// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "ui/base/dragdrop/os_exchange_data_provider_win.h"

#include <objbase.h>

#include <shobjidl.h>

#include <coml2api.h>
#include <objidl.h>
#include <shlobj.h>
#include <stdint.h>
#include <wrl/client.h>

#include <algorithm>
#include <iterator>
#include <optional>
#include <string>
#include <string_view>
#include <utility>

#include "base/check_op.h"
#include "base/containers/span.h"
#include "base/containers/to_vector.h"
#include "base/feature_list.h"
#include "base/files/file_path.h"
#include "base/functional/callback.h"
#include "base/i18n/file_util_icu.h"
#include "base/no_destructor.h"
#include "base/notreached.h"
#include "base/pickle.h"
#include "base/strings/strcat.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/win/scoped_hdc.h"
#include "base/win/scoped_hglobal.h"
#include "base/win/shlwapi.h"
#include "net/base/filename_util.h"
#include "skia/ext/skia_utils_win.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "ui/base/clipboard/clipboard_format_type.h"
#include "ui/base/clipboard/clipboard_util_win.h"
#include "ui/base/clipboard/file_info.h"
#include "ui/base/data_transfer_policy/data_transfer_policy_controller.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/l10n/l10n_util_win.h"
#include "ui/base/ui_base_features.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/image/image_skia.h"
#include "ui/gfx/skbitmap_operations.h"
#include "ui/strings/grit/ui_strings.h"
#include "url/gurl.h"
#include "url/origin.h"

namespace ui {

namespace {
constexpr STGMEDIUM kNullStorageMedium = {.tymed = TYMED_NULL,
                                          .pUnkForRelease = nullptr};

// Creates a new STGMEDIUM object to hold the specified text. The caller
// owns the resulting object. The "Bytes" version does not NULL terminate, the
// string version does.
STGMEDIUM CreateStorageForBytes(const void* data, size_t bytes);
STGMEDIUM CreateStorageForString(std::string_view data);
STGMEDIUM CreateStorageForString(std::u16string_view data);
STGMEDIUM CreateIdListStorageForFileName(const base::FilePath& path);
// Creates a File Descriptor for the creation of a file to the given URL and
// returns a handle to it.
STGMEDIUM CreateStorageForFileDescriptor(const base::FilePath& path);

const ClipboardFormatType& GetRendererTaintFormatType();
const ClipboardFormatType& GetFromPrivilegedFormatType();
const ClipboardFormatType& GetIgnoreFileContentsFormatType();
// Creates the contents of an Internet Shortcut file for the given URL.
std::string GetInternetShortcutFileContents(const GURL& url);
// Creates a valid file name given a suggested title and URL.
std::wstring CreateValidFileNameFromTitle(const GURL& url,
                                          const std::wstring& title);

}  // namespace

///////////////////////////////////////////////////////////////////////////////
// FormatEtcEnumerator

//
// This object implements an enumeration interface. The existence of an
// implementation of this interface is exposed to clients through
// OSExchangeData's EnumFormatEtc method. Our implementation is nobody's
// business but our own, so it lives in this file.
//
// This Windows API is truly a gem. It wants to be an enumerator but assumes
// some sort of sequential data (why not just use an array?). See comments
// throughout.
//
class FormatEtcEnumerator final : public IEnumFORMATETC {
 public:
  FormatEtcEnumerator(DataObjectImpl::StoredData::const_iterator begin,
                      DataObjectImpl::StoredData::const_iterator end);

  FormatEtcEnumerator(const FormatEtcEnumerator&) = delete;
  FormatEtcEnumerator& operator=(const FormatEtcEnumerator&) = delete;

  ~FormatEtcEnumerator();

  // IEnumFORMATETC implementation:
  HRESULT __stdcall Next(ULONG count,
                         FORMATETC* elements_array,
                         ULONG* elements_fetched) override;
  HRESULT __stdcall Skip(ULONG skip_count) override;
  HRESULT __stdcall Reset() override;
  HRESULT __stdcall Clone(IEnumFORMATETC** clone) override;

  // IUnknown implementation:
  HRESULT __stdcall QueryInterface(const IID& iid, void** object) override;
  ULONG __stdcall AddRef() override;
  ULONG __stdcall Release() override;

 private:
  // This can only be called from |CloneFromOther|, since it initializes the
  // contents_ from the other enumerator's contents.
  FormatEtcEnumerator() : cursor_(0), ref_count_(0) {
  }

  // Clone a new FormatEtc from another instance of this enumeration.
  static FormatEtcEnumerator* CloneFromOther(const FormatEtcEnumerator* other);

 private:
  // We are _forced_ to use a vector as our internal data model as Windows'
  // IEnumFORMATETC API assumes a deterministic ordering of elements through
  // methods like Next and Skip. This exposes the underlying data structure to
  // the user. Bah.
  std::vector<std::unique_ptr<FORMATETC>> contents_;

  // The cursor of the active enumeration - an index into |contents_|.
  size_t cursor_;

  ULONG ref_count_;
};

// Safely makes a copy of all of the relevant bits of a FORMATETC object.
static void CloneFormatEtc(const FORMATETC* source, FORMATETC* clone) {
  *clone = *source;
  if (source->ptd) {
    clone->ptd =
        static_cast<DVTARGETDEVICE*>(CoTaskMemAlloc(sizeof(DVTARGETDEVICE)));
    *(clone->ptd) = *(source->ptd);
  }
}

FormatEtcEnumerator::FormatEtcEnumerator(
    DataObjectImpl::StoredData::const_iterator start,
    DataObjectImpl::StoredData::const_iterator end)
    : cursor_(0), ref_count_(0) {
  // Copy FORMATETC data from our source into ourselves.
  while (start != end) {
    auto format_etc = std::make_unique<FORMATETC>();
    CloneFormatEtc(&(*start)->format_etc, format_etc.get());
    contents_.push_back(std::move(format_etc));
    ++start;
  }
}

FormatEtcEnumerator::~FormatEtcEnumerator() {
}

HRESULT FormatEtcEnumerator::Next(ULONG count,
                                  FORMATETC* elements_array,
                                  ULONG* elements_fetched) {
  // MSDN says |elements_fetched| is allowed to be NULL if count is 1.
  if (!elements_fetched)
    DCHECK_EQ(count, 1ul);

