// Copyright (c) 2012 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.

// An extremely simple implementation of DataSource that downloads the entire
// media resource into memory before signaling that initialization has finished.
// Primarily used to test <audio> and <video> with buffering/caching removed
// from the equation.

#ifndef WEBKIT_MEDIA_SIMPLE_DATA_SOURCE_H_
#define WEBKIT_MEDIA_SIMPLE_DATA_SOURCE_H_

#include <algorithm>
#include <string>

#include "base/memory/scoped_ptr.h"
#include "base/message_loop.h"
#include "googleurl/src/gurl.h"
#include "media/base/data_source.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURLLoader.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURLLoaderClient.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURLRequest.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURLResponse.h"
#include "webkit/media/web_data_source.h"

class MessageLoop;

namespace media {
class MediaLog;
}

namespace webkit_media {

class SimpleDataSource
    : public WebDataSource,
      public WebKit::WebURLLoaderClient {
 public:
  SimpleDataSource(MessageLoop* render_loop, WebKit::WebFrame* frame);
  virtual ~SimpleDataSource();

  // media::DataSource implementation.
  virtual void set_host(media::DataSourceHost* host) OVERRIDE;
  virtual void Stop(const base::Closure& callback) OVERRIDE;
  virtual void Read(int64 position,
                    size_t size,
                    uint8* data,
                    const DataSource::ReadCallback& read_callback) OVERRIDE;
  virtual bool GetSize(int64* size_out) OVERRIDE;
  virtual bool IsStreaming() OVERRIDE;
  virtual void SetPreload(media::Preload preload) OVERRIDE;
  virtual void SetBitrate(int bitrate) OVERRIDE;

  // Used to inject a mock used for unittests.
  virtual void SetURLLoaderForTest(WebKit::WebURLLoader* mock_loader);

  // WebKit::WebURLLoaderClient implementations.
  virtual void willSendRequest(
      WebKit::WebURLLoader* loader,
      WebKit::WebURLRequest& newRequest,
      const WebKit::WebURLResponse& redirectResponse);
  virtual void didSendData(
      WebKit::WebURLLoader* loader,
      unsigned long long bytesSent,
      unsigned long long totalBytesToBeSent);
  virtual void didReceiveResponse(
      WebKit::WebURLLoader* loader,
      const WebKit::WebURLResponse& response);
  virtual void didDownloadData(
      WebKit::WebURLLoader* loader,
      int dataLength);
  virtual void didReceiveData(
      WebKit::WebURLLoader* loader,
      const char* data,
      int dataLength,
      int encodedDataLength);
  virtual void didReceiveCachedMetadata(
      WebKit::WebURLLoader* loader,
      const char* data, int dataLength);
  virtual void didFinishLoading(
      WebKit::WebURLLoader* loader,
      double finishTime);
  virtual void didFail(
      WebKit::WebURLLoader* loader,
      const WebKit::WebURLError&);

  // webkit_glue::WebDataSource implementation.
  virtual void Initialize(const GURL& url,
                          const media::PipelineStatusCB& callback) OVERRIDE;
  virtual bool HasSingleOrigin() OVERRIDE;
  virtual void Abort() OVERRIDE;

 private:
  // Cancels and deletes the resource loading on the render thread.
  void CancelTask();
  void CancelTask_Locked();

  // Perform initialization completion tasks under a lock.
  void DoneInitialization_Locked(bool success);

  // Update host() stats like total bytes & buffered bytes.
  void UpdateHostState();

  // Primarily used for asserting the bridge is loading on the render thread.
  MessageLoop* render_loop_;

  // A webframe for loading.
  WebKit::WebFrame* frame_;

  // Does the work of loading and sends data back to this client.
  scoped_ptr<WebKit::WebURLLoader> url_loader_;

  GURL url_;
  std::string data_;
  int64 size_;
  bool single_origin_;

  // Simple state tracking variable.
  enum State {
    UNINITIALIZED,
    INITIALIZING,
    INITIALIZED,
    STOPPED,
  };
  State state_;

  // Used for accessing |state_|.
  base::Lock lock_;

  // Filter callbacks.
  media::PipelineStatusCB initialize_cb_;

  // Used to ensure mocks for unittests are used instead of reset in Start().
  bool keep_test_loader_;

  DISALLOW_COPY_AND_ASSIGN(SimpleDataSource);
};

}  // namespace webkit_media

#endif  // WEBKIT_MEDIA_SIMPLE_DATA_SOURCE_H_