/*

 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.

 *           (C) 2007 Graham Dennis (graham.dennis@gmail.com)

 *

 * 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 Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission. 

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS 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 APPLE OR ITS 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 "ResourceLoader.h"

#include "ApplicationCacheHost.h"

#include "DocumentLoader.h"

#include "Frame.h"

#include "FrameLoader.h"

#include "InspectorTimelineAgent.h"

#include "Page.h"

#include "ProgressTracker.h"

#include "ResourceHandle.h"

#include "ResourceError.h"

#include "Settings.h"

#include "SharedBuffer.h"

namespace WebCore {

PassRefPtr<SharedBuffer> ResourceLoader::resourceData()

{

    if (m_resourceData)

        return m_resourceData;

    if (ResourceHandle::supportsBufferedData() && m_handle)

        return m_handle->bufferedData();

    return 0;

}

ResourceLoader::ResourceLoader(Frame* frame, bool sendResourceLoadCallbacks, bool shouldContentSniff)

    : m_frame(frame)

    , m_documentLoader(frame->loader()->activeDocumentLoader())

    , m_identifier(0)

    , m_reachedTerminalState(false)

    , m_cancelled(false)

    , m_calledDidFinishLoad(false)

    , m_sendResourceLoadCallbacks(sendResourceLoadCallbacks)

    , m_shouldContentSniff(shouldContentSniff)

    , m_shouldBufferData(true)

    , m_defersLoading(frame->page()->defersLoading())

{

}

ResourceLoader::~ResourceLoader()

{

    ASSERT(m_reachedTerminalState);

}

void ResourceLoader::releaseResources()

{

    ASSERT(!m_reachedTerminalState);

    // It's possible that when we release the handle, it will be

    // deallocated and release the last reference to this object.

    // We need to retain to avoid accessing the object after it

    // has been deallocated and also to avoid reentering this method.

    RefPtr<ResourceLoader> protector(this);

    m_frame = 0;

    m_documentLoader = 0;

    // We need to set reachedTerminalState to true before we release

    // the resources to prevent a double dealloc of WebView <rdar://problem/4372628>

    m_reachedTerminalState = true;

    m_identifier = 0;

    if (m_handle) {

        // Clear out the ResourceHandle's client so that it doesn't try to call

        // us back after we release it, unless it has been replaced by someone else.

        if (m_handle->client() == this)

            m_handle->setClient(0);

        m_handle = 0;

    }

    m_resourceData = 0;

    m_deferredRequest = ResourceRequest();

}

bool ResourceLoader::load(const ResourceRequest& r)

{

    ASSERT(!m_handle);

    ASSERT(m_deferredRequest.isNull());

    ASSERT(!m_documentLoader->isSubstituteLoadPending(this));

    ResourceRequest clientRequest(r);

    // https://bugs.webkit.org/show_bug.cgi?id=26391

    // The various plug-in implementations call directly to ResourceLoader::load() instead of piping requests

    // through FrameLoader. As a result, they miss the FrameLoader::addExtraFieldsToRequest() step which sets

    // up the 1st party for cookies URL. Until plug-in implementations can be reigned in to pipe through that

    // method, we need to make sure there is always a 1st party for cookies set.

    if (clientRequest.firstPartyForCookies().isNull()) {

        if (Document* document = m_frame->document())

            clientRequest.setFirstPartyForCookies(document->firstPartyForCookies());

    }

    willSendRequest(clientRequest, ResourceResponse());

    if (clientRequest.isNull()) {

        didFail(frameLoader()->cancelledError(r));

        return false;

    }

    if (m_documentLoader->scheduleArchiveLoad(this, clientRequest, r.url()))

        return true;

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

    if (m_documentLoader->applicationCacheHost()->maybeLoadResource(this, clientRequest, r.url()))

        return true;

#endif

    if (m_defersLoading) {

        m_deferredRequest = clientRequest;

        return true;

    }

    m_handle = ResourceHandle::create(clientRequest, this, m_frame.get(), m_defersLoading, m_shouldContentSniff);

    return true;

}

void ResourceLoader::setDefersLoading(bool defers)

{

    m_defersLoading = defers;

    if (m_handle)

        m_handle->setDefersLoading(defers);

    if (!defers && !m_deferredRequest.isNull()) {

        ResourceRequest request(m_deferredRequest);

        m_deferredRequest = ResourceRequest();

        load(request);

    }

}

FrameLoader* ResourceLoader::frameLoader() const

{

    if (!m_frame)

        return 0;

    return m_frame->loader();

}

void ResourceLoader::setShouldBufferData(bool shouldBufferData)

{ 

    m_shouldBufferData = shouldBufferData; 

    // Reset any already buffered data

    if (!m_shouldBufferData)

        m_resourceData = 0;

}

void ResourceLoader::addData(const char* data, int length, bool allAtOnce)

