// Created on: 1995-02-23
// Created by: Remi LEQUETTE
// Copyright (c) 1995-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#include <Draw.hxx>
#include <Draw_Appli.hxx>
#include <Draw_Axis2D.hxx>
#include <Draw_Axis3D.hxx>
#include <Draw_Display.hxx>
#include <Draw_Drawable3D.hxx>
#include <Draw_Grid.hxx>
#include <Draw_Number.hxx>
#include <Draw_ProgressIndicator.hxx>
#include <Draw_SequenceOfDrawable3D.hxx>
#include <Message.hxx>
#include <NCollection_Array1.hxx>
#include <NCollection_Map.hxx>
#include <Standard_SStream.hxx>
#include <Standard_Stream.hxx>
#include <Standard_NotImplemented.hxx>
#include <TCollection_AsciiString.hxx>

#include <ios>
#ifdef _WIN32
extern Draw_Viewer dout;
#endif

#include <tcl.h>
#include <errno.h>

#include <OSD_Environment.hxx>
#include <OSD_OpenFile.hxx>

Standard_Boolean Draw_ParseFailed = Standard_True;

static Standard_Boolean autodisp = Standard_True;
static Standard_Boolean repaint2d = Standard_False, repaint3d = Standard_False;

//! Returns dictionary of variables
//! Variables are stored in a map Integer, Transient.
//! The Integer Value is the content of the Tcl variable.
static NCollection_Map<Handle(Draw_Drawable3D)>& Draw_changeDrawables()
{
  static NCollection_Map<Handle(Draw_Drawable3D)> theVariables;
  return theVariables;
}

//=======================================================================
//function : FindVariable
//purpose  : 
//=======================================================================

static Standard_Integer p_id = 0;
static Standard_Integer p_X = 0;
static Standard_Integer p_Y = 0;
static Standard_Integer p_b = 0;
static const char* p_Name = "";

//=======================================================================
// save
//=======================================================================
static Standard_Integer save (Draw_Interpretor& theDI,
                              Standard_Integer theNbArgs,
                              const char** theArgVec)
{
  if (theNbArgs != 3)
  {
    theDI << "Syntax error: wrong number of arguments!\n";
    theDI.PrintHelp (theArgVec[0]);
    return 1;
  }

  Handle(Draw_Drawable3D) aDrawable = Draw::Get (theArgVec[1]);
  if (aDrawable.IsNull())
  {
    theDI << "Syntax error: '" << theArgVec[1] << "' is not a drawable";
    return 1;
  }

  const char* aName = theArgVec[2];
  std::ofstream aStream;
  aStream.precision (15);
  OSD_OpenStream (aStream, aName, std::ios::out);
  if (!aStream.is_open() || !aStream.good())
  {
    theDI << "Error: cannot open file for writing " << aName;
    return 1;
  }

  try
  {
    Handle(Draw_ProgressIndicator) aProgress = new Draw_ProgressIndicator (theDI, 1);
    Standard_CString aToolTypeName = aDrawable->DynamicType()->Name();
    aStream << aToolTypeName << "\n";
    Draw::SetProgressBar (aProgress);
    aDrawable->Save (aStream);
  }
  catch (const Standard_NotImplemented& )
  {
    theDI << "Error: no method for saving " << theArgVec[1];
    return 1;
  }
  aStream << "\n";
  aStream << "0\n\n";
  Draw::SetProgressBar (Handle(Draw_ProgressIndicator)());

  errno = 0;
  const Standard_Boolean aRes = aStream.good() && !errno;
  if (!aRes)
  {
    theDI << "Error: file has not been written";
    return 1;
  }

  theDI << theArgVec[1];
  return 0;
}

//=======================================================================
// read
//=======================================================================
static Standard_Integer restore (Draw_Interpretor& theDI,
                                 Standard_Integer theNbArgs,
                                 const char** theArgVec)
{
  if (theNbArgs != 3)
  {
    return 1;
  }

  const char* aFileName = theArgVec[1];
  const char* aVarName  = theArgVec[2];
  
  std::filebuf aFileBuf;
  std::istream aStream (&aFileBuf);
  OSD_OpenStream (aFileBuf, aFileName, std::ios::in);
  if (!aFileBuf.is_open())
  {
    theDI << "Error: cannot open file for reading: '" << aFileName << "'";
    return 1;
  }

  char aType[255] = {};
  aStream >> aType;
  if (aStream.fail())
  {
    theDI << "Error: cannot read file: '" << aFileName << "'";
    return 1;
  }

