserConfig.empty
        .withInt(DataSourceConfig.SOURCE_READ_BATCH_SIZE, 1)
      val transform = new Transform[Any, Any](taskContext, runner)
      val sourceTask = new DataSourceTask[Any, Any](taskContext, config, dataSource, transform)

      sourceTask.onStart(startTime)

      verify(dataSource).open(taskContext, startTime)
    }
  }

  property("DataSourceTask should read from DataSource and transform inputs") {
    forAll(runnerGen, Gen.alphaStr) {
      (runner: Option[FunctionRunner[Any, Any]], str: String) =>
        val taskContext = MockUtil.mockTaskContext
        implicit val system = MockUtil.system
        val dataSource = mock[DataSource]
        val config = UserConfig.empty
          .withInt(DataSourceConfig.SOURCE_READ_BATCH_SIZE, 1)
        val transform = new Transform[Any, Any](taskContext, runner)
        val sourceTask = new DataSourceTask[Any, Any](taskContext, config, dataSource, transform)
        val msg = Message(str)
        when(dataSource.read()).thenReturn(msg)
        runner.foreach(r => {
          when(r.process(str)).thenReturn(Some(str))
          when(r.finish()).thenReturn(None)
        })

        sourceTask.onNext(Message("next"))
        sourceTask.onWatermarkProgress(Watermark.MAX)

        verify(taskContext).output(Message(str, Watermark.MAX))
    }
  }

  property("DataSourceTask should teardown DataSource") {
    forAll(runnerGen) { (runner: Option[FunctionRunner[Any, Any]]) =>
      val taskContext = MockUtil.mockTaskContext
      implicit val system = MockUtil.system
      val dataSource = mock[DataSource]
      val config = UserConfig.empty
        .withInt(DataSourceConfig.SOURCE_READ_BATCH_SIZE, 1)
      val transform = new Transform[Any, Any](taskContext, runner)
      val sourceTask = new DataSourceTask[Any, Any](taskContext, config, dataSource, transform)

      sourceTask.onStop()

      verify(dataSource).close()
    }
  }
}