/*

 * Copyright (C) 2010 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"

#include "DebuggerAgentManager.h"

#include "DebuggerAgentImpl.h"

#include "Frame.h"

#include "PageGroupLoadDeferrer.h"

#include "ScriptDebugServer.h"

#include "V8Proxy.h"

#include "WebDevToolsAgentImpl.h"

#include "WebFrameImpl.h"

#include "WebViewImpl.h"

#include <wtf/HashSet.h>

#include <wtf/Noncopyable.h>

namespace WebKit {

WebDevToolsAgent::MessageLoopDispatchHandler DebuggerAgentManager::s_messageLoopDispatchHandler = 0;

bool DebuggerAgentManager::s_inHostDispatchHandler = false;

DebuggerAgentManager::DeferrersMap DebuggerAgentManager::s_pageDeferrers;

bool DebuggerAgentManager::s_inUtilityContext = false;

bool DebuggerAgentManager::s_debugBreakDelayed = false;

bool DebuggerAgentManager::s_exposeV8DebuggerProtocol = false;

namespace {

class CallerIdWrapper : public v8::Debug::ClientData, public Noncopyable {

public:

    CallerIdWrapper() : m_callerIsMananager(true), m_callerId(0) { }

    explicit CallerIdWrapper(int callerId)

        : m_callerIsMananager(false)

        , m_callerId(callerId) { }

    ~CallerIdWrapper() { }

    bool callerIsMananager() const { return m_callerIsMananager; }

    int callerId() const { return m_callerId; }

private:

    bool m_callerIsMananager;

    int m_callerId;

};

} // namespace

void DebuggerAgentManager::debugHostDispatchHandler()

{

    if (!s_messageLoopDispatchHandler || !s_attachedAgentsMap)

        return;

    if (s_inHostDispatchHandler)

        return;

    s_inHostDispatchHandler = true;

    Vector<WebViewImpl*> views;

    // 1. Disable active objects and input events.

    for (AttachedAgentsMap::iterator it = s_attachedAgentsMap->begin(); it != s_attachedAgentsMap->end(); ++it) {

        DebuggerAgentImpl* agent = it->second;

        s_pageDeferrers.set(agent->webView(), new WebCore::PageGroupLoadDeferrer(agent->page(), true));

        views.append(agent->webView());

        agent->webView()->setIgnoreInputEvents(true);

    }

    // 2. Process messages.

    s_messageLoopDispatchHandler();

    // 3. Bring things back.

    for (Vector<WebViewImpl*>::iterator it = views.begin(); it != views.end(); ++it) {

        if (s_pageDeferrers.contains(*it)) {

            // The view was not closed during the dispatch.

            (*it)->setIgnoreInputEvents(false);

        }

    }

    deleteAllValues(s_pageDeferrers);

    s_pageDeferrers.clear();

    s_inHostDispatchHandler = false;

    if (!s_attachedAgentsMap) {

        // Remove handlers if all agents were detached within host dispatch.

        v8::Debug::SetMessageHandler(0);

        v8::Debug::SetHostDispatchHandler(0);

    }

}

DebuggerAgentManager::AttachedAgentsMap* DebuggerAgentManager::s_attachedAgentsMap = 0;

void DebuggerAgentManager::debugAttach(DebuggerAgentImpl* debuggerAgent)

{

    if (!s_exposeV8DebuggerProtocol)

        return;

    if (!s_attachedAgentsMap) {

        s_attachedAgentsMap = new AttachedAgentsMap();

        v8::Debug::SetMessageHandler2(&DebuggerAgentManager::onV8DebugMessage);

        v8::Debug::SetHostDispatchHandler(&DebuggerAgentManager::debugHostDispatchHandler, 100 /* ms */);

    }

    int hostId = debuggerAgent->webdevtoolsAgent()->hostId();

    ASSERT(hostId);

    s_attachedAgentsMap->set(hostId, debuggerAgent);

}

void DebuggerAgentManager::debugDetach(DebuggerAgentImpl* debuggerAgent)

{

    if (!s_exposeV8DebuggerProtocol)

        return;

    if (!s_attachedAgentsMap) {

        ASSERT_NOT_REACHED();

        return;

    }

    int hostId = debuggerAgent->webdevtoolsAgent()->hostId();

    ASSERT(s_attachedAgentsMap->get(hostId) == debuggerAgent);

    bool isOnBreakpoint = (findAgentForCurrentV8Context() == debuggerAgent);

    s_attachedAgentsMap->remove(hostId);

    if (s_attachedAgentsMap->isEmpty()) {

        delete s_attachedAgentsMap;

        s_attachedAgentsMap = 0;

        // Note that we do not empty handlers while in dispatch - we schedule

        // continue and do removal once we are out of the dispatch. Also there is

        // no need to send continue command in this case since removing message

        // handler will cause debugger unload and all breakpoints will be cleared.

        if (!s_inHostDispatchHandler) {

            v8::Debug::SetMessageHandler2(0);

            v8::Debug::SetHostDispatchHandler(0);

        }

    } else {

      // Remove all breakpoints set by the agent.

