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 /* This file is part of the KDE project
    Copyright (C) 2010 Maksim Orlovich <maksim@kde.org>
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #ifndef KJS_SCRIPTABLE_H
 #define KJS_SCRIPTABLE_H
 
 #include <khtml_part.h>
 #include <kparts/scriptableextension.h>
 #include <kjs/object.h>
 #include <kjs/list.h>
 #include <QHash>
 
 using namespace KParts;
 
 namespace KJS
 {
 
 // First, a couple of helpers: these let clients perform basic getOwnPropertySlot or
 // put (with a bool effect return) on the root of given extension.
 bool pluginRootGet(ExecState *exec, ScriptableExtension *ext, const KJS::Identifier &i, PropertySlot &slot);
 bool pluginRootPut(ExecState *exec, ScriptableExtension *ext, const KJS::Identifier &i, JSValue *v);
 
 class WrapScriptableObject;
 
 // We have two ScriptableExtension subclasses.
 // ScriptableOperations is a singleton used to perform operations on objects.
 // This is because objects in child  parts (and other windows) can survive their
 // parent, and we still need to perform operations on them.
 class ScriptableOperations: public ScriptableExtension
 {
     Q_OBJECT
 public:
     // ScriptableExtension API
     QVariant callAsFunction(ScriptableExtension *callerPrincipal, quint64 objId, const ArgList &args) override;
     virtual QVariant callFunctionReference(ScriptableExtension *callerPrincipal, quint64 objId,
                                            const QString &f, const ArgList &args) override;
     QVariant callAsConstructor(ScriptableExtension *callerPrincipal, quint64 objId, const ArgList &args) override;
     bool hasProperty(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
     QVariant get(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
     bool put(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName, const QVariant &value) override;
     bool removeProperty(ScriptableExtension *callerPrincipal, quint64 objId, const QString &propName) override;
     bool enumerateProperties(ScriptableExtension *callerPrincipal, quint64 objId, QStringList *result) override;
 
     void acquire(quint64 objid) override;
     void release(quint64 objid) override;
 
     // May return null.
     static JSObject *objectForId(quint64 objId);
 
     static ScriptableOperations *self();
 
     void mark();
 public:
     // We keep a weak table of our wrappers for external objects, so that
     // the same object gets the same wrapper all the time.
     static QHash<Object,      WrapScriptableObject *> *importedObjects();
     static QHash<FunctionRef, WrapScriptableObject *> *importedFunctions();
 
     // For exported objects, we keep refcounts, and mark them
     static QHash<JSObject *, int> *exportedObjects();
 
     static JSValue *importValue(ExecState *exec, const QVariant &v, bool alreadyRefd);
     static JSValue *importFunctionRef(ExecState *exec, const QVariant &v, bool alreadyRefd);
     static JSObject *importObject(ExecState *exec, const QVariant &v, bool alreadyRefd);
     static List importArgs(ExecState *exec, const ArgList &args);
 
     static QVariant exportValue(JSValue *v, bool preRef);
     static QVariant exportObject(JSObject *o, bool preRef);
     static QVariant exportFuncRef(JSObject *base, const QString &field, bool preRef);
 
     // Both methods may return 0. Used for security checks!
     static KHTMLPart *partForPrincipal(ScriptableExtension *callerPrincipal);
     static ExecState *execStateForPrincipal(ScriptableExtension *callerPrincipal);
 private:
     // input should not be a WrapScriptableObject.
     static ScriptableExtension::Object exportNativeObject(JSObject *o, bool preRef);
 
     // Checks exception state before handling conversion
     QVariant handleReturn(ExecState *exec, JSValue *v);
 
     // If the given object is owned by a KHTMLScriptable, return the
     // JS object for it. If not, return 0.
     static JSObject *tryGetNativeObject(const Object &sObj);
 
     static QHash<JSObject *, int> *s_exportedObjects;
     static QHash<Object,      WrapScriptableObject *> *s_importedObjects;
     static QHash<FunctionRef, WrapScriptableObject *> *s_importedFunctions;
 
