// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/extensions/clipboard_extension_helper_chromeos.h"

#include <utility>

#include "base/macros.h"
#include "base/metrics/histogram_macros.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/synchronization/atomic_flag.h"
#include "chrome/browser/image_decoder/image_decoder.h"
#include "content/public/browser/browser_thread.h"
#include "ui/base/clipboard/scoped_clipboard_writer.h"

using content::BrowserThread;

namespace extensions {

namespace clipboard = api::clipboard;

class ClipboardExtensionHelper::ClipboardImageDataDecoder
    : public ImageDecoder::ImageRequest {
 public:
  explicit ClipboardImageDataDecoder(ClipboardExtensionHelper* owner)
      : owner_(owner) {}

  ~ClipboardImageDataDecoder() override { ImageDecoder::Cancel(this); }

  bool has_request_pending() const { return has_request_pending_; }

  void Start(const std::vector<char>& image_data, clipboard::ImageType type) {
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    std::string image_data_str(image_data.begin(), image_data.end());

    ImageDecoder::ImageCodec codec = ImageDecoder::DEFAULT_CODEC;
    switch (type) {
      case clipboard::IMAGE_TYPE_PNG:
        codec = ImageDecoder::ROBUST_PNG_CODEC;
        break;
      case clipboard::IMAGE_TYPE_JPEG:
        codec = ImageDecoder::DEFAULT_CODEC;
        break;
      case clipboard::IMAGE_TYPE_NONE:
        NOTREACHED();
        break;
    }

    has_request_pending_ = true;
    ImageDecoder::StartWithOptions(this, image_data_str, codec, true);
  }

  void Cancel() {
    has_request_pending_ = false;
    ImageDecoder::Cancel(this);
    owner_->OnImageDecodeCancel();
  }

  void OnImageDecoded(const SkBitmap& decoded_image) override {
    has_request_pending_ = false;
    owner_->OnImageDecoded(decoded_image);
  }

  void OnDecodeImageFailed() override {
    has_request_pending_ = false;
    owner_->OnImageDecodeFailure();
  }

 private:
  ClipboardExtensionHelper* owner_;  // Not owned.
  bool has_request_pending_ = false;

  DISALLOW_COPY_AND_ASSIGN(ClipboardImageDataDecoder);
};

ClipboardExtensionHelper::ClipboardExtensionHelper() {
  clipboard_image_data_decoder_.reset(new ClipboardImageDataDecoder(this));
}

ClipboardExtensionHelper::~ClipboardExtensionHelper() {}

void ClipboardExtensionHelper::DecodeAndSaveImageData(
    const std::vector<char>& data,
    clipboard::ImageType type,
    AdditionalDataItemList additional_items,
    const base::Closure& success_callback,
    const base::Callback<void(const std::string&)>& error_callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  // If there is a previous image decoding request still running, cancel it
  // first. We only need the most recent image save request be completed, since
  // the clipboard will only store data set by the most recent request, which
  // is consistent with the clipboard "paste" behavior.
  if (clipboard_image_data_decoder_->has_request_pending())
    clipboard_image_data_decoder_->Cancel();

  // Cache additonal items.
  additonal_items_ = std::move(additional_items);

  image_save_success_callback_ = success_callback;
  image_save_error_callback_ = error_callback;
  clipboard_image_data_decoder_->Start(data, type);
}

void ClipboardExtensionHelper::OnImageDecodeFailure() {
  std::move(image_save_error_callback_).Run("Image data decoding failed.");
}

void ClipboardExtensionHelper::OnImageDecoded(const SkBitmap& bitmap) {
  {
    ui::ScopedClipboardWriter scw(ui::ClipboardBuffer::kCopyPaste);
    // Write the decoded image data to clipboard.
    if (!bitmap.empty() && !bitmap.isNull())
      scw.WriteImage(bitmap);

    for (const clipboard::AdditionalDataItem& item : additonal_items_) {
      if (item.type == clipboard::DATA_ITEM_TYPE_TEXTPLAIN)
        scw.WriteText(base::UTF8ToUTF16(item.data));
      else if (item.type == clipboard::DATA_ITEM_TYPE_TEXTHTML)
        scw.WriteHTML(base::UTF8ToUTF16(item.data), std::string());
    }
  }
  std::move(image_save_success_callback_).Run();
}

void ClipboardExtensionHelper::OnImageDecodeCancel() {
  std::move(image_save_error_callback_).Run("Request canceled.");
}

}  // namespace extensions