// -*- c-basic-offset: 2 -*-
/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
 *  Copyright (C) 2003, 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 *  Copyright (C) 2007, 2008 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_FUNCTION_H
#define KJS_FUNCTION_H

#include "SymbolTable.h"
#include "LocalStorage.h"
#include "JSVariableObject.h"
#include "object.h"
#include <wtf/OwnPtr.h>

namespace KJS {

  class ActivationImp;
  class FunctionPrototype;

  class KJS_EXPORT InternalFunctionImp : public JSObject {
  public:
    InternalFunctionImp();
    InternalFunctionImp(FunctionPrototype*);
    InternalFunctionImp(FunctionPrototype*, const Identifier&);

    virtual bool implementsCall() const;
    virtual JSValue* callAsFunction(ExecState*, JSObject* thisObjec, const List& args) = 0;
    virtual bool implementsHasInstance() const;

    virtual const ClassInfo* classInfo() const { return &info; }
    static const ClassInfo info;
    const Identifier& functionName() const { return m_name; }
    void setFunctionName(const Identifier& name) { m_name = name; }

  private:
    Identifier m_name;
#ifdef WIN32
    InternalFunctionImp(const InternalFunctionImp&);
    InternalFunctionImp& operator=(const InternalFunctionImp&);
#endif
  };

  /**
   * A minimal object that just throws an exception if executed.
   */
  class Thrower : public JSObject {
  public:
    Thrower(ErrorType type);

    virtual JSValue *callAsFunction(ExecState* exec, JSObject*, const List& args);
    virtual bool implementsCall() const { return true; };
  private:
    ErrorType m_type;
  };

  class BoundFunction : public InternalFunctionImp {
  public:
    explicit BoundFunction(ExecState* exec, JSObject* targetFunction, JSObject* boundThis, List boundArgs);

    void setTargetFunction(JSObject* targetFunction);
    void setBoundThis(JSObject* boundThis);
    void setBoundArgs(const List& boundArgs);

    virtual JSValue *callAsFunction(ExecState* exec, JSObject* thisObj, const List& extraArgs);
    virtual bool implementsCall() const { return true; };

    using KJS::JSObject::construct;
    virtual JSObject* construct(ExecState* exec, const List& extraArgs);
    virtual bool implementsConstruct() const { return true; };

    virtual bool hasInstance(ExecState *exec, JSValue *value);
    virtual bool implementsHasInstance() const { return true; };

  private:
    ProtectedPtr<JSObject> m_targetFunction;
    ProtectedPtr<JSObject> m_boundThis;
    List m_boundArgs;
  };

  /**
   * @internal
   *
   * The initial value of Function.prototype (and thus all objects created
   * with the Function constructor)
   */
  class FunctionPrototype : public InternalFunctionImp {
  public:
    FunctionPrototype(ExecState *exec);
    virtual ~FunctionPrototype();

    virtual JSValue *callAsFunction(ExecState *exec, JSObject *thisObj, const List &args);
  };

  class IndexToNameMap {
  public:
    IndexToNameMap(FunctionImp *func, const List &args);
    ~IndexToNameMap();

    Identifier& operator[](int index);
    Identifier& operator[](const Identifier &indexIdentifier);
    bool isMapped(const Identifier &index) const;
    void unMap(const Identifier &index);
    int size() const;

  private:
    IndexToNameMap(); // prevent construction w/o parameters
    int _size;
    Identifier * _map;
  };

  class Arguments : public JSObject {
  public:
    Arguments(ExecState *exec, FunctionImp *func, const List &args, ActivationImp *act);
    virtual void mark();
    using KJS::JSObject::getOwnPropertySlot;
    virtual bool getOwnPropertySlot(ExecState *, const Identifier &, PropertySlot&);
    using KJS::JSObject::put;
    virtual void put(ExecState *exec, const Identifier &propertyName, JSValue *value, int attr = None);
    using KJS::JSObject::deleteProperty;
    virtual bool deleteProperty(ExecState *exec, const Identifier &propertyName);
    virtual void getOwnPropertyNames(ExecState*, PropertyNameArray&, PropertyMap::PropertyMode mode);

    virtual bool defineOwnProperty(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& desc, bool shouldThrow);

    virtual const ClassInfo *classInfo() const { return &info; }
    static const ClassInfo info;
  private:
    static JSValue *mappedIndexGetter(ExecState *exec, JSObject *, const Identifier &, const PropertySlot& slot);

