/*

Copyright (C) 2007, 2008 Shai Ayal

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

/*

To initialize:

  __init_fltk__ ();
  set (gcf (), "__backend__", "fltk");
  plot (randn (1e3, 1));

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#if defined (HAVE_FLTK)

#include <map>
#include <set>
#include <sstream>
#include <iostream>

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Output.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Gl_Window.H>
#include <FL/fl_ask.H>
#include <FL/fl_draw.H>
#include <FL/gl.h>

#ifdef min
#undef min
#undef max
#endif

#include "cmd-edit.h"
#include "defun-dld.h"
#include "error.h"
#include "gl-render.h"
#include "graphics.h"
#include "parse.h"

#define FLTK_BACKEND_NAME "fltk"

const char* help_text = "\
Keyboard Shortcuts\n\
a - autoscale\n\
g - toggle grid\n\
\n\
Mouse\n\
left drag - zoom\n\
right click - unzoom\n\
double click - copy coordinates to clipboard\
";

class OpenGL_fltk : public Fl_Gl_Window
{
public:
  OpenGL_fltk (int xx, int yy, int ww, int hh, double num)
    : Fl_Gl_Window (xx, yy, ww, hh, 0), number (num), in_zoom (false)
  {
    // ask for double buffering and a depth buffer
    mode (FL_DEPTH | FL_DOUBLE);
  }

  ~OpenGL_fltk (void) { }

  void zoom (bool z) { in_zoom = z; }
  bool zoom (void) { return in_zoom; }
  void set_zoom_box (const Matrix& zb) { zoom_box = zb; }

private:
  double number;
  opengl_renderer renderer;
  bool in_zoom;

  // (x1,y1,x2,y2)
  Matrix zoom_box;

  void setup_viewport (int _w, int _h)
  {
    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    glViewport (0, 0, _w, _h);
  }

  void draw (void)
  {
    if (!valid ())
      {
	valid (1);
	setup_viewport (w (), h ());
      }

    renderer.draw (gh_manager::lookup (number));
  }

  void resize (int _x,int _y,int _w,int _h)
  {
    Fl_Gl_Window::resize (_x, _y, _w, _h);
    setup_viewport (_w, _h);
    redraw ();
  }

  void draw_overlay (void)
  {
    if (!in_zoom)
      return;

    if (!valid())
      {
	valid(1);
	setup_viewport (w (), h ());
      }

    glPushMatrix ();

    glMatrixMode (GL_MODELVIEW);
    glLoadIdentity ();

    glMatrixMode (GL_PROJECTION);
    glLoadIdentity ();
    gluOrtho2D (0.0, w (), 0.0, h ());

    glPushAttrib (GL_DEPTH_BUFFER_BIT | GL_CURRENT_BIT);
    glDisable (GL_DEPTH_TEST);

    glLineWidth (1);
    glBegin (GL_LINE_STRIP);
    gl_color(0);
    glVertex2d (zoom_box(0), h () - zoom_box(1));
    glVertex2d (zoom_box(0), h () - zoom_box(3));
    glVertex2d (zoom_box(2), h () - zoom_box(3));
    glVertex2d (zoom_box(2), h () - zoom_box(1));
    glVertex2d (zoom_box(0), h () - zoom_box(1));
    glEnd ();

    glPopAttrib ();
    glPopMatrix ();
  }

  int handle (int event)
  {
    int retval = Fl_Gl_Window::handle (event);

    switch (event)
      {
      case FL_ENTER:
	window ()->cursor (FL_CURSOR_CROSS);
	return 1;

      case FL_LEAVE:
	window ()->cursor (FL_CURSOR_DEFAULT);
	return 1;
      }

    return retval;
  }
};

class plot_window : public Fl_Window
{
public:
  plot_window (int _x, int _y, int _w, int _h, figure::properties& _fp)
    : Fl_Window (_x, _y, _w, _h, "octave"), fp (_fp)
  {
    callback (window_close, static_cast<void*> (this));

    begin ();
    {
      canvas = new
	OpenGL_fltk (0, 0, _w , _h - status_h, number ());

