/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Darin Fisher <darin@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsBrowserStatusFilter.h"
#include "nsIChannel.h"
#include "nsITimer.h"
#include "nsIServiceManager.h"
#include "nsString.h"

// XXX
// XXX  DO NOT TOUCH THIS CODE UNLESS YOU KNOW WHAT YOU'RE DOING !!!
// XXX

//-----------------------------------------------------------------------------
// nsBrowserStatusFilter <public>
//-----------------------------------------------------------------------------

nsBrowserStatusFilter::nsBrowserStatusFilter()
    : mCurProgress(0)
    , mMaxProgress(0)
    , mStatusIsDirty(PR_TRUE)
    , mCurrentPercentage(0)
    , mTotalRequests(0)
    , mFinishedRequests(0)
    , mUseRealProgressFlag(PR_FALSE)
    , mDelayedStatus(PR_FALSE)
    , mDelayedProgress(PR_FALSE)
{
}

nsBrowserStatusFilter::~nsBrowserStatusFilter()
{
    if (mTimer) {
        mTimer->Cancel();
    }
}

//-----------------------------------------------------------------------------
// nsBrowserStatusFilter::nsISupports
//-----------------------------------------------------------------------------

NS_IMPL_ISUPPORTS4(nsBrowserStatusFilter,
                   nsIWebProgress,
                   nsIWebProgressListener,
                   nsIWebProgressListener2,
                   nsISupportsWeakReference)

//-----------------------------------------------------------------------------
// nsBrowserStatusFilter::nsIWebProgress
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsBrowserStatusFilter::AddProgressListener(nsIWebProgressListener *aListener,
                                           PRUint32 aNotifyMask)
{
    mListener = aListener;
    return NS_OK;
}

NS_IMETHODIMP
nsBrowserStatusFilter::RemoveProgressListener(nsIWebProgressListener *aListener)
{
    if (aListener == mListener)
        mListener = nsnull;
    return NS_OK;
}

NS_IMETHODIMP
nsBrowserStatusFilter::GetDOMWindow(nsIDOMWindow **aResult)
{
    NS_NOTREACHED("nsBrowserStatusFilter::GetDOMWindow");
    return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsBrowserStatusFilter::GetIsLoadingDocument(PRBool *aIsLoadingDocument)
{
    NS_NOTREACHED("nsBrowserStatusFilter::GetIsLoadingDocument");
    return NS_ERROR_NOT_IMPLEMENTED;
}


//-----------------------------------------------------------------------------
// nsBrowserStatusFilter::nsIWebProgressListener
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsBrowserStatusFilter::OnStateChange(nsIWebProgress *aWebProgress,
                                     nsIRequest *aRequest,
                                     PRUint32 aStateFlags,
                                     nsresult aStatus)
{
    if (!mListener)
        return NS_OK;

    if (aStateFlags & STATE_START) {
        if (aStateFlags & STATE_IS_NETWORK) {
            ResetMembers();
        }
        if (aStateFlags & STATE_IS_REQUEST) {
            ++mTotalRequests;

            // if the total requests exceeds 1, then we'll base our progress
            // notifications on the percentage of completed requests.
            // otherwise, progress for the single request will be reported.
            mUseRealProgressFlag = (mTotalRequests == 1);
        }
    }
    else if (aStateFlags & STATE_STOP) {
        if (aStateFlags & STATE_IS_REQUEST) {
            ++mFinishedRequests;
            // Note: Do not return from here. This is necessary so that the
            // STATE_STOP can still be relayed to the listener if needed
            // (bug 209330)
            if (!mUseRealProgressFlag && mTotalRequests)
                OnProgressChange(nsnull, nsnull, 0, 0,
                                 mFinishedRequests, mTotalRequests);
        }
    }
    else if (aStateFlags & STATE_TRANSFERRING) {
        if (aStateFlags & STATE_IS_REQUEST) {
            if (!mUseRealProgressFlag && mTotalRequests)
                return OnProgressChange(nsnull, nsnull, 0, 0,
                                        mFinishedRequests, mTotalRequests);
        }

        // no need to forward this state change
        return NS_OK;
    } else {
        // no need to forward this state change
        return NS_OK;
    }

    // If we're here, we have either STATE_START or STATE_STOP.  The
    // listener only cares about these in certain conditions.
    PRBool isLoadingDocument = PR_FALSE;
    if ((aStateFlags & nsIWebProgressListener::STATE_IS_NETWORK ||
         (aStateFlags & nsIWebProgressListener::STATE_IS_REQUEST &&
          mFinishedRequests == mTotalRequests &&
          (aWebProgress->GetIsLoadingDocument(&isLoadingDocument),
           !isLoadingDocument)))) {
        if (mTimer && (aStateFlags & nsIWebProgressListener::STATE_STOP)) {
            mTimer->Cancel();
            ProcessTimeout();
        }

        return mListener->OnStateChange(aWebProgress, aRequest, aStateFlags,
                                        aStatus);
    }

    return NS_OK;
}

NS_IMETHODIMP
nsBrowserStatusFilter::OnProgressChange(nsIWebProgress *aWebProgress,
                                        nsIRequest *aRequest,
                                        PRInt32 aCurSelfProgress,
                                        PRInt32 aMaxSelfProgress,
                                        PRInt32 aCurTotalProgress,
                                        PRInt32 aMaxTotalProgress)
{
    if (!mListener)
        return NS_OK;

    if (!mUseRealProgressFlag && aRequest)
        return NS_OK;