{

    if (!m_shouldBufferData)

        return;

    if (allAtOnce) {

        m_resourceData = SharedBuffer::create(data, length);

        return;

    }

    if (ResourceHandle::supportsBufferedData()) {

        // Buffer data only if the connection has handed us the data because is has stopped buffering it.

        if (m_resourceData)

            m_resourceData->append(data, length);

    } else {

        if (!m_resourceData)

            m_resourceData = SharedBuffer::create(data, length);

        else

            m_resourceData->append(data, length);

    }

}

void ResourceLoader::clearResourceData()

{

    if (m_resourceData)

        m_resourceData->clear();

}

void ResourceLoader::willSendRequest(ResourceRequest& request, const ResourceResponse& redirectResponse)

{

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    ASSERT(!m_reachedTerminalState);

    if (m_sendResourceLoadCallbacks) {

        if (!m_identifier) {

            m_identifier = m_frame->page()->progress()->createUniqueIdentifier();

            frameLoader()->notifier()->assignIdentifierToInitialRequest(m_identifier, documentLoader(), request);

        }

        frameLoader()->notifier()->willSendRequest(this, request, redirectResponse);

    }

    m_request = request;

}

void ResourceLoader::didSendData(unsigned long long, unsigned long long)

{

}

void ResourceLoader::didReceiveResponse(const ResourceResponse& r)

{

    ASSERT(!m_reachedTerminalState);

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    m_response = r;

    if (FormData* data = m_request.httpBody())

        data->removeGeneratedFilesIfNeeded();

    if (m_sendResourceLoadCallbacks)

        frameLoader()->notifier()->didReceiveResponse(this, m_response);

}

void ResourceLoader::didReceiveData(const char* data, int length, long long lengthReceived, bool allAtOnce)

{

    // The following assertions are not quite valid here, since a subclass

    // might override didReceiveData in a way that invalidates them. This

    // happens with the steps listed in 3266216

    // ASSERT(con == connection);

    // ASSERT(!m_reachedTerminalState);

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    addData(data, length, allAtOnce);

    // FIXME: If we get a resource with more than 2B bytes, this code won't do the right thing.

    // However, with today's computers and networking speeds, this won't happen in practice.

    // Could be an issue with a giant local file.

    if (m_sendResourceLoadCallbacks && m_frame)

        frameLoader()->notifier()->didReceiveData(this, data, length, static_cast<int>(lengthReceived));

}

void ResourceLoader::willStopBufferingData(const char* data, int length)

{

    if (!m_shouldBufferData)

        return;

    ASSERT(!m_resourceData);

    m_resourceData = SharedBuffer::create(data, length);

}

void ResourceLoader::didFinishLoading()

{

    // If load has been cancelled after finishing (which could happen with a 

    // JavaScript that changes the window location), do nothing.

    if (m_cancelled)

        return;

    ASSERT(!m_reachedTerminalState);

    didFinishLoadingOnePart();

    releaseResources();

}

void ResourceLoader::didFinishLoadingOnePart()

{

    if (m_cancelled)

        return;

    ASSERT(!m_reachedTerminalState);

    if (m_calledDidFinishLoad)

        return;

    m_calledDidFinishLoad = true;

    if (m_sendResourceLoadCallbacks)

        frameLoader()->notifier()->didFinishLoad(this);

}

void ResourceLoader::didFail(const ResourceError& error)

{

    if (m_cancelled)

        return;

    ASSERT(!m_reachedTerminalState);

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    if (FormData* data = m_request.httpBody())

        data->removeGeneratedFilesIfNeeded();

    if (m_sendResourceLoadCallbacks && !m_calledDidFinishLoad)

        frameLoader()->notifier()->didFailToLoad(this, error);

    releaseResources();

}

void ResourceLoader::didCancel(const ResourceError& error)

{

    ASSERT(!m_cancelled);

    ASSERT(!m_reachedTerminalState);

    if (FormData* data = m_request.httpBody())

        data->removeGeneratedFilesIfNeeded();

    // This flag prevents bad behavior when loads that finish cause the

    // load itself to be cancelled (which could happen with a javascript that 

    // changes the window location). This is used to prevent both the body

    // of this method and the body of connectionDidFinishLoading: running

    // for a single delegate. Canceling wins.

    m_cancelled = true;

    if (m_handle)

        m_handle->clearAuthentication();

    m_documentLoader->cancelPendingSubstituteLoad(this);

    if (m_handle) {

        m_handle->cancel();

        m_handle = 0;

    }

    if (m_sendResourceLoadCallbacks && !m_calledDidFinishLoad)

        frameLoader()->notifier()->didFailToLoad(this, error);

    releaseResources();

}

void ResourceLoader::cancel()

{

    cancel(ResourceError());

}

void ResourceLoader::cancel(const ResourceError& error)

