/*
 * Copyright (C) 2011 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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,
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 * 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.
 */

#ifndef DOMWebSocket_h
#define DOMWebSocket_h

#include "bindings/core/v8/ActiveScriptWrappable.h"
#include "bindings/core/v8/ScriptWrappable.h"
#include "core/dom/SuspendableObject.h"
#include "core/events/EventListener.h"
#include "core/events/EventTarget.h"
#include "modules/EventTargetModules.h"
#include "modules/ModulesExport.h"
#include "modules/websockets/WebSocketChannel.h"
#include "modules/websockets/WebSocketChannelClient.h"
#include "platform/Timer.h"
#include "platform/heap/Handle.h"
#include "platform/weborigin/KURL.h"
#include "wtf/Deque.h"
#include "wtf/Forward.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RefPtr.h"
#include "wtf/text/WTFString.h"
#include <memory>
#include <stddef.h>
#include <stdint.h>

namespace blink {

class Blob;
class DOMArrayBuffer;
class DOMArrayBufferView;
class ExceptionState;
class ExecutionContext;
class StringOrStringSequence;

class MODULES_EXPORT DOMWebSocket : public EventTargetWithInlineData,
                                    public ActiveScriptWrappable<DOMWebSocket>,
                                    public SuspendableObject,
                                    public WebSocketChannelClient {
  DEFINE_WRAPPERTYPEINFO();
  USING_GARBAGE_COLLECTED_MIXIN(DOMWebSocket);

 public:
  static const char* subprotocolSeperator();
  // DOMWebSocket instances must be used with a wrapper since this class's
  // lifetime management is designed assuming the V8 holds a ref on it while
  // hasPendingActivity() returns true.
  static DOMWebSocket* create(ExecutionContext*,
                              const String& url,
                              ExceptionState&);
  static DOMWebSocket* create(ExecutionContext*,
                              const String& url,
                              const StringOrStringSequence& protocols,
                              ExceptionState&);
  ~DOMWebSocket() override;

  enum State { kConnecting = 0, kOpen = 1, kClosing = 2, kClosed = 3 };

  void connect(const String& url,
               const Vector<String>& protocols,
               ExceptionState&);

  void send(const String& message, ExceptionState&);
  void send(DOMArrayBuffer*, ExceptionState&);
  void send(DOMArrayBufferView*, ExceptionState&);
  void send(Blob*, ExceptionState&);

  // To distinguish close method call with the code parameter from one
  // without, we have these three signatures. Use of
  // Optional=DefaultIsUndefined in the IDL file doesn't help for now since
  // it's bound to a value of 0 which is indistinguishable from the case 0
  // is passed as code parameter.
  void close(unsigned short code, const String& reason, ExceptionState&);
  void close(ExceptionState&);
  void close(unsigned short code, ExceptionState&);

  const KURL& url() const;
  State readyState() const;
  unsigned bufferedAmount() const;

  String protocol() const;
  String extensions() const;

  String binaryType() const;
  void setBinaryType(const String&);

  DEFINE_ATTRIBUTE_EVENT_LISTENER(open);
  DEFINE_ATTRIBUTE_EVENT_LISTENER(message);
  DEFINE_ATTRIBUTE_EVENT_LISTENER(error);
  DEFINE_ATTRIBUTE_EVENT_LISTENER(close);

  // EventTarget functions.
  const AtomicString& interfaceName() const override;
  ExecutionContext* getExecutionContext() const override;

  // SuspendableObject functions.
  void contextDestroyed(ExecutionContext*) override;
  void suspend() override;
  void resume() override;

  // ScriptWrappable functions.
  // Prevent this instance from being collected while it's not in CLOSED
  // state.
  bool hasPendingActivity() const final;