  {
    Handle(Draw_ProgressIndicator) aProgress = new Draw_ProgressIndicator (theDI, 1);
    Draw::SetProgressBar (aProgress);
    Handle(Draw_Drawable3D) aDrawable = Draw_Drawable3D::Restore (aType, aStream);
    if (aDrawable.IsNull())
    {
      // assume that this file stores a DBRep_DrawableShape variable
      aStream.seekg (0, std::ios::beg);
      aDrawable = Draw_Drawable3D::Restore ("DBRep_DrawableShape", aStream);
    }
    if (aDrawable.IsNull())
    {
      theDI << "Error: cannot restore a " << aType;
      return 1;
    }

    Draw::Set (aVarName, aDrawable, aDrawable->IsDisplayable() && autodisp);
    Draw::SetProgressBar (Handle(Draw_ProgressIndicator)());
  }

  theDI << aVarName;
  return 0;
}

//=======================================================================
// display
//=======================================================================

static Standard_Integer display(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n <= 1) return 1;
  else {
    for (Standard_Integer i = 1; i < n; i++) {
      Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
      if (!D.IsNull()) {
	if (!D->Visible()) {
	  dout << D;
	  di << a[i] << " ";
	}
      }
    }
  }
  return 0;
}

//=======================================================================
// erase, clear, donly
//=======================================================================

static Standard_Integer erase(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  static Standard_Boolean draw_erase_mute = Standard_False;
  if (n == 2) {
    if (!strcasecmp(a[1],"-mute")) {
      draw_erase_mute = Standard_True;
      return 0;
    }
  }

  Standard_Boolean donly = !strcasecmp(a[0],"donly");
  
  if (n <= 1 || donly) {
    // clear, 2dclear, donly, erase (without arguments)
    Standard_Integer i;
    
    // solve the names for "." before erasing
    if (donly) {
      for (i = 1; i < n; i++) {
	Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
	if (D.IsNull()) {
	  if ((a[i][0] == '.') && (a[i][1] == '\0'))
	    std::cout << "Missed !!!" << std::endl;
	  return 0;
	}
      }
    }

    // sauvegarde des proteges visibles
    Draw_SequenceOfDrawable3D prot;
    for (NCollection_Map<Handle(Draw_Drawable3D)>::Iterator aMapIt (Draw::Drawables()); aMapIt.More(); aMapIt.Next())
    {
      const Handle(Draw_Drawable3D)& D = aMapIt.Key();
      if (!D.IsNull())
      {
        if (D->Protected() && D->Visible())
        {
          prot.Append(D);
        }
      }
    }
  
    // effacement de toutes les variables
    Standard_Integer erasemode = 1;
    if (a[0][0] == '2') erasemode = 2;
    if (a[0][0] == 'c') erasemode = 3;
    
    // effacement des graphiques non variables
    if (erasemode == 2) 
      dout.Clear2D();
    else if (erasemode == 3)
      dout.Clear3D();
    else
      dout.Clear();
    
    // affichage pour donly
    if (donly) {
      for (i = 1; i < n; i++) {
	Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
	if (!D.IsNull()) {
	  if (!D->Visible()) {
	    dout << D;
	    if (!draw_erase_mute) di << a[i] << " ";
	  }
	}
      }
    }
    
  // afficahge des proteges
    for (i = 1; i <= prot.Length(); i++)
      dout << prot(i);
    
    
  }
  else {
    for (Standard_Integer i = 1; i < n; i++) {
      Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
      if (!D.IsNull()) {
	if (D->Visible()) {
	    dout.RemoveDrawable(D);
	    if (!draw_erase_mute) di << D->Name() << " ";
	  }
      }
    }
    dout.Repaint2D();
    dout.Repaint3D();
  }
  draw_erase_mute = Standard_False;
  repaint2d = Standard_False;
  repaint3d = Standard_False;
  dout.Flush();
  return 0;
}



//=======================================================================
// draw
//=======================================================================

static Standard_Integer draw(Draw_Interpretor& , Standard_Integer n, const char** a)
{
  if (n < 3) return 1;
  Standard_Integer id = Draw::Atoi(a[1]);
  if (!dout.HasView(id)) {
    Message::SendFail() << "bad view number in draw";
    return 1;
  }
  Standard_Integer mo = Draw::Atoi(a[2]);
  Draw_Display d = dout.MakeDisplay(id);
  d.SetMode(mo);
  Standard_Integer i;
  for (i = 3; i < n; i++) {
    Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
    if (!D.IsNull()) D->DrawOn(d);
  }
  d.Flush();
  return 0;
}