      autoscale = new
	Fl_Button (0,
		   _h - status_h,
		   status_h,
		   status_h,
		   "A");
      autoscale->callback (button_callback, static_cast<void*> (this));

      togglegrid = new
	Fl_Button (status_h,
		   _h - status_h,
		   status_h,
		   status_h,
		   "G");
      togglegrid->callback (button_callback, static_cast<void*> (this));

      help = new
	Fl_Button (2*status_h,
		   _h - status_h,
		   status_h,
		   status_h,
		   "H");
      help->callback (button_callback, static_cast<void*> (this));

      status = new
	Fl_Output (3*status_h,
		   _h - status_h,
		   _w > 2*status_h ? _w - status_h : 0,
		   status_h, "");

      status->textcolor (FL_BLACK);
      status->color (FL_GRAY);
      status->textfont (FL_COURIER);
      status->textsize (10);
      status->box (FL_ENGRAVED_BOX);

      // This allows us to have a valid OpenGL context right away
      canvas->mode (FL_DEPTH | FL_DOUBLE );
      show ();
      canvas->show ();
      canvas->make_current ();
    }
    end ();

    status->show ();
    autoscale->show ();
    togglegrid->show ();

    resizable (canvas);
    size_range (4*status_h, 2*status_h);

    std::stringstream name;
    name << "octave: figure " << number ();
    label (name.str ().c_str ());
  }

  ~plot_window (void)
  {
    canvas->hide ();
    status->hide ();
    this->hide ();
    delete canvas;
    delete status;
  }

  // FIXME -- this could change
  double number (void) { return fp.get___myhandle__ ().value (); }

  void mark_modified (void)
  {
    damage (FL_DAMAGE_ALL);
    canvas->damage (FL_DAMAGE_ALL);
  }

private:
  // figure properties
  figure::properties& fp;

  // status area height
  static const int status_h = 20;

  // window callback
  static void window_close (Fl_Widget*, void* data)
  {
    octave_value_list args;
    args(0) = static_cast<plot_window*> (data)->number ();
    feval ("close", args);
  }

  // button callbacks
  static void button_callback (Fl_Widget* ww, void* data)
  {
    static_cast<plot_window*> (data)->button_press (ww);
  }

  void button_press (Fl_Widget* widg)
  {
    if (widg == autoscale)
      axis_auto ();

    if (widg == togglegrid)
      toggle_grid ();

    if (widg == help)
      fl_message (help_text);
  }

  OpenGL_fltk* canvas;
  Fl_Button* autoscale;
  Fl_Button* togglegrid;
  Fl_Button* help;
  Fl_Output* status;

  void axis_auto (void)
  {
    octave_value_list args;
    args(0) = "auto";
    feval ("axis",args);
    mark_modified ();
  }

  void toggle_grid (void)
  {
    feval ("grid");
    mark_modified ();
  }

  void pixel2pos (int px, int py, double& xx, double& yy) const
  {
    graphics_object ax = gh_manager::get_object (fp.get_currentaxes ());

    if (ax && ax.isa ("axes"))
      {
	axes::properties& ap =
	  dynamic_cast<axes::properties&> (ax.get_properties ());
	ColumnVector pp = ap.pixel2coord (px, py);
	xx = pp(0);
	yy = pp(1);
      }
  }

  graphics_handle pixel2axes (int /* px */, int /* py */)
  {
    Matrix kids = fp.get_children ();

    for (octave_idx_type n = 0; n < kids.numel (); n++)
      {
	graphics_object ax = gh_manager::get_object (kids (n));
	if (ax && ax.isa ("axes"))
	  {
#if 0
	     axes::properties& ap =
	       dynamic_cast<axes::properties&> (ax.get_properties ());

