/*

 *  This file is part of the KDE libraries

 *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)

 *  Copyright (C) 2001 Peter Kelly (pmk@post.com)

 *  Copyright (C) 2003 Apple Computer, Inc.

 *

 *  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_INTERPRETER_H_

#define _KJS_INTERPRETER_H_

#include "ExecState.h"

#include "protect.h"

#include "value.h"

#include "types.h"

namespace KJS {

  class ArrayObjectImp;

  class ArrayPrototype;

  class BooleanObjectImp;

  class BooleanPrototype;

  class Context;

  class DateObjectImp;

  class DatePrototype;

  class Debugger;

  class ErrorObjectImp;

  class ErrorPrototype;

  class EvalError;

  class EvalErrorPrototype;

  class FunctionObjectImp;

  class FunctionPrototype;

  class NativeErrorImp;

  class NativeErrorPrototype;

  class NumberObjectImp;

  class NumberPrototype;

  class ObjectObjectImp;

  class ObjectPrototype;

  class RangeError;

  class RangeErrorPrototype;

  class ReferenceError;

  class ReferenceError;

  class ReferenceErrorPrototype;

  class RegExpObjectImp;

  class RegExpPrototype;

  class RuntimeMethod;

  class SavedBuiltins;

  class ScopeChain;

  class StringObjectImp;

  class StringPrototype;

  class SyntaxErrorPrototype;

  class TypeError;

  class TypeErrorPrototype;

  class UriError;

  class UriErrorPrototype;

  /**

   * Interpreter objects can be used to evaluate ECMAScript code. Each

   * interpreter has a global object which is used for the purposes of code

   * evaluation, and also provides access to built-in properties such as

   * " Object" and "Number".

   */

  class Interpreter {

      friend class Collector;

  public:

    /**

     * Creates a new interpreter. The supplied object will be used as the global

     * object for all scripts executed with this interpreter. During

     * constuction, all the standard properties such as "Object" and "Number"

     * will be added to the global object.

     *

     * Note: You should not use the same global object for multiple

     * interpreters.

     *

     * This is due do the fact that the built-in properties are set in the

     * constructor, and if these objects have been modified from another

     * interpreter (e.g. a script modifying String.prototype), the changes will

     * be overridden.

     *

     * @param global The object to use as the global object for this interpreter

     */

    IMPORT Interpreter(JSObject* globalObject);

    /**

     * Creates a new interpreter. A global object will be created and

     * initialized with the standard global properties.

     */

    Interpreter();

    /**

     * Resets the global object's default properties and adds the default object 

     * prototype to its prototype chain.

     */

    void initGlobalObject();

    /**

     * Returns the object that is used as the global object during all script

     * execution performed by this interpreter

     */

    IMPORT JSObject* globalObject() const;

    /**

     * Returns the execution state object which can be used to execute

     * scripts using this interpreter at a the "global" level, i.e. one

     * with a execution context that has the global object as the "this"

     * value, and who's scope chain contains only the global object.

     *

     * Note: this pointer remains constant for the life of the interpreter

     * and should not be manually deleted.

     *

     * @return The interpreter global execution state object

     */

    IMPORT virtual ExecState *globalExec();

    /**

     * Parses the supplied ECMAScript code and checks for syntax errors.

     *

     * @param code The code to check

     * @return A normal completion if there were no syntax errors in the code, 

     * otherwise a throw completion with the syntax error as its value.

     */

    Completion checkSyntax(const UString& sourceURL, int startingLineNumber, const UString& code);

    Completion checkSyntax(const UString& sourceURL, int startingLineNumber, const UChar* code, int codeLength);

    /**

     * Evaluates the supplied ECMAScript code.

     *

     * Since this method returns a Completion, you should check the type of

     * completion to detect an error or before attempting to access the returned

     * value. For example, if an error occurs during script execution and is not

     * caught by the script, the completion type will be Throw.

     *

     * If the supplied code is invalid, a SyntaxError will be thrown.

     *

     * @param code The code to evaluate

     * @param thisV The value to pass in as the "this" value for the script

     * execution. This should either be jsNull() or an Object.

     * @return A completion object representing the result of the execution.

     */

    IMPORT Completion evaluate(const UString& sourceURL, int startingLineNumber, const UChar* code, int codeLength, JSValue* thisV = 0);

    IMPORT Completion evaluate(const UString& sourceURL, int startingLineNumber, const UString& code, JSValue* thisV = 0);

    /**

     * Returns the builtin "Object" object. This is the object that was set

     * as a property of the global object during construction; if the property

     * is replaced by script code, this method will still return the original

     * object.

