/*

 * Copyright (C) 2008, 2009 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 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 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 "ApplicationCacheHost.h"

#if ENABLE(OFFLINE_WEB_APPLICATIONS)

#include "ApplicationCache.h"

#include "ApplicationCacheGroup.h"

#include "ApplicationCacheResource.h"

#include "DocumentLoader.h"

#include "DOMApplicationCache.h"

#include "Frame.h"

#include "FrameLoader.h"

#include "FrameLoaderClient.h"

#include "MainResourceLoader.h"

#include "ProgressEvent.h"

#include "ResourceLoader.h"

#include "ResourceRequest.h"

#include "Settings.h"

namespace WebCore {

ApplicationCacheHost::ApplicationCacheHost(DocumentLoader* documentLoader)

    : m_domApplicationCache(0)

    , m_documentLoader(documentLoader)

    , m_defersEvents(true)

    , m_candidateApplicationCacheGroup(0)

{

    ASSERT(m_documentLoader);

}

ApplicationCacheHost::~ApplicationCacheHost()

{

    if (m_applicationCache)

        m_applicationCache->group()->disassociateDocumentLoader(m_documentLoader);

    else if (m_candidateApplicationCacheGroup)

        m_candidateApplicationCacheGroup->disassociateDocumentLoader(m_documentLoader);

}

void ApplicationCacheHost::selectCacheWithoutManifest()

{

    ApplicationCacheGroup::selectCacheWithoutManifestURL(m_documentLoader->frame());

}

void ApplicationCacheHost::selectCacheWithManifest(const KURL& manifestURL)

{

    ApplicationCacheGroup::selectCache(m_documentLoader->frame(), manifestURL);

}

void ApplicationCacheHost::maybeLoadMainResource(ResourceRequest& request, SubstituteData& substituteData)

{

    // Check if this request should be loaded from the application cache

    if (!substituteData.isValid() && isApplicationCacheEnabled()) {

        ASSERT(!m_mainResourceApplicationCache);

        m_mainResourceApplicationCache = ApplicationCacheGroup::cacheForMainRequest(request, m_documentLoader);

        if (m_mainResourceApplicationCache) {

            // Get the resource from the application cache. By definition, cacheForMainRequest() returns a cache that contains the resource.

            ApplicationCacheResource* resource = m_mainResourceApplicationCache->resourceForRequest(request);

            substituteData = SubstituteData(resource->data(), 

                                            resource->response().mimeType(),

                                            resource->response().textEncodingName(), KURL());

        }

    }

}

bool ApplicationCacheHost::maybeLoadFallbackForMainResponse(const ResourceRequest& request, const ResourceResponse& r)

{

    if (r.httpStatusCode() / 100 == 4 || r.httpStatusCode() / 100 == 5) {

        ASSERT(!m_mainResourceApplicationCache);

        if (isApplicationCacheEnabled()) {

            m_mainResourceApplicationCache = ApplicationCacheGroup::fallbackCacheForMainRequest(request, documentLoader());

            if (scheduleLoadFallbackResourceFromApplicationCache(documentLoader()->mainResourceLoader(), m_mainResourceApplicationCache.get()))

                return true;

        }

    }

    return false;

}

bool ApplicationCacheHost::maybeLoadFallbackForMainError(const ResourceRequest& request, const ResourceError& error)

{

    if (!error.isCancellation()) {

        ASSERT(!m_mainResourceApplicationCache);

        if (isApplicationCacheEnabled()) {

            m_mainResourceApplicationCache = ApplicationCacheGroup::fallbackCacheForMainRequest(request, m_documentLoader);

            if (scheduleLoadFallbackResourceFromApplicationCache(documentLoader()->mainResourceLoader(), m_mainResourceApplicationCache.get()))

                return true;

        }

    }

    return false;

}

void ApplicationCacheHost::mainResourceDataReceived(const char*, int, long long, bool)

{

    // This method is here to facilitate alternate implemetations of this interface by the host browser.

}

void ApplicationCacheHost::failedLoadingMainResource()

{

    ApplicationCacheGroup* group = m_candidateApplicationCacheGroup;

    if (!group && m_applicationCache) {

        ASSERT(!mainResourceApplicationCache()); // If the main resource were loaded from a cache, it wouldn't fail.

        group = m_applicationCache->group();

    }

    if (group)

        group->failedLoadingMainResource(m_documentLoader);

}

void ApplicationCacheHost::finishedLoadingMainResource()

{

    ApplicationCacheGroup* group = candidateApplicationCacheGroup();

    if (!group && applicationCache() && !mainResourceApplicationCache())

        group = applicationCache()->group();

    if (group)

        group->finishedLoadingMainResource(m_documentLoader);

}

bool ApplicationCacheHost::maybeLoadResource(ResourceLoader* loader, ResourceRequest& request, const KURL& originalURL)

