#ifndef __TaskManager_h
#define __TaskManager_h

#include <ctime>
#include <list>

namespace b2bua
{

/**
 * The TaskManager keeps a record of all recurring tasks, and
 * also tasks scheduled to take place at a specified time.
 * It provides an efficient way of giving CPU time to each task.
 * TaskManager is expected to be used with tasks that do not block
 * or run for extended periods of time.
 * TaskManager runs all tasks in a single thread.
 */

class TaskManager {

public:

  typedef enum TaskResult {
    TaskComplete,		// the task doesn't need to run again
    TaskNotComplete,		// the task would like to run again shortly
    TaskIndefinite		// the task can be run again, but doesn't
				// object if the TaskManager stops
  };

  class RecurringTask {
  public:
    virtual ~RecurringTask() {};
    virtual TaskResult doTaskProcessing() = 0;
    virtual void stop() = 0;
  };

  class ScheduledTask {
  public:
    virtual ~ScheduledTask() {};
    virtual void doTaskSchedule() = 0;
  };

  TaskManager();
  
  /**
   * Start the task manager - blocks until complete.
   * Exits when all recurring tasks exit and no scheduled tasks remain.
   */
  void start();
  void addRecurringTask(RecurringTask *t);
  void scheduleTask(ScheduledTask *t, time_t& executionTime);

  void stop();

protected:
  std::list<RecurringTask *> recurringTasks;
  std::list<ScheduledTask *> scheduleTasks;

};

}

#endif

/* ====================================================================
 *
 * Copyright 2012 Daniel Pocock.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. Neither the name of the author(s) nor the names of any contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 *
 *
 */