//=======================================================================
// protect, unprotect
//=======================================================================

static Standard_Integer protect(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n <= 1) return 1;
  Standard_Boolean prot = *a[0] != 'u';
  for (Standard_Integer i = 1; i < n; i++) {
    Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
    if (!D.IsNull()) {
      D->Protected(prot);
      di << a[i] << " ";
    }
  }
  return 0;
}

//=======================================================================
// autodisplay
//=======================================================================

static Standard_Integer autodisplay(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n <= 1)
    autodisp = !autodisp;
  else 
    autodisp = !(!strcasecmp(a[1],"0"));

  if (autodisp)
    di << "1";
  else
    di << "0";

  return 0;
}


//=======================================================================
// whatis
//=======================================================================

static Standard_Integer whatis(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n <= 1) return 1;
  for (Standard_Integer i = 1; i < n; i++) {
    Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
    if (!D.IsNull()) {
      D->Whatis(di);
    }
  }
  return 0;
}


//=======================================================================
// value
//=======================================================================

static Standard_Integer value(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n != 2) return 1;
  di << Draw::Atof(a[1]);

  return 0;
}

//=======================================================================
//function : dname
//purpose  : 
//=======================================================================
static Standard_Integer dname(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n <= 1) {
    return 1;
  }
  //
  Standard_PCharacter pC;
  Standard_Integer i;
  Handle(Draw_Drawable3D) aD;
  //
  for (i = 1; i < n; ++i) {
    aD = Draw::Get(a[i]);
    if (!aD.IsNull()) {
      //modified by NIZNHY-PKV Tue Jun 10 10:18:13 2008f
      //di << a[i];
      pC=(Standard_PCharacter)aD->Name();
      di << pC;
      //modified by NIZNHY-PKV Tue Jun 10 10:18:18 2008t
    }
  }
  return 0;
}

//=======================================================================
// dump
//=======================================================================


static Standard_Integer dump(Draw_Interpretor& DI, Standard_Integer n, const char** a)
{
  if(n < 2) return 1;
  Standard_Integer i;
  for (i = 1; i < n; i++) {
    Handle(Draw_Drawable3D) D = Draw::Get(a[i]);
    if (!D.IsNull()) {
      Standard_SStream sss;
      sss.precision(15);
      sss << "\n\n*********** Dump of " << a[i] << " *************\n";
      D->Dump(sss);
      DI << sss;
    }
  }
  return 0;
}

//=======================================================================
// copy
//=======================================================================

static Standard_Integer copy(Draw_Interpretor& , Standard_Integer n, const char** a)
{
  if (n < 3) return 1;
  Standard_Boolean cop = !strcasecmp(a[0],"copy");

  Handle(Draw_Drawable3D) D;
  for (Standard_Integer i = 1; i < n; i += 2) {
    if (i+1 >= n) return 0;
    D = Draw::Get(a[i]);
    if (!D.IsNull()) {
      if (cop) 
	D = D->Copy();
      else 
	// clear old name
	Draw::Set(a[i],Handle(Draw_Drawable3D)());

      Draw::Set(a[i+1],D);
    }
  }
  return 0;
}

//=======================================================================
//function : repaint
//purpose  : 
//=======================================================================

static Standard_Integer repaintall(Draw_Interpretor& , Standard_Integer , const char** )
{
  if (repaint2d) dout.Repaint2D();
  repaint2d = Standard_False;
  if (repaint3d) dout.Repaint3D();
  repaint3d = Standard_False;
  dout.Flush();
  return 0;
}

//=======================================================================
//function : set
//purpose  : 
//=======================================================================

static Standard_Integer set(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n < 2) return 1;
  Standard_Integer i = 1;
  Standard_Real val=0;
  for (i = 1; i < n; i += 2) {
    val = 0;
    if (i+1 < n) val = Draw::Atof(a[i+1]);
    Draw::Set(a[i],val);
  }
  di << val;
  return 0;
}

//=======================================================================
//function : dsetenv
//purpose  : 
//=======================================================================

static Standard_Integer dsetenv(Draw_Interpretor& /*di*/, Standard_Integer argc, const char** argv)
{
  if (argc < 2) {
    Message::SendFail() << "Use: " << argv[0] << " {varname} [value]";
    return 1;
  }

  OSD_Environment env (argv[1]);
  if (argc > 2 && argv[2][0] != '\0')
  {
    env.SetValue (argv[2]);
    env.Build();
  }
  else
    env.Remove();
  return env.Failed();
}

