/*

 * Copyright (C) 2007 Apple 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. 

 */

#include "config.h"

#include "ProgressTracker.h"

#include "DocumentLoader.h"

#include "Frame.h"

#include "FrameLoader.h"

#include "FrameLoaderStateMachine.h"

#include "FrameLoaderClient.h"

#include "Logging.h"

#include "ResourceResponse.h"

#include <wtf/text/CString.h>

#include <wtf/CurrentTime.h>

using std::min;

namespace WebCore {

// Always start progress at initialProgressValue. This helps provide feedback as 

// soon as a load starts.

static const double initialProgressValue = 0.1;

// Similarly, always leave space at the end. This helps show the user that we're not done

// until we're done.

static const double finalProgressValue = 0.9; // 1.0 - initialProgressValue

static const int progressItemDefaultEstimatedLength = 1024 * 16;

struct ProgressItem : Noncopyable {

    ProgressItem(long long length) 

        : bytesReceived(0)

        , estimatedLength(length) { }

    long long bytesReceived;

    long long estimatedLength;

};

ProgressTracker::ProgressTracker()

    : m_uniqueIdentifier(0)

    , m_totalPageAndResourceBytesToLoad(0)

    , m_totalBytesReceived(0)

    , m_lastNotifiedProgressValue(0)

    , m_lastNotifiedProgressTime(0)

    , m_progressNotificationInterval(0.02)

    , m_progressNotificationTimeInterval(0.1)

    , m_finalProgressChangedSent(false)

    , m_progressValue(0)

    , m_numProgressTrackedFrames(0)

{

}

ProgressTracker::~ProgressTracker()

{

    deleteAllValues(m_progressItems);

}

double ProgressTracker::estimatedProgress() const

{

    return m_progressValue;

}

void ProgressTracker::reset()

{

    deleteAllValues(m_progressItems);

    m_progressItems.clear();    

    m_totalPageAndResourceBytesToLoad = 0;

    m_totalBytesReceived = 0;

    m_progressValue = 0;

    m_lastNotifiedProgressValue = 0;

    m_lastNotifiedProgressTime = 0;

    m_finalProgressChangedSent = false;

    m_numProgressTrackedFrames = 0;

    m_originatingProgressFrame = 0;

}

void ProgressTracker::progressStarted(Frame* frame)

{

    LOG(Progress, "Progress started (%p) - frame %p(\"%s\"), value %f, tracked frames %d, originating frame %p", this, frame, frame->tree()->name().string().utf8().data(), m_progressValue, m_numProgressTrackedFrames, m_originatingProgressFrame.get());

    frame->loader()->client()->willChangeEstimatedProgress();

    if (m_numProgressTrackedFrames == 0 || m_originatingProgressFrame == frame) {

        reset();

        m_progressValue = initialProgressValue;

        m_originatingProgressFrame = frame;

        m_originatingProgressFrame->loader()->client()->postProgressStartedNotification();

    }

    m_numProgressTrackedFrames++;

    frame->loader()->client()->didChangeEstimatedProgress();

}

void ProgressTracker::progressCompleted(Frame* frame)

{

    LOG(Progress, "Progress completed (%p) - frame %p(\"%s\"), value %f, tracked frames %d, originating frame %p", this, frame, frame->tree()->name().string().utf8().data(), m_progressValue, m_numProgressTrackedFrames, m_originatingProgressFrame.get());

    if (m_numProgressTrackedFrames <= 0)

        return;

    frame->loader()->client()->willChangeEstimatedProgress();

    m_numProgressTrackedFrames--;

    if (m_numProgressTrackedFrames == 0 ||

        (frame == m_originatingProgressFrame && m_numProgressTrackedFrames != 0))

        finalProgressComplete();

    frame->loader()->client()->didChangeEstimatedProgress();

}

void ProgressTracker::finalProgressComplete()

{

    LOG(Progress, "Final progress complete (%p)", this);

    RefPtr<Frame> frame = m_originatingProgressFrame.release();

    // Before resetting progress value be sure to send client a least one notification

    // with final progress value.

    if (!m_finalProgressChangedSent) {

        m_progressValue = 1;

        frame->loader()->client()->postProgressEstimateChangedNotification();

    }

    reset();

    frame->loader()->client()->setMainFrameDocumentReady(true);

    frame->loader()->client()->postProgressFinishedNotification();

