/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/ArrayUtils.h"

#include "nspr.h"

#include "nsIFileStreams.h"       // New Necko file streams
#include <algorithm>

#include "nsAutoPtr.h"
#include "nsNetCID.h"
#include "nsNetUtil.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIPrivateBrowsingChannel.h"
#include "nsComponentManagerUtils.h"
#include "nsIComponentRegistrar.h"
#include "nsIStorageStream.h"
#include "nsISeekableStream.h"
#include "nsIHttpChannel.h"
#include "nsIHttpChannelInternal.h"
#include "nsIEncodedChannel.h"
#include "nsIUploadChannel.h"
#include "nsICacheInfoChannel.h"
#include "nsIFileChannel.h"
#include "nsEscape.h"
#include "nsUnicharUtils.h"
#include "nsIStringEnumerator.h"
#include "nsCRT.h"
#include "nsContentCID.h"
#include "nsStreamUtils.h"

#include "nsCExternalHandlerService.h"

#include "nsIURL.h"
#include "nsIFileURL.h"
#include "nsIWebProgressListener.h"
#include "nsIAuthPrompt.h"
#include "nsIPrompt.h"
#include "nsISHEntry.h"
#include "nsIWebPageDescriptor.h"
#include "nsIFormControl.h"
#include "nsContentUtils.h"

#include "nsIImageLoadingContent.h"

#include "ftpCore.h"
#include "nsITransport.h"
#include "nsISocketTransport.h"
#include "nsIStringBundle.h"
#include "nsIProtocolHandler.h"

#include "nsIWebBrowserPersistable.h"
#include "nsWebBrowserPersist.h"
#include "WebBrowserPersistLocalDocument.h"

#include "nsIContent.h"
#include "nsIMIMEInfo.h"
#include "mozilla/dom/HTMLInputElement.h"
#include "mozilla/dom/HTMLSharedElement.h"
#include "mozilla/dom/HTMLSharedObjectElement.h"

using namespace mozilla;
using namespace mozilla::dom;

// Buffer file writes in 32kb chunks
#define BUFFERED_OUTPUT_SIZE (1024 * 32)

struct nsWebBrowserPersist::WalkData
{
    nsCOMPtr<nsIWebBrowserPersistDocument> mDocument;
    nsCOMPtr<nsIURI> mFile;
    nsCOMPtr<nsIURI> mDataPath;
};

// Information about a DOM document
struct nsWebBrowserPersist::DocData
{
    nsCOMPtr<nsIURI> mBaseURI;
    nsCOMPtr<nsIWebBrowserPersistDocument> mDocument;
    nsCOMPtr<nsIURI> mFile;
    nsCString mCharset;
};

// Information about a URI
struct nsWebBrowserPersist::URIData
{
    bool mNeedsPersisting;
    bool mSaved;
    bool mIsSubFrame;
    bool mDataPathIsRelative;
    bool mNeedsFixup;
    nsString mFilename;
    nsString mSubFrameExt;
    nsCOMPtr<nsIURI> mFile;
    nsCOMPtr<nsIURI> mDataPath;
    nsCOMPtr<nsIURI> mRelativeDocumentURI;
    nsCString mRelativePathToData;
    nsCString mCharset;

    nsresult GetLocalURI(nsIURI *targetBaseURI, nsCString& aSpecOut);
};

// Information about the output stream
struct nsWebBrowserPersist::OutputData
{
    nsCOMPtr<nsIURI> mFile;
    nsCOMPtr<nsIURI> mOriginalLocation;
    nsCOMPtr<nsIOutputStream> mStream;
    int64_t mSelfProgress;
    int64_t mSelfProgressMax;
    bool mCalcFileExt;

    OutputData(nsIURI *aFile, nsIURI *aOriginalLocation, bool aCalcFileExt) :
        mFile(aFile),
        mOriginalLocation(aOriginalLocation),
        mSelfProgress(0),
        mSelfProgressMax(10000),
        mCalcFileExt(aCalcFileExt)
    {
    }
    ~OutputData()
    {
        if (mStream)
        {
            mStream->Close();
        }
    }
};

struct nsWebBrowserPersist::UploadData
{
    nsCOMPtr<nsIURI> mFile;
    int64_t mSelfProgress;
    int64_t mSelfProgressMax;

    explicit UploadData(nsIURI *aFile) :
        mFile(aFile),
        mSelfProgress(0),
        mSelfProgressMax(10000)
    {
    }
};

struct nsWebBrowserPersist::CleanupData
{
    nsCOMPtr<nsIFile> mFile;
    // Snapshot of what the file actually is at the time of creation so that if
    // it transmutes into something else later on it can be ignored. For example,
    // catch files that turn into dirs or vice versa.
    bool mIsDirectory;
};

class nsWebBrowserPersist::OnWalk final
    : public nsIWebBrowserPersistResourceVisitor
{
public:
    OnWalk(nsWebBrowserPersist* aParent, nsIURI* aFile, nsIFile* aDataPath)
    : mParent(aParent)
    , mFile(aFile)
    , mDataPath(aDataPath)
    { }

    NS_DECL_NSIWEBBROWSERPERSISTRESOURCEVISITOR
    NS_DECL_ISUPPORTS
private:
    RefPtr<nsWebBrowserPersist> mParent;
    nsCOMPtr<nsIURI> mFile;
    nsCOMPtr<nsIFile> mDataPath;

    virtual ~OnWalk() { }
};

NS_IMPL_ISUPPORTS(nsWebBrowserPersist::OnWalk,
                  nsIWebBrowserPersistResourceVisitor)

class nsWebBrowserPersist::OnWrite final
    : public nsIWebBrowserPersistWriteCompletion
{
public:
    OnWrite(nsWebBrowserPersist* aParent,
            nsIURI* aFile,
            nsIFile* aLocalFile)
    : mParent(aParent)
    , mFile(aFile)
    , mLocalFile(aLocalFile)
    { }

    NS_DECL_NSIWEBBROWSERPERSISTWRITECOMPLETION
    NS_DECL_ISUPPORTS
private:
    RefPtr<nsWebBrowserPersist> mParent;
    nsCOMPtr<nsIURI> mFile;
    nsCOMPtr<nsIFile> mLocalFile;

    virtual ~OnWrite() { }
};

NS_IMPL_ISUPPORTS(nsWebBrowserPersist::OnWrite,
                  nsIWebBrowserPersistWriteCompletion)

class nsWebBrowserPersist::FlatURIMap final
    : public nsIWebBrowserPersistURIMap
{
public:
    explicit FlatURIMap(const nsACString& aTargetBase)
    : mTargetBase(aTargetBase) { }

    void Add(const nsACString& aMapFrom, const nsACString& aMapTo) {
        mMapFrom.AppendElement(aMapFrom);
        mMapTo.AppendElement(aMapTo);
    }

    NS_DECL_NSIWEBBROWSERPERSISTURIMAP
    NS_DECL_ISUPPORTS

private:
    nsTArray<nsCString> mMapFrom;
    nsTArray<nsCString> mMapTo;
    nsCString mTargetBase;

    virtual ~FlatURIMap() { }
};

NS_IMPL_ISUPPORTS(nsWebBrowserPersist::FlatURIMap, nsIWebBrowserPersistURIMap)

NS_IMETHODIMP
nsWebBrowserPersist::FlatURIMap::GetNumMappedURIs(uint32_t* aNum)
{
    MOZ_ASSERT(mMapFrom.Length() == mMapTo.Length());
    *aNum = mMapTo.Length();
    return NS_OK;
}

NS_IMETHODIMP
nsWebBrowserPersist::FlatURIMap::GetTargetBaseURI(nsACString& aTargetBase)
{
    aTargetBase = mTargetBase;
    return NS_OK;
}

NS_IMETHODIMP
nsWebBrowserPersist::FlatURIMap::GetURIMapping(uint32_t aIndex,
                                      nsACString& aMapFrom,
                                      nsACString& aMapTo)
{
    MOZ_ASSERT(mMapFrom.Length() == mMapTo.Length());
    if (aIndex >= mMapTo.Length()) {
        return NS_ERROR_INVALID_ARG;
    }
    aMapFrom = mMapFrom[aIndex];
    aMapTo = mMapTo[aIndex];
    return NS_OK;
}


// Maximum file length constant. The max file name length is
// volume / server dependent but it is difficult to obtain
// that information. Instead this constant is a reasonable value that
// modern systems should able to cope with.
const uint32_t kDefaultMaxFilenameLength = 64;

// Default flags for persistence
const uint32_t kDefaultPersistFlags =
    nsIWebBrowserPersist::PERSIST_FLAGS_NO_CONVERSION |
    nsIWebBrowserPersist::PERSIST_FLAGS_REPLACE_EXISTING_FILES;

// String bundle where error messages come from
const char *kWebBrowserPersistStringBundle =
    "chrome://global/locale/nsWebBrowserPersist.properties";

nsWebBrowserPersist::nsWebBrowserPersist() :
    mCurrentDataPathIsRelative(false),
    mCurrentThingsToPersist(0),
    mFirstAndOnlyUse(true),
    mSavingDocument(false),
    mCancel(false),
    mCompleted(false),
    mStartSaving(false),
    mReplaceExisting(true),
    mSerializingOutput(false),
    mIsPrivate(false),
    mPersistFlags(kDefaultPersistFlags),
    mPersistResult(NS_OK),
    mTotalCurrentProgress(0),
    mTotalMaxProgress(0),
    mWrapColumn(72),
    mEncodingFlags(0)
{
}

nsWebBrowserPersist::~nsWebBrowserPersist()
{
    Cleanup();
}

//*****************************************************************************
// nsWebBrowserPersist::nsISupports
//*****************************************************************************

NS_IMPL_ADDREF(nsWebBrowserPersist)
NS_IMPL_RELEASE(nsWebBrowserPersist)

NS_INTERFACE_MAP_BEGIN(nsWebBrowserPersist)
    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIWebBrowserPersist)
    NS_INTERFACE_MAP_ENTRY(nsIWebBrowserPersist)
    NS_INTERFACE_MAP_ENTRY(nsICancelable)
    NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
    NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
    NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
    NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
    NS_INTERFACE_MAP_ENTRY(nsIProgressEventSink)
NS_INTERFACE_MAP_END


//*****************************************************************************
// nsWebBrowserPersist::nsIInterfaceRequestor
//*****************************************************************************

NS_IMETHODIMP nsWebBrowserPersist::GetInterface(const nsIID & aIID, void **aIFace)
{
    NS_ENSURE_ARG_POINTER(aIFace);

    *aIFace = nullptr;

    nsresult rv = QueryInterface(aIID, aIFace);
    if (NS_SUCCEEDED(rv))
    {
        return rv;
    }

    if (mProgressListener && (aIID.Equals(NS_GET_IID(nsIAuthPrompt))
                             || aIID.Equals(NS_GET_IID(nsIPrompt))))
    {
        mProgressListener->QueryInterface(aIID, aIFace);
        if (*aIFace)
            return NS_OK;
    }

    nsCOMPtr<nsIInterfaceRequestor> req = do_QueryInterface(mProgressListener);
    if (req)
    {
        return req->GetInterface(aIID, aIFace);
    }

    return NS_ERROR_NO_INTERFACE;
}


//*****************************************************************************
// nsWebBrowserPersist::nsIWebBrowserPersist
//*****************************************************************************