	     // std::cout << "\npixpos="<<pixpos<<"(px,py)=("<<px<<","<<py<<")\n";
	     if (px >= pixpos(0) && px <= pixpos(2)
		 && py >= pixpos(1) && py <= pixpos(3))
	       return ap.get___myhandle__ ();
#endif
	  }
      }

    return graphics_handle ();
  }

  void pixel2status (int px0, int py0, int px1 = -1, int py1 = -1)
  {
    double x0, y0, x1, y1;
    std::stringstream cbuf;

    pixel2pos (px0, py0, x0, y0);
    cbuf << "[" << x0 << ", " << y0 << "]";
    if (px1 >= 0)
      {
	pixel2pos (px1, py1, x1, y1);
	cbuf << " -> ["<< x1 << ", " << y1 << "]";
      }

    status->value (cbuf.str ().c_str ());
    status->redraw ();
  }

  void resize (int _x,int _y,int _w,int _h)
  {
    Fl_Window::resize (_x, _y, _w, _h);

    Matrix pos (1,4,0);
    pos(0) = _x;
    pos(1) = _y;
    pos(2) = _w;
    pos(3) = _h - status_h;

    fp.set_position (pos);
  }

  void draw (void)
  {
    Matrix pos = fp.get_position ().matrix_value ();
    Fl_Window::resize (pos(0), pos(1) , pos(2), pos(3) + status_h);

    return Fl_Window::draw ();
  }

  int handle (int event)
  {
    static int px0,py0;
    static graphics_handle h0 = graphics_handle ();

    int retval = Fl_Window::handle (event);

    // we only handle events which are in the canvas area
    if (Fl::event_y () >= h() - status_h)
      return retval;

    switch (event)
      {
      case FL_KEYDOWN:
	switch(Fl::event_key ())
	  {
	  case 'a':
	  case 'A':
	    axis_auto ();
	    break;

	  case 'g':
	  case 'G':
	    toggle_grid ();
	    break;
	  }
	break;

      case FL_MOVE:
	pixel2status (Fl::event_x (), Fl::event_y ());
	break;

      case FL_PUSH:
	if (Fl::event_button () == 1)
	  {
	    px0 = Fl::event_x ();
	    py0 = Fl::event_y ();
	    h0 = pixel2axes (Fl::event_x (), Fl::event_y ());
	    return 1;
	  }
	break;

      case FL_DRAG:
	pixel2status (px0, py0, Fl::event_x (), Fl::event_y ());
	if (Fl::event_button () == 1)
	  {
	    canvas->zoom (true);
	    Matrix zoom_box (1,4,0);
	    zoom_box (0) = px0;
	    zoom_box (1) = py0;
	    zoom_box (2) =  Fl::event_x ();
	    zoom_box (3) =  Fl::event_y ();
	    canvas->set_zoom_box (zoom_box);
	    canvas->redraw_overlay ();
	    return 1;
	  }
	break;

      case FL_RELEASE:
	if (Fl::event_button () == 1)
	  {
	    // end of drag -- zoom
	    if (canvas->zoom ())
	      {
		canvas->zoom (false);
		double x0,y0,x1,y1;
		graphics_object ax =
		  gh_manager::get_object (fp.get_currentaxes ());
		if (ax && ax.isa ("axes"))
		  {
		    axes::properties& ap =
		      dynamic_cast<axes::properties&> (ax.get_properties ());
		    pixel2pos (px0, py0, x0, y0);
		    pixel2pos (Fl::event_x (), Fl::event_y (), x1, y1);
		    Matrix xl (1,2,0);
		    Matrix yl (1,2,0);
		    if (x0 < x1)
		      {
			xl(0) = x0;
			xl(1) = x1;
		      }
		    else
		      {
			xl(0) = x1;
			xl(1) = x0;
		      }

		    if (y0 < y1)
		      {
			yl(0) = y0;
			yl(1) = y1;
		      }
		    else
		      {
			yl(0) = y1;
			yl(1) = y0;
		      }
		    ap.zoom (xl, yl);
		    mark_modified ();
		  }
	      }
	    // one click -- select axes
	    else if ( Fl::event_clicks () == 0)
	      {
		std::cout << "ca="<< h0.value ()<<"\n";
		if (h0.ok ())
		  fp.set_currentaxes (h0.value());
		return 1;
	      }
	  }
	else if (Fl::event_button () == 3)
	  {
	    graphics_object ax =
	      gh_manager::get_object (fp.get_currentaxes ());
	    if (ax && ax.isa ("axes"))
	      {
		axes::properties& ap =
		  dynamic_cast<axes::properties&> (ax.get_properties ());
		ap.unzoom ();
		mark_modified ();
	      }
	  }
	break;
      }

    return retval;
  }
};

class figure_manager
{
public:

  static figure_manager& Instance (void)
  {
    static figure_manager fm;
    return fm;
  }