     *

     * @return The builtin "Object" object

     */

    JSObject *builtinObject() const;

    /**

     * Returns the builtin "Function" object.

     */

    IMPORT JSObject *builtinFunction() const;

    /**

     * Returns the builtin "Array" object.

     */

    IMPORT JSObject *builtinArray() const;

    /**

     * Returns the builtin "Boolean" object.

     */

    JSObject *builtinBoolean() const;

    /**

     * Returns the builtin "String" object.

     */

    JSObject *builtinString() const;

    /**

     * Returns the builtin "Number" object.

     */

    JSObject *builtinNumber() const;

    /**

     * Returns the builtin "Date" object.

     */

    JSObject *builtinDate() const;

    /**

     * Returns the builtin "RegExp" object.

     */

    JSObject *builtinRegExp() const;

    /**

     * Returns the builtin "Error" object.

     */

    JSObject *builtinError() const;

    /**

     * Returns the builtin "Object.prototype" object.

     */

    IMPORT JSObject *builtinObjectPrototype() const;

    /**

     * Returns the builtin "Function.prototype" object.

     */

    IMPORT JSObject *builtinFunctionPrototype() const;

    /**

     * Returns the builtin "Array.prototype" object.

     */

    JSObject *builtinArrayPrototype() const;

    /**

     * Returns the builtin "Boolean.prototype" object.

     */

    JSObject *builtinBooleanPrototype() const;

    /**

     * Returns the builtin "String.prototype" object.

     */

    IMPORT JSObject *builtinStringPrototype() const;

    /**

     * Returns the builtin "Number.prototype" object.

     */

    JSObject *builtinNumberPrototype() const;

    /**

     * Returns the builtin "Date.prototype" object.

     */

    JSObject *builtinDatePrototype() const;

    /**

     * Returns the builtin "RegExp.prototype" object.

     */

    JSObject *builtinRegExpPrototype() const;

    /**

     * Returns the builtin "Error.prototype" object.

     */

    JSObject *builtinErrorPrototype() const;

    /**

     * The initial value of "Error" global property

     */

    JSObject *builtinEvalError() const;

    JSObject *builtinRangeError() const;

    JSObject *builtinReferenceError() const;

    JSObject *builtinSyntaxError() const;

    JSObject *builtinTypeError() const;

    JSObject *builtinURIError() const;

    JSObject *builtinEvalErrorPrototype() const;

    JSObject *builtinRangeErrorPrototype() const;

    JSObject *builtinReferenceErrorPrototype() const;

    JSObject *builtinSyntaxErrorPrototype() const;

    JSObject *builtinTypeErrorPrototype() const;

    JSObject *builtinURIErrorPrototype() const;

    enum CompatMode { NativeMode, IECompat, NetscapeCompat };

    /**

     * Call this to enable a compatibility mode with another browser.

     * (by default konqueror is in "native mode").

     * Currently, in KJS, this only changes the behavior of Date::getYear()

     * which returns the full year under IE.

     */

    void setCompatMode(CompatMode mode) { m_compatMode = mode; }

    CompatMode compatMode() const { return m_compatMode; }

    /**

     * Run the garbage collection. Returns true when at least one object

     * was collected; false otherwise.

     */

    IMPORT static bool collect();

    /**

     * Called during the mark phase of the garbage collector. Subclasses 

     * implementing custom mark methods must make sure to chain to this one.

     */

    IMPORT virtual void mark();

#ifdef KJS_DEBUG_MEM

    /**

     * @internal

     */

    static void finalCheck();

#endif

    IMPORT static bool shouldPrintExceptions();

    IMPORT static void setShouldPrintExceptions(bool);

    IMPORT void saveBuiltins (SavedBuiltins&) const;

    IMPORT void restoreBuiltins (const SavedBuiltins&);

    /**

     * Determine if the value is a global object (for any interpreter).  This may

     * be difficult to determine for multiple uses of JSC in a process that are

     * logically independent of each other.  In the case of WebCore, this method

     * is used to determine if an object is the Window object so we can perform

     * security checks.

     */

    virtual bool isGlobalObject(JSValue*) { return false; }

    /** 

     * Find the interpreter for a particular global object.  This should really

     * be a static method, but we can't do that is C++.  Again, as with isGlobalObject()

     * implementation really need to know about all instances of Interpreter

     * created in an application to correctly implement this method.  The only

     * override of this method is currently in WebCore.

