/*

 * Copyright (C) 2009 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,

 * 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.

 */

#include "config.h"

#if ENABLE(WEB_SOCKETS)

#include "WebSocket.h"

#include "DOMWindow.h"

#include "Event.h"

#include "EventException.h"

#include "EventListener.h"

#include "EventNames.h"

#include "Logging.h"

#include "MessageEvent.h"

#include "ScriptExecutionContext.h"

#include "StringBuilder.h"

#include "ThreadableWebSocketChannel.h"

#include "WebSocketChannel.h"

#include <wtf/text/CString.h>

#include <wtf/StdLibExtras.h>

namespace WebCore {

static bool isValidProtocolString(const String& protocol)

{

    if (protocol.isNull())

        return true;

    if (protocol.isEmpty())

        return false;

    const UChar* characters = protocol.characters();

    for (size_t i = 0; i < protocol.length(); i++) {

        if (characters[i] < 0x20 || characters[i] > 0x7E)

            return false;

    }

    return true;

}

static String encodeProtocolString(const String& protocol)

{

    StringBuilder builder;

    for (size_t i = 0; i < protocol.length(); i++) {

        if (protocol[i] < 0x20 || protocol[i] > 0x7E)

            builder.append(String::format("\\u%04X", protocol[i]));

        else if (protocol[i] == 0x5c)

            builder.append("\\\\");

        else

            builder.append(protocol[i]);

    }

    return builder.toString();

}

static bool webSocketsAvailable = false;

void WebSocket::setIsAvailable(bool available)

{

    webSocketsAvailable = available;

}

bool WebSocket::isAvailable()

{

    return webSocketsAvailable;

}

WebSocket::WebSocket(ScriptExecutionContext* context)

    : ActiveDOMObject(context, this)

    , m_state(CONNECTING)

    , m_bufferedAmountAfterClose(0)

{

}

WebSocket::~WebSocket()

{

    if (m_channel)

        m_channel->disconnect();

}

void WebSocket::connect(const KURL& url, ExceptionCode& ec)

{

    connect(url, String(), ec);

}

void WebSocket::connect(const KURL& url, const String& protocol, ExceptionCode& ec)

{

    LOG(Network, "WebSocket %p connect to %s protocol=%s", this, url.string().utf8().data(), protocol.utf8().data());

    m_url = url;

    m_protocol = protocol;

    if (!m_url.isValid()) {

        scriptExecutionContext()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, "Invalid url for WebSocket " + url.string(), 0, scriptExecutionContext()->securityOrigin()->toString());

        m_state = CLOSED;

        ec = SYNTAX_ERR;

        return;

    }

    if (!m_url.protocolIs("ws") && !m_url.protocolIs("wss")) {

        scriptExecutionContext()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, "Wrong url scheme for WebSocket " + url.string(), 0, scriptExecutionContext()->securityOrigin()->toString());

        m_state = CLOSED;

        ec = SYNTAX_ERR;

        return;

    }

    if (m_url.hasFragmentIdentifier()) {

        scriptExecutionContext()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, "URL has fragment component " + url.string(), 0, scriptExecutionContext()->securityOrigin()->toString());

        m_state = CLOSED;

        ec = SYNTAX_ERR;

        return;

    }

    if (!isValidProtocolString(m_protocol)) {

        scriptExecutionContext()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, "Wrong protocol for WebSocket '" + encodeProtocolString(m_protocol) + "'", 0, scriptExecutionContext()->securityOrigin()->toString());

        m_state = CLOSED;

        ec = SYNTAX_ERR;

        return;

    }

    if (!portAllowed(url)) {

        scriptExecutionContext()->addMessage(JSMessageSource, LogMessageType, ErrorMessageLevel, String::format("WebSocket port %d blocked", url.port()), 0, scriptExecutionContext()->securityOrigin()->toString());

        m_state = CLOSED;

        ec = SECURITY_ERR;

        return;

    }

    m_channel = ThreadableWebSocketChannel::create(scriptExecutionContext(), this, m_url, m_protocol);

    m_channel->connect();

    ActiveDOMObject::setPendingActivity(this);

}

bool WebSocket::send(const String& message, ExceptionCode& ec)

{

    LOG(Network, "WebSocket %p send %s", this, message.utf8().data());

    if (m_state == CONNECTING) {

        ec = INVALID_STATE_ERR;

        return false;

    }

    // No exception is raised if the connection was once established but has subsequently been closed.

    if (m_state == CLOSED) {

        m_bufferedAmountAfterClose += message.utf8().length() + 2; // 2 for frameing

        return false;

    }

    // FIXME: check message is valid utf8.

