/*
 * 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.
 * 3.  Neither the name of Apple 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 "LegacyWebArchive.h"

#include "CachedResource.h"
#include "Document.h"
#include "DocumentLoader.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameSelection.h"
#include "FrameTree.h"
#include "HTMLFrameElement.h"
#include "HTMLFrameOwnerElement.h"
#include "HTMLIFrameElement.h"
#include "HTMLNames.h"
#include "HTMLObjectElement.h"
#include "Image.h"
#include "URLHash.h"
#include "Logging.h"
#include "MemoryCache.h"
#include "Page.h"
#include "Range.h"
#include "Settings.h"
#include "markup.h"
#include <wtf/ListHashSet.h>
#include <wtf/RetainPtr.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/CString.h>

namespace WebCore {

static const CFStringRef LegacyWebArchiveMainResourceKey = CFSTR("WebMainResource");
static const CFStringRef LegacyWebArchiveSubresourcesKey = CFSTR("WebSubresources");
static const CFStringRef LegacyWebArchiveSubframeArchivesKey = CFSTR("WebSubframeArchives");
static const CFStringRef LegacyWebArchiveResourceDataKey = CFSTR("WebResourceData");
static const CFStringRef LegacyWebArchiveResourceFrameNameKey = CFSTR("WebResourceFrameName");
static const CFStringRef LegacyWebArchiveResourceMIMETypeKey = CFSTR("WebResourceMIMEType");
static const CFStringRef LegacyWebArchiveResourceURLKey = CFSTR("WebResourceURL");
static const CFStringRef LegacyWebArchiveResourceTextEncodingNameKey = CFSTR("WebResourceTextEncodingName");
static const CFStringRef LegacyWebArchiveResourceResponseKey = CFSTR("WebResourceResponse");
static const CFStringRef LegacyWebArchiveResourceResponseVersionKey = CFSTR("WebResourceResponseVersion");

RetainPtr<CFDictionaryRef> LegacyWebArchive::createPropertyListRepresentation(ArchiveResource* resource, MainResourceStatus isMainResource)
{
    if (!resource) {
        // The property list representation of a null/empty WebResource has the following 3 objects stored as nil.
        // FIXME: 0 is not serializable. Presumably we need to use kCFNull here instead for compatibility.
        // FIXME: But why do we need to support a resource of 0? Who relies on that?
        RetainPtr<CFMutableDictionaryRef> propertyList = adoptCF(CFDictionaryCreateMutable(0, 3, 0, 0));
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceDataKey, 0);
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceURLKey, 0);
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceMIMETypeKey, 0);
        return propertyList;
    }

    auto propertyList = adoptCF(CFDictionaryCreateMutable(0, 6, 0, &kCFTypeDictionaryValueCallBacks));

    // Resource data can be empty, but must be represented by an empty CFDataRef
    auto& data = resource->data();

    CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceDataKey, data.createCFData().get());

    // Resource URL cannot be null
    if (auto cfURL = resource->url().string().createCFString())
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceURLKey, cfURL.get());
    else {
        LOG(Archives, "LegacyWebArchive - NULL resource URL is invalid - returning null property list");
        return nullptr;
    }

    // FrameName should be left out if empty for subresources, but always included for main resources
    auto& frameName = resource->frameName();
    if (!frameName.isEmpty() || isMainResource)
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceFrameNameKey, frameName.createCFString().get());

    // Set MIMEType, TextEncodingName, and ResourceResponse only if they actually exist
    auto& mimeType = resource->mimeType();
    if (!mimeType.isEmpty())
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceMIMETypeKey, mimeType.createCFString().get());

    auto& textEncoding = resource->textEncoding();
    if (!textEncoding.isEmpty())
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceTextEncodingNameKey, textEncoding.createCFString().get());

    // Don't include the resource response for the main resource
    if (!isMainResource) {
        if (auto resourceResponseData = createPropertyListRepresentation(resource->response()))
            CFDictionarySetValue(propertyList.get(), LegacyWebArchiveResourceResponseKey, resourceResponseData.get());    
    }
    
    return propertyList;
}

RetainPtr<CFDictionaryRef> LegacyWebArchive::createPropertyListRepresentation(Archive& archive)
{
    auto propertyList = adoptCF(CFDictionaryCreateMutable(0, 3, 0, &kCFTypeDictionaryValueCallBacks));

    auto mainResourceDict = createPropertyListRepresentation(archive.mainResource(), MainResource);
    ASSERT(mainResourceDict);
    if (!mainResourceDict)
        return nullptr;
    CFDictionarySetValue(propertyList.get(), LegacyWebArchiveMainResourceKey, mainResourceDict.get());

