/*
 * 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 "core/dom/ActiveDOMObject.h"
#include "core/events/EventListener.h"
#include "modules/EventTargetModules.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/text/AtomicStringHash.h"

namespace blink {

class Blob;
class ExceptionState;

class DOMWebSocket : public RefCountedGarbageCollectedWillBeGarbageCollectedFinalized<DOMWebSocket>, public EventTargetWithInlineData, public ActiveDOMObject, public WebSocketChannelClient {
    DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<DOMWebSocket>);
    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 String& protocol, ExceptionState&);
    static DOMWebSocket* create(ExecutionContext*, const String& url, const Vector<String>& protocols, ExceptionState&);
    virtual ~DOMWebSocket();

    enum State {
        CONNECTING = 0,
        OPEN = 1,
        CLOSING = 2,
        CLOSED = 3
    };

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

    void send(const String& message, ExceptionState&);
    void send(ArrayBuffer*, ExceptionState&);
    void send(ArrayBufferView*, 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 long 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.
    virtual const AtomicString& interfaceName() const OVERRIDE;
    virtual ExecutionContext* executionContext() const OVERRIDE;
    virtual bool dispatchEvent(PassRefPtr<Event>) OVERRIDE;
    using EventTarget::dispatchEvent;

    // ActiveDOMObject functions.
    virtual void contextDestroyed() OVERRIDE;
    // Prevent this instance from being collected while it's not in CLOSED
    // state.
    virtual bool hasPendingActivity() const OVERRIDE;
    virtual bool canSuspend() const OVERRIDE;
    virtual bool canSuspend(ReasonForSuspension) const OVERRIDE;
    virtual void suspend(ReasonForSuspension) OVERRIDE;
    virtual void resume() OVERRIDE;
    virtual void stop() OVERRIDE;

    // WebSocketChannelClient functions.
    virtual void didConnect(const String& subprotocol, const String& extensions) OVERRIDE;
    virtual void didReceiveMessage(const String& message) OVERRIDE;
    virtual void didReceiveBinaryData(PassOwnPtr<Vector<char> >) OVERRIDE;
    virtual void didReceiveMessageError() OVERRIDE;
    virtual void didConsumeBufferedAmount(unsigned long) OVERRIDE;
    virtual void didStartClosingHandshake() OVERRIDE;
    virtual void didClose(ClosingHandshakeCompletionStatus, unsigned short code, const String& reason) OVERRIDE;

    virtual void trace(Visitor*) OVERRIDE;

    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(PassRefPtrWillBeRawPtr<Event> /* event */);

        bool isEmpty() const;

        void suspend();
        void resume();
        void stop();

        void trace(Visitor*);

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

        explicit EventQueue(EventTarget*);

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

        State m_state;
        EventTarget* m_target;
        WillBeHeapDeque<RefPtrWillBeMember<Event> > m_events;
        Timer<EventQueue> m_resumeTimer;
    };

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

    // 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&);

    void dispatchDeferredEvents(Timer<DOMWebSocket>*);

    size_t getFramingOverhead(size_t payloadSize);

    // Updates m_bufferedAmountAfterClose given the amount of data passed to
    // send() method after the state changed to CLOSING or CLOSED.
    void updateBufferedAmountAfterClose(unsigned long);
    void reflectBufferedAmountConsumption(Timer<DOMWebSocket>*);

    void releaseChannel();

    enum BinaryType {
        BinaryTypeBlob,
        BinaryTypeArrayBuffer
    };

    Member<WebSocketChannel> m_channel;

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

    bool m_closedWhileSuspended;
    typedef Vector<RefPtr<Event> > EventVector;
    EventVector m_eventsDeferredWhileSuspended;
    Timer<DOMWebSocket> m_dispatchDeferredEventsTimer;

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

} // namespace blink

#endif // DOMWebSocket_h
