/*
 * Copyright (C) 2006 Apple Computer, Inc.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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. 
 */

#ifndef WebTimerBase_h
#define WebTimerBase_h

#include <wtf/Noncopyable.h>
#include <wtf/Threading.h>
#include <wtf/FastAllocBase.h>
#include <wtf/Vector.h>
#include <vector>
#include "third_party/WebKit/public/platform/WebTraceLocation.h"
#include "third_party/WebKit/public/platform/WebThread.h"

namespace blink {

class Task;

} // blink

namespace content {

// Time intervals are all in seconds.

class TimerHeapElement;
class WebThreadImpl;

class WebTimerBase {
    WTF_MAKE_NONCOPYABLE(WebTimerBase); WTF_MAKE_FAST_ALLOCATED(WebTimerBase);
public:
    static WebTimerBase* create(WebThreadImpl* threadTimers, const blink::WebTraceLocation& location, blink::WebThread::Task* task, int priority)
    {
        return new WebTimerBase(threadTimers, location, task, priority);
    }
    ~WebTimerBase();

    std::vector<WebTimerBase*>& timerHeap();
    const std::vector<WebTimerBase*>& timerHeap() const;

    void start(double nextFireInterval, double repeatInterval);

    void startRepeating(double repeatInterval) { start(repeatInterval, repeatInterval); }
    void startOneShot(double interval) { start(interval, 0); }

    void stop();
    bool isActive() const;

    double nextFireInterval() const;
    double repeatInterval() const { return m_repeatInterval; }

    void augmentFireInterval(double delta) { setNextFireTime(m_nextFireTime + delta, nullptr); }
    void augmentRepeatInterval(double delta) { augmentFireInterval(delta); m_repeatInterval += delta; }

    static void fireTimersInNestedEventLoop();

    virtual void fired();

    void ref();
    void deref();
    int refCount() const;

private:
    WebTimerBase(WebThreadImpl* threadTimers, const blink::WebTraceLocation& location, blink::WebThread::Task* task, int priority);

    void startFromOtherThread(double interval, double* createTimeOnOtherThread, unsigned* heapInsertionOrder);

    void checkConsistency() const;
    void checkHeapIndex() const;

    void setNextFireTime(double, unsigned* heapInsertionOrder);

    bool inHeap() const { return m_heapIndex != -1; }

    void heapDecreaseKey();
    void heapDelete();
    void heapDeleteMin();
    void heapIncreaseKey();
    void heapInsert();
    void heapPop();
    void heapPopMin();

    void deleteLastOne();

    WebThreadImpl* m_threadTimers;

    double m_nextFireTime; // 0 if inactive
    double m_repeatInterval; // 0 if not repeating
    int m_heapIndex; // -1 if not in heap
    unsigned m_heapInsertionOrder; // Used to keep order among equal-fire-time timers

#ifndef NDEBUG
    ThreadIdentifier m_thread;
#endif

    friend class TimerHeapElement;
    friend class WebThreadImpl;
    friend bool operator<(const TimerHeapElement&, const TimerHeapElement&);

    blink::WebTraceLocation m_location;
    blink::WebThread::Task* m_task;

    int m_ref;
    int m_priority;
};

inline bool WebTimerBase::isActive() const
{
    //ASSERT(m_thread == currentThread());
    return m_nextFireTime != 0.0;
}

} // content

#endif // WebTimerBase
