/*
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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
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*/
package org.apache.griffin.measure.step.write

import org.apache.commons.lang.StringUtils
import org.apache.spark.sql.DataFrame

import org.apache.griffin.measure.context.DQContext

/**
  * update data source streaming cache
  */
case class DataSourceUpdateWriteStep(dsName: String,
                                     inputName: String
                                    ) extends WriteStep {

  val name: String = ""
  val writeTimestampOpt: Option[Long] = None

  def execute(context: DQContext): Boolean = {
    getDataSourceCacheUpdateDf(context) match {
      case Some(df) =>
        context.dataSources
          .find(ds => StringUtils.equals(ds.name, dsName))
          .foreach(_.updateData(df))
      case _ =>
        warn(s"update ${dsName} from ${inputName} fails")
    }
    true
  }

  private def getDataFrame(context: DQContext, name: String): Option[DataFrame] = {
    try {
      val df = context.sqlContext.table(s"`${name}`")
      Some(df)
    } catch {
      case e: Throwable =>
        error(s"get data frame ${name} fails", e)
        None
    }
  }

  private def getDataSourceCacheUpdateDf(context: DQContext): Option[DataFrame]
    = getDataFrame(context, inputName)

}