//=======================================================================
//function : dgetenv
//purpose  : 
//=======================================================================

static Standard_Integer dgetenv(Draw_Interpretor& di, Standard_Integer argc, const char** argv)
{
  if (argc < 2) {
    Message::SendFail() << "Use: " << argv[0] << " {varname}";
    return 1;
  }

  const char* val = getenv (argv[1]);
  di << ( val ? val : "" );
  return 0;
}

//=======================================================================
//function : isdraw
//purpose  : 
//=======================================================================

static Standard_Integer isdraw(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n != 2) return 1;
  Handle(Draw_Drawable3D) D = Draw::Get (a[1]);
  if (D.IsNull())
    di << "0";
  else
    di << "1";
  return 0;
}

//=======================================================================
//function : isprot
//purpose  : 
//=======================================================================

Standard_Integer isprot(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n != 2) return 1;
  Handle(Draw_Drawable3D) D = Draw::Get(a[1]);
  if (D.IsNull())
    di << "0";
  else {
    if (D->Protected())
      di << "1";
    else
      di << "0";
  }
  return 0;
}


//=======================================================================
//function : pick
//purpose  : 
//=======================================================================

static Standard_Integer pick(Draw_Interpretor& , Standard_Integer n, const char** a)
{
  if (n < 6) return 1;
  Standard_Integer id;
  Standard_Integer X,Y,b;
  Standard_Boolean wait = (n == 6);
  if (!wait) id = Draw::Atoi(a[1]);
  dout.Select(id,X,Y,b,wait);
  Standard_Real z = dout.Zoom(id);
  gp_Pnt P((Standard_Real)X /z,(Standard_Real)Y /z,0);
  gp_Trsf T;
  dout.GetTrsf(id,T);
  T.Invert();
  P.Transform(T);
  Draw::Set(a[1],id);
  Draw::Set(a[2],P.X());
  Draw::Set(a[3],P.Y());
  Draw::Set(a[4],P.Z());
  Draw::Set(a[5],b);
  return 0;
}


//=======================================================================
//function : lastrep
//purpose  : 
//=======================================================================

static Standard_Integer lastrep(Draw_Interpretor& di, Standard_Integer n, const char** a)
{
  if (n < 5) return 1;

  Draw::Set(a[1],p_id);
  if (n == 5) {
    Draw::Set(a[2],p_X);
    Draw::Set(a[3],p_Y);
  }
  else if (n == 6) {
    Standard_Real z = dout.Zoom(p_id);
    gp_Pnt P((Standard_Real)p_X /z,(Standard_Real)p_Y /z,0);
    gp_Trsf T;
    dout.GetTrsf(p_id,T);
    T.Invert();
    P.Transform(T);
    Draw::Set(a[2],P.X());
    Draw::Set(a[3],P.Y());
    Draw::Set(a[4],P.Z());
  }
  else {
    di << "Too many args";
    return 1;
  }
  Draw::Set(a[n-1],p_b);
  di << p_Name;
  return 0;
}


//=======================================================================
//function : Set
//purpose  : 
//=======================================================================
void Draw::Set(const Standard_CString name, 
	       const Handle(Draw_Drawable3D)& D)
{
 Draw::Set(name,D,autodisp);
}

// MKV 29.03.05
static char* tracevar(ClientData CD, Tcl_Interp*,const char* name,const char*, int)
{
  // protect if the map was destroyed before the interpretor
  if (Draw::Drawables().IsEmpty())
  {
    return NULL;
  }

  Draw_Interpretor& aCommands = Draw::GetInterpretor();

  // MSV 9.10.14 CR25344
  Handle(Draw_Drawable3D) D(reinterpret_cast<Draw_Drawable3D*>(CD));
  if (D.IsNull()) {
    Tcl_UntraceVar(aCommands.Interp(),name,TCL_TRACE_UNSETS | TCL_TRACE_WRITES,
                   tracevar,CD);
    return NULL;
  }
  if (D->Protected()) {
    D->Name(Tcl_SetVar(aCommands.Interp(),name,name,0));
    return (char*) "variable is protected";
  } else {
    if (D->Visible()) {
      dout.RemoveDrawable(D);
      if (D->Is3D()) 
          repaint3d = Standard_True;
      else
          repaint2d = Standard_True;
    }
    Tcl_UntraceVar(aCommands.Interp(),name,TCL_TRACE_UNSETS | TCL_TRACE_WRITES,
                   tracevar,CD);
    Draw_changeDrawables().Remove(D);
    return NULL;
  }
}