  // This method copies count elements into |elements_array|.
  ULONG index = 0;
  while (cursor_ < contents_.size() && index < count) {
    CloneFormatEtc(contents_[cursor_].get(), &elements_array[index]);
    ++cursor_;
    ++index;
  }
  // The out param is for how many we actually copied.
  if (elements_fetched)
    *elements_fetched = index;

  // If the two don't agree, then we fail.
  return index == count ? S_OK : S_FALSE;
}

HRESULT FormatEtcEnumerator::Skip(ULONG skip_count) {
  cursor_ += skip_count;
  // MSDN implies it's OK to leave the enumerator trashed.
  // "Whatever you say, boss"
  return cursor_ <= contents_.size() ? S_OK : S_FALSE;
}

HRESULT FormatEtcEnumerator::Reset() {
  cursor_ = 0;
  return S_OK;
}

HRESULT FormatEtcEnumerator::Clone(IEnumFORMATETC** clone) {
  // Clone the current enumerator in its exact state, including cursor.
  FormatEtcEnumerator* e = CloneFromOther(this);
  e->AddRef();
  *clone = e;
  return S_OK;
}

HRESULT FormatEtcEnumerator::QueryInterface(const IID& iid, void** object) {
  *object = NULL;
  if (IsEqualIID(iid, IID_IUnknown) || IsEqualIID(iid, IID_IEnumFORMATETC)) {
    *object = this;
  } else {
    return E_NOINTERFACE;
  }
  AddRef();
  return S_OK;
}

ULONG FormatEtcEnumerator::AddRef() {
  return InterlockedIncrement(&ref_count_);
}

ULONG FormatEtcEnumerator::Release() {
  if (InterlockedDecrement(&ref_count_) == 0) {
    ULONG copied_refcnt = ref_count_;
    delete this;
    return copied_refcnt;
  }
  return ref_count_;
}

// static
FormatEtcEnumerator* FormatEtcEnumerator::CloneFromOther(
    const FormatEtcEnumerator* other) {
  FormatEtcEnumerator* e = new FormatEtcEnumerator;
  // Copy FORMATETC data from our source into ourselves.
  std::ranges::transform(other->contents_, std::back_inserter(e->contents_),
                         [](const std::unique_ptr<FORMATETC>& format_etc) {
                           auto clone = std::make_unique<FORMATETC>();
                           CloneFormatEtc(format_etc.get(), clone.get());
                           return clone;
                         });
  // Carry over
  e->cursor_ = other->cursor_;
  return e;
}

///////////////////////////////////////////////////////////////////////////////
// OSExchangeDataProviderWin, public:

// static
DataObjectImpl* OSExchangeDataProviderWin::GetDataObjectImpl(
    const OSExchangeData& data) {
  return static_cast<const OSExchangeDataProviderWin*>(&data.provider())->
      data_.get();
}

// static
IDataObject* OSExchangeDataProviderWin::GetIDataObject(
    const OSExchangeData& data) {
  return static_cast<const OSExchangeDataProviderWin*>(&data.provider())->
      data_object();
}

OSExchangeDataProviderWin::OSExchangeDataProviderWin(IDataObject* source)
    : data_(new DataObjectImpl()),
      source_object_(source) {
}

OSExchangeDataProviderWin::OSExchangeDataProviderWin()
    : data_(new DataObjectImpl()),
      source_object_(data_.get()) {
}

OSExchangeDataProviderWin::~OSExchangeDataProviderWin() {
}

std::unique_ptr<OSExchangeDataProvider> OSExchangeDataProviderWin::Clone()
    const {
  return std::make_unique<OSExchangeDataProviderWin>(data_object());
}

void OSExchangeDataProviderWin::MarkRendererTaintedFromOrigin(
    const url::Origin& origin) {
  STGMEDIUM storage = CreateStorageForString(
      origin.opaque() ? std::string() : origin.Serialize());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      GetRendererTaintFormatType().ToFormatEtc(), storage));
}

bool OSExchangeDataProviderWin::IsRendererTainted() const {
  return HasCustomFormat(GetRendererTaintFormatType());
}

std::optional<url::Origin> OSExchangeDataProviderWin::GetRendererTaintedOrigin()
    const {
  STGMEDIUM medium;
  FORMATETC format_etc = GetRendererTaintFormatType().ToFormatEtc();
  if (FAILED(source_object_->GetData(&format_etc, &medium))) {
    return std::nullopt;
  }
  base::win::ScopedHGlobal<char*> data(medium.hGlobal);
  if (data.size() == 0) {
    return url::Origin();
  }
  return url::Origin::Create(GURL(std::string_view(data.data(), data.size())));
}

void OSExchangeDataProviderWin::MarkAsFromPrivileged() {
  STGMEDIUM storage = CreateStorageForString(std::string_view());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      GetFromPrivilegedFormatType().ToFormatEtc(), storage));
}

bool OSExchangeDataProviderWin::IsFromPrivileged() const {
  return HasCustomFormat(GetFromPrivilegedFormatType());
}

void OSExchangeDataProviderWin::SetString(std::u16string_view data) {
  STGMEDIUM storage = CreateStorageForString(data);
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::PlainTextType().ToFormatEtc(), storage));

  // Also add the UTF8-encoded version.
  storage = CreateStorageForString(base::UTF16ToUTF8(data));
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::PlainTextAType().ToFormatEtc(), storage));
}

void OSExchangeDataProviderWin::SetURL(const GURL& url,
                                       std::u16string_view title) {
  // NOTE WELL:
  // Every time you change the order of the first two CLIPFORMATS that get
  // added here, you need to update the EnumerationViaCOM test case in
  // the _unittest.cc file to reflect the new arrangement otherwise that test
  // will fail! It assumes an insertion order.

  // Add text/x-moz-url for drags from Firefox
  STGMEDIUM storage = CreateStorageForString(
      base::StrCat({base::UTF8ToUTF16(url.spec()), u"\n", title}));
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::MozUrlType().ToFormatEtc(), storage));

  // Add a .URL shortcut file for dragging to Explorer if there is not already
  // FileContents from dragging an image.  Also mark the synthesized file
  // contents to be ignored if the drag ends up targeting Chrome. Otherwise,
  // this may confuse some web pages into dropping a file rather than a link.
  // See https://crbug.com/1274395 for background.
  if (!HasFileContents()) {
    std::wstring valid_file_name =
        CreateValidFileNameFromTitle(url, base::AsWString(title));
    std::string shortcut_url_file_contents =
        GetInternetShortcutFileContents(url);
    SetFileContents(base::FilePath(valid_file_name),
                    shortcut_url_file_contents);
    storage = CreateStorageForString(std::string_view());
    data_->contents_.push_back(
        DataObjectImpl::StoredDataInfo::TakeStorageMedium(
            GetIgnoreFileContentsFormatType().ToFormatEtc(), storage));
  }

  // Add a UniformResourceLocator link for apps like IE and Word.
  storage = CreateStorageForString(base::UTF8ToUTF16(url.spec()));
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::UrlType().ToFormatEtc(), storage));
  storage = CreateStorageForString(url.spec());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::UrlAType().ToFormatEtc(), storage));

  // TODO(crbug.com/41292596): add CF_HTML.