NS_IMETHODIMP nsWebBrowserPersist::GetPersistFlags(uint32_t *aPersistFlags)
{
    NS_ENSURE_ARG_POINTER(aPersistFlags);
    *aPersistFlags = mPersistFlags;
    return NS_OK;
}
NS_IMETHODIMP nsWebBrowserPersist::SetPersistFlags(uint32_t aPersistFlags)
{
    mPersistFlags = aPersistFlags;
    mReplaceExisting = (mPersistFlags & PERSIST_FLAGS_REPLACE_EXISTING_FILES) ? true : false;
    mSerializingOutput = (mPersistFlags & PERSIST_FLAGS_SERIALIZE_OUTPUT) ? true : false;
    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::GetCurrentState(uint32_t *aCurrentState)
{
    NS_ENSURE_ARG_POINTER(aCurrentState);
    if (mCompleted)
    {
        *aCurrentState = PERSIST_STATE_FINISHED;
    }
    else if (mFirstAndOnlyUse)
    {
        *aCurrentState = PERSIST_STATE_SAVING;
    }
    else
    {
        *aCurrentState = PERSIST_STATE_READY;
    }
    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::GetResult(nsresult *aResult)
{
    NS_ENSURE_ARG_POINTER(aResult);
    *aResult = mPersistResult;
    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::GetProgressListener(
    nsIWebProgressListener * *aProgressListener)
{
    NS_ENSURE_ARG_POINTER(aProgressListener);
    *aProgressListener = mProgressListener;
    NS_IF_ADDREF(*aProgressListener);
    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::SetProgressListener(
    nsIWebProgressListener * aProgressListener)
{
    mProgressListener = aProgressListener;
    mProgressListener2 = do_QueryInterface(aProgressListener);
    mEventSink = do_GetInterface(aProgressListener);
    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::SaveURI(
    nsIURI *aURI, nsISupports *aCacheKey,
    nsIURI *aReferrer, uint32_t aReferrerPolicy,
    nsIInputStream *aPostData, const char *aExtraHeaders,
    nsISupports *aFile, nsILoadContext* aPrivacyContext)
{
    return SavePrivacyAwareURI(aURI, aCacheKey, aReferrer, aReferrerPolicy,
                               aPostData, aExtraHeaders, aFile,
                               aPrivacyContext && aPrivacyContext->UsePrivateBrowsing());
}

NS_IMETHODIMP nsWebBrowserPersist::SavePrivacyAwareURI(
    nsIURI *aURI, nsISupports *aCacheKey,
    nsIURI *aReferrer, uint32_t aReferrerPolicy,
    nsIInputStream *aPostData, const char *aExtraHeaders, 
    nsISupports *aFile, bool aIsPrivate)
{
    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
    mFirstAndOnlyUse = false; // Stop people from reusing this object!

    nsCOMPtr<nsIURI> fileAsURI;
    nsresult rv;
    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);

    // SaveURI doesn't like broken uris.
    mPersistFlags |= PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS;
    rv = SaveURIInternal(aURI, aCacheKey, aReferrer, aReferrerPolicy,
                         aPostData, aExtraHeaders, fileAsURI, false, aIsPrivate);
    return NS_FAILED(rv) ? rv : NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::SaveChannel(
    nsIChannel *aChannel, nsISupports *aFile)
{
    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
    mFirstAndOnlyUse = false; // Stop people from reusing this object!

    nsCOMPtr<nsIURI> fileAsURI;
    nsresult rv;
    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);

    rv = aChannel->GetURI(getter_AddRefs(mURI));
    NS_ENSURE_SUCCESS(rv, rv);

    // SaveURI doesn't like broken uris.
    mPersistFlags |= PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS;
    rv = SaveChannelInternal(aChannel, fileAsURI, false);
    return NS_FAILED(rv) ? rv : NS_OK;
}


NS_IMETHODIMP nsWebBrowserPersist::SaveDocument(
    nsISupports *aDocument, nsISupports *aFile, nsISupports *aDataPath,
    const char *aOutputContentType, uint32_t aEncodingFlags, uint32_t aWrapColumn)
{
    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
    mFirstAndOnlyUse = false; // Stop people from reusing this object!

    // We need a STATE_IS_NETWORK start/stop pair to bracket the
    // notification callbacks.  For a whole document we generate those
    // here and in EndDownload(), but for the single-request methods
    // that's done in On{Start,Stop}Request instead.
    mSavingDocument = true;

    NS_ENSURE_ARG_POINTER(aDocument);
    NS_ENSURE_ARG_POINTER(aFile);

    nsCOMPtr<nsIURI> fileAsURI;
    nsCOMPtr<nsIURI> datapathAsURI;
    nsresult rv;

    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
    if (aDataPath)
    {
        rv = GetValidURIFromObject(aDataPath, getter_AddRefs(datapathAsURI));
        NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
    }

    mWrapColumn = aWrapColumn;
    mEncodingFlags = aEncodingFlags;

    if (aOutputContentType)
    {
        mContentType.AssignASCII(aOutputContentType);
    }

    // State start notification
    if (mProgressListener) {
        mProgressListener->OnStateChange(nullptr, nullptr,
            nsIWebProgressListener::STATE_START
            | nsIWebProgressListener::STATE_IS_NETWORK, NS_OK);
    }

    nsCOMPtr<nsIWebBrowserPersistDocument> doc = do_QueryInterface(aDocument);
    if (!doc) {
        nsCOMPtr<nsIDocument> localDoc = do_QueryInterface(aDocument);
        if (localDoc) {
            doc = new mozilla::WebBrowserPersistLocalDocument(localDoc);
        } else {
            rv = NS_ERROR_NO_INTERFACE;
        }
    }
    if (doc) {
        rv = SaveDocumentInternal(doc, fileAsURI, datapathAsURI);
    }
    if (NS_FAILED(rv)) {
        SendErrorStatusChange(true, rv, nullptr, mURI);
        EndDownload(rv);
    }
    return rv;
}

NS_IMETHODIMP nsWebBrowserPersist::Cancel(nsresult aReason)
{
    mCancel = true;
    EndDownload(aReason);
    return NS_OK;
}


NS_IMETHODIMP nsWebBrowserPersist::CancelSave()
{
    return Cancel(NS_BINDING_ABORTED);
}


nsresult
nsWebBrowserPersist::StartUpload(nsIStorageStream *storStream,
    nsIURI *aDestinationURI, const nsACString &aContentType)
{
     // setup the upload channel if the destination is not local
    nsCOMPtr<nsIInputStream> inputstream;
    nsresult rv = storStream->NewInputStream(0, getter_AddRefs(inputstream));
    NS_ENSURE_TRUE(inputstream, NS_ERROR_FAILURE);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
    return StartUpload(inputstream, aDestinationURI, aContentType);
}

nsresult
nsWebBrowserPersist::StartUpload(nsIInputStream *aInputStream,
    nsIURI *aDestinationURI, const nsACString &aContentType)
{
    nsCOMPtr<nsIChannel> destChannel;
    CreateChannelFromURI(aDestinationURI, getter_AddRefs(destChannel));
    nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(destChannel));
    NS_ENSURE_TRUE(uploadChannel, NS_ERROR_FAILURE);

    // Set the upload stream
    // NOTE: ALL data must be available in "inputstream"
    nsresult rv = uploadChannel->SetUploadStream(aInputStream, aContentType, -1);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
    rv = destChannel->AsyncOpen2(this);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // add this to the upload list
    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(destChannel);
    mUploadList.Put(keyPtr, new UploadData(aDestinationURI));

    return NS_OK;
}

void
nsWebBrowserPersist::SerializeNextFile()
{
    nsresult rv = NS_OK;
    MOZ_ASSERT(mWalkStack.Length() == 0);

    // First, handle gathered URIs.
    // Count how many URIs in the URI map require persisting
    uint32_t urisToPersist = 0;
    if (mURIMap.Count() > 0) {
        // This is potentially O(n^2), when taking into account the
        // number of times this method is called.  If it becomes a
        // bottleneck, the count of not-yet-persisted URIs could be
        // maintained separately.
        for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
            URIData *data = iter.UserData();
            if (data->mNeedsPersisting && !data->mSaved) {
                urisToPersist++;
            }
        }
    }

    if (urisToPersist > 0) {
        // Persist each file in the uri map. The document(s)
        // will be saved after the last one of these is saved.
        for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
            URIData *data = iter.UserData();

            if (!data->mNeedsPersisting || data->mSaved) {
                continue;
            }

            nsresult rv;

            // Create a URI from the key.
            nsCOMPtr<nsIURI> uri;
            rv = NS_NewURI(getter_AddRefs(uri), iter.Key(),
                           data->mCharset.get());
            if (NS_WARN_IF(NS_FAILED(rv))) {
                break;
            }

            // Make a URI to save the data to.
            nsCOMPtr<nsIURI> fileAsURI;
            rv = data->mDataPath->Clone(getter_AddRefs(fileAsURI));
            if (NS_WARN_IF(NS_FAILED(rv))) {
                break;
            }
            rv = AppendPathToURI(fileAsURI, data->mFilename);
            if (NS_WARN_IF(NS_FAILED(rv))) {
                break;
            }

            // The Referrer Policy doesn't matter here since the referrer is
            // nullptr.
            rv = SaveURIInternal(uri, nullptr, nullptr,
                                 mozilla::net::RP_Default, nullptr, nullptr,
                                 fileAsURI, true, mIsPrivate);
            // If SaveURIInternal fails, then it will have called EndDownload,
            // which means that |data| is no longer valid memory. We MUST bail.
            if (NS_WARN_IF(NS_FAILED(rv))) {
                break;
            }

            if (rv == NS_OK) {
                // Store the actual object because once it's persisted this
                // will be fixed up with the right file extension.
                data->mFile = fileAsURI;
                data->mSaved = true;
            } else {
                data->mNeedsFixup = false;
            }

            if (mSerializingOutput) {
                break;
            }
        }
    }

    // If there are downloads happening, wait until they're done; the
    // OnStopRequest handler will call this method again.
    if (mOutputMap.Count() > 0) {
        return;
    }

    // If serializing, also wait until last upload is done.
    if (mSerializingOutput && mUploadList.Count() > 0) {
        return;
    }

    // If there are also no more documents, then we're done.
    if (mDocList.Length() == 0) {
        // ...or not quite done, if there are still uploads.
        if (mUploadList.Count() > 0) {
            return;
        }
        // Finish and clean things up.  Defer this because the caller
        // may have been expecting to use the listeners that that
        // method will clear.
        NS_DispatchToCurrentThread(NewRunnableMethod(this,
            &nsWebBrowserPersist::FinishDownload));
        return;
    }

    // There are no URIs to save, so just save the next document.
    mStartSaving = true;
    mozilla::UniquePtr<DocData> docData(mDocList.ElementAt(0));
    mDocList.RemoveElementAt(0); // O(n^2) but probably doesn't matter.
    MOZ_ASSERT(docData);
    if (!docData) {
        EndDownload(NS_ERROR_FAILURE);
        return;
    }

    mCurrentBaseURI = docData->mBaseURI;
    mCurrentCharset = docData->mCharset;
    mTargetBaseURI = docData->mFile;

    // Save the document, fixing it up with the new URIs as we do

    nsAutoCString targetBaseSpec;
    if (mTargetBaseURI) {
        rv = mTargetBaseURI->GetSpec(targetBaseSpec);
        if (NS_FAILED(rv)) {
            SendErrorStatusChange(true, rv, nullptr, nullptr);
            EndDownload(rv);
            return;
        }
    }