    auto subresourcesArray = adoptCF(CFArrayCreateMutable(0, archive.subresources().size(), &kCFTypeArrayCallBacks));
    for (auto& resource : archive.subresources()) {
        if (auto subresource = createPropertyListRepresentation(resource.ptr(), Subresource))
            CFArrayAppendValue(subresourcesArray.get(), subresource.get());
        else
            LOG(Archives, "LegacyWebArchive - Failed to create property list for subresource");
    }
    if (CFArrayGetCount(subresourcesArray.get()))
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveSubresourcesKey, subresourcesArray.get());

    auto subframesArray = adoptCF(CFArrayCreateMutable(0, archive.subframeArchives().size(), &kCFTypeArrayCallBacks));
    for (auto& subframe : archive.subframeArchives()) {
        if (auto subframeArchive = createPropertyListRepresentation(subframe.get()))
            CFArrayAppendValue(subframesArray.get(), subframeArchive.get());
        else
            LOG(Archives, "LegacyWebArchive - Failed to create property list for subframe archive");
    }
    if (CFArrayGetCount(subframesArray.get()))
        CFDictionarySetValue(propertyList.get(), LegacyWebArchiveSubframeArchivesKey, subframesArray.get());

    return propertyList;
}

ResourceResponse LegacyWebArchive::createResourceResponseFromPropertyListData(CFDataRef data, CFStringRef responseDataType)
{
    ASSERT(data);
    if (!data)
        return ResourceResponse();

    // If the ResourceResponseVersion (passed in as responseDataType) exists at all, this is a "new" web archive that we
    // can parse well in a cross platform manner If it doesn't exist, we will assume this is an "old" web archive with,
    // NSURLResponse objects in it and parse the ResourceResponse as such.
    if (!responseDataType)
        return createResourceResponseFromMacArchivedData(data);

    // FIXME: Parse the "new" format that the above comment references here. This format doesn't exist yet.
    return ResourceResponse();
}

RefPtr<ArchiveResource> LegacyWebArchive::createResource(CFDictionaryRef dictionary)
{
    ASSERT(dictionary);
    if (!dictionary)
        return nullptr;

    auto resourceData = static_cast<CFDataRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceDataKey));
    if (resourceData && CFGetTypeID(resourceData) != CFDataGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Resource data is not of type CFData, cannot create invalid resource");
        return nullptr;
    }

    auto frameName = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceFrameNameKey));
    if (frameName && CFGetTypeID(frameName) != CFStringGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Frame name is not of type CFString, cannot create invalid resource");
        return nullptr;
    }

    auto mimeType = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceMIMETypeKey));
    if (mimeType && CFGetTypeID(mimeType) != CFStringGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - MIME type is not of type CFString, cannot create invalid resource");
        return nullptr;
    }

    auto url = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceURLKey));
    if (url && CFGetTypeID(url) != CFStringGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - URL is not of type CFString, cannot create invalid resource");
        return nullptr;
    }

    auto textEncoding = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceTextEncodingNameKey));
    if (textEncoding && CFGetTypeID(textEncoding) != CFStringGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Text encoding is not of type CFString, cannot create invalid resource");
        return nullptr;
    }

    ResourceResponse response;

    if (auto resourceResponseData = static_cast<CFDataRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceResponseKey))) {
        if (CFGetTypeID(resourceResponseData) != CFDataGetTypeID()) {
            LOG(Archives, "LegacyWebArchive - Resource response data is not of type CFData, cannot create invalid resource");
            return nullptr;
        }
        
        auto resourceResponseVersion = static_cast<CFStringRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveResourceResponseVersionKey));
        if (resourceResponseVersion && CFGetTypeID(resourceResponseVersion) != CFStringGetTypeID()) {
            LOG(Archives, "LegacyWebArchive - Resource response version is not of type CFString, cannot create invalid resource");
            return nullptr;
        }
        
        response = createResourceResponseFromPropertyListData(resourceResponseData, resourceResponseVersion);
    }

    return ArchiveResource::create(SharedBuffer::create(resourceData), URL(URL(), url), mimeType, textEncoding, frameName, response);
}

Ref<LegacyWebArchive> LegacyWebArchive::create()
{
    return adoptRef(*new LegacyWebArchive);
}