{

    if (!isApplicationCacheEnabled())

        return false;

    if (request.url() != originalURL)

        return false;

    ApplicationCacheResource* resource;

    if (!shouldLoadResourceFromApplicationCache(request, resource))

        return false;

    m_documentLoader->m_pendingSubstituteResources.set(loader, resource);

    m_documentLoader->deliverSubstituteResourcesAfterDelay();

    return true;

}

bool ApplicationCacheHost::maybeLoadFallbackForRedirect(ResourceLoader* resourceLoader, ResourceRequest& request, const ResourceResponse& redirectResponse)

{

    if (!redirectResponse.isNull() && !protocolHostAndPortAreEqual(request.url(), redirectResponse.url()))

        if (scheduleLoadFallbackResourceFromApplicationCache(resourceLoader))

            return true;

    return false;

}

bool ApplicationCacheHost::maybeLoadFallbackForResponse(ResourceLoader* resourceLoader, const ResourceResponse& response)

{

    if (response.httpStatusCode() / 100 == 4 || response.httpStatusCode() / 100 == 5)

        if (scheduleLoadFallbackResourceFromApplicationCache(resourceLoader))

            return true;

    return false;

}

bool ApplicationCacheHost::maybeLoadFallbackForError(ResourceLoader* resourceLoader, const ResourceError& error)

{

    if (!error.isCancellation())

        if (scheduleLoadFallbackResourceFromApplicationCache(resourceLoader))

            return true;

    return false;

}

bool ApplicationCacheHost::maybeLoadSynchronously(ResourceRequest& request, ResourceError& error, ResourceResponse& response, Vector<char>& data)

{

    ApplicationCacheResource* resource;

    if (shouldLoadResourceFromApplicationCache(request, resource)) {

        if (resource) {

            response = resource->response();

            data.append(resource->data()->data(), resource->data()->size());

        } else {

            error = documentLoader()->frameLoader()->client()->cannotShowURLError(request);

        }

        return true;

    }

    return false;

}

void ApplicationCacheHost::maybeLoadFallbackSynchronously(const ResourceRequest& request, ResourceError& error, ResourceResponse& response, Vector<char>& data)

{

    // If normal loading results in a redirect to a resource with another origin (indicative of a captive portal), or a 4xx or 5xx status code or equivalent,

    // or if there were network errors (but not if the user canceled the download), then instead get, from the cache, the resource of the fallback entry

    // corresponding to the matched namespace.

    if ((!error.isNull() && !error.isCancellation())

         || response.httpStatusCode() / 100 == 4 || response.httpStatusCode() / 100 == 5

         || !protocolHostAndPortAreEqual(request.url(), response.url())) {

        ApplicationCacheResource* resource;

        if (getApplicationCacheFallbackResource(request, resource)) {

            response = resource->response();

            data.clear();

            data.append(resource->data()->data(), resource->data()->size());

        }

    }

}

bool ApplicationCacheHost::canCacheInPageCache() const 

{

    return !applicationCache() && !candidateApplicationCacheGroup();

}

void ApplicationCacheHost::setDOMApplicationCache(DOMApplicationCache* domApplicationCache)

{

    ASSERT(!m_domApplicationCache || !domApplicationCache);

    m_domApplicationCache = domApplicationCache;

}

void ApplicationCacheHost::notifyDOMApplicationCache(EventID id, int total, int done)

{

    if (m_defersEvents) {

        // Event dispatching is deferred until document.onload has fired.

        m_deferredEvents.append(DeferredEvent(id, total, done));

        return;

    }

    dispatchDOMEvent(id, total, done);

}

void ApplicationCacheHost::stopDeferringEvents()

{

    RefPtr<DocumentLoader> protect(documentLoader());

    for (unsigned i = 0; i < m_deferredEvents.size(); ++i) {

        const DeferredEvent& deferred = m_deferredEvents[i];

        dispatchDOMEvent(deferred.eventID, deferred.progressTotal, deferred.progressDone);

    }

    m_deferredEvents.clear();

    m_defersEvents = false;

}

void ApplicationCacheHost::dispatchDOMEvent(EventID id, int total, int done)

{

    if (m_domApplicationCache) {

        const AtomicString& eventType = DOMApplicationCache::toEventType(id);

        ExceptionCode ec = 0;

        RefPtr<Event> event;

        if (id == PROGRESS_EVENT)

            event = ProgressEvent::create(eventType, true, done, total);

        else

            event = Event::create(eventType, false, false);

        m_domApplicationCache->dispatchEvent(event, ec);

        ASSERT(!ec);

    }

}

void ApplicationCacheHost::setCandidateApplicationCacheGroup(ApplicationCacheGroup* group)