    ASSERT(m_channel);

    return m_channel->send(message);

}

void WebSocket::close()

{

    LOG(Network, "WebSocket %p close", this);

    if (m_state == CLOSED)

        return;

    m_state = CLOSED;

    m_bufferedAmountAfterClose = m_channel->bufferedAmount();

    // didClose notification may be already queued, which we will inadvertently process while waiting for bufferedAmount() to return.

    // In this case m_channel will be set to null during didClose() call, thus we need to test validness of m_channel here.

    if (m_channel)

        m_channel->close();

}

const KURL& WebSocket::url() const

{

    return m_url;

}

WebSocket::State WebSocket::readyState() const

{

    return m_state;

}

unsigned long WebSocket::bufferedAmount() const

{

    if (m_state == OPEN)

        return m_channel->bufferedAmount();

    return m_bufferedAmountAfterClose;

}

ScriptExecutionContext* WebSocket::scriptExecutionContext() const

{

    return ActiveDOMObject::scriptExecutionContext();

}

void WebSocket::contextDestroyed()

{

    LOG(Network, "WebSocket %p scriptExecutionContext destroyed", this);

    ASSERT(!m_channel);

    ASSERT(m_state == CLOSED);

    ActiveDOMObject::contextDestroyed();

}

bool WebSocket::canSuspend() const

{

    return !m_channel;

}

void WebSocket::suspend()

{

    if (m_channel)

        m_channel->suspend();

}

void WebSocket::resume()

{

    if (m_channel)

        m_channel->resume();

}

void WebSocket::stop()

{

    bool pending = hasPendingActivity();

    if (m_channel)

        m_channel->disconnect();

    m_channel = 0;

    m_state = CLOSED;

    ActiveDOMObject::stop();

    if (pending)

        ActiveDOMObject::unsetPendingActivity(this);

}

void WebSocket::didConnect()

{

    LOG(Network, "WebSocket %p didConnect", this);

    if (m_state != CONNECTING) {

        didClose(0);

        return;

    }

    ASSERT(scriptExecutionContext());

    m_state = OPEN;

    dispatchEvent(Event::create(eventNames().openEvent, false, false));

}

void WebSocket::didReceiveMessage(const String& msg)

{

    LOG(Network, "WebSocket %p didReceiveMessage %s", this, msg.utf8().data());

    if (m_state != OPEN)

        return;

    ASSERT(scriptExecutionContext());

    RefPtr<MessageEvent> evt = MessageEvent::create();

    evt->initMessageEvent(eventNames().messageEvent, false, false, SerializedScriptValue::create(msg), "", "", 0, 0);

    dispatchEvent(evt);

}

void WebSocket::didReceiveMessageError()

{

    LOG(Network, "WebSocket %p didReceiveErrorMessage", this);

    if (m_state != OPEN)

        return;

    ASSERT(scriptExecutionContext());

    dispatchEvent(Event::create(eventNames().errorEvent, false, false));

}

void WebSocket::didClose(unsigned long unhandledBufferedAmount)

{

    LOG(Network, "WebSocket %p didClose", this);

    if (!m_channel)

        return;

    m_state = CLOSED;

    m_bufferedAmountAfterClose += unhandledBufferedAmount;

    ASSERT(scriptExecutionContext());

    dispatchEvent(Event::create(eventNames().closeEvent, false, false));

    m_channel = 0;

    if (hasPendingActivity())

        ActiveDOMObject::unsetPendingActivity(this);

}

EventTargetData* WebSocket::eventTargetData()

{

    return &m_eventTargetData;

}

EventTargetData* WebSocket::ensureEventTargetData()

{

    return &m_eventTargetData;

}

}  // namespace WebCore

#endif