  // Also add text representations (these should be last since they're the
  // least preferable).
  SetString(base::UTF8ToUTF16(url.spec()));
}

void OSExchangeDataProviderWin::SetFilename(const base::FilePath& path) {
  SetFilenames({FileInfo(path, base::FilePath())});

  STGMEDIUM storage = CreateIdListStorageForFileName(path);
  if (storage.tymed == TYMED_NULL)
    return;
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::IDListType().ToFormatEtc(), storage));
}

void OSExchangeDataProviderWin::SetFilenames(
    const std::vector<FileInfo>& filenames) {
  STGMEDIUM storage = clipboard_util::CreateStorageForFileNames(filenames);
  if (storage.tymed == TYMED_NULL)
    return;

  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::CFHDropType().ToFormatEtc(), storage));
}

bool OSExchangeDataProviderWin::HasPlainTextURL() const {
  return GetPlainTextURL().has_value();
}

std::optional<GURL> OSExchangeDataProviderWin::GetPlainTextURL() const {
  std::u16string plain_text;
  if (clipboard_util::GetPlainText(source_object_.Get(), &plain_text) &&
      !plain_text.empty()) {
    GURL gurl(plain_text);
    if (!gurl.is_valid()) {
      return std::nullopt;
    }
    if (base::FeatureList::IsEnabled(
            features::kDragDropOnlySynthesizeHttpOrHttpsUrlsFromText) &&
        IsRendererTainted() && !gurl.SchemeIsHTTPOrHTTPS()) {
      return std::nullopt;
    }
    return gurl;
  }
  return std::nullopt;
}

void OSExchangeDataProviderWin::SetVirtualFileContentsForTesting(
    const std::vector<std::pair<base::FilePath, std::string>>&
        filenames_and_contents,
    DWORD tymed) {
  size_t num_files = filenames_and_contents.size();
  if (!num_files)
    return;

  // Allocate storage for the file group descriptor as CFSTR_FILEDESCRIPTORW.
  // The fgd[] member of FILEGROUPDESCRIPTORW is of size one, thus sizeof
  // (FILEDESCRIPTORW) is already the correct allocation size if there is only
  // one item. Otherwise need to add room for each FILEDESCRIPTORW struct.
  const size_t total_bytes_fgd = sizeof(FILEGROUPDESCRIPTORW) +
                                 (sizeof(FILEDESCRIPTORW) * (num_files - 1));

  HANDLE hdata = ::GlobalAlloc(GPTR, total_bytes_fgd);
  if (!hdata)
    return;

  base::win::ScopedHGlobal<FILEGROUPDESCRIPTORW*> locked_mem(hdata);

  FILEGROUPDESCRIPTORW* descriptor = locked_mem.data();
  descriptor->cItems = base::checked_cast<UINT>(num_files);

  STGMEDIUM storage = {
      .tymed = TYMED_HGLOBAL, .hGlobal = hdata, .pUnkForRelease = nullptr};
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::FileDescriptorType().ToFormatEtc(), storage));

  for (size_t i = 0; i < num_files; i++) {
    // Fill in each FILEDESCRIPTORW with file name.
    descriptor->fgd[i].dwFlags |= static_cast<DWORD>(FD_UNICODE);
    std::wstring file_name = filenames_and_contents[i].first.value();
    wcsncpy_s(descriptor->fgd[i].cFileName, MAX_PATH, file_name.c_str(),
              std::min(file_name.size(), static_cast<size_t>(MAX_PATH - 1u)));

    // Add the contents of each file as CFSTR_FILECONTENTS.
    base::span<const uint8_t> data_buffer =
        base::span(reinterpret_cast<const uint8_t*>(
                       filenames_and_contents[i].second.data()),
                   filenames_and_contents[i].second.length());
    SetVirtualFileContentAtIndexForTesting(data_buffer, tymed,  // IN-TEST
                                           static_cast<LONG>(i));
  }
}

void OSExchangeDataProviderWin::SetVirtualFileContentAtIndexForTesting(
    base::span<const uint8_t> data_buffer,
    DWORD tymed,
    LONG index) {
  STGMEDIUM storage_for_contents = kNullStorageMedium;

  if (tymed == TYMED_ISTORAGE) {
    Microsoft::WRL::ComPtr<ILockBytes> lock_bytes;
    HRESULT hr = ::CreateILockBytesOnHGlobal(
        nullptr, /* fDeleteOnRelease*/ TRUE, &lock_bytes);

    if (SUCCEEDED(hr)) {
      hr = ::StgCreateDocfileOnILockBytes(
          lock_bytes.Get(), STGM_READWRITE | STGM_SHARE_EXCLUSIVE | STGM_CREATE,
          0, &storage_for_contents.pstg);
    }

    Microsoft::WRL::ComPtr<IStream> destination_stream;
    if (SUCCEEDED(hr)) {
      hr = storage_for_contents.pstg->CreateStream(
          L"Contents", STGM_READWRITE | STGM_SHARE_EXCLUSIVE | STGM_CREATE, 0,
          0, &destination_stream);
    }

    Microsoft::WRL::ComPtr<IStream> source_stream;
    if (SUCCEEDED(hr)) {
      source_stream = ::SHCreateMemStream(
          data_buffer.data(),
          base::checked_cast<UINT>(data_buffer.size_bytes()));
    }

    if (source_stream) {
      // Copy the data to the storage stream.
      ULARGE_INTEGER bytes_to_copy;
      bytes_to_copy.QuadPart = data_buffer.size_bytes();
      hr = source_stream->CopyTo(destination_stream.Get(), bytes_to_copy,
                                 nullptr, nullptr);
    }
    if (SUCCEEDED(hr))
      hr = storage_for_contents.pstg->Commit(STGC_DEFAULT);
    if (SUCCEEDED(hr))
      storage_for_contents.tymed = TYMED_ISTORAGE;