    // mFlatURIMap must be rebuilt each time through SerializeNextFile, as
    // mTargetBaseURI is used to create the relative URLs and will be different
    // with each serialized document.
    RefPtr<FlatURIMap> flatMap = new FlatURIMap(targetBaseSpec);
    for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
        nsAutoCString mapTo;
        nsresult rv = iter.UserData()->GetLocalURI(mTargetBaseURI, mapTo);
        if (NS_SUCCEEDED(rv) || !mapTo.IsVoid()) {
            flatMap->Add(iter.Key(), mapTo);
        }
    }
    mFlatURIMap = flatMap.forget();

    nsCOMPtr<nsIFile> localFile;
    GetLocalFileFromURI(docData->mFile, getter_AddRefs(localFile));
    if (localFile) {
        // if we're not replacing an existing file but the file
        // exists, something is wrong
        bool fileExists = false;
        rv = localFile->Exists(&fileExists);
        if (NS_SUCCEEDED(rv) && !mReplaceExisting && fileExists) {
            rv = NS_ERROR_FILE_ALREADY_EXISTS;
        }
        if (NS_FAILED(rv)) {
            SendErrorStatusChange(false, rv, nullptr, docData->mFile);
            EndDownload(rv);
            return;
        }
    }
    nsCOMPtr<nsIOutputStream> outputStream;
    rv = MakeOutputStream(docData->mFile, getter_AddRefs(outputStream));
    if (NS_SUCCEEDED(rv) && !outputStream) {
        rv = NS_ERROR_FAILURE;
    }
    if (NS_FAILED(rv)) {
        SendErrorStatusChange(false, rv, nullptr, docData->mFile);
        EndDownload(rv);
        return;
    }

    RefPtr<OnWrite> finish = new OnWrite(this, docData->mFile, localFile);
    rv = docData->mDocument->WriteContent(outputStream,
                                          mFlatURIMap,
                                          NS_ConvertUTF16toUTF8(mContentType),
                                          mEncodingFlags,
                                          mWrapColumn,
                                          finish);
    if (NS_FAILED(rv)) {
        SendErrorStatusChange(false, rv, nullptr, docData->mFile);
        EndDownload(rv);
    }
}

NS_IMETHODIMP
nsWebBrowserPersist::OnWrite::OnFinish(nsIWebBrowserPersistDocument* aDoc,
                                       nsIOutputStream *aStream,
                                       const nsACString& aContentType,
                                       nsresult aStatus)
{
    nsresult rv = aStatus;

    if (NS_FAILED(rv)) {
        mParent->SendErrorStatusChange(false, rv, nullptr, mFile);
        mParent->EndDownload(rv);
        return NS_OK;
    }
    if (!mLocalFile) {
        nsCOMPtr<nsIStorageStream> storStream(do_QueryInterface(aStream));
        if (storStream) {
            aStream->Close();
            rv = mParent->StartUpload(storStream, mFile, aContentType);
            if (NS_FAILED(rv)) {
                mParent->SendErrorStatusChange(false, rv, nullptr, mFile);
                mParent->EndDownload(rv);
            }
            // Either we failed and we're done, or we're uploading and
            // the OnStopRequest callback is responsible for the next
            // SerializeNextFile().
            return NS_OK;
        }
    }
    NS_DispatchToCurrentThread(NewRunnableMethod(mParent,
        &nsWebBrowserPersist::SerializeNextFile));
    return NS_OK;
}

//*****************************************************************************
// nsWebBrowserPersist::nsIRequestObserver
//*****************************************************************************

NS_IMETHODIMP nsWebBrowserPersist::OnStartRequest(
    nsIRequest* request, nsISupports *ctxt)
{
    if (mProgressListener)
    {
        uint32_t stateFlags = nsIWebProgressListener::STATE_START |
                              nsIWebProgressListener::STATE_IS_REQUEST;
        if (!mSavingDocument) {
            stateFlags |= nsIWebProgressListener::STATE_IS_NETWORK;
        }
        mProgressListener->OnStateChange(nullptr, request, stateFlags, NS_OK);
    }

    nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
    NS_ENSURE_TRUE(channel, NS_ERROR_FAILURE);

    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
    OutputData *data = mOutputMap.Get(keyPtr);

    // NOTE: This code uses the channel as a hash key so it will not
    //       recognize redirected channels because the key is not the same.
    //       When that happens we remove and add the data entry to use the
    //       new channel as the hash key.
    if (!data)
    {
        UploadData *upData = mUploadList.Get(keyPtr);
        if (!upData)
        {
            // Redirect? Try and fixup the output table
            nsresult rv = FixRedirectedChannelEntry(channel);
            NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

            // Should be able to find the data after fixup unless redirects
            // are disabled.
            data = mOutputMap.Get(keyPtr);
            if (!data)
            {
                return NS_ERROR_FAILURE;
            }
        }
    }

    if (data && data->mFile)
    {
        // If PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION is set in mPersistFlags,
        // try to determine whether this channel needs to apply Content-Encoding
        // conversions.
        NS_ASSERTION(!((mPersistFlags & PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION) &&
                      (mPersistFlags & PERSIST_FLAGS_NO_CONVERSION)),
                     "Conflict in persist flags: both AUTODETECT and NO_CONVERSION set");
        if (mPersistFlags & PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION)
            SetApplyConversionIfNeeded(channel);

        if (data->mCalcFileExt && !(mPersistFlags & PERSIST_FLAGS_DONT_CHANGE_FILENAMES))
        {
            // this is the first point at which the server can tell us the mimetype
            CalculateAndAppendFileExt(data->mFile, channel, data->mOriginalLocation);

            // now make filename conformant and unique
            CalculateUniqueFilename(data->mFile);
        }

        // compare uris and bail before we add to output map if they are equal
        bool isEqual = false;
        if (NS_SUCCEEDED(data->mFile->Equals(data->mOriginalLocation, &isEqual))
            && isEqual)
        {
            // remove from output map
            mOutputMap.Remove(keyPtr);

            // cancel; we don't need to know any more
            // stop request will get called
            request->Cancel(NS_BINDING_ABORTED);
        }
    }

    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::OnStopRequest(
    nsIRequest* request, nsISupports *ctxt, nsresult status)
{
    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
    OutputData *data = mOutputMap.Get(keyPtr);
    if (data) {
        if (NS_SUCCEEDED(mPersistResult) && NS_FAILED(status)) {
            SendErrorStatusChange(true, status, request, data->mFile);
        }

        // This will automatically close the output stream
        mOutputMap.Remove(keyPtr);
    } else {
        // if we didn't find the data in mOutputMap, try mUploadList
        UploadData *upData = mUploadList.Get(keyPtr);
        if (upData) {
            mUploadList.Remove(keyPtr);
        }
    }

    // Do more work.
    SerializeNextFile();

    if (mProgressListener) {
        uint32_t stateFlags = nsIWebProgressListener::STATE_STOP |
                              nsIWebProgressListener::STATE_IS_REQUEST;
        if (!mSavingDocument) {
            stateFlags |= nsIWebProgressListener::STATE_IS_NETWORK;
        }
        mProgressListener->OnStateChange(nullptr, request, stateFlags, status);
    }

    return NS_OK;
}

//*****************************************************************************
// nsWebBrowserPersist::nsIStreamListener
//*****************************************************************************

NS_IMETHODIMP
nsWebBrowserPersist::OnDataAvailable(
    nsIRequest* request, nsISupports *aContext, nsIInputStream *aIStream,
    uint64_t aOffset, uint32_t aLength)
{
    bool cancel = mCancel;
    if (!cancel)
    {
        nsresult rv = NS_OK;
        uint32_t bytesRemaining = aLength;

        nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
        NS_ENSURE_TRUE(channel, NS_ERROR_FAILURE);

        nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
        OutputData *data = mOutputMap.Get(keyPtr);
        if (!data) {
            // might be uploadData; consume necko's buffer and bail...
            uint32_t n;
            return aIStream->ReadSegments(NS_DiscardSegment, nullptr, aLength, &n);
        }

        bool readError = true;

        // Make the output stream
        if (!data->mStream)
        {
            rv = MakeOutputStream(data->mFile, getter_AddRefs(data->mStream));
            if (NS_FAILED(rv))
            {
                readError = false;
                cancel = true;
            }
        }

        // Read data from the input and write to the output
        char buffer[8192];
        uint32_t bytesRead;
        while (!cancel && bytesRemaining)
        {
            readError = true;
            rv = aIStream->Read(buffer,
                                std::min(uint32_t(sizeof(buffer)), bytesRemaining),
                                &bytesRead);
            if (NS_SUCCEEDED(rv))
            {
                readError = false;
                // Write out the data until something goes wrong, or, it is
                // all written.  We loop because for some errors (e.g., disk
                // full), we get NS_OK with some bytes written, then an error.
                // So, we want to write again in that case to get the actual
                // error code.
                const char *bufPtr = buffer; // Where to write from.
                while (NS_SUCCEEDED(rv) && bytesRead)
                {
                    uint32_t bytesWritten = 0;
                    rv = data->mStream->Write(bufPtr, bytesRead, &bytesWritten);
                    if (NS_SUCCEEDED(rv))
                    {
                        bytesRead -= bytesWritten;
                        bufPtr += bytesWritten;
                        bytesRemaining -= bytesWritten;
                        // Force an error if (for some reason) we get NS_OK but
                        // no bytes written.
                        if (!bytesWritten)
                        {
                            rv = NS_ERROR_FAILURE;
                            cancel = true;
                        }
                    }
                    else
                    {
                        // Disaster - can't write out the bytes - disk full / permission?
                        cancel = true;
                    }
                }
            }
            else
            {
                // Disaster - can't read the bytes - broken link / file error?
                cancel = true;
            }
        }

        int64_t channelContentLength = -1;
        if (!cancel &&
            NS_SUCCEEDED(channel->GetContentLength(&channelContentLength)))
        {
            // if we get -1 at this point, we didn't get content-length header
            // assume that we got all of the data and push what we have;
            // that's the best we can do now
            if ((-1 == channelContentLength) ||
                ((channelContentLength - (aOffset + aLength)) == 0))
            {
                NS_WARNING_ASSERTION(
                    channelContentLength != -1,
                    "nsWebBrowserPersist::OnDataAvailable() no content length "
                    "header, pushing what we have");
                // we're done with this pass; see if we need to do upload
                nsAutoCString contentType;
                channel->GetContentType(contentType);
                // if we don't have the right type of output stream then it's a local file
                nsCOMPtr<nsIStorageStream> storStream(do_QueryInterface(data->mStream));
                if (storStream)
                {
                    data->mStream->Close();
                    data->mStream = nullptr; // null out stream so we don't close it later
                    rv = StartUpload(storStream, data->mFile, contentType);
                    if (NS_FAILED(rv))
                    {
                        readError = false;
                        cancel = true;
                    }
                }
            }
        }

        // Notify listener if an error occurred.
        if (cancel)
        {
            SendErrorStatusChange(readError, rv,
                readError ? request : nullptr, data->mFile);
        }
    }

    // Cancel reading?
    if (cancel)
    {
        EndDownload(NS_BINDING_ABORTED);
    }

    return NS_OK;
}


//*****************************************************************************
// nsWebBrowserPersist::nsIProgressEventSink
//*****************************************************************************

NS_IMETHODIMP nsWebBrowserPersist::OnProgress(
    nsIRequest *request, nsISupports *ctxt, int64_t aProgress,
    int64_t aProgressMax)
{
    if (!mProgressListener)
    {
        return NS_OK;
    }

    // Store the progress of this request
    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
    OutputData *data = mOutputMap.Get(keyPtr);
    if (data)
    {
        data->mSelfProgress = aProgress;
        data->mSelfProgressMax = aProgressMax;
    }
    else
    {
        UploadData *upData = mUploadList.Get(keyPtr);
        if (upData)
        {
            upData->mSelfProgress = aProgress;
            upData->mSelfProgressMax = aProgressMax;
        }
    }

