/* 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 "nsDownloader.h"
#include "nsIInputStream.h"
#include "nsDirectoryServiceUtils.h"
#include "nsDirectoryServiceDefs.h"
#include "nsNetUtil.h"
#include "nsCRTGlue.h"

nsDownloader::~nsDownloader() {
  if (mLocation && mLocationIsTemp) {
    // release the sink first since it may still hold an open file
    // descriptor to mLocation.  this needs to happen before the
    // file can be removed otherwise the Remove call will fail.
    if (mSink) {
      mSink->Close();
      mSink = nullptr;
    }

    nsresult rv = mLocation->Remove(false);
    if (NS_FAILED(rv)) NS_ERROR("unable to remove temp file");
  }
}

NS_IMPL_ISUPPORTS(nsDownloader, nsIDownloader, nsIStreamListener,
                  nsIRequestObserver)

NS_IMETHODIMP
nsDownloader::Init(nsIDownloadObserver* observer, nsIFile* location) {
  mObserver = observer;
  mLocation = location;
  return NS_OK;
}

NS_IMETHODIMP
nsDownloader::OnStartRequest(nsIRequest* request) {
  nsresult rv;
  if (!mLocation) {
    nsCOMPtr<nsIFile> location;
    rv = NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(location));
    if (NS_FAILED(rv)) return rv;

    char buf[13];
    NS_MakeRandomString(buf, 8);
    memcpy(buf + 8, ".tmp", 5);
    rv = location->AppendNative(nsDependentCString(buf, 12));
    if (NS_FAILED(rv)) return rv;

    rv = location->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
    if (NS_FAILED(rv)) return rv;

    location.swap(mLocation);
    mLocationIsTemp = true;
  }

  rv = NS_NewLocalFileOutputStream(getter_AddRefs(mSink), mLocation);
  if (NS_FAILED(rv)) return rv;

  // we could wrap this output stream with a buffered output stream,
  // but it shouldn't be necessary since we will be writing large
  // chunks given to us via OnDataAvailable.

  return NS_OK;
}

NS_IMETHODIMP
nsDownloader::OnStopRequest(nsIRequest* request, nsresult status) {
  if (mSink) {
    mSink->Close();
    mSink = nullptr;
  }

  mObserver->OnDownloadComplete(this, request, status, mLocation);
  mObserver = nullptr;

  return NS_OK;
}

nsresult nsDownloader::ConsumeData(nsIInputStream* in, void* closure,
                                   const char* fromRawSegment,
                                   uint32_t toOffset, uint32_t count,
                                   uint32_t* writeCount) {
  nsDownloader* self = (nsDownloader*)closure;
  if (self->mSink) return self->mSink->Write(fromRawSegment, count, writeCount);

  *writeCount = count;
  return NS_OK;
}

NS_IMETHODIMP
nsDownloader::OnDataAvailable(nsIRequest* request, nsIInputStream* inStr,
                              uint64_t sourceOffset, uint32_t count) {
  uint32_t n;
  return inStr->ReadSegments(ConsumeData, this, count, &n);
}