  ~figure_manager (void)
  {
    close_all ();
  }

  void close_all (void)
  {
    wm_iterator win;
    for (win = windows.begin (); win != windows.end (); win++)
      delete (*win).second;
    windows.clear ();
  }

  void new_window (figure::properties& fp)
  {
    int x, y, w, h;

    int idx = figprops2idx (fp);
    if (idx >= 0 && windows.find (idx) == windows.end ())
      {
	default_size(x,y,w,h);
	idx2figprops (curr_index , fp);
	windows[curr_index++] = new plot_window (x, y, w, h, fp);
      }
  }

  void delete_window (int idx)
  {
    wm_iterator win;
    if ((win = windows.find (idx)) != windows.end ())
      {
	delete (*win).second;
	windows.erase (win);
      }
  }

  void delete_window (std::string idx_str)
  {
    delete_window (str2idx (idx_str));
  }

  void mark_modified (int idx)
  {
    wm_iterator win;
    if ((win=windows.find (idx)) != windows.end ())
      {
	(*win).second->mark_modified ();
      }
  }

  void mark_modified (const graphics_handle& gh)
  {
    mark_modified (hnd2idx (gh));
  }

  Matrix get_size (int idx)
  {
    Matrix sz (1, 2, 0.0);

    wm_iterator win;
    if ((win = windows.find (idx)) != windows.end ())
      {
	sz(0) = (*win).second->w ();
	sz(1) = (*win).second->h ();
      }

    return sz;
  }

  Matrix get_size (const graphics_handle& gh)
  {
    return get_size (hnd2idx (gh));
  }

private:
  figure_manager (void) { }
  figure_manager (const figure_manager&) { }
  figure_manager& operator = (const figure_manager&) { return *this; }
  // singelton -- hide all of the above

  static int curr_index;
  typedef std::map<int, plot_window*> window_map;
  typedef window_map::iterator wm_iterator;;
  window_map windows;

  static std::string fltk_idx_header;

  void default_size (int& x, int& y, int& w, int& h)
  {
    x = 10;
    y = 10;
    w = 400;
    h = 300;
  }

  int str2idx (const caseless_str clstr)
  {
    int ind;
    if (clstr.find (fltk_idx_header,0) == 0)
      {
	std::istringstream istr (clstr.substr (fltk_idx_header.size ()));
	if (istr >> ind)
	  return ind;
      }
    error ("fltk_backend: could not recognize fltk index");
    return -1;
  }

  void idx2figprops (int idx, figure::properties& fp)
  {
    std::ostringstream ind_str;
    ind_str << fltk_idx_header << idx;
    fp.set___plot_stream__ (ind_str.str ());
  }

  int figprops2idx (const figure::properties& fp)
  {
    if (fp.get___backend__ () == FLTK_BACKEND_NAME)
      {
	octave_value ps = fp.get___plot_stream__ ();
	if (ps.is_string ())
	  return str2idx (ps.string_value ());
	else
	  return 0;
      }
    error ("fltk_backend:: figure is not fltk");
    return -1;
  }

  int hnd2idx (const graphics_handle& fh)
  {
    return hnd2idx (fh.value ());
  }

  int hnd2idx (const double h)
  {
    graphics_object fobj = gh_manager::get_object (h);
    if (fobj &&  fobj.isa ("figure"))
      {
	figure::properties& fp =
	  dynamic_cast<figure::properties&> (fobj.get_properties ());
	return figprops2idx (fp);
      }
    error ("fltk_backend:: not a figure");
    return -1;
  }
};

std::string figure_manager::fltk_idx_header="fltk index=";
int figure_manager::curr_index = 1;

class fltk_backend : public base_graphics_backend
{
public:
  fltk_backend (void)
    : base_graphics_backend (FLTK_BACKEND_NAME) { }