Ref<LegacyWebArchive> LegacyWebArchive::create(Ref<ArchiveResource>&& mainResource, Vector<Ref<ArchiveResource>>&& subresources, Vector<Ref<LegacyWebArchive>>&& subframeArchives)
{
    auto archive = create();

    archive->setMainResource(WTFMove(mainResource));

    for (auto& subresource : subresources)
        archive->addSubresource(WTFMove(subresource));

    for (auto& subframeArchive : subframeArchives)
        archive->addSubframeArchive(WTFMove(subframeArchive));

    return archive;
}

RefPtr<LegacyWebArchive> LegacyWebArchive::create(SharedBuffer& data)
{
    return create(URL(), data);
}

RefPtr<LegacyWebArchive> LegacyWebArchive::create(const URL&, SharedBuffer& data)
{
    LOG(Archives, "LegacyWebArchive - Creating from raw data");
    
    Ref<LegacyWebArchive> archive = create();
        
    RetainPtr<CFDataRef> cfData = data.createCFData();
    if (!cfData)
        return nullptr;
        
    CFErrorRef error = nullptr;
    
    RetainPtr<CFDictionaryRef> plist = adoptCF(static_cast<CFDictionaryRef>(CFPropertyListCreateWithData(0, cfData.get(), kCFPropertyListImmutable, 0, &error)));
    if (!plist) {
#ifndef NDEBUG
        RetainPtr<CFStringRef> errorString = error ? adoptCF(CFErrorCopyDescription(error)) : 0;
        const char* cError = errorString ? CFStringGetCStringPtr(errorString.get(), kCFStringEncodingUTF8) : "unknown error";
        LOG(Archives, "LegacyWebArchive - Error parsing PropertyList from archive data - %s", cError);
#endif
        if (error)
            CFRelease(error);
        return nullptr;
    }
    
    if (CFGetTypeID(plist.get()) != CFDictionaryGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Archive property list is not the expected CFDictionary, aborting invalid WebArchive");
        return nullptr;
    }
    
    if (!archive->extract(plist.get()))
        return nullptr;

    return WTFMove(archive);
}

bool LegacyWebArchive::extract(CFDictionaryRef dictionary)
{
    ASSERT(dictionary);
    if (!dictionary) {
        LOG(Archives, "LegacyWebArchive - Null root CFDictionary, aborting invalid WebArchive");
        return false;
    }
    
    CFDictionaryRef mainResourceDict = static_cast<CFDictionaryRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveMainResourceKey));
    if (!mainResourceDict) {
        LOG(Archives, "LegacyWebArchive - No main resource in archive, aborting invalid WebArchive");
        return false;
    }
    if (CFGetTypeID(mainResourceDict) != CFDictionaryGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Main resource is not the expected CFDictionary, aborting invalid WebArchive");
        return false;
    }

    auto mainResource = createResource(mainResourceDict);
    if (!mainResource) {
        LOG(Archives, "LegacyWebArchive - Failed to parse main resource from CFDictionary or main resource does not exist, aborting invalid WebArchive");
        return false;
    }

    if (mainResource->mimeType().isNull()) {
        LOG(Archives, "LegacyWebArchive - Main resource MIME type is required, but was null.");
        return false;
    }

    setMainResource(mainResource.releaseNonNull());

    auto subresourceArray = static_cast<CFArrayRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveSubresourcesKey));
    if (subresourceArray && CFGetTypeID(subresourceArray) != CFArrayGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Subresources is not the expected Array, aborting invalid WebArchive");
        return false;
    }

    if (subresourceArray) {
        auto count = CFArrayGetCount(subresourceArray);
        for (CFIndex i = 0; i < count; ++i) {
            auto subresourceDict = static_cast<CFDictionaryRef>(CFArrayGetValueAtIndex(subresourceArray, i));
            if (CFGetTypeID(subresourceDict) != CFDictionaryGetTypeID()) {
                LOG(Archives, "LegacyWebArchive - Subresource is not expected CFDictionary, aborting invalid WebArchive");
                return false;
            }
            
            if (auto subresource = createResource(subresourceDict))
                addSubresource(subresource.releaseNonNull());
        }
    }

    auto subframeArray = static_cast<CFArrayRef>(CFDictionaryGetValue(dictionary, LegacyWebArchiveSubframeArchivesKey));
    if (subframeArray && CFGetTypeID(subframeArray) != CFArrayGetTypeID()) {
        LOG(Archives, "LegacyWebArchive - Subframe archives is not the expected Array, aborting invalid WebArchive");
        return false;
    }

    if (subframeArray) {
        auto count = CFArrayGetCount(subframeArray);
        for (CFIndex i = 0; i < count; ++i) {
            auto subframeDict = static_cast<CFDictionaryRef>(CFArrayGetValueAtIndex(subframeArray, i));
            if (CFGetTypeID(subframeDict) != CFDictionaryGetTypeID()) {
                LOG(Archives, "LegacyWebArchive - Subframe array is not expected CFDictionary, aborting invalid WebArchive");
                return false;
            }
            