    //
    // limit frequency of calls to OnProgressChange
    //

    mCurProgress = (PRInt64)aCurTotalProgress;
    mMaxProgress = (PRInt64)aMaxTotalProgress;

    if (mDelayedProgress)
        return NS_OK;

    if (!mDelayedStatus) {
        MaybeSendProgress();
        StartDelayTimer();
    }

    mDelayedProgress = PR_TRUE;

    return NS_OK;
}

NS_IMETHODIMP
nsBrowserStatusFilter::OnLocationChange(nsIWebProgress *aWebProgress,
                                        nsIRequest *aRequest,
                                        nsIURI *aLocation)
{
    if (!mListener)
        return NS_OK;

    return mListener->OnLocationChange(aWebProgress, aRequest, aLocation);
}

NS_IMETHODIMP
nsBrowserStatusFilter::OnStatusChange(nsIWebProgress *aWebProgress,
                                      nsIRequest *aRequest,
                                      nsresult aStatus,
                                      const PRUnichar *aMessage)
{
    if (!mListener)
        return NS_OK;

    //
    // limit frequency of calls to OnStatusChange
    //
    if (mStatusIsDirty || !mCurrentStatusMsg.Equals(aMessage)) {
        mStatusIsDirty = PR_TRUE;
        mStatusMsg = aMessage;
    }

    if (mDelayedStatus)
        return NS_OK;

    if (!mDelayedProgress) {
      MaybeSendStatus();
      StartDelayTimer();
    }

    mDelayedStatus = PR_TRUE;

    return NS_OK;
}

NS_IMETHODIMP
nsBrowserStatusFilter::OnSecurityChange(nsIWebProgress *aWebProgress,
                                        nsIRequest *aRequest,
                                        PRUint32 aState)
{
    if (!mListener)
        return NS_OK;

    return mListener->OnSecurityChange(aWebProgress, aRequest, aState);
}

//-----------------------------------------------------------------------------
// nsBrowserStatusFilter::nsIWebProgressListener2
//-----------------------------------------------------------------------------
NS_IMETHODIMP
nsBrowserStatusFilter::OnProgressChange64(nsIWebProgress *aWebProgress,
                                          nsIRequest *aRequest,
                                          PRInt64 aCurSelfProgress,
                                          PRInt64 aMaxSelfProgress,
                                          PRInt64 aCurTotalProgress,
                                          PRInt64 aMaxTotalProgress)
{
    // XXX truncates 64-bit to 32-bit
    return OnProgressChange(aWebProgress, aRequest,
                            (PRInt32)aCurSelfProgress,
                            (PRInt32)aMaxSelfProgress,
                            (PRInt32)aCurTotalProgress,
                            (PRInt32)aMaxTotalProgress);
}

NS_IMETHODIMP
nsBrowserStatusFilter::OnRefreshAttempted(nsIWebProgress *aWebProgress,
                                          nsIURI *aUri,
                                          PRInt32 aDelay,
                                          PRBool aSameUri,
                                          PRBool *allowRefresh)
{
    nsCOMPtr<nsIWebProgressListener2> listener =
        do_QueryInterface(mListener);
    if (!listener) {
        *allowRefresh = PR_TRUE;
        return NS_OK;
    }

    return listener->OnRefreshAttempted(aWebProgress, aUri, aDelay, aSameUri,
                                        allowRefresh);
}

//-----------------------------------------------------------------------------
// nsBrowserStatusFilter <private>
//-----------------------------------------------------------------------------

void
nsBrowserStatusFilter::ResetMembers()
{
    mTotalRequests = 0;
    mFinishedRequests = 0;
    mUseRealProgressFlag = PR_FALSE;
    mMaxProgress = 0;
    mCurProgress = 0;
    mCurrentPercentage = 0;
    mStatusIsDirty = PR_TRUE;
}

void
nsBrowserStatusFilter::MaybeSendProgress() 
{
    if (mCurProgress > mMaxProgress || mCurProgress <= 0) 
        return;

    // check our percentage
    PRInt32 percentage = (PRInt32) double(mCurProgress) * 100 / mMaxProgress;

    // The progress meter only updates for increases greater than 3 percent
    if (percentage > (mCurrentPercentage + 3)) {
        mCurrentPercentage = percentage;
        // XXX truncates 64-bit to 32-bit
        mListener->OnProgressChange(nsnull, nsnull, 0, 0,
                                    (PRInt32)mCurProgress,
                                    (PRInt32)mMaxProgress);
    }
}

void
nsBrowserStatusFilter::MaybeSendStatus()
{
    if (mStatusIsDirty) {
        mListener->OnStatusChange(nsnull, nsnull, 0, mStatusMsg.get());
        mCurrentStatusMsg = mStatusMsg;
        mStatusIsDirty = PR_FALSE;
    }
}

nsresult
nsBrowserStatusFilter::StartDelayTimer()
{
    NS_ASSERTION(!DelayInEffect(), "delay should not be in effect");

    mTimer = do_CreateInstance("@mozilla.org/timer;1");
    if (!mTimer)
        return NS_ERROR_FAILURE;

    return mTimer->InitWithFuncCallback(TimeoutHandler, this, 160, 
                                        nsITimer::TYPE_ONE_SHOT);
}

void
nsBrowserStatusFilter::ProcessTimeout()
{
    mTimer = nsnull;

    if (!mListener)
        return;

    if (mDelayedStatus) {
        mDelayedStatus = PR_FALSE;
        MaybeSendStatus();
    }

    if (mDelayedProgress) {
        mDelayedProgress = PR_FALSE;
        MaybeSendProgress();
    }
}

void
nsBrowserStatusFilter::TimeoutHandler(nsITimer *aTimer, void *aClosure)
{
    nsBrowserStatusFilter *self = reinterpret_cast<nsBrowserStatusFilter *>(aClosure);
    if (!self) {
        NS_ERROR("no self");
        return;
    }

    self->ProcessTimeout();
}