  } else if (tymed == TYMED_ISTREAM) {
    storage_for_contents.pstm = ::SHCreateMemStream(
        data_buffer.data(), base::checked_cast<UINT>(data_buffer.size_bytes()));
    if (storage_for_contents.pstm) {
      // A properly implemented IDataObject::GetData moves the stream pointer
      // to end.
      const LARGE_INTEGER kZeroDisplacement = {};
      HRESULT hr = storage_for_contents.pstm->Seek(kZeroDisplacement,
                                                   STREAM_SEEK_END, nullptr);
      if (SUCCEEDED(hr))
        storage_for_contents.tymed = TYMED_ISTREAM;
    }
  } else if (tymed == TYMED_HGLOBAL) {
    storage_for_contents =
        CreateStorageForBytes(data_buffer.data(), data_buffer.size_bytes());
  }
  ClipboardFormatType type = ClipboardFormatType::FileContentAtIndexType(index);
  // Pass ownership of |storage_for_contents| here.
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      type.ToFormatEtc(), storage_for_contents));
}

void OSExchangeDataProviderWin::SetPickledData(
    const ClipboardFormatType& format,
    const base::Pickle& data) {
  STGMEDIUM storage = CreateStorageForBytes(data.data(), data.size());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      format.ToFormatEtc(), storage));
}

void OSExchangeDataProviderWin::SetFileContents(
    const base::FilePath& filename,
    const std::string& file_contents) {
  // Add CFSTR_FILEDESCRIPTORW.
  STGMEDIUM storage = CreateStorageForFileDescriptor(filename);
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::FileDescriptorType().ToFormatEtc(), storage));

  // Add CFSTR_FILECONTENTS.
  STGMEDIUM storage_contents =
      CreateStorageForBytes(file_contents.data(), file_contents.length());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::FileContentZeroType().ToFormatEtc(),
      storage_contents));
}

void OSExchangeDataProviderWin::SetHtml(const std::u16string& html,
                                        const GURL& base_url) {
  // Add both MS CF_HTML and text/html format.  CF_HTML should be in utf-8.
  std::string utf8_html = base::UTF16ToUTF8(html);
  std::string url = base_url.is_valid() ? base_url.spec() : std::string();

  std::string cf_html = clipboard_util::HtmlToCFHtml(utf8_html, url);
  STGMEDIUM storage = CreateStorageForBytes(cf_html.c_str(), cf_html.size());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::HtmlType().ToFormatEtc(), storage));

  STGMEDIUM storage_plain =
      CreateStorageForBytes(utf8_html.c_str(), utf8_html.size());
  data_->contents_.push_back(DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::TextHtmlType().ToFormatEtc(), storage_plain));
}

std::optional<std::u16string> OSExchangeDataProviderWin::GetString() const {
  std::u16string data;
  if (clipboard_util::GetPlainText(source_object_.Get(), &data)) {
    return std::move(data);
  }
  return std::nullopt;
}

std::optional<OSExchangeDataProvider::UrlInfo>
OSExchangeDataProviderWin::GetURLAndTitle(FilenameToURLPolicy policy) const {
  GURL url;
  std::u16string title;
  if (clipboard_util::GetUrl(
          source_object_.Get(), &url, &title,
          policy == FilenameToURLPolicy::CONVERT_FILENAMES ? true : false)) {
    DCHECK(url.is_valid());
    return UrlInfo{std::move(url), std::move(title)};
  } else if (std::optional<GURL> plaintext_url = GetPlainTextURL();
             plaintext_url.has_value()) {
    DCHECK(plaintext_url->is_valid());
    title = net::GetSuggestedFilename(*plaintext_url, "", "", "", "",
                                      std::string());
    return UrlInfo{std::move(plaintext_url).value(), std::move(title)};
  }
  return std::nullopt;
}

std::optional<std::vector<GURL>> OSExchangeDataProviderWin::GetURLs(
    FilenameToURLPolicy policy) const {
  std::vector<GURL> local_urls;

  if (std::optional<UrlInfo> url_info =
          GetURLAndTitle(FilenameToURLPolicy::DO_NOT_CONVERT_FILENAMES);
      url_info.has_value()) {
    local_urls.push_back(url_info->url);
  }

  if (policy == FilenameToURLPolicy::CONVERT_FILENAMES) {
    if (std::optional<std::vector<FileInfo>> fileinfos = GetFilenames();
        fileinfos.has_value()) {
      for (const auto& fileinfo : fileinfos.value()) {
        local_urls.push_back(net::FilePathToFileURL(fileinfo.path));
      }
    }
  }

  if (local_urls.size()) {
    return local_urls;
  }
  return std::nullopt;
}

std::optional<std::vector<FileInfo>> OSExchangeDataProviderWin::GetFilenames()
    const {
  std::vector<std::wstring> filenames_local;
  bool success =
      clipboard_util::GetFilenames(source_object_.Get(), &filenames_local);
  if (!success) {
    return std::nullopt;
  }

  return base::ToVector(filenames_local, [](const std::wstring& filename) {
    return FileInfo(base::FilePath(filename), base::FilePath());
  });
}

bool OSExchangeDataProviderWin::HasVirtualFilenames() const {
  return clipboard_util::HasVirtualFilenames(source_object_.Get());
}

std::optional<std::vector<FileInfo>>
OSExchangeDataProviderWin::GetVirtualFilenames() const {
  // ui_base_clipboard can't use FileInfo struct which is part of ui_base, so
  // use FilePath instead.
  // TODO(crbug.com/41451590): ui_base_clipboard can't use FileInfo struct
  // which is part of ui_base (layering issue).
  std::optional<std::vector<base::FilePath>> display_names =
      clipboard_util::GetVirtualFilenames(source_object_.Get());
  if (!display_names) {
    return std::nullopt;
  }