            auto subframeArchive = create();
            if (subframeArchive->extract(subframeDict))
                addSubframeArchive(WTFMove(subframeArchive));
            else
                LOG(Archives, "LegacyWebArchive - Invalid subframe archive skipped");
        }
    }
    
    return true;
}

RetainPtr<CFDataRef> LegacyWebArchive::rawDataRepresentation()
{
    auto propertyList = createPropertyListRepresentation(*this);
    ASSERT(propertyList);
    if (!propertyList) {
        LOG(Archives, "LegacyWebArchive - Failed to create property list for archive, returning no data");
        return nullptr;
    }

    auto stream = adoptCF(CFWriteStreamCreateWithAllocatedBuffers(0, 0));

    CFWriteStreamOpen(stream.get());
    CFPropertyListWrite(propertyList.get(), stream.get(), kCFPropertyListBinaryFormat_v1_0, 0, 0);

    auto plistData = adoptCF(static_cast<CFDataRef>(CFWriteStreamCopyProperty(stream.get(), kCFStreamPropertyDataWritten)));
    ASSERT(plistData);

    CFWriteStreamClose(stream.get());

    if (!plistData) {
        LOG(Archives, "LegacyWebArchive - Failed to convert property list into raw data, returning no data");
        return nullptr;
    }

    return plistData;
}

#if !PLATFORM(COCOA)

ResourceResponse LegacyWebArchive::createResourceResponseFromMacArchivedData(CFDataRef responseData)
{
    // FIXME: If is is possible to parse in a serialized NSURLResponse manually, without using
    // NSKeyedUnarchiver, manipulating plists directly, then we want to do that here.
    // Until then, this can be done on Mac only.
    return ResourceResponse();
}

RetainPtr<CFDataRef> LegacyWebArchive::createPropertyListRepresentation(const ResourceResponse& response)
{
    // FIXME: Write out the "new" format described in createResourceResponseFromPropertyListData once we invent it.
    return nullptr;
}

#endif

RefPtr<LegacyWebArchive> LegacyWebArchive::create(Node& node, WTF::Function<bool (Frame&)>&& frameFilter)
{
    Frame* frame = node.document().frame();
    if (!frame)
        return create();

    // If the page was loaded with javascript enabled, we don't want to archive <noscript> tags
    // In practice we don't actually know whether scripting was enabled when the page was originally loaded
    // but we can approximate that by checking if scripting is enabled right now.
    std::unique_ptr<Vector<QualifiedName>> tagNamesToFilter;
    if (frame->page() && frame->page()->settings().isScriptEnabled()) {
        tagNamesToFilter = std::make_unique<Vector<QualifiedName>>();
        tagNamesToFilter->append(HTMLNames::noscriptTag);
    }

    Vector<Node*> nodeList;
    String markupString = createMarkup(node, IncludeNode, &nodeList, DoNotResolveURLs, tagNamesToFilter.get());
    auto nodeType = node.nodeType();
    if (nodeType != Node::DOCUMENT_NODE && nodeType != Node::DOCUMENT_TYPE_NODE)
        markupString = documentTypeString(node.document()) + markupString;

    return create(markupString, *frame, nodeList, WTFMove(frameFilter));
}

RefPtr<LegacyWebArchive> LegacyWebArchive::create(Frame& frame)
{
    auto* documentLoader = frame.loader().documentLoader();
    if (!documentLoader)
        return nullptr;

    auto mainResource = documentLoader->mainResource();
    if (!mainResource)
        return nullptr;

    Vector<Ref<LegacyWebArchive>> subframeArchives;
    for (unsigned i = 0; i < frame.tree().childCount(); ++i) {
        if (auto childFrameArchive = create(*frame.tree().child(i)))
            subframeArchives.append(childFrameArchive.releaseNonNull());
    }

    return create(mainResource.releaseNonNull(), documentLoader->subresources(), WTFMove(subframeArchives));
}

RefPtr<LegacyWebArchive> LegacyWebArchive::create(Range* range)
{
    if (!range)
        return nullptr;
        
    auto& document = range->startContainer().document();
    auto* frame = document.frame();
    if (!frame)
        return nullptr;

    // FIXME: This is always "for interchange". Is that right?
    Vector<Node*> nodeList;
    String markupString = documentTypeString(document) + createMarkup(*range, &nodeList, AnnotateForInterchange);
    return create(markupString, *frame, nodeList, nullptr);
}