//=======================================================================
//function : Set
//purpose  : 
//=======================================================================
void Draw::Set(const Standard_CString name, 
               const Handle(Draw_Drawable3D)& D,
               const Standard_Boolean displ)
{
  Draw_Interpretor& aCommands = Draw::GetInterpretor();

  if ((name[0] == '.') && (name[1] == '\0')) {
    if (!D.IsNull()) {
      dout.RemoveDrawable(D);
      if (displ) dout << D;
    }
  }
  else {
    // Check if the variable with the same name exists
    ClientData aCD =
      Tcl_VarTraceInfo(aCommands.Interp(),name,TCL_TRACE_UNSETS | TCL_TRACE_WRITES,
                       tracevar, NULL);
    Handle(Draw_Drawable3D) anOldD(reinterpret_cast<Draw_Drawable3D*>(aCD));
    if (!anOldD.IsNull()) {
      if (Draw::Drawables().Contains(anOldD) && anOldD->Protected()) {
        std::cout << "variable is protected" << std::endl;
        return;
      }
      anOldD.Nullify();
    }

    Tcl_UnsetVar(aCommands.Interp(),name,0);

    if (!D.IsNull()) {
      Draw_changeDrawables().Add(D);
      D->Name(Tcl_SetVar(aCommands.Interp(),name,name,0));
    
      // set the trace function
      Tcl_TraceVar(aCommands.Interp(),name,TCL_TRACE_UNSETS | TCL_TRACE_WRITES,
                   tracevar,reinterpret_cast<ClientData>(D.operator->()));
      if (displ) {
        if (!D->Visible())
          dout << D;
      }
      else if (D->Visible())
        dout.RemoveDrawable(D);
    }
  }
}
//=======================================================================
//function : Set
//purpose  : 
//=======================================================================
void Draw::Set(const Standard_CString theName, const Standard_Real theValue)
{
  if (Handle(Draw_Number) aNumber = Handle(Draw_Number)::DownCast (Draw::GetExisting (theName)))
  {
    aNumber->Value (theValue);
  }
  else
  {
    aNumber = new Draw_Number (theValue);
    Draw::Set (theName, aNumber, Standard_False);
  }
}

//=======================================================================
//function : getDrawable
//purpose  :
//=======================================================================
Handle(Draw_Drawable3D) Draw::getDrawable (Standard_CString& theName,
                                           Standard_Boolean theToAllowPick)
{
  const Standard_Boolean toPick = ((theName[0] == '.') && (theName[1] == '\0'));
  if (!toPick)
  {
    ClientData aCD = Tcl_VarTraceInfo (Draw::GetInterpretor().Interp(), theName, TCL_TRACE_UNSETS | TCL_TRACE_WRITES, tracevar, NULL);
    Handle(Draw_Drawable3D) aDrawable = reinterpret_cast<Draw_Drawable3D*>(aCD);
    return Draw::Drawables().Contains (aDrawable)
         ? aDrawable
         : Handle(Draw_Drawable3D)();
  }
  else if (!theToAllowPick)
  {
    return Handle(Draw_Drawable3D)();
  }

  std::cout << "Pick an object" << std::endl;
  Handle(Draw_Drawable3D) aDrawable;
  dout.Select (p_id, p_X, p_Y, p_b);
  dout.Pick (p_id, p_X, p_Y, 5, aDrawable, 0);
  if (!aDrawable.IsNull()
    && aDrawable->Name() != NULL)
  {
    theName = p_Name = aDrawable->Name();
  }
  return aDrawable;
}

//=======================================================================
//function : Get
//purpose  : 
//=======================================================================
Standard_Boolean Draw::Get (const Standard_CString theName,
                            Standard_Real& theValue)
{
  if (Handle(Draw_Number) aNumber = Handle(Draw_Number)::DownCast (Draw::GetExisting (theName)))
  {
    theValue = aNumber->Value();
    return Standard_True;
  }
  return Standard_False;
}

//=======================================================================
//function : LastPick
//purpose  : 
//=======================================================================
void  Draw::LastPick(Standard_Integer& view, 
		     Standard_Integer& X, 
		     Standard_Integer& Y, 
		     Standard_Integer& button)
{
  view = p_id;
  X = p_X;
  Y = p_Y;
  button = p_b;
}
//=======================================================================
//function : Repaint
//purpose  : 
//=======================================================================
void  Draw::Repaint()
{
  repaint2d = Standard_True;
  repaint3d = Standard_True;
}

//=======================================================================
//function : trigonometric functions
//purpose  : 
//=======================================================================