  // On dragenter scenarios, need a placeholder file path for drag metadata
  // checks without actually creating the temp file.
  base::FilePath temp_path(FILE_PATH_LITERAL("temp.tmp"));

  std::vector<FileInfo> result;
  for (const auto& display_name : display_names.value()) {
    result.emplace_back(temp_path, display_name);
  }

  return result;
}

void OSExchangeDataProviderWin::GetVirtualFilesAsTempFiles(
    base::OnceCallback<
        void(const std::vector<std::pair<base::FilePath, base::FilePath>>&)>
        callback) const {
  clipboard_util::GetVirtualFilesAsTempFiles(source_object_.Get(),
                                             std::move(callback));
}

std::optional<base::Pickle> OSExchangeDataProviderWin::GetPickledData(
    const ClipboardFormatType& format) const {
  STGMEDIUM medium;
  FORMATETC format_etc = format.ToFormatEtc();
  if (SUCCEEDED(source_object_->GetData(&format_etc, &medium))) {
    if (medium.tymed & TYMED_HGLOBAL) {
      base::win::ScopedHGlobal<char*> c_data(medium.hGlobal);
      DCHECK_GT(c_data.size(), 0u);
      return base::Pickle::WithData(base::as_bytes(base::span(c_data)));
    }
    ReleaseStgMedium(&medium);
  }
  return std::nullopt;
}

std::optional<OSExchangeDataProvider::FileContentsInfo>
OSExchangeDataProviderWin::GetFileContents() const {
  if (HasCustomFormat(GetIgnoreFileContentsFormatType())) {
    return std::nullopt;
  }

  std::wstring filename_str;
  std::string file_contents;
  if (!clipboard_util::GetFileContents(source_object_.Get(), &filename_str,
                                       &file_contents) ||
      filename_str.empty()) {
    return std::nullopt;
  }

  return FileContentsInfo{.filename = base::FilePath(filename_str),
                          .file_contents = std::move(file_contents)};
}

std::optional<OSExchangeDataProvider::HtmlInfo>
OSExchangeDataProviderWin::GetHtml() const {
  std::u16string html;
  std::string url;
  bool success = clipboard_util::GetHtml(source_object_.Get(), &html, &url);
  if (!success) {
    return std::nullopt;
  }

  return HtmlInfo{
      .html = html,
      .base_url = GURL(url),
  };
}

bool OSExchangeDataProviderWin::HasString() const {
  return clipboard_util::HasPlainText(source_object_.Get());
}

bool OSExchangeDataProviderWin::HasURL(FilenameToURLPolicy policy) const {
  return (
      clipboard_util::HasUrl(
          source_object_.Get(),
          policy == FilenameToURLPolicy::CONVERT_FILENAMES ? true : false) ||
      HasPlainTextURL());
}

bool OSExchangeDataProviderWin::HasFile() const {
  return clipboard_util::HasFilenames(source_object_.Get());
}

bool OSExchangeDataProviderWin::HasFileContents() const {
  return clipboard_util::HasFileContents(source_object_.Get()) &&
         !HasCustomFormat(GetIgnoreFileContentsFormatType());
}

bool OSExchangeDataProviderWin::HasHtml() const {
  return clipboard_util::HasHtml(source_object_.Get());
}

bool OSExchangeDataProviderWin::HasCustomFormat(
    const ClipboardFormatType& format) const {
  FORMATETC format_etc = format.ToFormatEtc();
  return (source_object_->QueryGetData(&format_etc) == S_OK);
}

void OSExchangeDataProviderWin::SetDownloadFileInfo(
    DownloadFileInfo* download) {
  // If the filename is not provided, set storage to NULL to indicate that
  // the delay rendering will be used.
  // TODO(dcheng): Is it actually possible for filename to be empty here? I
  // think we always synthesize one in WebContentsDragWin.
  STGMEDIUM storage = kNullStorageMedium;
  if (!download->filename.empty()) {
    clipboard_util::CreateStorageForFileNames(
        {FileInfo(download->filename, base::FilePath())});
  }

  // Add CF_HDROP.
  auto info = DataObjectImpl::StoredDataInfo::TakeStorageMedium(
      ClipboardFormatType::CFHDropType().ToFormatEtc(), storage);
  info->downloader = std::move(download->downloader);
  data_->contents_.push_back(std::move(info));

  // Adding a download file always enables async mode.
  data_->SetAsyncMode(VARIANT_TRUE);
}

void OSExchangeDataProviderWin::SetDragImage(
    const gfx::ImageSkia& image_skia,
    const gfx::Vector2d& cursor_offset) {
  DCHECK(!image_skia.size().IsEmpty());

  // InitializeFromBitmap() doesn't expect an alpha channel and is confused
  // by premultiplied colors, so unpremultiply the bitmap.
  SkBitmap unpremul_bitmap =
      SkBitmapOperations::UnPreMultiply(*image_skia.bitmap());

  Microsoft::WRL::ComPtr<IDragSourceHelper> helper;
  HRESULT rv = CoCreateInstance(CLSID_DragDropHelper, 0, CLSCTX_INPROC_SERVER,
                                IID_PPV_ARGS(&helper));
  if (!SUCCEEDED(rv))
    return;

  base::win::ScopedGDIObject<HBITMAP> hbitmap =
      skia::CreateHBitmapFromN32SkBitmap(unpremul_bitmap);
  if (!hbitmap.is_valid())
    return;

  // InitializeFromBitmap() takes ownership of |hbitmap|.
  SHDRAGIMAGE sdi;
  sdi.sizeDragImage.cx = unpremul_bitmap.width();
  sdi.sizeDragImage.cy = unpremul_bitmap.height();
  sdi.crColorKey = 0xFFFFFFFF;
  sdi.hbmpDragImage = hbitmap.release();
  sdi.ptOffset = gfx::PointAtOffsetFromOrigin(cursor_offset).ToPOINT();
  helper->InitializeFromBitmap(&sdi, data_object());
}

gfx::ImageSkia OSExchangeDataProviderWin::GetDragImage() const {
  // This class sets the image on data_object() so it shouldn't be used in
  // situations where the drag image is later queried. In that case a different
  // OSExchangeDataProvider should be used.
  NOTREACHED();
}

gfx::Vector2d OSExchangeDataProviderWin::GetDragImageOffset() const {
  // This class sets the image on data_object() so it shouldn't be used in
  // situations where the drag image is later queried. In that case a different
  // OSExchangeDataProvider should be used.
  NOTREACHED();
}

void OSExchangeDataProviderWin::SetSource(
    std::unique_ptr<DataTransferEndpoint> data_source) {}

DataTransferEndpoint* OSExchangeDataProviderWin::GetSource() const {
  return nullptr;
}

///////////////////////////////////////////////////////////////////////////////
// DataObjectImpl, IDataObject implementation:

// The following function, DuplicateMedium, is derived from WCDataObject.cpp
// in the WebKit source code. This is the license information for the file:
/*
 * Copyright (C) 2007 Apple Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
static STGMEDIUM DuplicateMedium(CLIPFORMAT clipformat,
                                 const STGMEDIUM& storage) {
  STGMEDIUM copied = kNullStorageMedium;
  switch (storage.tymed) {
    case TYMED_HGLOBAL:
      copied.hGlobal = static_cast<HGLOBAL>(
          OleDuplicateData(storage.hGlobal, clipformat, 0));
      break;
    case TYMED_MFPICT:
      copied.hMetaFilePict = static_cast<HMETAFILEPICT>(
          OleDuplicateData(storage.hMetaFilePict, clipformat, 0));
      break;
    case TYMED_GDI:
      copied.hBitmap = static_cast<HBITMAP>(
          OleDuplicateData(storage.hBitmap, clipformat, 0));
      break;
    case TYMED_ENHMF:
      copied.hEnhMetaFile = static_cast<HENHMETAFILE>(
          OleDuplicateData(storage.hEnhMetaFile, clipformat, 0));
      break;
    case TYMED_FILE:
      copied.lpszFileName = static_cast<LPOLESTR>(
          OleDuplicateData(storage.lpszFileName, clipformat, 0));
      break;
    case TYMED_ISTREAM:
      copied.pstm = storage.pstm;
      copied.pstm->AddRef();
      break;
    case TYMED_ISTORAGE:
      copied.pstg = storage.pstg;
      copied.pstg->AddRef();
      break;
  }

  copied.tymed = storage.tymed;
  copied.pUnkForRelease = storage.pUnkForRelease;
  if (copied.pUnkForRelease)
    copied.pUnkForRelease->AddRef();

  return copied;
}

DataObjectImpl::StoredDataInfo::~StoredDataInfo() {
  ReleaseStgMedium(&medium);
  if (downloader.get())
    downloader->Stop();
}

// Takes ownership of and nullifies `medium`.
std::unique_ptr<DataObjectImpl::StoredDataInfo>
DataObjectImpl::StoredDataInfo::TakeStorageMedium(const FORMATETC& format_etc,
                                                  STGMEDIUM& medium) {
  std::unique_ptr<StoredDataInfo> info(new StoredDataInfo(format_etc, medium));

  // Null `medium` out.
  medium = kNullStorageMedium;
  return info;
}

DataObjectImpl::StoredDataInfo::StoredDataInfo(const FORMATETC& format_etc,
                                               const STGMEDIUM& medium)
    : format_etc(format_etc), medium(medium) {}

DataObjectImpl::DataObjectImpl()
    : is_aborting_(false),
      in_drag_loop_(false),
      in_async_mode_(false),
      async_operation_started_(false) {}

DataObjectImpl::~DataObjectImpl() {
  StopDownloads();
}

void DataObjectImpl::StopDownloads() {
  for (const std::unique_ptr<StoredDataInfo>& content : contents_) {
    if (content->downloader.get()) {
      content->downloader->Stop();
      content->downloader = 0;
    }
  }
}

void DataObjectImpl::RemoveData(const FORMATETC& format) {
  if (format.ptd)
    return;  // Don't attempt to compare target devices.

  for (StoredData::iterator i = contents_.begin(); i != contents_.end(); ++i) {
    if (!(*i)->format_etc.ptd &&
        format.cfFormat == (*i)->format_etc.cfFormat &&
        format.dwAspect == (*i)->format_etc.dwAspect &&
        format.lindex == (*i)->format_etc.lindex &&
        format.tymed == (*i)->format_etc.tymed) {
      contents_.erase(i);
      return;
    }
  }
}

void DataObjectImpl::OnDownloadCompleted(const base::FilePath& file_path) {
  for (std::unique_ptr<StoredDataInfo>& content : contents_) {
    if (content->format_etc.cfFormat == CF_HDROP) {
      // Retrieve the downloader first so it won't get destroyed.
      auto downloader = std::move(content->downloader);
      if (downloader)
        downloader->Stop();
      // Replace stored data.
      STGMEDIUM storage = clipboard_util::CreateStorageForFileNames(
          {FileInfo(file_path, base::FilePath())});
      content = StoredDataInfo::TakeStorageMedium(
          ClipboardFormatType::CFHDropType().ToFormatEtc(), storage);
      content->downloader = std::move(downloader);
      break;
    }
  }
}

void DataObjectImpl::OnDownloadAborted() {}

HRESULT DataObjectImpl::GetData(FORMATETC* format_etc, STGMEDIUM* medium) {
  if (is_aborting_)
    return DV_E_FORMATETC;

  for (const std::unique_ptr<StoredDataInfo>& content : contents_) {
    if (content->format_etc.cfFormat == format_etc->cfFormat &&
        content->format_etc.lindex == format_etc->lindex &&
        (content->format_etc.tymed & format_etc->tymed)) {
      // If medium is NULL, delay-rendering will be used.
      if (content->medium.tymed != TYMED_NULL) {
        *medium =
            DuplicateMedium(content->format_etc.cfFormat, content->medium);
        return S_OK;
      }
      // Fail all GetData() attempts for DownloadURL data if the drag and drop
      // operation is still in progress.
      if (in_drag_loop_)
        return DV_E_FORMATETC;

      bool wait_for_data = false;

      // In async mode, we do not want to start waiting for the data before
      // the async operation is started. This is because we want to postpone
      // until Shell kicks off a background thread to do the work so that
      // we do not block the UI thread.
      if (!in_async_mode_ || async_operation_started_)
        wait_for_data = true;

      if (!wait_for_data)
        return DV_E_FORMATETC;

      // Now we can start the download.
      if (content->downloader.get()) {
        content->downloader->Start(this);
        if (!content->downloader->Wait()) {
          is_aborting_ = true;
          return DV_E_FORMATETC;
        }
      }
      // The stored data should have been updated with the final version.
      // So we just need to call this function again to retrieve it.
      return GetData(format_etc, medium);
    }
  }

  return DV_E_FORMATETC;
}

HRESULT DataObjectImpl::GetDataHere(FORMATETC* format_etc,
                                    STGMEDIUM* medium) {
  return DATA_E_FORMATETC;
}

HRESULT DataObjectImpl::QueryGetData(FORMATETC* format_etc) {
  for (const std::unique_ptr<StoredDataInfo>& content : contents_) {
    if (content->format_etc.cfFormat == format_etc->cfFormat)
      return S_OK;
  }
  return DV_E_FORMATETC;
}

HRESULT DataObjectImpl::GetCanonicalFormatEtc(
    FORMATETC* format_etc, FORMATETC* result) {
  format_etc->ptd = NULL;
  return E_NOTIMPL;
}