RefPtr<LegacyWebArchive> LegacyWebArchive::create(const String& markupString, Frame& frame, const Vector<Node*>& nodes, WTF::Function<bool (Frame&)>&& frameFilter)
{
    auto& response = frame.loader().documentLoader()->response();
    URL responseURL = response.url();
    
    // it's possible to have a response without a URL here
    // <rdar://problem/5454935>
    if (responseURL.isNull())
        responseURL = URL(ParsedURLString, emptyString());

    auto mainResource = ArchiveResource::create(utf8Buffer(markupString), responseURL, response.mimeType(), "UTF-8", frame.tree().uniqueName());
    if (!mainResource)
        return nullptr;

    Vector<Ref<LegacyWebArchive>> subframeArchives;
    Vector<Ref<ArchiveResource>> subresources;
    HashSet<URL> uniqueSubresources;

    for (auto& nodePtr : nodes) {
        Node& node = *nodePtr;
        Frame* childFrame;
        if ((is<HTMLFrameElementBase>(node) || is<HTMLObjectElement>(node))
            && (childFrame = downcast<HTMLFrameOwnerElement>(node).contentFrame())) {
            if (frameFilter && !frameFilter(*childFrame))
                continue;
            if (auto subframeArchive = create(*childFrame->document(), WTFMove(frameFilter)))
                subframeArchives.append(subframeArchive.releaseNonNull());
            else
                LOG_ERROR("Unabled to archive subframe %s", childFrame->tree().uniqueName().string().utf8().data());

        } else {
            ListHashSet<URL> subresourceURLs;
            node.getSubresourceURLs(subresourceURLs);

            ASSERT(frame.loader().documentLoader());
            auto& documentLoader = *frame.loader().documentLoader();

            for (auto& subresourceURL : subresourceURLs) {
                if (uniqueSubresources.contains(subresourceURL))
                    continue;

                uniqueSubresources.add(subresourceURL);

                if (auto resource = documentLoader.subresource(subresourceURL)) {
                    subresources.append(resource.releaseNonNull());
                    continue;
                }

                ResourceRequest request(subresourceURL);
                request.setDomainForCachePartition(frame.document()->domainForCachePartition());

                if (auto* cachedResource = MemoryCache::singleton().resourceForRequest(request, frame.page()->sessionID())) {
                    if (auto resource = ArchiveResource::create(cachedResource->resourceBuffer(), subresourceURL, cachedResource->response())) {
                        subresources.append(resource.releaseNonNull());
                        continue;
                    }
                }

                // FIXME: should do something better than spew to console here
                LOG_ERROR("Failed to archive subresource for %s", subresourceURL.string().utf8().data());
            }
        }
    }

    // If we are archiving the entire page, add any link icons that we have data for.
    if (!nodes.isEmpty() && nodes[0]->isDocumentNode()) {
        auto* documentLoader = frame.loader().documentLoader();
        ASSERT(documentLoader);
        for (auto& icon : documentLoader->linkIcons()) {
            if (auto resource = documentLoader->subresource(icon.url))
                subresources.append(resource.releaseNonNull());
        }
    }

    return create(mainResource.releaseNonNull(), WTFMove(subresources), WTFMove(subframeArchives));
}

RefPtr<LegacyWebArchive> LegacyWebArchive::createFromSelection(Frame* frame)
{
    if (!frame)
        return nullptr;

    auto* document = frame->document();
    if (!document)
        return nullptr;

    StringBuilder builder;
    builder.append(documentTypeString(*document));

    Vector<Node*> nodeList;
    if (auto selectionRange = frame->selection().toNormalizedRange())
        builder.append(createMarkup(*selectionRange, &nodeList, AnnotateForInterchange));

    auto archive = create(builder.toString(), *frame, nodeList, nullptr);
    
    if (!document->isFrameSet())
        return archive;
        
    // Wrap the frameset document in an iframe so it can be pasted into
    // another document (which will have a body or frameset of its own). 
    String iframeMarkup = "<iframe frameborder=\"no\" marginwidth=\"0\" marginheight=\"0\" width=\"98%%\" height=\"98%%\" src=\"" + frame->loader().documentLoader()->response().url().string() + "\"></iframe>";
    auto iframeResource = ArchiveResource::create(utf8Buffer(iframeMarkup), blankURL(), "text/html", "UTF-8", String());

    Vector<Ref<LegacyWebArchive>> subframeArchives;
    subframeArchives.reserveInitialCapacity(1);
    subframeArchives.uncheckedAppend(archive.releaseNonNull());

    return create(iframeResource.releaseNonNull(), { }, WTFMove(subframeArchives));
}

}