     ScriptableOperations();
     ~ScriptableOperations();
 
     // copy ctor, etc., disabled already, being a QObject
     static ScriptableOperations *s_instance;
 };
 
 // KHTMLPartScriptable, on other hands, is tied to a part, and
 // is used for part-specific operations such as looking up
 // root objects and script execution.
 class KHTMLPartScriptable: public ScriptableExtension
 {
     Q_OBJECT
     friend class ScriptableOperations;
 public:
     KHTMLPartScriptable(KHTMLPart *part);
 
     QVariant rootObject() override;
     QVariant encloserForKid(KParts::ScriptableExtension *kid) override;
 
     bool setException(ScriptableExtension *callerPrincipal, const QString &message) override;
 
     virtual QVariant evaluateScript(ScriptableExtension *callerPrincipal,
                                     quint64 contextObjectId,
                                     const QString &code,
                                     ScriptLanguage language = ECMAScript) override;
     bool isScriptLanguageSupported(ScriptLanguage lang) const override;
 
     // For paranoia: forward to ScriptOperations
     void acquire(quint64 objid) override;
     void release(quint64 objid) override;
 private:
     KJS::Interpreter *interpreter();
     KHTMLPart *m_part;
 };
 
 // This represents an object we imported from a foreign ScriptableExtension
 class WrapScriptableObject: public JSObject
 {
 public:
     friend class ScriptableOperations;
 
     enum Type {
         Object,
         FunctionRef
     };
 
     WrapScriptableObject(ExecState *exec, Type t,
                          ScriptableExtension *owner, quint64 objId,
                          const QString &field = QString());
 
     ~WrapScriptableObject();
 
     const ClassInfo *classInfo() const override
     {
         return &info;
     }
     static const ClassInfo info;
 
     bool getOwnPropertySlot(ExecState *, const Identifier &, PropertySlot &) override;
     using JSObject::getOwnPropertySlot;
     void put(ExecState *exec, const Identifier &propertyName, JSValue *value, int) override;
     using JSObject::put;
     bool deleteProperty(ExecState *exec, const Identifier &i) override;
     using JSObject::deleteProperty;
 
     bool isFunctionType() const override
     {
         return false;
     }
     bool implementsCall() const override
     {
         return true;
     }
     JSValue *callAsFunction(ExecState *exec, JSObject *thisObj, const List &args) override;
 
     // We claim true, since may be calleable
     bool implementsConstruct() const override
     {
         return true;
     }
     JSObject *construct(ExecState *exec, const List &args) override;
     using JSObject::construct;
 
     void getOwnPropertyNames(ExecState *, PropertyNameArray &, PropertyMap::PropertyMode mode) override;
 
     UString toString(ExecState *exec) const override;
 
     // This method is used to note that the object has been ref'd on our
     // behalf by an external producer.
     void reportRef();
 private:
     // If we're a function reference type, before we perform non-call operations we need
     // to actually lookup the field. This takes care of that.
     ScriptableExtension::Object resolveAnyReferences(ExecState *exec, bool *ok);
 
     // resolves all function references to get an ref, if any.
     ScriptableExtension::Object resolveReferences(ExecState *exec,
             const ScriptableExtension::FunctionRef &f,
             bool *ok);
 
     // gets a field of the given object id, base
     QVariant doGet(ExecState *exec, const ScriptableExtension::Object &o,
                    const QString &field, bool *ok);
 
     ScriptableExtension::ArgList exportArgs(const List &l);
     void releaseArgs(ScriptableExtension::ArgList &a);
 
     // Looks up the principal we're running as
     ScriptableExtension *principal(ExecState *exec);
 
     // what we wrap
     QWeakPointer<ScriptableExtension> objExtension;
     quint64 objId;
     QString field;
     Type    type;
     int     refsByUs; // how many references we hold
 
     // this is an unguarded copy of objExtension. We need it in order to
     // clean ourselves up from the imports tables properly even if the peer
     // was destroyed.
     ScriptableExtension *tableKey;
 };
 
 }
 
 #endif