HRESULT DataObjectImpl::SetData(
    FORMATETC* format_etc, STGMEDIUM* medium, BOOL should_release) {
  RemoveData(*format_etc);

  // If `should_release` is true, ownership of the original data in `medium` is
  // transferred to `this`. Otherwise it remains with the caller. To prevent
  // lifetime issues, perform a deep copy of `medium`.
  STGMEDIUM local_medium =
      should_release ? *medium : DuplicateMedium(format_etc->cfFormat, *medium);
  DCHECK_EQ(local_medium.tymed, format_etc->tymed);
  auto info = StoredDataInfo::TakeStorageMedium(*format_etc, local_medium);

  // Make newly added data appear first.
  // TODO(dcheng): Make various setters agree whether elements should be
  // prioritized from front to back or back to front.
  contents_.insert(contents_.begin(), std::move(info));

  return S_OK;
}

HRESULT DataObjectImpl::EnumFormatEtc(
    DWORD direction, IEnumFORMATETC** enumerator) {
  if (direction == DATADIR_GET) {
    FormatEtcEnumerator* e =
        new FormatEtcEnumerator(contents_.begin(), contents_.end());
    e->AddRef();
    *enumerator = e;
    return S_OK;
  }
  return E_NOTIMPL;
}

HRESULT DataObjectImpl::DAdvise(
    FORMATETC* format_etc, DWORD advf, IAdviseSink* sink, DWORD* connection) {
  return OLE_E_ADVISENOTSUPPORTED;
}

HRESULT DataObjectImpl::DUnadvise(DWORD connection) {
  return OLE_E_ADVISENOTSUPPORTED;
}

HRESULT DataObjectImpl::EnumDAdvise(IEnumSTATDATA** enumerator) {
  return OLE_E_ADVISENOTSUPPORTED;
}

///////////////////////////////////////////////////////////////////////////////
// DataObjectImpl, IDataObjectAsyncCapability implementation:

HRESULT DataObjectImpl::EndOperation(
    HRESULT result, IBindCtx* reserved, DWORD effects) {
  async_operation_started_ = false;
  return S_OK;
}

HRESULT DataObjectImpl::GetAsyncMode(BOOL* is_op_async) {
  *is_op_async = in_async_mode_ ? VARIANT_TRUE : VARIANT_FALSE;
  return S_OK;
}

HRESULT DataObjectImpl::InOperation(BOOL* in_async_op) {
  *in_async_op = async_operation_started_ ? VARIANT_TRUE : VARIANT_FALSE;
  return S_OK;
}

HRESULT DataObjectImpl::SetAsyncMode(BOOL do_op_async) {
  in_async_mode_ = !!do_op_async;
  return S_OK;
}

HRESULT DataObjectImpl::StartOperation(IBindCtx* reserved) {
  async_operation_started_ = true;
  return S_OK;
}

///////////////////////////////////////////////////////////////////////////////
// DataObjectImpl, IUnknown implementation:

HRESULT DataObjectImpl::QueryInterface(const IID& iid, void** object) {
  if (!object)
    return E_POINTER;
  if (IsEqualIID(iid, IID_IDataObject) || IsEqualIID(iid, IID_IUnknown)) {
    *object = static_cast<IDataObject*>(this);
  } else if (in_async_mode_ &&
             IsEqualIID(iid, __uuidof(IDataObjectAsyncCapability))) {
    *object = static_cast<IDataObjectAsyncCapability*>(this);
  } else {
    *object = NULL;
    return E_NOINTERFACE;
  }
  AddRef();
  return S_OK;
}

ULONG DataObjectImpl::AddRef() {
  base::RefCountedThreadSafe<DownloadFileObserver>::AddRef();
  return 0;
}

ULONG DataObjectImpl::Release() {
  base::RefCountedThreadSafe<DownloadFileObserver>::Release();
  return 0;
}

///////////////////////////////////////////////////////////////////////////////
// anonymous namespace functions
namespace {
STGMEDIUM CreateStorageForBytes(const void* data, size_t bytes) {
  HANDLE handle = GlobalAlloc(GPTR, bytes);
  if (handle) {
    base::win::ScopedHGlobal<uint8_t*> scoped(handle);
    memcpy(scoped.data(), data, bytes);
  }

  return STGMEDIUM{
      .tymed = TYMED_HGLOBAL, .hGlobal = handle, .pUnkForRelease = nullptr};
}

STGMEDIUM CreateStorageForString(std::string_view data) {
  HANDLE handle = GlobalAlloc(GPTR, data.size() + 1);
  if (handle) {
    base::win::ScopedHGlobal<uint8_t*> scoped(handle);
    memcpy(scoped.data(), data.data(), data.size());
    scoped.data()[data.size()] = 0;
  }

  return STGMEDIUM{
      .tymed = TYMED_HGLOBAL, .hGlobal = handle, .pUnkForRelease = nullptr};
}

STGMEDIUM CreateStorageForString(std::u16string_view data) {
  const size_t size = data.size() * sizeof(char16_t);
  HANDLE handle = GlobalAlloc(GPTR, size + sizeof(char16_t));
  if (handle) {
    base::win::ScopedHGlobal<uint8_t*> scoped(handle);
    memcpy(scoped.data(), data.data(), size);
    memset(scoped.data() + size, 0, sizeof(char16_t));
  }

  return STGMEDIUM{
      .tymed = TYMED_HGLOBAL, .hGlobal = handle, .pUnkForRelease = nullptr};
}

LPITEMIDLIST PIDLNext(LPITEMIDLIST pidl) {
  return reinterpret_cast<LPITEMIDLIST>(
      reinterpret_cast<BYTE*>(pidl) + pidl->mkid.cb);
}

size_t PIDLSize(LPITEMIDLIST pidl) {
  size_t s = 0;
  while (pidl->mkid.cb > 0) {
    s += pidl->mkid.cb;
    pidl = PIDLNext(pidl);
  }
  // We add 2 because an LPITEMIDLIST is terminated by two NULL bytes.
  return 2 + s;
}

LPITEMIDLIST GetNthPIDL(CIDA* cida, int n) {
  return reinterpret_cast<LPITEMIDLIST>(
      reinterpret_cast<LPBYTE>(cida) + cida->aoffset[n]);
}

LPITEMIDLIST GetPidlFromPath(const base::FilePath& path) {
  LPITEMIDLIST pidl = NULL;
  LPSHELLFOLDER desktop_folder = NULL;
  LPWSTR path_str = const_cast<LPWSTR>(path.value().c_str());

  if (FAILED(SHGetDesktopFolder(&desktop_folder)))
    return NULL;

