/*
Copyright 2003-2012 Dmitry Barashev, GanttProject Team

This file is part of GanttProject, an opensource project management tool.

GanttProject is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

GanttProject is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GanttProject.  If not, see <http://www.gnu.org/licenses/>.
 */
package net.sourceforge.ganttproject.task.algorithm;

import net.sourceforge.ganttproject.task.Task;
import net.sourceforge.ganttproject.task.TaskContainmentHierarchyFacade;

public abstract class RecalculateTaskCompletionPercentageAlgorithm extends AlgorithmBase {
  @Override
  public void run() {
    if (!isEnabled()) {
      return;
    }
    TaskContainmentHierarchyFacade facade = createContainmentFacade();
    for (Task t : facade.getTasksInDocumentOrder()) {
      if (!facade.hasNestedTasks(t)) {
        run(t);
      }
    }
  }

  public void run(Task task) {
    if (!isEnabled()) {
      return;
    }
    TaskContainmentHierarchyFacade facade = createContainmentFacade();
    recalculateSupertaskCompletionPercentageBottomUp(task, facade);
  }

  private void recalculateSupertaskCompletionPercentageBottomUp(Task task, TaskContainmentHierarchyFacade facade) {
    while (task != null) {
      recalculateSupertaskCompletionPercentage(task, facade);
      task = facade.getContainer(task);
    }
  }

  private void recalculateSupertaskCompletionPercentage(Task task, TaskContainmentHierarchyFacade facade) {
    Task[] nestedTasks = facade.getNestedTasks(task);
    if (nestedTasks.length > 0) {
      int completedDays = 0;
      long plannedDays = 0;
      for (int i = 0; i < nestedTasks.length; i++) {
        Task next = nestedTasks[i];
        long nextDuration = next.isMilestone() ? 1 : next.getDuration().getLength();
        completedDays += nextDuration * next.getCompletionPercentage();
        plannedDays += nextDuration;
      }
      int completionPercentage = plannedDays == 0 ? 0 : (int) (completedDays / plannedDays);
      task.setCompletionPercentage(completionPercentage);
    }
  }

  protected abstract TaskContainmentHierarchyFacade createContainmentFacade();

}