// updateMakespans
func updateMakespans(b *build.Build) error {
	// find all tasks associated with the build
	tasks, err := task.Find(task.ByBuildId(b.Id))
	if err != nil {
		return err
	}

	depPath := FindPredictedMakespan(tasks)
	return b.UpdateMakespans(depPath.TotalTime, CalculateActualMakespan(tasks))
}

//AddTasksToBuild creates the tasks for the given build of a project
func AddTasksToBuild(b *build.Build, project *Project, v *version.Version,
	taskNames []string) (*build.Build, error) {

	// find the build variant for this project/build
	buildVariant := project.FindBuildVariant(b.BuildVariant)
	if buildVariant == nil {
		return nil, fmt.Errorf("Could not find build %v in %v project file",
			b.BuildVariant, project.Identifier)
	}

	// create the new tasks for the build
	tasks, err := createTasksForBuild(
		project, buildVariant, b, v, BuildTaskIdTable(project, v), taskNames)
	if err != nil {
		return nil, fmt.Errorf("error creating tasks for build %v: %v",
			b.Id, err)
	}

	// insert the tasks into the db
	for _, task := range tasks {
		evergreen.Logger.Logf(slogger.INFO, "Creating task “%v”", task.DisplayName)
		if err := task.Insert(); err != nil {
			return nil, fmt.Errorf("error inserting task %v: %v", task.Id, err)
		}
	}

	// create task caches for all of the tasks, and add them into the build
	for _, t := range tasks {
		b.Tasks = append(b.Tasks, cacheFromTask(t))
	}

	// update the build to hold the new tasks
	if err = build.SetTasksCache(b.Id, b.Tasks); err != nil {
		return nil, err
	}

	return b, nil
}

func TestMarkAsDispatched(t *testing.T) {

	var (
		taskId  string
		hostId  string
		buildId string
		task    *Task
		myHost  *host.Host
		b       *build.Build
	)

	Convey("With a task", t, func() {

		taskId = "t1"
		hostId = "h1"
		buildId = "b1"

		task = &Task{
			Id:      taskId,
			BuildId: buildId,
		}

		myHost = &host.Host{
			Id: hostId,
		}

		b = &build.Build{
			Id: buildId,
			Tasks: []build.TaskCache{
				{Id: taskId},
			},
		}

		testutil.HandleTestingErr(
			db.ClearCollections(TasksCollection, build.Collection, host.Collection),
			t, "Error clearing test collections")

		So(task.Insert(), ShouldBeNil)
		So(myHost.Insert(), ShouldBeNil)
		So(b.Insert(), ShouldBeNil)

		Convey("when marking the task as dispatched, the fields for"+
			" the task, the host it is on, and the build it is a part of"+
			" should be set to reflect this", func() {

			// mark the task as dispatched
			So(task.MarkAsDispatched(myHost, time.Now()), ShouldBeNil)

			// make sure the task's fields were updated, both in memory and
			// in the db
			So(task.DispatchTime, ShouldNotResemble, time.Unix(0, 0))
			So(task.Status, ShouldEqual, evergreen.TaskDispatched)
			So(task.HostId, ShouldEqual, myHost.Id)
			So(task.LastHeartbeat, ShouldResemble, task.DispatchTime)
			task, err := FindTask(taskId)
			So(err, ShouldBeNil)
			So(task.DispatchTime, ShouldNotResemble, time.Unix(0, 0))
			So(task.Status, ShouldEqual, evergreen.TaskDispatched)
			So(task.HostId, ShouldEqual, myHost.Id)
			So(task.LastHeartbeat, ShouldResemble, task.DispatchTime)

			// make sure the build's fields were updated in the db
			b, err = build.FindOne(build.ById(buildId))
			So(err, ShouldBeNil)
			So(b.Tasks[0].Status, ShouldEqual, evergreen.TaskDispatched)

		})

	})

}