}

void ProgressTracker::incrementProgress(unsigned long identifier, const ResourceResponse& response)

{

    LOG(Progress, "Progress incremented (%p) - value %f, tracked frames %d, originating frame %p", this, m_progressValue, m_numProgressTrackedFrames, m_originatingProgressFrame.get());

    if (m_numProgressTrackedFrames <= 0)

        return;

    long long estimatedLength = response.expectedContentLength();

    if (estimatedLength < 0)

        estimatedLength = progressItemDefaultEstimatedLength;

    m_totalPageAndResourceBytesToLoad += estimatedLength;

    if (ProgressItem* item = m_progressItems.get(identifier)) {

        item->bytesReceived = 0;

        item->estimatedLength = estimatedLength;

    } else

        m_progressItems.set(identifier, new ProgressItem(estimatedLength));

}

void ProgressTracker::incrementProgress(unsigned long identifier, const char*, int length)

{

    ProgressItem* item = m_progressItems.get(identifier);

    // FIXME: Can this ever happen?

    if (!item)

        return;

    RefPtr<Frame> frame = m_originatingProgressFrame;

    frame->loader()->client()->willChangeEstimatedProgress();

    unsigned bytesReceived = length;

    double increment, percentOfRemainingBytes;

    long long remainingBytes, estimatedBytesForPendingRequests;

    item->bytesReceived += bytesReceived;

    if (item->bytesReceived > item->estimatedLength) {

        m_totalPageAndResourceBytesToLoad += ((item->bytesReceived * 2) - item->estimatedLength);

        item->estimatedLength = item->bytesReceived * 2;

    }

    int numPendingOrLoadingRequests = frame->loader()->numPendingOrLoadingRequests(true);

    estimatedBytesForPendingRequests = progressItemDefaultEstimatedLength * numPendingOrLoadingRequests;

    remainingBytes = ((m_totalPageAndResourceBytesToLoad + estimatedBytesForPendingRequests) - m_totalBytesReceived);

    if (remainingBytes > 0)  // Prevent divide by 0.

        percentOfRemainingBytes = (double)bytesReceived / (double)remainingBytes;

    else

        percentOfRemainingBytes = 1.0;

    // For documents that use WebCore's layout system, treat first layout as the half-way point.

    // FIXME: The hasHTMLView function is a sort of roundabout way of asking "do you use WebCore's layout system".

    bool useClampedMaxProgress = frame->loader()->client()->hasHTMLView()

        && !frame->loader()->stateMachine()->firstLayoutDone();

    double maxProgressValue = useClampedMaxProgress ? 0.5 : finalProgressValue;

    increment = (maxProgressValue - m_progressValue) * percentOfRemainingBytes;

    m_progressValue += increment;

    m_progressValue = min(m_progressValue, maxProgressValue);

    ASSERT(m_progressValue >= initialProgressValue);

    m_totalBytesReceived += bytesReceived;

    double now = currentTime();

    double notifiedProgressTimeDelta = now - m_lastNotifiedProgressTime;

    LOG(Progress, "Progress incremented (%p) - value %f, tracked frames %d", this, m_progressValue, m_numProgressTrackedFrames);

    double notificationProgressDelta = m_progressValue - m_lastNotifiedProgressValue;

    if ((notificationProgressDelta >= m_progressNotificationInterval ||

         notifiedProgressTimeDelta >= m_progressNotificationTimeInterval) &&

        m_numProgressTrackedFrames > 0) {

        if (!m_finalProgressChangedSent) {

            if (m_progressValue == 1)

                m_finalProgressChangedSent = true;

            frame->loader()->client()->postProgressEstimateChangedNotification();

            m_lastNotifiedProgressValue = m_progressValue;

            m_lastNotifiedProgressTime = now;

        }

    }

    frame->loader()->client()->didChangeEstimatedProgress();

}

void ProgressTracker::completeProgress(unsigned long identifier)

{

    ProgressItem* item = m_progressItems.get(identifier);

    // FIXME: Can this happen?

    if (!item)

        return;

    // Adjust the total expected bytes to account for any overage/underage.

    long long delta = item->bytesReceived - item->estimatedLength;

    m_totalPageAndResourceBytesToLoad += delta;

    item->estimatedLength = item->bytesReceived;

    m_progressItems.remove(identifier);

    delete item;

}

unsigned long ProgressTracker::createUniqueIdentifier()

{

    return ++m_uniqueIdentifier;

}

}