      String clearBreakpointGroupCmd = String::format(

          "{\"seq\":1,\"type\":\"request\",\"command\":\"clearbreakpointgroup\","

              "\"arguments\":{\"groupId\":%d}}",

          hostId);

      sendCommandToV8(clearBreakpointGroupCmd, new CallerIdWrapper());

      if (isOnBreakpoint) {

          // Force continue if detach happened in nessted message loop while

          // debugger was paused on a breakpoint(as long as there are other

          // attached agents v8 will wait for explicit'continue' message).

          sendContinueCommandToV8();

      }

    }

}

void DebuggerAgentManager::onV8DebugMessage(const v8::Debug::Message& message)

{

    v8::HandleScope scope;

    v8::String::Value value(message.GetJSON());

    String out(reinterpret_cast<const UChar*>(*value), value.length());

    // If callerData is not 0 the message is a response to a debugger command.

    if (v8::Debug::ClientData* callerData = message.GetClientData()) {

        CallerIdWrapper* wrapper = static_cast<CallerIdWrapper*>(callerData);

        if (wrapper->callerIsMananager()) {

            // Just ignore messages sent by this manager.

            return;

        }

        DebuggerAgentImpl* debuggerAgent = debuggerAgentForHostId(wrapper->callerId());

        if (debuggerAgent)

            debuggerAgent->debuggerOutput(out);

        else if (!message.WillStartRunning()) {

            // Autocontinue execution if there is no handler.

            sendContinueCommandToV8();

        }

        return;

    } // Otherwise it's an event message.

    ASSERT(message.IsEvent());

    // Ignore unsupported event types.

    if (message.GetEvent() != v8::AfterCompile && message.GetEvent() != v8::Break && message.GetEvent() != v8::Exception)

        return;

    v8::Handle<v8::Context> context = message.GetEventContext();

    // If the context is from one of the inpected tabs it should have its context

    // data.

    if (context.IsEmpty()) {

        // Unknown context, skip the event.

        return;

    }

    if (s_inUtilityContext && message.GetEvent() == v8::Break) {

        // This may happen when two tabs are being debugged in the same process.

        // Suppose that first debugger is pauesed on an exception. It will run

        // nested MessageLoop which may process Break request from the second

        // debugger.

        s_debugBreakDelayed = true;

    } else {

        // If the context is from one of the inpected tabs or injected extension

        // scripts it must have hostId in the data field.

        int hostId = WebCore::V8Proxy::contextDebugId(context);

        if (hostId != -1) {

            DebuggerAgentImpl* agent = debuggerAgentForHostId(hostId);

            if (agent) {

                if (agent->autoContinueOnException()

                    && message.GetEvent() == v8::Exception) {

                    sendContinueCommandToV8();

                    return;

                }

                agent->debuggerOutput(out);

                return;

            }

        }

    }

    if (!message.WillStartRunning()) {

        // Autocontinue execution on break and exception  events if there is no

        // handler.

        sendContinueCommandToV8();

    }

}

void DebuggerAgentManager::pauseScript()

{

    if (s_inUtilityContext)

        s_debugBreakDelayed = true;

    else

        v8::Debug::DebugBreak();

}

void DebuggerAgentManager::executeDebuggerCommand(const String& command, int callerId)

{

    sendCommandToV8(command, new CallerIdWrapper(callerId));

}

void DebuggerAgentManager::setMessageLoopDispatchHandler(WebDevToolsAgent::MessageLoopDispatchHandler handler)

{

    s_messageLoopDispatchHandler = handler;

}

void DebuggerAgentManager::setExposeV8DebuggerProtocol(bool value)

{

    s_exposeV8DebuggerProtocol = value;

    WebCore::ScriptDebugServer::shared().setEnabled(!s_exposeV8DebuggerProtocol);

}

void DebuggerAgentManager::setHostId(WebFrameImpl* webframe, int hostId)

{

    ASSERT(hostId > 0);

    WebCore::V8Proxy* proxy = WebCore::V8Proxy::retrieve(webframe->frame());

    if (proxy)

        proxy->setContextDebugId(hostId);

}

void DebuggerAgentManager::onWebViewClosed(WebViewImpl* webview)

{

    if (s_pageDeferrers.contains(webview)) {

        delete s_pageDeferrers.get(webview);

        s_pageDeferrers.remove(webview);

    }

}

void DebuggerAgentManager::onNavigate()

{

    if (s_inHostDispatchHandler)

        DebuggerAgentManager::sendContinueCommandToV8();

}

void DebuggerAgentManager::sendCommandToV8(const String& cmd, v8::Debug::ClientData* data)

{

    v8::Debug::SendCommand(reinterpret_cast<const uint16_t*>(cmd.characters()), cmd.length(), data);

}

void DebuggerAgentManager::sendContinueCommandToV8()

{

    String continueCmd("{\"seq\":1,\"type\":\"request\",\"command\":\"continue\"}");

    sendCommandToV8(continueCmd, new CallerIdWrapper());

}

DebuggerAgentImpl* DebuggerAgentManager::findAgentForCurrentV8Context()

{

    if (!s_attachedAgentsMap)

        return 0;

    ASSERT(!s_attachedAgentsMap->isEmpty());

    WebCore::Frame* frame = WebCore::V8Proxy::retrieveFrameForEnteredContext();

    if (!frame)

        return 0;

    WebCore::Page* page = frame->page();

    for (AttachedAgentsMap::iterator it = s_attachedAgentsMap->begin(); it != s_attachedAgentsMap->end(); ++it) {

        if (it->second->page() == page)

            return it->second;

    }

    return 0;

}

DebuggerAgentImpl* DebuggerAgentManager::debuggerAgentForHostId(int hostId)

{

    if (!s_attachedAgentsMap)

        return 0;

    return s_attachedAgentsMap->get(hostId);

}

} // namespace WebKit