/*
 * 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.
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 * 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
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ScriptController_h
#define ScriptController_h

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

#include "V8Proxy.h"

#include <v8.h>

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

namespace WebCore {
    class DOMWrapperWorld;
    class Event;
    class Frame;
    class HTMLPlugInElement;
    class ScriptSourceCode;
    class ScriptState;
    class String;
    class Widget;
    class XSSAuditor;

    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&, bool userGesture = false, bool replaceDocument = true);

        // 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);

        // Executes JavaScript in a new context associated with the web frame. The
        // script gets its own global scope and its own prototypes for intrinsic
        // JavaScript objects (String, Array, and so-on). It shares the wrappers for
        // all DOM nodes and DOM constructors.
        void evaluateInNewContext(const Vector<ScriptSourceCode>&, int extensionGroup);

        // 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; }

        XSSAuditor* xssAuditor() { return m_XSSAuditor.get(); }

        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;

        bool isEnabled() const;

        // 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);

        // Protect and unprotect the JS wrapper from garbage collected.
        static void gcProtectJSWrapper(void*);
        static void gcUnprotectJSWrapper(void*);

        void finishedWithEvent(Event*);
        void setEventHandlerLineNumber(int lineNumber);

        void setProcessingTimerCallback(bool processingTimerCallback) { m_processingTimerCallback = processingTimerCallback; }
        bool processingUserGesture() const;

        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();
        void updateDocument();

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

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

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

        // Script state for the main world context.
        ScriptState* mainWorldScriptState();

    private:
        Frame* m_frame;
        const String* m_sourceURL;

        bool m_inExecuteScript;

        bool m_processingTimerCallback;
        bool m_paused;

        OwnPtr<V8Proxy> m_proxy;
        typedef HashMap<Widget*, NPObject*> PluginObjectMap;

        // 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)
        NPObject* m_windowScriptNPObject;
#endif
        // The XSSAuditor associated with this ScriptController.
        OwnPtr<XSSAuditor> m_XSSAuditor;

        // Script state for the main world context.
        OwnPtr<ScriptState> m_mainWorldScriptState;
    };

} // namespace WebCore

#endif // ScriptController_h