  HRESULT hr = desktop_folder->ParseDisplayName(
      NULL, NULL, path_str, NULL, &pidl, NULL);

  return SUCCEEDED(hr) ? pidl : NULL;
}

STGMEDIUM CreateIdListStorageForFileName(const base::FilePath& path) {
  LPITEMIDLIST pidl = GetPidlFromPath(path);
  if (!pidl)
    return kNullStorageMedium;

  // When using CFSTR_SHELLIDLIST the hGlobal field of the STGMEDIUM is a
  // pointer to a CIDA*. A CIDA is a variable length struct that contains a PIDL
  // count (a UINT), an array of offsets of the following PIDLs (a UINT[]) and
  // then a series of PIDLs laid out contiguously in memory. A PIDL is
  // represented by an ITEMIDLIST struct, which contains a single SHITEMID.
  // Despite only containing a single SHITEMID, ITEMIDLISTs are so-named because
  // SHITEMIDs contain their own size and so given one, the next can be found by
  // looking at the section of memory after it. The end of a list is indicated
  // by two NULL bytes.
  // Here we require two PIDLs - the first PIDL is the parent folder and is
  // NULL here to indicate that the parent folder is the desktop, and the second
  // is the PIDL of |path|.
  const size_t kPIDLCountSize = sizeof(UINT);
  const size_t kPIDLOffsetsSize = 2 * sizeof(UINT);
  const size_t kFirstPIDLOffset = kPIDLCountSize + kPIDLOffsetsSize;
  const size_t kFirstPIDLSize = 2;  // Empty PIDL - 2 NULL bytes.
  const size_t kSecondPIDLSize = PIDLSize(pidl);
  const size_t kCIDASize = kFirstPIDLOffset + kFirstPIDLSize + kSecondPIDLSize;
  HANDLE hdata = GlobalAlloc(GMEM_MOVEABLE, kCIDASize);

  base::win::ScopedHGlobal<CIDA*> locked_mem(hdata);
  CIDA* cida = locked_mem.data();
  cida->cidl = 1;     // We have one PIDL (not including the 0th root PIDL).
  cida->aoffset[0] = kFirstPIDLOffset;
  cida->aoffset[1] = kFirstPIDLOffset + kFirstPIDLSize;
  LPITEMIDLIST idl = GetNthPIDL(cida, 0);
  idl->mkid.cb = 0;
  idl->mkid.abID[0] = 0;
  idl = GetNthPIDL(cida, 1);
  memcpy(idl, pidl, kSecondPIDLSize);

  STGMEDIUM storage = {
      .tymed = TYMED_HGLOBAL, .hGlobal = hdata, .pUnkForRelease = nullptr};
  return storage;
}

STGMEDIUM CreateStorageForFileDescriptor(const base::FilePath& path) {
  std::wstring file_name = path.value();
  DCHECK(!file_name.empty());
  HANDLE hdata = GlobalAlloc(GPTR, sizeof(FILEGROUPDESCRIPTORW));
  base::win::ScopedHGlobal<FILEGROUPDESCRIPTORW*> locked_mem(hdata);

  FILEGROUPDESCRIPTORW* descriptor = locked_mem.data();
  descriptor->cItems = 1;
  descriptor->fgd[0].dwFlags = FD_LINKUI;
  wcsncpy_s(descriptor->fgd[0].cFileName, MAX_PATH, file_name.c_str(),
            std::min(file_name.size(), static_cast<size_t>(MAX_PATH - 1u)));

  STGMEDIUM storage = {
      .tymed = TYMED_HGLOBAL, .hGlobal = hdata, .pUnkForRelease = nullptr};
  return storage;
}

const ClipboardFormatType& GetRendererTaintFormatType() {
  static base::NoDestructor<ClipboardFormatType> format(
      ClipboardFormatType::CustomPlatformType("chromium/x-renderer-taint"));
  return *format;
}

const ClipboardFormatType& GetFromPrivilegedFormatType() {
  static base::NoDestructor<ClipboardFormatType> format(
      ClipboardFormatType::CustomPlatformType("chromium/from-privileged"));
  return *format;
}

// Used to mark file content as synthesized by Chrome itself during a non-file
// drag for interoperating with the native OS. Synthesized file contents will be
// treated as non-existent for the purposes of GetFileContent() to avoid
// confusing web pages that might not expect the synthesized file. See
// https://crbug.com/1274395 for background.
const ClipboardFormatType& GetIgnoreFileContentsFormatType() {
  static base::NoDestructor<ClipboardFormatType> format(
      ClipboardFormatType::CustomPlatformType(
          "chromium/x-ignore-file-contents"));
  return *format;
}

std::string GetInternetShortcutFileContents(const GURL& url) {
  static constexpr char kInternetShortcutFileStart[] =
      "[InternetShortcut]\r\nURL=";
  static constexpr char kInternetShortcutFileEnd[] = "\r\n";
  return kInternetShortcutFileStart + url.spec() + kInternetShortcutFileEnd;
}

std::wstring CreateValidFileNameFromTitle(const GURL& url,
                                          const std::wstring& title) {
  std::wstring validated;
  if (title.empty()) {
    if (url.is_valid()) {
      validated = base::AsWString(
          net::GetSuggestedFilename(url, "", "", "", "", std::string()));
    } else {
      // Nothing else can be done, just use a default.
      validated = l10n_util::GetWideString(IDS_APP_UNTITLED_SHORTCUT_FILE_NAME);
    }
  } else {
    validated = title;
    base::i18n::ReplaceIllegalCharactersInPath(&validated, '-');
  }
  static const wchar_t kExtension[] = L".url";

  // The value of kMaxFileNameLength was chosen to account for local file paths
  // that can cause total paths to be greater than MAX_PATH while still allowing
  // for a relatively long title. The total path may still exceed MAX_PATH when
  // the local path length exceeds MAX_PATH - kMaxFileNameLength. See
  // crbug.com/779414.
  static constexpr size_t kMaxFileNameLength = MAX_PATH / 2;

  // Maximum length of title after truncation.
  static constexpr size_t kMaxFileTitleLength =
      kMaxFileNameLength - std::size(kExtension);

  if (validated.size() > kMaxFileTitleLength)
    validated.erase(kMaxFileTitleLength);
  validated += kExtension;

  return validated;
}

}  // namespace

}  // namespace ui