     */

    virtual Interpreter* interpreterForGlobalObject(const JSValue*) { return 0; }

    /**

     * Determine if the it is 'safe' to execute code in the target interpreter from an

     * object that originated in this interpreter.  This check is used to enforce WebCore

     * cross frame security rules.  In particular, attempts to access 'bound' objects are

     * not allowed unless isSafeScript returns true.

     */

    virtual bool isSafeScript(const Interpreter*) { return true; }

    // Chained list of interpreters (ring)

    static Interpreter* firstInterpreter() { return s_hook; }

    Interpreter* nextInterpreter() const { return next; }

    Interpreter* prevInterpreter() const { return prev; }

    Debugger* debugger() const { return m_debugger; }

    void setDebugger(Debugger* d) { m_debugger = d; }

    void setContext(Context* c) { m_context = c; }

    Context* context() const { return m_context; }

    static Interpreter* interpreterWithGlobalObject(JSObject*);

    void setTimeoutTime(unsigned timeoutTime) { m_timeoutTime = timeoutTime; }

    IMPORT void startTimeoutCheck();

    IMPORT void stopTimeoutCheck();

    bool timedOut();

    void ref() { ++m_refCount; }

    void deref() { if (--m_refCount <= 0) delete this; }

    int refCount() const { return m_refCount; }

protected:

    virtual ~Interpreter(); // only deref should delete us

    virtual bool shouldInterruptScript() const { return true; }

    unsigned m_timeoutTime;

#if PLATFORM(SYMBIAN)

public:

	void incStatementCount()		{ m_statementCount ++; }

	void resetStatementCount() 	{ m_statementCount  = 0; }

	int statementCount() const 	{ return m_statementCount; }

private:

	int m_statementCount;

#endif

private:

    void init();

    void resetTimeoutCheck();

    bool checkTimeout();

    // Uncopyable

    Interpreter(const Interpreter&);

    Interpreter operator=(const Interpreter&);

    int m_refCount;

    ExecState m_globalExec;

    // Chained list of interpreters (ring) - for collector

    static Interpreter* s_hook;

    Interpreter *next, *prev;

    int m_recursion;

    Debugger* m_debugger;

    Context* m_context;

    CompatMode m_compatMode;

    unsigned m_timeAtLastCheckTimeout;

    unsigned m_timeExecuting;

    unsigned m_timeoutCheckCount;

    unsigned m_tickCount;

    unsigned m_ticksUntilNextTimeoutCheck;

    JSObject* m_globalObject;

    ObjectObjectImp* m_Object;

    FunctionObjectImp* m_Function;

    ArrayObjectImp* m_Array;

    BooleanObjectImp* m_Boolean;

    StringObjectImp* m_String;

    NumberObjectImp* m_Number;

    DateObjectImp* m_Date;

    RegExpObjectImp* m_RegExp;

    ErrorObjectImp* m_Error;

    ObjectPrototype* m_ObjectPrototype;

    FunctionPrototype* m_FunctionPrototype;

    ArrayPrototype* m_ArrayPrototype;

    BooleanPrototype* m_BooleanPrototype;

    StringPrototype* m_StringPrototype;

    NumberPrototype* m_NumberPrototype;

    DatePrototype* m_DatePrototype;

    RegExpPrototype* m_RegExpPrototype;

    ErrorPrototype* m_ErrorPrototype;

    NativeErrorImp* m_EvalError;

    NativeErrorImp* m_RangeError;

    NativeErrorImp* m_ReferenceError;

    NativeErrorImp* m_SyntaxError;

    NativeErrorImp* m_TypeError;

    NativeErrorImp* m_UriError;

    NativeErrorPrototype* m_EvalErrorPrototype;

    NativeErrorPrototype* m_RangeErrorPrototype;

    NativeErrorPrototype* m_ReferenceErrorPrototype;

    NativeErrorPrototype* m_SyntaxErrorPrototype;

    NativeErrorPrototype* m_TypeErrorPrototype;

    NativeErrorPrototype* m_UriErrorPrototype;

  };

  inline bool Interpreter::timedOut()

  {

      m_tickCount++;

      if (m_tickCount != m_ticksUntilNextTimeoutCheck)

          return false;

      return checkTimeout();

  }

} // namespace

#endif // _KJS_INTERPRETER_H_