    // Notify listener of total progress
    CalcTotalProgress();
    if (mProgressListener2)
    {
      mProgressListener2->OnProgressChange64(nullptr, request, aProgress,
            aProgressMax, mTotalCurrentProgress, mTotalMaxProgress);
    }
    else
    {
      // have to truncate 64-bit to 32bit
      mProgressListener->OnProgressChange(nullptr, request, uint64_t(aProgress),
              uint64_t(aProgressMax), mTotalCurrentProgress, mTotalMaxProgress);
    }

    // If our progress listener implements nsIProgressEventSink,
    // forward the notification
    if (mEventSink)
    {
        mEventSink->OnProgress(request, ctxt, aProgress, aProgressMax);
    }

    return NS_OK;
}

NS_IMETHODIMP nsWebBrowserPersist::OnStatus(
    nsIRequest *request, nsISupports *ctxt, nsresult status,
    const char16_t *statusArg)
{
    if (mProgressListener)
    {
        // We need to filter out non-error error codes.
        // Is the only NS_SUCCEEDED value NS_OK?
        switch ( status )
        {
        case NS_NET_STATUS_RESOLVING_HOST:
        case NS_NET_STATUS_RESOLVED_HOST:
        case NS_NET_STATUS_BEGIN_FTP_TRANSACTION:
        case NS_NET_STATUS_END_FTP_TRANSACTION:
        case NS_NET_STATUS_CONNECTING_TO:
        case NS_NET_STATUS_CONNECTED_TO:
        case NS_NET_STATUS_SENDING_TO:
        case NS_NET_STATUS_RECEIVING_FROM:
        case NS_NET_STATUS_WAITING_FOR:
        case NS_NET_STATUS_READING:
        case NS_NET_STATUS_WRITING:
            break;

        default:
            // Pass other notifications (for legitimate errors) along.
            mProgressListener->OnStatusChange(nullptr, request, status, statusArg);
            break;
        }

    }

    // If our progress listener implements nsIProgressEventSink,
    // forward the notification
    if (mEventSink)
    {
        mEventSink->OnStatus(request, ctxt, status, statusArg);
    }

    return NS_OK;
}


//*****************************************************************************
// nsWebBrowserPersist private methods
//*****************************************************************************

// Convert error info into proper message text and send OnStatusChange notification
// to the web progress listener.
nsresult nsWebBrowserPersist::SendErrorStatusChange(
    bool aIsReadError, nsresult aResult, nsIRequest *aRequest, nsIURI *aURI)
{
    NS_ENSURE_ARG_POINTER(aURI);

    if (!mProgressListener)
    {
        // Do nothing
        return NS_OK;
    }

    // Get the file path or spec from the supplied URI
    nsCOMPtr<nsIFile> file;
    GetLocalFileFromURI(aURI, getter_AddRefs(file));
    nsAutoString path;
    nsresult rv;
    if (file)
    {
        file->GetPath(path);
    }
    else
    {
        nsAutoCString fileurl;
        rv = aURI->GetSpec(fileurl);
        NS_ENSURE_SUCCESS(rv, rv);
        AppendUTF8toUTF16(fileurl, path);
    }

    nsAutoString msgId;
    switch(aResult)
    {
    case NS_ERROR_FILE_NAME_TOO_LONG:
        // File name too long.
        msgId.AssignLiteral("fileNameTooLongError");
        break;
    case NS_ERROR_FILE_ALREADY_EXISTS:
        // File exists with same name as directory.
        msgId.AssignLiteral("fileAlreadyExistsError");
        break;
    case NS_ERROR_FILE_DISK_FULL:
    case NS_ERROR_FILE_NO_DEVICE_SPACE:
        // Out of space on target volume.
        msgId.AssignLiteral("diskFull");
        break;

    case NS_ERROR_FILE_READ_ONLY:
        // Attempt to write to read/only file.
        msgId.AssignLiteral("readOnly");
        break;

    case NS_ERROR_FILE_ACCESS_DENIED:
        // Attempt to write without sufficient permissions.
        msgId.AssignLiteral("accessError");
        break;

    default:
        // Generic read/write error message.
        if (aIsReadError)
            msgId.AssignLiteral("readError");
        else
            msgId.AssignLiteral("writeError");
        break;
    }
    // Get properties file bundle and extract status string.
    nsCOMPtr<nsIStringBundleService> s = do_GetService(NS_STRINGBUNDLE_CONTRACTID, &rv);
    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && s, NS_ERROR_FAILURE);

    nsCOMPtr<nsIStringBundle> bundle;
    rv = s->CreateBundle(kWebBrowserPersistStringBundle, getter_AddRefs(bundle));
    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && bundle, NS_ERROR_FAILURE);

    nsXPIDLString msgText;
    const char16_t *strings[1];
    strings[0] = path.get();
    rv = bundle->FormatStringFromName(msgId.get(), strings, 1, getter_Copies(msgText));
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    mProgressListener->OnStatusChange(nullptr, aRequest, aResult, msgText);

    return NS_OK;
}

nsresult nsWebBrowserPersist::GetValidURIFromObject(nsISupports *aObject, nsIURI **aURI) const
{
    NS_ENSURE_ARG_POINTER(aObject);
    NS_ENSURE_ARG_POINTER(aURI);

    nsCOMPtr<nsIFile> objAsFile = do_QueryInterface(aObject);
    if (objAsFile)
    {
        return NS_NewFileURI(aURI, objAsFile);
    }
    nsCOMPtr<nsIURI> objAsURI = do_QueryInterface(aObject);
    if (objAsURI)
    {
        *aURI = objAsURI;
        NS_ADDREF(*aURI);
        return NS_OK;
    }

    return NS_ERROR_FAILURE;
}

/* static */ nsresult
nsWebBrowserPersist::GetLocalFileFromURI(nsIURI *aURI, nsIFile **aLocalFile)
{
    nsresult rv;

    nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
    if (NS_FAILED(rv))
        return rv;

    nsCOMPtr<nsIFile> file;
    rv = fileURL->GetFile(getter_AddRefs(file));
    if (NS_FAILED(rv)) {
        return rv;
    }

    file.forget(aLocalFile);
    return NS_OK;
}

/* static */ nsresult
nsWebBrowserPersist::AppendPathToURI(nsIURI *aURI, const nsAString & aPath)
{
    NS_ENSURE_ARG_POINTER(aURI);

    nsAutoCString newPath;
    nsresult rv = aURI->GetPath(newPath);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // Append a forward slash if necessary
    int32_t len = newPath.Length();
    if (len > 0 && newPath.CharAt(len - 1) != '/')
    {
        newPath.Append('/');
    }

    // Store the path back on the URI
    AppendUTF16toUTF8(aPath, newPath);
    aURI->SetPath(newPath);

    return NS_OK;
}

nsresult nsWebBrowserPersist::SaveURIInternal(
    nsIURI *aURI, nsISupports *aCacheKey, nsIURI *aReferrer,
    uint32_t aReferrerPolicy, nsIInputStream *aPostData,
    const char *aExtraHeaders, nsIURI *aFile,
    bool aCalcFileExt, bool aIsPrivate)
{
    NS_ENSURE_ARG_POINTER(aURI);
    NS_ENSURE_ARG_POINTER(aFile);

    nsresult rv = NS_OK;

    mURI = aURI;

    nsLoadFlags loadFlags = nsIRequest::LOAD_NORMAL;
    if (mPersistFlags & PERSIST_FLAGS_BYPASS_CACHE)
    {
        loadFlags |= nsIRequest::LOAD_BYPASS_CACHE;
    }
    else if (mPersistFlags & PERSIST_FLAGS_FROM_CACHE)
    {
        loadFlags |= nsIRequest::LOAD_FROM_CACHE;
    }

    // Extract the cache key
    nsCOMPtr<nsISupports> cacheKey;
    if (aCacheKey)
    {
        // Test if the cache key is actually a web page descriptor (docshell)
        // or session history entry.
        nsCOMPtr<nsISHEntry> shEntry = do_QueryInterface(aCacheKey);
        if (!shEntry)
        {
            nsCOMPtr<nsIWebPageDescriptor> webPageDescriptor =
                do_QueryInterface(aCacheKey);
            if (webPageDescriptor)
            {
                nsCOMPtr<nsISupports> currentDescriptor;
                webPageDescriptor->GetCurrentDescriptor(getter_AddRefs(currentDescriptor));
                shEntry = do_QueryInterface(currentDescriptor);
            }
        }

        if (shEntry)
        {
            shEntry->GetCacheKey(getter_AddRefs(cacheKey));
        }
        else
        {
            // Assume a plain cache key
            cacheKey = aCacheKey;
        }
    }

    // Open a channel to the URI
    nsCOMPtr<nsIChannel> inputChannel;
    rv = NS_NewChannel(getter_AddRefs(inputChannel),
                       aURI,
                       nsContentUtils::GetSystemPrincipal(),
                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
                       nsIContentPolicy::TYPE_OTHER,
                       nullptr,  // aLoadGroup
                       static_cast<nsIInterfaceRequestor*>(this),
                       loadFlags);

    nsCOMPtr<nsIPrivateBrowsingChannel> pbChannel = do_QueryInterface(inputChannel);
    if (pbChannel)
    {
        pbChannel->SetPrivate(aIsPrivate);
    }

    if (NS_FAILED(rv) || inputChannel == nullptr)
    {
        EndDownload(NS_ERROR_FAILURE);
        return NS_ERROR_FAILURE;
    }

    // Disable content conversion
    if (mPersistFlags & PERSIST_FLAGS_NO_CONVERSION)
    {
        nsCOMPtr<nsIEncodedChannel> encodedChannel(do_QueryInterface(inputChannel));
        if (encodedChannel)
        {
            encodedChannel->SetApplyConversion(false);
        }
    }

    if (mPersistFlags & PERSIST_FLAGS_FORCE_ALLOW_COOKIES)
    {
        nsCOMPtr<nsIHttpChannelInternal> httpChannelInternal =
                do_QueryInterface(inputChannel);
        if (httpChannelInternal)
            httpChannelInternal->SetThirdPartyFlags(nsIHttpChannelInternal::THIRD_PARTY_FORCE_ALLOW);
    }

    // Set the referrer, post data and headers if any
    nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(inputChannel));
    if (httpChannel)
    {
        // Referrer
        if (aReferrer)
        {
            httpChannel->SetReferrerWithPolicy(aReferrer, aReferrerPolicy);
        }

        // Post data
        if (aPostData)
        {
            nsCOMPtr<nsISeekableStream> stream(do_QueryInterface(aPostData));
            if (stream)
            {
                // Rewind the postdata stream
                stream->Seek(nsISeekableStream::NS_SEEK_SET, 0);
                nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(httpChannel));
                NS_ASSERTION(uploadChannel, "http must support nsIUploadChannel");
                // Attach the postdata to the http channel
                uploadChannel->SetUploadStream(aPostData, EmptyCString(), -1);
            }
        }

        // Cache key
        nsCOMPtr<nsICacheInfoChannel> cacheChannel(do_QueryInterface(httpChannel));
        if (cacheChannel && cacheKey)
        {
            cacheChannel->SetCacheKey(cacheKey);
        }