//static Standard_Integer trigo (Draw_Interpretor& di, Standard_Integer n, const char** a)
static Standard_Integer trigo (Draw_Interpretor& di, Standard_Integer , const char** a)
{

  Standard_Real x = Draw::Atof(a[1]);

  if (!strcasecmp(a[0],"cos"))
    di << Cos(x);
  else if (!strcasecmp(a[0],"sin"))
    di << Sin(x);
  else if (!strcasecmp(a[0],"tan"))
    di << Tan(x);
  else if (!strcasecmp(a[0],"sqrt"))
    di << Sqrt(x);
  else if (!strcasecmp(a[0],"acos"))
    di << ACos(x);
  else if (!strcasecmp(a[0],"asin"))
    di << ASin(x);
  else if (!strcasecmp(a[0],"atan2"))
    di << ATan2(x,Draw::Atof(a[2]));

  return 0;
}


//=======================================================================
// Atof and Atoi
//=======================================================================

static Standard_Boolean Numeric(char c)
{
  return (c == '.' || (c >= '0' && c <= '9'));
}

static Standard_Boolean Alphabetic(char c)
{
  return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c == '_'));
}

static Standard_Real Parse(char*&);

static Standard_Real ParseValue (char*& theName)
{
  while (*theName == ' ' || *theName == '\t') { ++theName; }
  Standard_Real x = 0;
  switch (*theName)
  {
    case '\0':
    {
      break;
    }
    case '(':
    {
      ++theName;
      x = Parse (theName);
      if (*theName != ')')
      {
        std::cout << "Mismatched parenthesis" << std::endl;
      }
      ++theName;
      break;
    }
    case '+':
    {
      ++theName;
      x = ParseValue (theName);
      break;
    }
    case '-':
    {
      ++theName;
      x = - ParseValue (theName);
      break;
    }
    default:
    {
      // process a string
      char* p = theName;
      while (Numeric (*p)) { ++p; }
      // process scientific notation
      if ((*p == 'e') || (*p == 'E'))
      {
        if (Numeric (*(p+1)) || *(p+1) == '+' || *(p+1) == '-')
        {
          p+= 2;
        }
      }
      while (Numeric (*p) || Alphabetic (*p)) { p++; }
      char c = *p;
      *p = '\0';

      if (Numeric (*theName))   // numeric literal
      {
        x = Atof (theName);
      }
      else if (!Draw::Get ((Standard_CString )theName, x)) // variable
      {
        // search for a function ...
        *p = c;
        // count arguments
        Standard_Integer argc = 1;
        char* q = p;
        while ((*q == ' ') || (*q == '\t')) { ++q; }
        if (*q == '(')
        {
          Standard_Integer pc = 1;
          argc = 2;
          q++;
          while ((pc > 0) && *q)
          {
            if (*q == '(') { ++pc; }
            if (*q == ')') { --pc; }
            if ((pc == 1) && (*q == ',')) { ++argc; }
            ++q;
          }
          if (pc > 0)
          {
            std::cout << "Unclosed parenthesis"<< std::endl;
            x = 0;
          }
          else
          {
            // build function call
            // replace , and first and last () by space
            if (argc > 1)
            {
              Standard_Integer i = 2;
              while (*p != '(') { ++p; }
              *p = ' ';
              ++p;
              pc = 1;
              while (pc > 0)
              {
                if (*p == '(') { ++pc; }
                if (*p == ')') { --pc; }
                if ((pc == 1) && (*p == ','))
                {
                  *p = ' ';
                  ++p;
                  ++i;
                }
                else
                {
                  ++p;
                }
              }
              *(p-1) = '\0';
              c = *p;

              Draw_Interpretor& aCommands = Draw::GetInterpretor();

              // call the function, save the current result
              TCollection_AsciiString sv (aCommands.Result());
              if (*aCommands.Result())
              {
                aCommands.Reset();
              }
              if (aCommands.Eval (theName) != 0)
              {
                std::cout << "Call of function " << theName << " failed" << std::endl;
                x = 0;
              }
              else
              {
                x = Atof (aCommands.Result());
              }
              aCommands.Reset();
              if (!sv.IsEmpty())
              {
                aCommands << sv;
              }
            }
          }
        }
        else
        {
          Draw_ParseFailed = Standard_True;
        }
      }
      *p = c;
      theName = p;
    }
    break;
  }

  while (*theName == ' ' || *theName == '\t')
  {
    ++theName;
  }
  return x;
}


static Standard_Real ParseFactor(char*& name)
{
  Standard_Real x = ParseValue(name);

  for(;;) {
    char c = *name;
    if (c == '\0') return x;
    name++;
    switch (c) {

    case '*' :
      x *= ParseValue(name);
      break;

    case '/' :
      x /= ParseValue(name);
      break;

      default :
	name--;
	return x;
      