{

    ASSERT(!m_applicationCache);

    m_candidateApplicationCacheGroup = group;

}

void ApplicationCacheHost::setApplicationCache(PassRefPtr<ApplicationCache> applicationCache)

{

    if (m_candidateApplicationCacheGroup) {

        ASSERT(!m_applicationCache);

        m_candidateApplicationCacheGroup = 0;

    }

    m_applicationCache = applicationCache;

}

bool ApplicationCacheHost::shouldLoadResourceFromApplicationCache(const ResourceRequest& request, ApplicationCacheResource*& resource)

{

    ApplicationCache* cache = applicationCache();

    if (!cache || !cache->isComplete())

        return false;

    // If the resource is not to be fetched using the HTTP GET mechanism or equivalent, or if its URL has a different

    // <scheme> component than the application cache's manifest, then fetch the resource normally.

    if (!ApplicationCache::requestIsHTTPOrHTTPSGet(request) || !equalIgnoringCase(request.url().protocol(), cache->manifestResource()->url().protocol()))

        return false;

    // If the resource's URL is an master entry, the manifest, an explicit entry, or a fallback entry

    // in the application cache, then get the resource from the cache (instead of fetching it).

    resource = cache->resourceForURL(request.url());

    // Resources that match fallback namespaces or online whitelist entries are fetched from the network,

    // unless they are also cached.

    if (!resource && (cache->urlMatchesFallbackNamespace(request.url()) || cache->isURLInOnlineWhitelist(request.url())))

        return false;

    // Resources that are not present in the manifest will always fail to load (at least, after the

    // cache has been primed the first time), making the testing of offline applications simpler.

    return true;

}

bool ApplicationCacheHost::getApplicationCacheFallbackResource(const ResourceRequest& request, ApplicationCacheResource*& resource, ApplicationCache* cache)

{

    if (!cache) {

        cache = applicationCache();

        if (!cache)

            return false;

    }

    if (!cache->isComplete())

        return false;

    // If the resource is not a HTTP/HTTPS GET, then abort

    if (!ApplicationCache::requestIsHTTPOrHTTPSGet(request))

        return false;

    KURL fallbackURL;

    if (!cache->urlMatchesFallbackNamespace(request.url(), &fallbackURL))

        return false;

    resource = cache->resourceForURL(fallbackURL);

    ASSERT(resource);

    return true;

}

bool ApplicationCacheHost::scheduleLoadFallbackResourceFromApplicationCache(ResourceLoader* loader, ApplicationCache* cache)

{

    if (!isApplicationCacheEnabled())

        return false;

    ApplicationCacheResource* resource;

    if (!getApplicationCacheFallbackResource(loader->request(), resource, cache))

        return false;

    m_documentLoader->m_pendingSubstituteResources.set(loader, resource);

    m_documentLoader->deliverSubstituteResourcesAfterDelay();

    loader->handle()->cancel();

    return true;

}

ApplicationCacheHost::Status ApplicationCacheHost::status() const

{

    ApplicationCache* cache = applicationCache();    

    if (!cache)

        return UNCACHED;

    switch (cache->group()->updateStatus()) {

        case ApplicationCacheGroup::Checking:

            return CHECKING;

        case ApplicationCacheGroup::Downloading:

            return DOWNLOADING;

        case ApplicationCacheGroup::Idle: {

            if (cache->group()->isObsolete())

                return OBSOLETE;

            if (cache != cache->group()->newestCache())

                return UPDATEREADY;

            return IDLE;

        }

    }

    ASSERT_NOT_REACHED();

    return UNCACHED;

}

bool ApplicationCacheHost::update()

{

    ApplicationCache* cache = applicationCache();

    if (!cache)

        return false;

    cache->group()->update(m_documentLoader->frame(), ApplicationCacheUpdateWithoutBrowsingContext);

    return true;

}

bool ApplicationCacheHost::swapCache()

{

    ApplicationCache* cache = applicationCache();

    if (!cache)

        return false;

    // If the group of application caches to which cache belongs has the lifecycle status obsolete, unassociate document from cache.

    if (cache->group()->isObsolete()) {

        cache->group()->disassociateDocumentLoader(m_documentLoader);

        return true;

    }

    // If there is no newer cache, raise an INVALID_STATE_ERR exception.

    ApplicationCache* newestCache = cache->group()->newestCache();

    if (cache == newestCache)

        return false;

    ASSERT(cache->group() == newestCache->group());

    setApplicationCache(newestCache);

    return true;

}

bool ApplicationCacheHost::isApplicationCacheEnabled()

{

    return m_documentLoader->frame()->settings()

           && m_documentLoader->frame()->settings()->offlineWebApplicationCacheEnabled();

}

}  // namespace WebCore

#endif  // ENABLE(OFFLINE_WEB_APPLICATIONS)