  // WebSocketChannelClient functions.
  void didConnect(const String& subprotocol, const String& extensions) override;
  void didReceiveTextMessage(const String& message) override;
  void didReceiveBinaryMessage(std::unique_ptr<Vector<char>>) override;
  void didError() override;
  void didConsumeBufferedAmount(uint64_t) override;
  void didStartClosingHandshake() override;
  void didClose(ClosingHandshakeCompletionStatus,
                unsigned short code,
                const String& reason) override;

  DECLARE_VIRTUAL_TRACE();

  static bool isValidSubprotocolString(const String&);

 protected:
  explicit DOMWebSocket(ExecutionContext*);

 private:
  // FIXME: This should inherit blink::EventQueue.
  class EventQueue final : public GarbageCollectedFinalized<EventQueue> {
   public:
    static EventQueue* create(EventTarget* target) {
      return new EventQueue(target);
    }
    ~EventQueue();

    // Dispatches the event if this queue is active.
    // Queues the event if this queue is suspended.
    // Does nothing otherwise.
    void dispatch(Event* /* event */);

    bool isEmpty() const;

    void suspend();
    void resume();
    void contextDestroyed();

    DECLARE_TRACE();

   private:
    enum State {
      Active,
      Suspended,
      Stopped,
    };

    explicit EventQueue(EventTarget*);

    // Dispatches queued events if this queue is active.
    // Does nothing otherwise.
    void dispatchQueuedEvents();
    void resumeTimerFired(TimerBase*);

    State m_state;
    Member<EventTarget> m_target;
    HeapDeque<Member<Event>> m_events;
    Timer<EventQueue> m_resumeTimer;
  };

  enum WebSocketSendType {
    WebSocketSendTypeString,
    WebSocketSendTypeArrayBuffer,
    WebSocketSendTypeArrayBufferView,
    WebSocketSendTypeBlob,
    WebSocketSendTypeMax,
  };

  enum WebSocketReceiveType {
    WebSocketReceiveTypeString,
    WebSocketReceiveTypeArrayBuffer,
    WebSocketReceiveTypeBlob,
    WebSocketReceiveTypeMax,
  };

  enum BinaryType { BinaryTypeBlob, BinaryTypeArrayBuffer };

  // This function is virtual for unittests.
  // FIXME: Move WebSocketChannel::create here.
  virtual WebSocketChannel* createChannel(ExecutionContext* context,
                                          WebSocketChannelClient* client) {
    return WebSocketChannel::create(context, client);
  }

  // Adds a console message with JSMessageSource and ErrorMessageLevel.
  void logError(const String& message);

  // Handle the JavaScript close method call. close() methods on this class
  // are just for determining if the optional code argument is supplied or
  // not.
  void closeInternal(int, const String&, ExceptionState&);

  // Updates m_bufferedAmountAfterClose given the amount of data passed to
  // send() method after the state changed to CLOSING or CLOSED.
  void updateBufferedAmountAfterClose(uint64_t);
  void reflectBufferedAmountConsumption(TimerBase*);

  void releaseChannel();
  void recordSendTypeHistogram(WebSocketSendType);
  void recordSendMessageSizeHistogram(WebSocketSendType, size_t);
  void recordReceiveTypeHistogram(WebSocketReceiveType);
  void recordReceiveMessageSizeHistogram(WebSocketReceiveType, size_t);

  void setBinaryTypeInternal(BinaryType);
  void logBinaryTypeChangesAfterOpen();

  Member<WebSocketChannel> m_channel;

  State m_state;
  KURL m_url;
  uint64_t m_bufferedAmount;
  // The consumed buffered amount that will be reflected to m_bufferedAmount
  // later. It will be cleared once reflected.
  uint64_t m_consumedBufferedAmount;
  uint64_t m_bufferedAmountAfterClose;
  BinaryType m_binaryType;
  int m_binaryTypeChangesAfterOpen;
  // The subprotocol the server selected.
  String m_subprotocol;
  String m_extensions;

  Member<EventQueue> m_eventQueue;
  Timer<DOMWebSocket> m_bufferedAmountConsumeTimer;
};

}  // namespace blink

#endif  // DOMWebSocket_h