    }
  }
}

static Standard_Real Parse(char*& name)
{
  Standard_Real x = ParseFactor(name);

  for(;;) {
    char c = *name;
    if (c == '\0') return x;
    name++;
    switch (c) {

    case '+' :
      x += ParseFactor(name);
      break;

    case '-' :
      x -= ParseFactor(name);
      break;

      default :
  name--;
  return x;
      
    }
  }
}

//=======================================================================
// function : Atof
// purpose  :
//=======================================================================
Standard_Real Draw::Atof(const Standard_CString theName)
{
  // copy the string
  NCollection_Array1<char> aBuff (0, (Standard_Integer )strlen (theName));
  char* n = &aBuff.ChangeFirst();
  strcpy (n, theName);
  Draw_ParseFailed = Standard_False;
  Standard_Real x = Parse(n);
  while ((*n == ' ') || (*n == '\t')) n++;
  if (*n) Draw_ParseFailed = Standard_True;
  return x;
}

//=======================================================================
// function : ParseReal
// purpose  :
//=======================================================================
bool Draw::ParseReal (const Standard_CString theExpressionString, Standard_Real& theParsedRealValue)
{
  const Standard_Real aParsedRealValue = Atof (theExpressionString);
  if (Draw_ParseFailed)
  {
    Draw_ParseFailed = Standard_False;
    return false;
  }
  theParsedRealValue = aParsedRealValue;
  return true;
}

//=======================================================================
// function : Atoi
// purpose  :
//=======================================================================
Standard_Integer Draw::Atoi(const Standard_CString name)
{
  return (Standard_Integer) Draw::Atof(name);
}

//=======================================================================
// function : ParseInteger
// purpose  :
//=======================================================================
bool Draw::ParseInteger (const Standard_CString theExpressionString, Standard_Integer& theParsedIntegerValue)
{
  Standard_Real aParsedRealValue = 0.0;
  if (!ParseReal (theExpressionString, aParsedRealValue))
  {
    return false;
  }
  const Standard_Integer aParsedIntegerValue = static_cast<Standard_Integer> (aParsedRealValue);
  if (static_cast<Standard_Real> (aParsedIntegerValue) != aParsedRealValue)
  {
    return false;
  }
  theParsedIntegerValue = aParsedIntegerValue;
  return true;
}

//=======================================================================
//function : Set
//purpose  : set a TCL var
//=======================================================================
void Draw::Set(const Standard_CString Name, const Standard_CString val)
{
  Standard_PCharacter pName, pVal;
  //
  pName=(Standard_PCharacter)Name;
  pVal=(Standard_PCharacter)val;
  //
  Tcl_SetVar(Draw::GetInterpretor().Interp(), pName, pVal, 0);
}

//=======================================================================
//function : Drawables
//purpose  :
//=======================================================================
const NCollection_Map<Handle(Draw_Drawable3D)>& Draw::Drawables()
{
  return Draw_changeDrawables();
}

//=======================================================================
// Command management
// refresh the screen
//=======================================================================

static void before()
{
  repaint2d = Standard_False;
  repaint3d = Standard_False;
}

void Draw_RepaintNowIfNecessary()
{
  if (repaint2d) dout.Repaint2D();
  if (repaint3d) dout.Repaint3D();
  repaint2d = Standard_False;
  repaint3d = Standard_False;
}

static void  after(Standard_Integer)
{
  Draw_RepaintNowIfNecessary();
}

extern void (*Draw_BeforeCommand)();
extern void (*Draw_AfterCommand)(Standard_Integer);


//=======================================================================
//function : Commands
//purpose  : 
//=======================================================================
void  Draw::VariableCommands(Draw_Interpretor& theCommandsArg)
{
  static Standard_Boolean Done = Standard_False;
  if (Done) return;
  Done = Standard_True;

  // set up start and stop command
  Draw_BeforeCommand = &before;
  Draw_AfterCommand  = &after;

  // Register save/restore tools
  Draw_Number::RegisterFactory();

  // set up some variables
  const char* n;
  Handle(Draw_Axis3D) theAxes3d = new Draw_Axis3D(gp_Pnt(0,0,0),Draw_bleu,20);
  n = "axes";
  Draw::Set(n,theAxes3d);
  theAxes3d->Protected(Standard_True);