  ~fltk_backend (void) { }

  bool is_valid (void) const { return true; }

  void object_destroyed (const graphics_object& go)
  {
    if (go.isa ("figure"))
      {
	octave_value ov = go.get (caseless_str ("__plot_stream__"));
	figure_manager::Instance ().delete_window (ov.string_value ());
      }
  }

  void property_changed (const graphics_object& go, int id)
  {
    if (go.isa ("figure"))
      {
	octave_value ov = go.get (caseless_str ("__plot_stream__"));
	
	if (! ov.is_empty ())
	  {
	    switch (id)
	      {
	      case base_properties::VISIBLE:
		// FIXME: something to do here
		break;
	      }
	  }
      }
  }

  void redraw_figure (const graphics_handle& fh) const
  {
    figure_manager::Instance ().mark_modified (fh);
  }

  void print_figure (const graphics_handle& /*fh*/,
		     const std::string& /*term*/,
		     const std::string& /*file*/, bool /*mono*/,
		     const std::string& /*debug_file*/) const { }

  Matrix get_canvas_size (const graphics_handle& fh) const
  {
    return figure_manager::Instance ().get_size (fh);
  }

  double get_screen_resolution (void) const
  {
    // FLTK doesn't give this info
    return 72.0;
  }

  Matrix get_screen_size (void) const
  {
    Matrix sz (1, 2, 0.0);
    sz(0) = Fl::w ();
    sz(1) = Fl::h ();
    return sz;
  }
};

static bool backend_registered = false;
// give FLTK no more than 0.01 sec to do it's stuff
static double fltk_maxtime = 1e-2;

static int
__fltk_redraw__ (void)
{
  if (backend_registered)
    {
      // we scan all figures and add those which use FLTK as a backend
      graphics_object obj = gh_manager::get_object (0);
      if (obj && obj.isa ("root_figure"))
	{
	  base_properties& props = obj.get_properties ();
	  Matrix children = props.get_children ();

	  for (octave_idx_type n = 0; n < children.numel (); n++)
	    {
	      graphics_object fobj = gh_manager::get_object (children (n));
	      if (fobj && fobj.isa ("figure"))
		{
		  figure::properties& fp =
		      dynamic_cast<figure::properties&> (fobj.get_properties ());
		  if (fp.get___backend__ () == FLTK_BACKEND_NAME)
		    figure_manager::Instance ().new_window (fp);
		}
	    }
	}

      Fl::wait (fltk_maxtime);
    }

  return 0;
}

// call this to init the fltk backend
DEFUN_DLD (__init_fltk__, , , "")
{
  if (! backend_registered)
    {
      graphics_backend::register_backend (new fltk_backend);
      backend_registered = true;
      
      command_editor::add_event_hook (__fltk_redraw__);
    }

  octave_value retval;
  return retval;
}


// call this to delete the fltk backend
DEFUN_DLD (__remove_fltk__, , , "")
{
  if (backend_registered)
    {
      figure_manager::Instance ().close_all ();
      graphics_backend::unregister_backend (FLTK_BACKEND_NAME);
      backend_registered = false;

      command_editor::remove_event_hook (__fltk_redraw__);

      // FIXME ???
      // give FLTK 10 seconds to wrap it up
      Fl::wait(10);
    }

  octave_value retval;
  return retval;	
}

// call this to delete the fltk backend
DEFUN_DLD (__fltk_maxtime__, args, ,"")
{
  octave_value retval = fltk_maxtime;

  if (args.length () == 1)
    {
      if (args(0).is_real_scalar ())
      fltk_maxtime = args(0).double_value ();
    else
      error ("argument must be a real scalar");
    }

  return retval;
}

#endif

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/