package org.broadinstitute.sting.queue.engine

import org.jgrapht.traverse.TopologicalOrderIterator
import org.jgrapht.event.{EdgeTraversalEvent, TraversalListenerAdapter}
import collection.JavaConversions._
import org.broadinstitute.sting.queue.util.Logging
import org.broadinstitute.sting.queue.function.{MappingFunction, CommandLineFunction, DispatchFunction, QFunction}

/**
 * Loops over the job graph running jobs as the edges are traversed
 */
abstract class TopologicalJobScheduler(private val qGraph: QGraph)
    extends CommandLineRunner with DispatchJobRunner with Logging {

  protected val iterator = new TopologicalOrderIterator(this.qGraph.jobGraph)

  iterator.addTraversalListener(new TraversalListenerAdapter[QNode, QFunction] {
    override def edgeTraversed(event: EdgeTraversalEvent[QNode, QFunction]) = event.getEdge match {
      case f: DispatchFunction if (TopologicalJobScheduler.this.qGraph.bsubAllJobs) => dispatch(f, qGraph)
      case f: CommandLineFunction => run(f, qGraph)
      case f: MappingFunction => /* do nothing for mapping functions */
    }
  })

  def runJobs = {
    logger.info("Number of jobs: %s".format(this.qGraph.numJobs))
    for (target <- iterator) {
      // Do nothing for now, let event handler respond
    }
  }
}