  Handle(Draw_Axis2D) theAxes2d = new Draw_Axis2D(gp_Pnt2d(0,0),Draw_bleu,20);
  n = "axes2d";
  Draw::Set(n,theAxes2d);
  theAxes2d->Protected(Standard_True);

  n = "pi";
  Draw::Set(n,M_PI);
  Draw::Get(n)->Protected(Standard_True);

  n = "pinf";
  Draw::Set(n,RealLast());
  Draw::Get(n)->Protected(Standard_True);

  n = "minf";
  Draw::Set(n,RealFirst());
  Draw::Get(n)->Protected(Standard_True);

  n = "grid";
  Handle(Draw_Grid) theGrid = new Draw_Grid();
  Draw::Set(n, theGrid);
  theGrid->Protected(Standard_True);
  

  const char* g;

  g = "DRAW Numeric functions";

  theCommandsArg.Add("cos" ,"cos(x)" ,__FILE__,trigo,g);
  theCommandsArg.Add("sin" ,"sin(x)" ,__FILE__,trigo,g);
  theCommandsArg.Add("tan" ,"tan(x)" ,__FILE__,trigo,g);
  theCommandsArg.Add("acos" ,"acos(x)" ,__FILE__,trigo,g);
  theCommandsArg.Add("asin" ,"asin(x)" ,__FILE__,trigo,g);
  theCommandsArg.Add("atan2" ,"atan2(x,y)" ,__FILE__,trigo,g);
  theCommandsArg.Add("sqrt","sqrt(x)",__FILE__,trigo,g);

  g = "DRAW Variables management";

  theCommandsArg.Add("protect","protect name ...",__FILE__,protect,g);
  theCommandsArg.Add("unprotect","unprotect name ...",__FILE__,protect,g);

  theCommandsArg.Add("bsave","bsave name filename",__FILE__,save,g);
  theCommandsArg.Add("brestore","brestore filename name",__FILE__,restore,g);

  theCommandsArg.Add("isdraw","isdraw var, return 1 if Draw value",__FILE__,isdraw,g);
  theCommandsArg.Add("isprot","isprot var, return 1 if Draw var is protected",__FILE__,isprot,g);
  
  theCommandsArg.Add("autodisplay","toggle autodisplay [0/1]",__FILE__,autodisplay,g);
  theCommandsArg.Add("display","display [name1 name2 ...], no names display all",__FILE__,display,g);
  theCommandsArg.Add("donly","donly [name1 name2 ...], erase and display",__FILE__,erase,g);
  theCommandsArg.Add("erase","erase [name1 name2 ...], no names erase all",__FILE__,erase,g);
  theCommandsArg.Add("draw","draw view mode [name1 name2 ...], draw on view with mode",__FILE__,draw,g);
  theCommandsArg.Add("clear","clear display",__FILE__,erase,g);
  theCommandsArg.Add("2dclear","clear display (2d objects)",__FILE__,erase,g);
  theCommandsArg.Add("repaint","repaint, force redraw",__FILE__,repaintall,g);

  theCommandsArg.Add("dtyp", "dtyp name1 name2",__FILE__,whatis,g);
  theCommandsArg.Add("dval", "dval name, return value",__FILE__,value,g);
  theCommandsArg.Add("dname", "dname name, print name",__FILE__,dname,g);
  theCommandsArg.Add("dump", "dump name1 name2 ...",__FILE__,dump,g);
  theCommandsArg.Add("copy",  "copy name1 toname1 name2 toname2 ...",__FILE__,copy,g);
  // san - 02/08/2002 - `rename` command changed to `renamevar` since it conflicts with 
  // the built-in Tcl command `rename`
  //theCommands.Add("rename","rename name1 toname1 name2 toname2 ...",__FILE__,copy,g);
  theCommandsArg.Add("renamevar","renamevar name1 toname1 name2 toname2 ...",__FILE__,copy,g);
  theCommandsArg.Add("dset","var1 value1 vr2 value2 ...",__FILE__,set,g);

  // commands to access C environment variables; see Mantis issue #23197
  theCommandsArg.Add("dgetenv","var : get value of environment variable in C subsystem",__FILE__,dgetenv,g);
  theCommandsArg.Add("dsetenv","var [value] : set (unset if value is empty) environment variable in C subsystem",__FILE__,dsetenv,g);

  theCommandsArg.Add("pick","pick id X Y Z b [nowait]",__FILE__,pick,g);
  theCommandsArg.Add("lastrep","lastrep id X Y [Z] b, return name",__FILE__,lastrep,g);
}