        // Headers
        if (aExtraHeaders)
        {
            nsAutoCString oneHeader;
            nsAutoCString headerName;
            nsAutoCString headerValue;
            int32_t crlf = 0;
            int32_t colon = 0;
            const char *kWhitespace = "\b\t\r\n ";
            nsAutoCString extraHeaders(aExtraHeaders);
            while (true)
            {
                crlf = extraHeaders.Find("\r\n", true);
                if (crlf == -1)
                    break;
                extraHeaders.Mid(oneHeader, 0, crlf);
                extraHeaders.Cut(0, crlf + 2);
                colon = oneHeader.Find(":");
                if (colon == -1)
                    break; // Should have a colon
                oneHeader.Left(headerName, colon);
                colon++;
                oneHeader.Mid(headerValue, colon, oneHeader.Length() - colon);
                headerName.Trim(kWhitespace);
                headerValue.Trim(kWhitespace);
                // Add the header (merging if required)
                rv = httpChannel->SetRequestHeader(headerName, headerValue, true);
                if (NS_FAILED(rv))
                {
                    EndDownload(NS_ERROR_FAILURE);
                    return NS_ERROR_FAILURE;
                }
            }
        }
    }
    return SaveChannelInternal(inputChannel, aFile, aCalcFileExt);
}

nsresult nsWebBrowserPersist::SaveChannelInternal(
    nsIChannel *aChannel, nsIURI *aFile, bool aCalcFileExt)
{
    NS_ENSURE_ARG_POINTER(aChannel);
    NS_ENSURE_ARG_POINTER(aFile);

    // The default behaviour of SaveChannelInternal is to download the source
    // into a storage stream and upload that to the target. MakeOutputStream
    // special-cases a file target and creates a file output stream directly.
    // We want to special-case a file source and create a file input stream,
    // but we don't need to do this in the case of a file target.
    nsCOMPtr<nsIFileChannel> fc(do_QueryInterface(aChannel));
    nsCOMPtr<nsIFileURL> fu(do_QueryInterface(aFile));

    if (fc && !fu) {
        nsCOMPtr<nsIInputStream> fileInputStream, bufferedInputStream;
        nsresult rv = NS_MaybeOpenChannelUsingOpen2(aChannel,
                        getter_AddRefs(fileInputStream));
        NS_ENSURE_SUCCESS(rv, rv);
        rv = NS_NewBufferedInputStream(getter_AddRefs(bufferedInputStream),
                                       fileInputStream, BUFFERED_OUTPUT_SIZE);
        NS_ENSURE_SUCCESS(rv, rv);
        nsAutoCString contentType;
        aChannel->GetContentType(contentType);
        return StartUpload(bufferedInputStream, aFile, contentType);
    }

    // Read from the input channel
    nsresult rv = NS_MaybeOpenChannelUsingAsyncOpen2(aChannel, this);
    if (rv == NS_ERROR_NO_CONTENT)
    {
        // Assume this is a protocol such as mailto: which does not feed out
        // data and just ignore it.
        return NS_SUCCESS_DONT_FIXUP;
    }

    if (NS_FAILED(rv))
    {
        // Opening failed, but do we care?
        if (mPersistFlags & PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS)
        {
            SendErrorStatusChange(true, rv, aChannel, aFile);
            EndDownload(NS_ERROR_FAILURE);
            return NS_ERROR_FAILURE;
        }
        return NS_SUCCESS_DONT_FIXUP;
    }

    // Add the output transport to the output map with the channel as the key
    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(aChannel);
    mOutputMap.Put(keyPtr, new OutputData(aFile, mURI, aCalcFileExt));

    return NS_OK;
}

nsresult
nsWebBrowserPersist::GetExtensionForContentType(const char16_t *aContentType, char16_t **aExt)
{
    NS_ENSURE_ARG_POINTER(aContentType);
    NS_ENSURE_ARG_POINTER(aExt);

    *aExt = nullptr;

    nsresult rv;
    if (!mMIMEService)
    {
        mMIMEService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
        NS_ENSURE_TRUE(mMIMEService, NS_ERROR_FAILURE);
    }

    nsAutoCString contentType;
    contentType.AssignWithConversion(aContentType);
    nsAutoCString ext;
    rv = mMIMEService->GetPrimaryExtension(contentType, EmptyCString(), ext);
    if (NS_SUCCEEDED(rv))
    {
        *aExt = UTF8ToNewUnicode(ext);
        NS_ENSURE_TRUE(*aExt, NS_ERROR_OUT_OF_MEMORY);
        return NS_OK;
    }

    return NS_ERROR_FAILURE;
}

nsresult
nsWebBrowserPersist::SaveDocumentDeferred(mozilla::UniquePtr<WalkData>&& aData)
{
    nsresult rv =
        SaveDocumentInternal(aData->mDocument, aData->mFile, aData->mDataPath);
    if (NS_FAILED(rv)) {
        SendErrorStatusChange(true, rv, nullptr, mURI);
        EndDownload(rv);
    }
    return rv;
}

nsresult nsWebBrowserPersist::SaveDocumentInternal(
    nsIWebBrowserPersistDocument *aDocument, nsIURI *aFile, nsIURI *aDataPath)
{
    mURI = nullptr;
    NS_ENSURE_ARG_POINTER(aDocument);
    NS_ENSURE_ARG_POINTER(aFile);

    nsresult rv = aDocument->SetPersistFlags(mPersistFlags);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = aDocument->GetIsPrivate(&mIsPrivate);
    NS_ENSURE_SUCCESS(rv, rv);

    // See if we can get the local file representation of this URI
    nsCOMPtr<nsIFile> localFile;
    rv = GetLocalFileFromURI(aFile, getter_AddRefs(localFile));

    nsCOMPtr<nsIFile> localDataPath;
    if (NS_SUCCEEDED(rv) && aDataPath)
    {
        // See if we can get the local file representation of this URI
        rv = GetLocalFileFromURI(aDataPath, getter_AddRefs(localDataPath));
        NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
    }

    // Persist the main document
    rv = aDocument->GetCharacterSet(mCurrentCharset);
    NS_ENSURE_SUCCESS(rv, rv);
    nsAutoCString uriSpec;
    rv = aDocument->GetDocumentURI(uriSpec);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = NS_NewURI(getter_AddRefs(mURI), uriSpec, mCurrentCharset.get());
    NS_ENSURE_SUCCESS(rv, rv);
    rv = aDocument->GetBaseURI(uriSpec);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = NS_NewURI(getter_AddRefs(mCurrentBaseURI), uriSpec,
                   mCurrentCharset.get());
    NS_ENSURE_SUCCESS(rv, rv);

    // Does the caller want to fixup the referenced URIs and save those too?
    if (aDataPath)
    {
        // Basic steps are these.
        //
        // 1. Iterate through the document (and subdocuments) building a list
        //    of unique URIs.
        // 2. For each URI create an OutputData entry and open a channel to save
        //    it. As each URI is saved, discover the mime type and fix up the
        //    local filename with the correct extension.
        // 3. Store the document in a list and wait for URI persistence to finish
        // 4. After URI persistence completes save the list of documents,
        //    fixing it up as it goes out to file.

        mCurrentDataPathIsRelative = false;
        mCurrentDataPath = aDataPath;
        mCurrentRelativePathToData = "";
        mCurrentThingsToPersist = 0;
        mTargetBaseURI = aFile;

        // Determine if the specified data path is relative to the
        // specified file, (e.g. c:\docs\htmldata is relative to
        // c:\docs\myfile.htm, but not to d:\foo\data.

        // Starting with the data dir work back through its parents
        // checking if one of them matches the base directory.

        if (localDataPath && localFile)
        {
            nsCOMPtr<nsIFile> baseDir;
            localFile->GetParent(getter_AddRefs(baseDir));

            nsAutoCString relativePathToData;
            nsCOMPtr<nsIFile> dataDirParent;
            dataDirParent = localDataPath;
            while (dataDirParent)
            {
                bool sameDir = false;
                dataDirParent->Equals(baseDir, &sameDir);
                if (sameDir)
                {
                    mCurrentRelativePathToData = relativePathToData;
                    mCurrentDataPathIsRelative = true;
                    break;
                }

                nsAutoString dirName;
                dataDirParent->GetLeafName(dirName);

                nsAutoCString newRelativePathToData;
                newRelativePathToData = NS_ConvertUTF16toUTF8(dirName)
                                      + NS_LITERAL_CSTRING("/")
                                      + relativePathToData;
                relativePathToData = newRelativePathToData;

                nsCOMPtr<nsIFile> newDataDirParent;
                rv = dataDirParent->GetParent(getter_AddRefs(newDataDirParent));
                dataDirParent = newDataDirParent;
            }
        }
        else
        {
            // generate a relative path if possible
            nsCOMPtr<nsIURL> pathToBaseURL(do_QueryInterface(aFile));
            if (pathToBaseURL)
            {
                nsAutoCString relativePath;  // nsACString
                if (NS_SUCCEEDED(pathToBaseURL->GetRelativeSpec(aDataPath, relativePath)))
                {
                    mCurrentDataPathIsRelative = true;
                    mCurrentRelativePathToData = relativePath;
                }
            }
        }

        // Store the document in a list so when URI persistence is done and the
        // filenames of saved URIs are known, the documents can be fixed up and
        // saved

        DocData *docData = new DocData;
        docData->mBaseURI = mCurrentBaseURI;
        docData->mCharset = mCurrentCharset;
        docData->mDocument = aDocument;
        docData->mFile = aFile;
        mDocList.AppendElement(docData);

        // Walk the DOM gathering a list of externally referenced URIs in the uri map
        nsCOMPtr<nsIWebBrowserPersistResourceVisitor> visit =
            new OnWalk(this, aFile, localDataPath);
        return aDocument->ReadResources(visit);
    }
    else
    {
        DocData *docData = new DocData;
        docData->mBaseURI = mCurrentBaseURI;
        docData->mCharset = mCurrentCharset;
        docData->mDocument = aDocument;
        docData->mFile = aFile;
        mDocList.AppendElement(docData);

        // Not walking DOMs, so go directly to serialization.
        SerializeNextFile();
        return NS_OK;
    }
}

NS_IMETHODIMP
nsWebBrowserPersist::OnWalk::VisitResource(nsIWebBrowserPersistDocument* aDoc,
                                           const nsACString& aURI)
{
    return mParent->StoreURI(nsAutoCString(aURI).get());
}

NS_IMETHODIMP
nsWebBrowserPersist::OnWalk::VisitDocument(nsIWebBrowserPersistDocument* aDoc,
                                             nsIWebBrowserPersistDocument* aSubDoc)
{
    URIData* data = nullptr;
    nsAutoCString uriSpec;
    nsresult rv = aSubDoc->GetDocumentURI(uriSpec);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = mParent->StoreURI(uriSpec.get(), false, &data);
    NS_ENSURE_SUCCESS(rv, rv);
    if (!data) {
        // If the URI scheme isn't persistable, then don't persist.
        return NS_OK;
    }
    data->mIsSubFrame = true;
    return mParent->SaveSubframeContent(aSubDoc, uriSpec, data);
}


