/*
 * Copyright (C) 2008, 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. 
 */

#ifndef ScriptController_h
#define ScriptController_h

#include "ScriptControllerBase.h"
#include "ScriptInstance.h"
#include "ScriptValue.h"

#include "V8Proxy.h"

#include <v8.h>

#include <wtf/Forward.h>
#include <wtf/HashMap.h>
#include <wtf/RefCounted.h>
#include <wtf/Vector.h>

#if PLATFORM(QT)
#include <qglobal.h>
QT_BEGIN_NAMESPACE
class QScriptEngine;
QT_END_NAMESPACE
#endif

struct NPObject;

namespace WebCore {

class DOMWrapperWorld;
class Event;
class Frame;
class HTMLPlugInElement;
class ScriptSourceCode;
class Widget;

class ScriptController {
public:
    ScriptController(Frame*);
    ~ScriptController();

    // FIXME: V8Proxy should either be folded into ScriptController
    // or this accessor should be made JSProxy*
    V8Proxy* proxy() { return m_proxy.get(); }

    ScriptValue executeScript(const ScriptSourceCode&);
    ScriptValue executeScript(const String& script, bool forceUserGesture = false);

    // Returns true if argument is a JavaScript URL. 
    bool executeIfJavaScriptURL(const KURL&, ShouldReplaceDocumentIfJavaScriptURL shouldReplaceDocumentIfJavaScriptURL = ReplaceDocumentIfJavaScriptURL);

    // This function must be called from the main thread.  It is safe to call it repeatedly. 
    static void initializeThreading();

    // Evaluate a script file in the environment of this proxy. 
    // If succeeded, 'succ' is set to true and result is returned
    // as a string. 
    ScriptValue evaluate(const ScriptSourceCode&);

    void evaluateInIsolatedWorld(unsigned worldID, const Vector<ScriptSourceCode>&);

    // Executes JavaScript in an isolated world.  The script gets its own global scope,
    // its own prototypes for intrinsic JavaScript objects (String, Array, and so-on),
    // and its own wrappers for all DOM nodes and DOM constructors. 
    //
    // If an isolated world with the specified ID already exists, it is reused. 
    // Otherwise, a new world is created. 
    //
    // If the worldID is 0, a new world is always created. 
    //
    // FIXME: Get rid of extensionGroup here. 
    void evaluateInIsolatedWorld(unsigned worldID, const Vector<ScriptSourceCode>&, int extensionGroup);

    // Associates an isolated world (see above for description) with a security
    // origin.  XMLHttpRequest instances used in that world will be considered
    // to come from that origin, not the frame's. 
    void setIsolatedWorldSecurityOrigin(int worldID, PassRefPtr<SecurityOrigin>);

    // Masquerade 'this' as the windowShell. 
    // This is a bit of a hack, but provides reasonable compatibility
    // with what JSC does as well. 
    ScriptController* windowShell(DOMWrapperWorld*) { return this; }
    ScriptController* existingWindowShell(DOMWrapperWorld*) { return this; }

    void collectGarbage();

    // Notify V8 that the system is running low on memory. 
    void lowMemoryNotification();

    // Creates a property of the global object of a frame. 
    void bindToWindowObject(Frame*, const String& key, NPObject*);

    PassScriptInstance createScriptInstanceForWidget(Widget*);

    // Check if the javascript engine has been initialized. 
    bool haveInterpreter() const;

    void disableEval();

    static bool canAccessFromCurrentOrigin(Frame*);

#if ENABLE(INSPECTOR)
    static void setCaptureCallStackForUncaughtExceptions(bool);
#endif

    bool canExecuteScripts(ReasonForCallingCanExecuteScripts);

    // FIXME: void* is a compile hack. 
    void attachDebugger(void*);

    // --- Static methods assume we are running VM in single thread, ---
    // --- and there is only one VM instance.                         ---

    // Returns the frame for the entered context.  See comments in
    // V8Proxy::retrieveFrameForEnteredContext() for more information. 
    static Frame* retrieveFrameForEnteredContext();

    // Returns the frame for the current context.  See comments in
    // V8Proxy::retrieveFrameForEnteredContext() for more information. 
    static Frame* retrieveFrameForCurrentContext();

    // Check whether it is safe to access a frame in another domain. 
    static bool isSafeScript(Frame*);

    // Pass command-line flags to the JS engine. 
    static void setFlags(const char* string, int length);

    void finishedWithEvent(Event*);

    TextPosition eventHandlerPosition() const;

    static bool processingUserGesture();

    void setPaused(bool paused) { m_paused = paused; }
    bool isPaused() const { return m_paused; }

    const String* sourceURL() const { return m_sourceURL; } // 0 if we are not evaluating any script. 

    void clearWindowShell(bool = false);
    void updateDocument();

    void namedItemAdded(HTMLDocument*, const AtomicString&);
    void namedItemRemoved(HTMLDocument*, const AtomicString&);

    void updateSecurityOrigin();
    void clearScriptObjects();
    void updatePlatformScriptObjects();
    void cleanupScriptObjectsForPlugin(Widget*);

#if ENABLE(NETSCAPE_PLUGIN_API)
    NPObject* createScriptObjectForPluginElement(HTMLPlugInElement*);
    NPObject* windowScriptNPObject();
#endif

#if PLATFORM(QT)
    QScriptEngine* qtScriptEngine();
#endif

    // Dummy method to avoid a bunch of ifdef's in WebCore. 
    void evaluateInWorld(const ScriptSourceCode&, DOMWrapperWorld*);
    static void getAllWorlds(Vector<DOMWrapperWorld*>& worlds);

private:
    Frame* m_frame;
    const String* m_sourceURL;

    bool m_inExecuteScript;

    bool m_paused;

    OwnPtr<V8Proxy> m_proxy;
    typedef HashMap<Widget*, NPObject*> PluginObjectMap;
#if PLATFORM(QT)
    OwnPtr<QScriptEngine> m_qtScriptEngine;
#endif

    // A mapping between Widgets and their corresponding script object. 
    // This list is used so that when the plugin dies, we can immediately
    // invalidate all sub-objects which are associated with that plugin. 
    // The frame keeps a NPObject reference for each item on the list. 
    PluginObjectMap m_pluginObjects;
#if ENABLE(NETSCAPE_PLUGIN_API)
    // The window script object can get destroyed while there are outstanding
    // references to it.  Please refer to ScriptController::clearScriptObjects
    // for more information as to why this is necessary.  To avoid crashes due
    // to calls on the destroyed window object, we return a proxy NPObject
    // which wraps the underlying window object.  The wrapped window object
    // pointer in this object is cleared out when the window object is
    // destroyed. 
    NPObject* m_wrappedWindowScriptNPObject;
#endif
};

} // namespace WebCore

#endif // ScriptController_h