    ActivationImp *_activationObject;
    mutable IndexToNameMap indexToNameMap;
  };

  class ActivationImp : public JSVariableObject {
  public:
    enum {
      FunctionSlot        = NumVarObjectSlots,
      ArgumentsObjectSlot,
      NumReservedSlots = ArgumentsObjectSlot + 1
    };

    void setup(ExecState* exec, FunctionImp *function, const List* arguments,
               LocalStorageEntry* stackSpace);

    // Request that this activation be torn off when the code using it stops running
    void requestTearOff();
    void performTearOff();

    using KJS::JSObject::getOwnPropertySlot;
    virtual bool getOwnPropertySlot(ExecState *exec, const Identifier &, PropertySlot&);
    using KJS::JSObject::put;
    virtual void put(ExecState *exec, const Identifier &propertyName, JSValue *value, int attr = None);
    using KJS::JSObject::deleteProperty;
    virtual bool deleteProperty(ExecState *exec, const Identifier &propertyName);

    virtual void putDirect(const Identifier &propertyName, JSValue *value, int attr = 0);
    using JSObject::putDirect;
    virtual JSValue *getDirect(const Identifier& propertyName) const;
    virtual bool getPropertyAttributes(const Identifier& propertyName, unsigned& attributes) const;

    bool isLocalReadOnly(int propertyID) const {
      return (localStorage[propertyID].attributes & ReadOnly) == ReadOnly;
    }

    virtual const ClassInfo *classInfo() const { return &info; }
    static const ClassInfo info;

    virtual bool isActivation() const { return true; }
    void setupLocals(FunctionBodyNode* fbody);
    void setupFunctionLocals(FunctionBodyNode* fbody, ExecState *exec);

    const List& passedInArguments() const { return *arguments; }

    // really FunctionImp, but type isn't declared yet
    JSValue* function() { return functionSlot(); }
  private:
    JSValue*& functionSlot() {
          return localStorage[FunctionSlot].val.valueVal;
    }

    JSValue*& argumentsObjectSlot() {
          return localStorage[ArgumentsObjectSlot].val.valueVal;
    }

    static PropertySlot::GetValueFunc getArgumentsGetter();
    static JSValue *argumentsGetter(ExecState *exec, JSObject *, const Identifier &, const PropertySlot& slot);
    void createArgumentsObject(ExecState *exec);

    int  numLocals() const        { return lengthSlot(); }
    bool validLocal(int id) const { return 0 <= id && id < numLocals(); }
    const List* arguments;
  };

  class GlobalFuncImp : public InternalFunctionImp {
  public:
    GlobalFuncImp(ExecState*, FunctionPrototype*, int i, int len, const Identifier&);
    virtual JSValue *callAsFunction(ExecState *exec, JSObject *thisObj, const List &args);
    enum { Eval, ParseInt, ParseFloat, IsNaN, IsFinite, Escape, UnEscape,
           DecodeURI, DecodeURIComponent, EncodeURI, EncodeURIComponent
#ifndef NDEBUG
           , KJSPrint
#endif
};
  private:
    int id;
  };

  static const double mantissaOverflowLowerBound = 9007199254740992.0;
  double parseIntOverflow(const char* s, int length, int radix);

  double parseInt(const UString &s, int radix);
  double parseFloat(const UString &s);

} // namespace

#endif