NS_IMETHODIMP
nsWebBrowserPersist::OnWalk::EndVisit(nsIWebBrowserPersistDocument* aDoc,
                                      nsresult aStatus)
{
    if (NS_FAILED(aStatus)) {
        mParent->SendErrorStatusChange(true, aStatus, nullptr, mFile);
        mParent->EndDownload(aStatus);
        return aStatus;
    }
    mParent->FinishSaveDocumentInternal(mFile, mDataPath);
    return NS_OK;
}

void
nsWebBrowserPersist::FinishSaveDocumentInternal(nsIURI* aFile,
                                                nsIFile* aDataPath)
{
    // If there are things to persist, create a directory to hold them
    if (mCurrentThingsToPersist > 0) {
        if (aDataPath) {
            bool exists = false;
            bool haveDir = false;

            aDataPath->Exists(&exists);
            if (exists) {
                aDataPath->IsDirectory(&haveDir);
            }
            if (!haveDir) {
                nsresult rv =
                    aDataPath->Create(nsIFile::DIRECTORY_TYPE, 0755);
                if (NS_SUCCEEDED(rv)) {
                    haveDir = true;
                } else {
                    SendErrorStatusChange(false, rv, nullptr, aFile);
                }
            }
            if (!haveDir) {
                EndDownload(NS_ERROR_FAILURE);
                return;
            }
            if (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE) {
                // Add to list of things to delete later if all goes wrong
                CleanupData *cleanupData = new CleanupData;
                cleanupData->mFile = aDataPath;
                cleanupData->mIsDirectory = true;
                mCleanupList.AppendElement(cleanupData);
            }
        }
    }

    if (mWalkStack.Length() > 0) {
        mozilla::UniquePtr<WalkData> toWalk;
        mWalkStack.LastElement().swap(toWalk);
        mWalkStack.TruncateLength(mWalkStack.Length() - 1);
        // Bounce this off the event loop to avoid stack overflow.
        typedef StoreCopyPassByRRef<decltype(toWalk)> WalkStorage;
        auto saveMethod = &nsWebBrowserPersist::SaveDocumentDeferred;
        nsCOMPtr<nsIRunnable> saveLater =
            NewRunnableMethod<WalkStorage>(this, saveMethod,
                                           mozilla::Move(toWalk));
        NS_DispatchToCurrentThread(saveLater);
    } else {
        // Done walking DOMs; on to the serialization phase.
        SerializeNextFile();
    }
}

void nsWebBrowserPersist::Cleanup()
{
    mURIMap.Clear();
    for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
        nsCOMPtr<nsIChannel> channel = do_QueryInterface(iter.Key());
        if (channel) {
            channel->Cancel(NS_BINDING_ABORTED);
        }
    }
    mOutputMap.Clear();

    for (auto iter = mUploadList.Iter(); !iter.Done(); iter.Next()) {
        nsCOMPtr<nsIChannel> channel = do_QueryInterface(iter.Key());
        if (channel) {
            channel->Cancel(NS_BINDING_ABORTED);
        }
    }
    mUploadList.Clear();

    uint32_t i;
    for (i = 0; i < mDocList.Length(); i++) {
        DocData *docData = mDocList.ElementAt(i);
        delete docData;
    }
    mDocList.Clear();

    for (i = 0; i < mCleanupList.Length(); i++) {
        CleanupData *cleanupData = mCleanupList.ElementAt(i);
        delete cleanupData;
    }
    mCleanupList.Clear();

    mFilenameList.Clear();
}

void nsWebBrowserPersist::CleanupLocalFiles()
{
    // Two passes, the first pass cleans up files, the second pass tests
    // for and then deletes empty directories. Directories that are not
    // empty after the first pass must contain files from something else
    // and are not deleted.
    int pass;
    for (pass = 0; pass < 2; pass++)
    {
        uint32_t i;
        for (i = 0; i < mCleanupList.Length(); i++)
        {
            CleanupData *cleanupData = mCleanupList.ElementAt(i);
            nsCOMPtr<nsIFile> file = cleanupData->mFile;

            // Test if the dir / file exists (something in an earlier loop
            // may have already removed it)
            bool exists = false;
            file->Exists(&exists);
            if (!exists)
                continue;

            // Test if the file has changed in between creation and deletion
            // in some way that means it should be ignored
            bool isDirectory = false;
            file->IsDirectory(&isDirectory);
            if (isDirectory != cleanupData->mIsDirectory)
                continue; // A file has become a dir or vice versa !

            if (pass == 0 && !isDirectory)
            {
                file->Remove(false);
            }
            else if (pass == 1 && isDirectory) // Directory
            {
                // Directories are more complicated. Enumerate through
                // children looking for files. Any files created by the
                // persist object would have been deleted by the first
                // pass so if there are any there at this stage, the dir
                // cannot be deleted because it has someone else's files
                // in it. Empty child dirs are deleted but they must be
                // recursed through to ensure they are actually empty.

                bool isEmptyDirectory = true;
                nsCOMArray<nsISimpleEnumerator> dirStack;
                int32_t stackSize = 0;

                // Push the top level enum onto the stack
                nsCOMPtr<nsISimpleEnumerator> pos;
                if (NS_SUCCEEDED(file->GetDirectoryEntries(getter_AddRefs(pos))))
                    dirStack.AppendObject(pos);

                while (isEmptyDirectory && (stackSize = dirStack.Count()))
                {
                    // Pop the last element
                    nsCOMPtr<nsISimpleEnumerator> curPos;
                    curPos = dirStack[stackSize-1];
                    dirStack.RemoveObjectAt(stackSize - 1);

                    // Test if the enumerator has any more files in it
                    bool hasMoreElements = false;
                    curPos->HasMoreElements(&hasMoreElements);
                    if (!hasMoreElements)
                    {
                        continue;
                    }

                    // Child files automatically make this code drop out,
                    // while child dirs keep the loop going.
                    nsCOMPtr<nsISupports> child;
                    curPos->GetNext(getter_AddRefs(child));
                    NS_ASSERTION(child, "No child element, but hasMoreElements says otherwise");
                    if (!child)
                        continue;
                    nsCOMPtr<nsIFile> childAsFile = do_QueryInterface(child);
                    NS_ASSERTION(childAsFile, "This should be a file but isn't");

                    bool childIsSymlink = false;
                    childAsFile->IsSymlink(&childIsSymlink);
                    bool childIsDir = false;
                    childAsFile->IsDirectory(&childIsDir);
                    if (!childIsDir || childIsSymlink)
                    {
                        // Some kind of file or symlink which means dir
                        // is not empty so just drop out.
                        isEmptyDirectory = false;
                        break;
                    }
                    // Push parent enumerator followed by child enumerator
                    nsCOMPtr<nsISimpleEnumerator> childPos;
                    childAsFile->GetDirectoryEntries(getter_AddRefs(childPos));
                    dirStack.AppendObject(curPos);
                    if (childPos)
                        dirStack.AppendObject(childPos);

                }
                dirStack.Clear();

                // If after all that walking the dir is deemed empty, delete it
                if (isEmptyDirectory)
                {
                    file->Remove(true);
                }
            }
        }
    }
}

nsresult
nsWebBrowserPersist::CalculateUniqueFilename(nsIURI *aURI)
{
    nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
    NS_ENSURE_TRUE(url, NS_ERROR_FAILURE);

    bool nameHasChanged = false;
    nsresult rv;

    // Get the old filename
    nsAutoCString filename;
    rv = url->GetFileName(filename);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
    nsAutoCString directory;
    rv = url->GetDirectory(directory);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // Split the filename into a base and an extension.
    // e.g. "foo.html" becomes "foo" & ".html"
    //
    // The nsIURL methods GetFileBaseName & GetFileExtension don't
    // preserve the dot whereas this code does to save some effort
    // later when everything is put back together.
    int32_t lastDot = filename.RFind(".");
    nsAutoCString base;
    nsAutoCString ext;
    if (lastDot >= 0)
    {
        filename.Mid(base, 0, lastDot);
        filename.Mid(ext, lastDot, filename.Length() - lastDot); // includes dot
    }
    else
    {
        // filename contains no dot
        base = filename;
    }

    // Test if the filename is longer than allowed by the OS
    int32_t needToChop = filename.Length() - kDefaultMaxFilenameLength;
    if (needToChop > 0)
    {
        // Truncate the base first and then the ext if necessary
        if (base.Length() > (uint32_t) needToChop)
        {
            base.Truncate(base.Length() - needToChop);
        }
        else
        {
            needToChop -= base.Length() - 1;
            base.Truncate(1);
            if (ext.Length() > (uint32_t) needToChop)
            {
                ext.Truncate(ext.Length() - needToChop);
            }
            else
            {
                ext.Truncate(0);
            }
            // If kDefaultMaxFilenameLength were 1 we'd be in trouble here,
            // but that won't happen because it will be set to a sensible
            // value.
        }

        filename.Assign(base);
        filename.Append(ext);
        nameHasChanged = true;
    }

    // Ensure the filename is unique
    // Create a filename if it's empty, or if the filename / datapath is
    // already taken by another URI and create an alternate name.

    if (base.IsEmpty() || !mFilenameList.IsEmpty())
    {
        nsAutoCString tmpPath;
        nsAutoCString tmpBase;
        uint32_t duplicateCounter = 1;
        while (1)
        {
            // Make a file name,
            // Foo become foo_001, foo_002, etc.
            // Empty files become _001, _002 etc.

            if (base.IsEmpty() || duplicateCounter > 1)
            {
                char * tmp = PR_smprintf("_%03d", duplicateCounter);
                NS_ENSURE_TRUE(tmp, NS_ERROR_OUT_OF_MEMORY);
                if (filename.Length() < kDefaultMaxFilenameLength - 4)
                {
                    tmpBase = base;
                }
                else
                {
                    base.Mid(tmpBase, 0, base.Length() - 4);
                }
                tmpBase.Append(tmp);
                PR_smprintf_free(tmp);
            }
            else
            {
                tmpBase = base;
            }

            tmpPath.Assign(directory);
            tmpPath.Append(tmpBase);
            tmpPath.Append(ext);

            // Test if the name is a duplicate
            if (!mFilenameList.Contains(tmpPath))
            {
                if (!base.Equals(tmpBase))
                {
                    filename.Assign(tmpBase);
                    filename.Append(ext);
                    nameHasChanged = true;
                }
                break;
            }
            duplicateCounter++;
        }
    }

    // Add name to list of those already used
    nsAutoCString newFilepath(directory);
    newFilepath.Append(filename);
    mFilenameList.AppendElement(newFilepath);

    // Update the uri accordingly if the filename actually changed
    if (nameHasChanged)
    {
        // Final sanity test
        if (filename.Length() > kDefaultMaxFilenameLength)
        {
            NS_WARNING("Filename wasn't truncated less than the max file length - how can that be?");
            return NS_ERROR_FAILURE;
        }

        nsCOMPtr<nsIFile> localFile;
        GetLocalFileFromURI(aURI, getter_AddRefs(localFile));

        if (localFile)
        {
            nsAutoString filenameAsUnichar;
            filenameAsUnichar.AssignWithConversion(filename.get());
            localFile->SetLeafName(filenameAsUnichar);

            // Resync the URI with the file after the extension has been appended
            nsresult rv;
            nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
            NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
            fileURL->SetFile(localFile);  // this should recalculate uri
        }
        else
        {
            url->SetFileName(filename);
        }
    }

    return NS_OK;
}


nsresult
nsWebBrowserPersist::MakeFilenameFromURI(nsIURI *aURI, nsString &aFilename)
{
    // Try to get filename from the URI.
    nsAutoString fileName;

    // Get a suggested file name from the URL but strip it of characters
    // likely to cause the name to be illegal.

    nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
    if (url)
    {
        nsAutoCString nameFromURL;
        url->GetFileName(nameFromURL);
        if (mPersistFlags & PERSIST_FLAGS_DONT_CHANGE_FILENAMES)
        {
            fileName.AssignWithConversion(NS_UnescapeURL(nameFromURL).BeginReading());
            aFilename = fileName;
            return NS_OK;
        }
        if (!nameFromURL.IsEmpty())
        {
            // Unescape the file name (GetFileName escapes it)
            NS_UnescapeURL(nameFromURL);
            uint32_t nameLength = 0;
            const char *p = nameFromURL.get();
            for (;*p && *p != ';' && *p != '?' && *p != '#' && *p != '.'
                 ;p++)
            {
                if (nsCRT::IsAsciiAlpha(*p) || nsCRT::IsAsciiDigit(*p)
                    || *p == '.' || *p == '-' ||  *p == '_' || (*p == ' '))
                {
                    fileName.Append(char16_t(*p));
                    if (++nameLength == kDefaultMaxFilenameLength)
                    {
                        // Note:
                        // There is no point going any further since it will be
                        // truncated in CalculateUniqueFilename anyway.
                        // More importantly, certain implementations of
                        // nsIFile (e.g. the Mac impl) might truncate
                        // names in undesirable ways, such as truncating from
                        // the middle, inserting ellipsis and so on.
                        break;
                    }
                }
            }
        }
    }

    // Empty filenames can confuse the local file object later
    // when it attempts to set the leaf name in CalculateUniqueFilename
    // for duplicates and ends up replacing the parent dir. To avoid
    // the problem, all filenames are made at least one character long.
    if (fileName.IsEmpty())
    {
        fileName.Append(char16_t('a')); // 'a' is for arbitrary
    }

    aFilename = fileName;
    return NS_OK;
}


nsresult
nsWebBrowserPersist::CalculateAndAppendFileExt(nsIURI *aURI, nsIChannel *aChannel, nsIURI *aOriginalURIWithExtension)
{
    nsresult rv;

    if (!mMIMEService)
    {
        mMIMEService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
        NS_ENSURE_TRUE(mMIMEService, NS_ERROR_FAILURE);
    }

    nsAutoCString contentType;

    // Get the content type from the channel
    aChannel->GetContentType(contentType);

    // Get the content type from the MIME service
    if (contentType.IsEmpty())
    {
        nsCOMPtr<nsIURI> uri;
        aChannel->GetOriginalURI(getter_AddRefs(uri));
        mMIMEService->GetTypeFromURI(uri, contentType);
    }

    // Append the extension onto the file
    if (!contentType.IsEmpty())
    {
        nsCOMPtr<nsIMIMEInfo> mimeInfo;
        mMIMEService->GetFromTypeAndExtension(
            contentType, EmptyCString(), getter_AddRefs(mimeInfo));

        nsCOMPtr<nsIFile> localFile;
        GetLocalFileFromURI(aURI, getter_AddRefs(localFile));

        if (mimeInfo)
        {
            nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
            NS_ENSURE_TRUE(url, NS_ERROR_FAILURE);

            nsAutoCString newFileName;
            url->GetFileName(newFileName);

            // Test if the current extension is current for the mime type
            bool hasExtension = false;
            int32_t ext = newFileName.RFind(".");
            if (ext != -1)
            {
                mimeInfo->ExtensionExists(Substring(newFileName, ext + 1), &hasExtension);
            }

            // Append the mime file extension
            nsAutoCString fileExt;
            if (!hasExtension)
            {
                // Test if previous extension is acceptable
                nsCOMPtr<nsIURL> oldurl(do_QueryInterface(aOriginalURIWithExtension));
                NS_ENSURE_TRUE(oldurl, NS_ERROR_FAILURE);
                oldurl->GetFileExtension(fileExt);
                bool useOldExt = false;
                if (!fileExt.IsEmpty())
                {
                    mimeInfo->ExtensionExists(fileExt, &useOldExt);
                }

                // can't use old extension so use primary extension
                if (!useOldExt)
                {
                    mimeInfo->GetPrimaryExtension(fileExt);
                }

                if (!fileExt.IsEmpty())
                {
                    uint32_t newLength = newFileName.Length() + fileExt.Length() + 1;
                    if (newLength > kDefaultMaxFilenameLength)
                    {
                        if (fileExt.Length() > kDefaultMaxFilenameLength/2)
                            fileExt.Truncate(kDefaultMaxFilenameLength/2);

                        uint32_t diff = kDefaultMaxFilenameLength - 1 -
                                        fileExt.Length();
                        if (newFileName.Length() > diff)
                            newFileName.Truncate(diff);
                    }
                    newFileName.Append('.');
                    newFileName.Append(fileExt);
                }

                if (localFile)
                {
                    localFile->SetLeafName(NS_ConvertUTF8toUTF16(newFileName));

                    // Resync the URI with the file after the extension has been appended
                    nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
                    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
                    fileURL->SetFile(localFile);  // this should recalculate uri
                }
                else
                {
                    url->SetFileName(newFileName);
                }
            }

        }
    }

    return NS_OK;
}

nsresult
nsWebBrowserPersist::MakeOutputStream(
    nsIURI *aURI, nsIOutputStream **aOutputStream)
{
    nsresult rv;

    nsCOMPtr<nsIFile> localFile;
    GetLocalFileFromURI(aURI, getter_AddRefs(localFile));
    if (localFile)
        rv = MakeOutputStreamFromFile(localFile, aOutputStream);
    else
        rv = MakeOutputStreamFromURI(aURI, aOutputStream);

    return rv;
}

nsresult
nsWebBrowserPersist::MakeOutputStreamFromFile(
    nsIFile *aFile, nsIOutputStream **aOutputStream)
{
    nsresult rv = NS_OK;

    nsCOMPtr<nsIFileOutputStream> fileOutputStream =
        do_CreateInstance(NS_LOCALFILEOUTPUTSTREAM_CONTRACTID, &rv);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // XXX brade:  get the right flags here!
    int32_t ioFlags = -1;
    if (mPersistFlags & nsIWebBrowserPersist::PERSIST_FLAGS_APPEND_TO_FILE)
      ioFlags = PR_APPEND | PR_CREATE_FILE | PR_WRONLY;
    rv = fileOutputStream->Init(aFile, ioFlags, -1, 0);
    NS_ENSURE_SUCCESS(rv, rv);

    *aOutputStream = NS_BufferOutputStream(fileOutputStream,
                                           BUFFERED_OUTPUT_SIZE).take();

    if (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE)
    {
        // Add to cleanup list in event of failure
        CleanupData *cleanupData = new CleanupData;
        if (!cleanupData) {
          NS_RELEASE(*aOutputStream);
          return NS_ERROR_OUT_OF_MEMORY;
        }
        cleanupData->mFile = aFile;
        cleanupData->mIsDirectory = false;
        mCleanupList.AppendElement(cleanupData);
    }

    return NS_OK;
}

nsresult
nsWebBrowserPersist::MakeOutputStreamFromURI(
    nsIURI *aURI, nsIOutputStream  **aOutputStream)
{
    uint32_t segsize = 8192;
    uint32_t maxsize = uint32_t(-1);
    nsCOMPtr<nsIStorageStream> storStream;
    nsresult rv = NS_NewStorageStream(segsize, maxsize, getter_AddRefs(storStream));
    NS_ENSURE_SUCCESS(rv, rv);

    NS_ENSURE_SUCCESS(CallQueryInterface(storStream, aOutputStream), NS_ERROR_FAILURE);
    return NS_OK;
}

void
nsWebBrowserPersist::FinishDownload()
{
    EndDownload(NS_OK);
}

void
nsWebBrowserPersist::EndDownload(nsresult aResult)
{
    // Store the error code in the result if it is an error
    if (NS_SUCCEEDED(mPersistResult) && NS_FAILED(aResult))
    {
        mPersistResult = aResult;
    }

    // mCompleted needs to be set before issuing the stop notification.
    // (Bug 1224437)
    mCompleted = true;
    // State stop notification
    if (mProgressListener) {
        mProgressListener->OnStateChange(nullptr, nullptr,
            nsIWebProgressListener::STATE_STOP
            | nsIWebProgressListener::STATE_IS_NETWORK, mPersistResult);
    }

    // Do file cleanup if required
    if (NS_FAILED(aResult) && (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE))
    {
        CleanupLocalFiles();
    }

    // Cleanup the channels
    Cleanup();

    mProgressListener = nullptr;
    mProgressListener2 = nullptr;
    mEventSink = nullptr;
}

nsresult
nsWebBrowserPersist::FixRedirectedChannelEntry(nsIChannel *aNewChannel)
{
    NS_ENSURE_ARG_POINTER(aNewChannel);

    // Iterate through existing open channels looking for one with a URI
    // matching the one specified.
    nsCOMPtr<nsIURI> originalURI;
    aNewChannel->GetOriginalURI(getter_AddRefs(originalURI));
    nsISupports* matchingKey = nullptr;
    for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
        nsISupports* key = iter.Key();
        nsCOMPtr<nsIChannel> thisChannel = do_QueryInterface(key);
        nsCOMPtr<nsIURI> thisURI;

        thisChannel->GetOriginalURI(getter_AddRefs(thisURI));

        // Compare this channel's URI to the one passed in.
        bool matchingURI = false;
        thisURI->Equals(originalURI, &matchingURI);
        if (matchingURI) {
            matchingKey = key;
            break;
        }
    }

    if (matchingKey) {
        // If a match was found, remove the data entry with the old channel
        // key and re-add it with the new channel key.
        nsAutoPtr<OutputData> outputData;
        mOutputMap.RemoveAndForget(matchingKey, outputData);
        NS_ENSURE_TRUE(outputData, NS_ERROR_FAILURE);

        // Store data again with new channel unless told to ignore redirects.
        if (!(mPersistFlags & PERSIST_FLAGS_IGNORE_REDIRECTED_DATA)) {
            nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(aNewChannel);
            mOutputMap.Put(keyPtr, outputData.forget());
        }
    }

    return NS_OK;
}

void
nsWebBrowserPersist::CalcTotalProgress()
{
    mTotalCurrentProgress = 0;
    mTotalMaxProgress = 0;

    if (mOutputMap.Count() > 0) {
        // Total up the progress of each output stream
        for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
            // Only count toward total progress if destination file is local.
            OutputData* data = iter.UserData();
            nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(data->mFile);
            if (fileURL) {
                mTotalCurrentProgress += data->mSelfProgress;
                mTotalMaxProgress += data->mSelfProgressMax;
            }
        }
    }

    if (mUploadList.Count() > 0) {
        // Total up the progress of each upload
        for (auto iter = mUploadList.Iter(); !iter.Done(); iter.Next()) {
            UploadData* data = iter.UserData();
            if (data) {
                mTotalCurrentProgress += data->mSelfProgress;
                mTotalMaxProgress += data->mSelfProgressMax;
            }
        }
    }

    // XXX this code seems pretty bogus and pointless
    if (mTotalCurrentProgress == 0 && mTotalMaxProgress == 0)
    {
        // No output streams so we must be complete
        mTotalCurrentProgress = 10000;
        mTotalMaxProgress = 10000;
    }
}

nsresult
nsWebBrowserPersist::StoreURI(
    const char *aURI, bool aNeedsPersisting, URIData **aData)
{
    NS_ENSURE_ARG_POINTER(aURI);

    nsCOMPtr<nsIURI> uri;
    nsresult rv = NS_NewURI(getter_AddRefs(uri),
                            nsDependentCString(aURI),
                            mCurrentCharset.get(),
                            mCurrentBaseURI);
    NS_ENSURE_SUCCESS(rv, rv);

    return StoreURI(uri, aNeedsPersisting, aData);
}

nsresult
nsWebBrowserPersist::StoreURI(
    nsIURI *aURI, bool aNeedsPersisting, URIData **aData)
{
    NS_ENSURE_ARG_POINTER(aURI);
    if (aData)
    {
        *aData = nullptr;
    }