{

    if (m_reachedTerminalState)

        return;

    if (!error.isNull())

        didCancel(error);

    else

        didCancel(cancelledError());

}

const ResourceResponse& ResourceLoader::response() const

{

    return m_response;

}

ResourceError ResourceLoader::cancelledError()

{

    return frameLoader()->cancelledError(m_request);

}

ResourceError ResourceLoader::blockedError()

{

    return frameLoader()->blockedError(m_request);

}

ResourceError ResourceLoader::cannotShowURLError()

{

    return frameLoader()->cannotShowURLError(m_request);

}

void ResourceLoader::willSendRequest(ResourceHandle*, ResourceRequest& request, const ResourceResponse& redirectResponse)

{

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

    if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForRedirect(this, request, redirectResponse))

        return;

#endif

    willSendRequest(request, redirectResponse);

}

void ResourceLoader::didSendData(ResourceHandle*, unsigned long long bytesSent, unsigned long long totalBytesToBeSent)

{

    didSendData(bytesSent, totalBytesToBeSent);

}

void ResourceLoader::didReceiveResponse(ResourceHandle*, const ResourceResponse& response)

{

#if ENABLE(INSPECTOR)

    if (InspectorTimelineAgent::instanceCount()) {

        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;

        if (timelineAgent)

            timelineAgent->willReceiveResourceResponse(identifier(), response);

    }

#endif

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

    if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForResponse(this, response))

        return;

#endif

    didReceiveResponse(response);

#if ENABLE(INSPECTOR)

    if (InspectorTimelineAgent::instanceCount()) {

        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;

        if (timelineAgent)

            timelineAgent->didReceiveResourceResponse();

    }

#endif

}

void ResourceLoader::didReceiveData(ResourceHandle*, const char* data, int length, int lengthReceived)

{

#if ENABLE(INSPECTOR)

    if (InspectorTimelineAgent::instanceCount()) {

        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;

        if (timelineAgent)

            timelineAgent->willReceiveResourceData(identifier());

    }

#endif

    didReceiveData(data, length, lengthReceived, false);

#if ENABLE(INSPECTOR)

    if (InspectorTimelineAgent::instanceCount()) {

        InspectorTimelineAgent* timelineAgent = m_frame->page() ? m_frame->page()->inspectorTimelineAgent() : 0;

        if (timelineAgent)

            timelineAgent->didReceiveResourceData();

    }

#endif

}

void ResourceLoader::didFinishLoading(ResourceHandle*)

{

    didFinishLoading();

}

void ResourceLoader::didFail(ResourceHandle*, const ResourceError& error)

{

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

    if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForError(this, error))

        return;

#endif

    didFail(error);

}

void ResourceLoader::wasBlocked(ResourceHandle*)

{

    didFail(blockedError());

}

void ResourceLoader::cannotShowURL(ResourceHandle*)

{

    didFail(cannotShowURLError());

}

bool ResourceLoader::shouldUseCredentialStorage()

{

    RefPtr<ResourceLoader> protector(this);

    return frameLoader()->shouldUseCredentialStorage(this);

}

void ResourceLoader::didReceiveAuthenticationChallenge(const AuthenticationChallenge& challenge)

{

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    frameLoader()->notifier()->didReceiveAuthenticationChallenge(this, challenge);

}

void ResourceLoader::didCancelAuthenticationChallenge(const AuthenticationChallenge& challenge)

{

    // Protect this in this delegate method since the additional processing can do

    // anything including possibly derefing this; one example of this is Radar 3266216.

    RefPtr<ResourceLoader> protector(this);

    frameLoader()->notifier()->didCancelAuthenticationChallenge(this, challenge);

}

#if USE(PROTECTION_SPACE_AUTH_CALLBACK)

bool ResourceLoader::canAuthenticateAgainstProtectionSpace(const ProtectionSpace& protectionSpace)

{

    RefPtr<ResourceLoader> protector(this);

    return frameLoader()->canAuthenticateAgainstProtectionSpace(this, protectionSpace);

}

#endif

void ResourceLoader::receivedCancellation(const AuthenticationChallenge&)

{

    cancel();

}

void ResourceLoader::willCacheResponse(ResourceHandle*, CacheStoragePolicy& policy)

{

    // <rdar://problem/7249553> - There are reports of crashes with this method being called

    // with a null m_frame->settings(), which can only happen if the frame doesn't have a page.

    // Sadly we have no reproducible cases of this.

    // We think that any frame without a page shouldn't have any loads happening in it, yet

    // there is at least one code path where that is not true.

    ASSERT(m_frame->settings());

    // When in private browsing mode, prevent caching to disk

    if (policy == StorageAllowed && m_frame->settings() && m_frame->settings()->privateBrowsingEnabled())

        policy = StorageAllowedInMemoryOnly;    

}

}