    // Test if this URI should be persisted. By default
    // we should assume the URI  is persistable.
    bool doNotPersistURI;
    nsresult rv = NS_URIChainHasFlags(aURI,
                                      nsIProtocolHandler::URI_NON_PERSISTABLE,
                                      &doNotPersistURI);
    if (NS_FAILED(rv))
    {
        doNotPersistURI = false;
    }

    if (doNotPersistURI)
    {
        return NS_OK;
    }

    URIData *data = nullptr;
    MakeAndStoreLocalFilenameInURIMap(aURI, aNeedsPersisting, &data);
    if (aData)
    {
        *aData = data;
    }

    return NS_OK;
}

nsresult
nsWebBrowserPersist::URIData::GetLocalURI(nsIURI *targetBaseURI, nsCString& aSpecOut)
{
    aSpecOut.SetIsVoid(true);
    if (!mNeedsFixup) {
        return NS_OK;
    }
    nsresult rv;
    nsCOMPtr<nsIURI> fileAsURI;
    if (mFile) {
        rv = mFile->Clone(getter_AddRefs(fileAsURI));
        NS_ENSURE_SUCCESS(rv, rv);
    } else {
        rv = mDataPath->Clone(getter_AddRefs(fileAsURI));
        NS_ENSURE_SUCCESS(rv, rv);
        rv = AppendPathToURI(fileAsURI, mFilename);
        NS_ENSURE_SUCCESS(rv, rv);
    }

    // remove username/password if present
    fileAsURI->SetUserPass(EmptyCString());

    // reset node attribute
    // Use relative or absolute links
    if (mDataPathIsRelative) {
        bool isEqual = false;
        if (NS_SUCCEEDED(mRelativeDocumentURI->Equals(targetBaseURI, &isEqual)) && isEqual) {
            nsCOMPtr<nsIURL> url(do_QueryInterface(fileAsURI));
            if (!url) {
                return NS_ERROR_FAILURE;
            }
            
            nsAutoCString filename;
            url->GetFileName(filename);
            
            nsAutoCString rawPathURL(mRelativePathToData);
            rawPathURL.Append(filename);
            
            rv = NS_EscapeURL(rawPathURL, esc_FilePath, aSpecOut, fallible);
            NS_ENSURE_SUCCESS(rv, rv);
        } else {
            nsAutoCString rawPathURL;
            
            nsCOMPtr<nsIFile> dataFile;
            rv = GetLocalFileFromURI(mFile, getter_AddRefs(dataFile));
            NS_ENSURE_SUCCESS(rv, rv);
            
            nsCOMPtr<nsIFile> docFile;
            rv = GetLocalFileFromURI(targetBaseURI, getter_AddRefs(docFile));
            NS_ENSURE_SUCCESS(rv, rv);
            
            nsCOMPtr<nsIFile> parentDir;
            rv = docFile->GetParent(getter_AddRefs(parentDir));
            NS_ENSURE_SUCCESS(rv, rv);
            
            rv = dataFile->GetRelativePath(parentDir, rawPathURL);
            NS_ENSURE_SUCCESS(rv, rv);
            
            rv = NS_EscapeURL(rawPathURL, esc_FilePath, aSpecOut, fallible);
            NS_ENSURE_SUCCESS(rv, rv);
        }
    } else {
        fileAsURI->GetSpec(aSpecOut);
    }
    if (mIsSubFrame) {
        AppendUTF16toUTF8(mSubFrameExt, aSpecOut);
    }

    return NS_OK;
}

bool
nsWebBrowserPersist::DocumentEncoderExists(const char *aContentType)
{
    // Check if there is an encoder for the desired content type.
    nsAutoCString contractID(NS_DOC_ENCODER_CONTRACTID_BASE);
    contractID.Append(aContentType);

    nsCOMPtr<nsIComponentRegistrar> registrar;
    NS_GetComponentRegistrar(getter_AddRefs(registrar));
    if (registrar)
    {
        bool result;
        nsresult rv = registrar->IsContractIDRegistered(contractID.get(),
                                                        &result);
        if (NS_SUCCEEDED(rv) && result)
        {
            return true;
        }
    }
    return false;
}

nsresult
nsWebBrowserPersist::SaveSubframeContent(
    nsIWebBrowserPersistDocument *aFrameContent,
    const nsCString& aURISpec,
    URIData *aData)
{
    NS_ENSURE_ARG_POINTER(aData);

    // Extract the content type for the frame's contents.
    nsAutoCString contentType;
    nsresult rv = aFrameContent->GetContentType(contentType);
    NS_ENSURE_SUCCESS(rv, rv);

    nsXPIDLString ext;
    GetExtensionForContentType(NS_ConvertASCIItoUTF16(contentType).get(),
                               getter_Copies(ext));

    // We must always have an extension so we will try to re-assign
    // the original extension if GetExtensionForContentType fails.
    if (ext.IsEmpty()) {
        nsCOMPtr<nsIURI> docURI;
        rv = NS_NewURI(getter_AddRefs(docURI), aURISpec, mCurrentCharset.get());
        NS_ENSURE_SUCCESS(rv, rv);

        nsCOMPtr<nsIURL> url(do_QueryInterface(docURI, &rv));
        nsAutoCString extension;
        if (NS_SUCCEEDED(rv)) {
            url->GetFileExtension(extension);
        } else {
            extension.AssignLiteral("htm");
        }
        aData->mSubFrameExt.Assign(char16_t('.'));
        AppendUTF8toUTF16(extension, aData->mSubFrameExt);
    } else {
        aData->mSubFrameExt.Assign(char16_t('.'));
        aData->mSubFrameExt.Append(ext);
    }

    nsString filenameWithExt = aData->mFilename;
    filenameWithExt.Append(aData->mSubFrameExt);

    // Work out the path for the subframe
    nsCOMPtr<nsIURI> frameURI;
    rv = mCurrentDataPath->Clone(getter_AddRefs(frameURI));
    NS_ENSURE_SUCCESS(rv, rv);
    rv = AppendPathToURI(frameURI, filenameWithExt);
    NS_ENSURE_SUCCESS(rv, rv);

    // Work out the path for the subframe data
    nsCOMPtr<nsIURI> frameDataURI;
    rv = mCurrentDataPath->Clone(getter_AddRefs(frameDataURI));
    NS_ENSURE_SUCCESS(rv, rv);
    nsAutoString newFrameDataPath(aData->mFilename);

    // Append _data
    newFrameDataPath.AppendLiteral("_data");
    rv = AppendPathToURI(frameDataURI, newFrameDataPath);
    NS_ENSURE_SUCCESS(rv, rv);

    // Make frame document & data path conformant and unique
    rv = CalculateUniqueFilename(frameURI);
    NS_ENSURE_SUCCESS(rv, rv);
    rv = CalculateUniqueFilename(frameDataURI);
    NS_ENSURE_SUCCESS(rv, rv);

    mCurrentThingsToPersist++;

    // We shouldn't use SaveDocumentInternal for the contents
    // of frames that are not documents, e.g. images.
    if (DocumentEncoderExists(contentType.get())) {
        auto toWalk = mozilla::MakeUnique<WalkData>();
        toWalk->mDocument = aFrameContent;
        toWalk->mFile = frameURI;
        toWalk->mDataPath = frameDataURI;
        mWalkStack.AppendElement(mozilla::Move(toWalk));
    } else {
        rv = StoreURI(aURISpec.get());
    }
    NS_ENSURE_SUCCESS(rv, rv);

    // Store the updated uri to the frame
    aData->mFile = frameURI;
    aData->mSubFrameExt.Truncate(); // we already put this in frameURI

    return NS_OK;
}

nsresult
nsWebBrowserPersist::CreateChannelFromURI(nsIURI *aURI, nsIChannel **aChannel)
{
    nsresult rv = NS_OK;
    *aChannel = nullptr;

    rv = NS_NewChannel(aChannel,
                       aURI,
                       nsContentUtils::GetSystemPrincipal(),
                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
                       nsIContentPolicy::TYPE_OTHER);
    NS_ENSURE_SUCCESS(rv, rv);
    NS_ENSURE_ARG_POINTER(*aChannel);

    rv = (*aChannel)->SetNotificationCallbacks(static_cast<nsIInterfaceRequestor*>(this));
    NS_ENSURE_SUCCESS(rv, rv);
    return NS_OK;
}


// we store the current location as the key (absolutized version of domnode's attribute's value)
nsresult
nsWebBrowserPersist::MakeAndStoreLocalFilenameInURIMap(
    nsIURI *aURI, bool aNeedsPersisting, URIData **aData)
{
    NS_ENSURE_ARG_POINTER(aURI);

    nsAutoCString spec;
    nsresult rv = aURI->GetSpec(spec);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // Create a sensibly named filename for the URI and store in the URI map
    URIData *data;
    if (mURIMap.Contains(spec))
    {
        data = mURIMap.Get(spec);
        if (aNeedsPersisting)
        {
          data->mNeedsPersisting = true;
        }
        if (aData)
        {
            *aData = data;
        }
        return NS_OK;
    }

    // Create a unique file name for the uri
    nsString filename;
    rv = MakeFilenameFromURI(aURI, filename);
    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);

    // Store the file name
    data = new URIData;
    NS_ENSURE_TRUE(data, NS_ERROR_OUT_OF_MEMORY);

    data->mNeedsPersisting = aNeedsPersisting;
    data->mNeedsFixup = true;
    data->mFilename = filename;
    data->mSaved = false;
    data->mIsSubFrame = false;
    data->mDataPath = mCurrentDataPath;
    data->mDataPathIsRelative = mCurrentDataPathIsRelative;
    data->mRelativePathToData = mCurrentRelativePathToData;
    data->mRelativeDocumentURI = mTargetBaseURI;
    data->mCharset = mCurrentCharset;

    if (aNeedsPersisting)
        mCurrentThingsToPersist++;

    mURIMap.Put(spec, data);
    if (aData)
    {
        *aData = data;
    }

    return NS_OK;
}

// Decide if we need to apply conversion to the passed channel.
void nsWebBrowserPersist::SetApplyConversionIfNeeded(nsIChannel *aChannel)
{
    nsresult rv = NS_OK;
    nsCOMPtr<nsIEncodedChannel> encChannel = do_QueryInterface(aChannel, &rv);
    if (NS_FAILED(rv))
        return;

    // Set the default conversion preference:
    encChannel->SetApplyConversion(false);

    nsCOMPtr<nsIURI> thisURI;
    aChannel->GetURI(getter_AddRefs(thisURI));
    nsCOMPtr<nsIURL> sourceURL(do_QueryInterface(thisURI));
    if (!sourceURL)
        return;
    nsAutoCString extension;
    sourceURL->GetFileExtension(extension);

    nsCOMPtr<nsIUTF8StringEnumerator> encEnum;
    encChannel->GetContentEncodings(getter_AddRefs(encEnum));
    if (!encEnum)
        return;
    nsCOMPtr<nsIExternalHelperAppService> helperAppService =
        do_GetService(NS_EXTERNALHELPERAPPSERVICE_CONTRACTID, &rv);
    if (NS_FAILED(rv))
        return;
    bool hasMore;
    rv = encEnum->HasMore(&hasMore);
    if (NS_SUCCEEDED(rv) && hasMore)
    {
        nsAutoCString encType;
        rv = encEnum->GetNext(encType);
        if (NS_SUCCEEDED(rv))
        {
            bool applyConversion = false;
            rv = helperAppService->ApplyDecodingForExtension(extension, encType,
                                                             &applyConversion);
            if (NS_SUCCEEDED(rv))
                encChannel->SetApplyConversion(applyConversion);
        }
    }
}
