/* 
 * Copyright (c) 2007, 2014, Oracle and/or its affiliates. All rights reserved.
 *
 * This program 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; version 2 of the
 * License.
 * 
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301  USA
 */

#include "layer_figure.h"
#include "figure_common.h"
#include <grts/structs.model.h>

using namespace std;
using namespace wbfig;
using namespace base;

#define MIN_LAYER_TITLE_WIDTH 120.0
#define MIN_LAYER_SIZE 10.0

//--------------------------------------------------------------------------------------------------

LayerAreaGroup::LayerAreaGroup(mdc::Layer *layer, FigureEventHub *hub, model_Object *represented_object)
: mdc::AreaGroup(layer), _represented_object(represented_object), _hub(hub)
{
  set_cache_toplevel_contents(false);

  set_auto_sizing(false);
//  set_background(_layer_back);
  set_draggable(true);

  // Even though the extents are invalid we set some reasonable default values for width and height.
  // This is necessary to make working with them in environments where the figure is never rendered
  // possible (e.g. in unit tests).
  _extents_invalid= true;
  _extents.width = 130;
  _extents.height = 20;

  _font= layer->get_view()->get_default_font();
  _font.weight= mdc::WBold;

  _title_fore= Color::Black();
  _title_back= Color(0.85, 0.85, 0.85);

  _min_size.width= MIN_LAYER_SIZE;
  _min_size.height= MIN_LAYER_SIZE;

  _drag_selects_contents= true;
  
  _resizing= false;

  _text_texture= 0;
  _display_list= 0;
}

//--------------------------------------------------------------------------------------------------

LayerAreaGroup::~LayerAreaGroup()
{
  if (_display_list != 0)
    glDeleteLists(_display_list, 1);

  if (_text_texture != 0)
    glDeleteTextures(1, &_text_texture);
}

//--------------------------------------------------------------------------------------------------

void LayerAreaGroup::set_title(const std::string &title)
{
  _title= title;
  _extents_invalid= true;
  set_needs_repaint();
}


void LayerAreaGroup::set_font(const mdc::FontSpec &font)
{
  _font= font;
  _extents_invalid= true;
  set_needs_repaint();
}


static void get_bounding_area(mdc::CanvasItem *item, Point *maxpos)
{
  Rect bounds= item->get_bounds();

  maxpos->x= max(maxpos->x, bounds.right());
  maxpos->y= max(maxpos->y, bounds.bottom());
}


void LayerAreaGroup::move_item(mdc::CanvasItem *item, const Point &pos)
{
  item->move_to(pos);
}


bool LayerAreaGroup::on_drag_handle(mdc::ItemHandle *handle, const Point &pos, bool dragging)
{
  if (!_resizing)
  {
    Point maxpos;

    _initial_bounds= get_root_bounds();
    _resizing= true;

    foreach(boost::bind(get_bounding_area, _1, &maxpos));

    _min_size.width= max(maxpos.x, MIN_LAYER_SIZE);
    _min_size.height= max(maxpos.y, MIN_LAYER_SIZE);
    _min_size_invalid= false;
  }

  bool flag= mdc::AreaGroup::on_drag_handle(handle, get_view()->snap_to_grid(pos), dragging);

  if (!dragging)
  {
    _resizing= false;
    _min_size.width= MIN_LAYER_SIZE;
    _min_size.height= MIN_LAYER_SIZE;
    _min_size_invalid= false;

    _resize_signal(_initial_bounds);
  }

  return flag;
}


bool LayerAreaGroup::on_button_press(mdc::CanvasItem *target, const Point &point, mdc::MouseButton button, mdc::EventState state)
{
  if (mdc::bounds_contain_point(get_title_bounds(), point.x, point.y))
  {
    _drag_selects_contents= false;
  }

  if (!_hub || !_hub->figure_button_release(_represented_object, target, point, button, state))
    return super::on_button_press(target, point, button, state);
  
  return false;
}


bool LayerAreaGroup::on_button_release(mdc::CanvasItem *target, const Point &point, mdc::MouseButton button, mdc::EventState state)
{
  bool ret= false;
  
  if (!_hub || !_hub->figure_button_release(_represented_object, target, point, button, state))
    ret= super::on_button_release(target, point, button, state);

  _drag_selects_contents= true;
  
  return ret;
}

//--------------------------------------------------------------------------------------------------

bool LayerAreaGroup::on_click(mdc::CanvasItem *target, const Point &point, mdc::MouseButton button, mdc::EventState state)
{
  if (!_hub || !_hub->figure_click(_represented_object, target, point, button, state))
    return mdc::AreaGroup::on_click(target, point, button, state);

  return false;
}

//--------------------------------------------------------------------------------------------------

bool LayerAreaGroup::on_double_click(mdc::CanvasItem *target, const Point &point, mdc::MouseButton button, mdc::EventState state)
{
  if (!_hub || !_hub->figure_double_click(_represented_object, target, point, button, state))
    return mdc::AreaGroup::on_double_click(target, point, button, state);

  return false;
}

//--------------------------------------------------------------------------------------------------

bool LayerAreaGroup::on_enter(mdc::CanvasItem *target, const Point &point)
{
  if (!_hub || !_hub->figure_enter(_represented_object, target, point))
    return super::on_enter(target, point);
  return false;
}


bool LayerAreaGroup::on_leave(mdc::CanvasItem *target, const Point &point)
{
  if (!_hub || !_hub->figure_leave(_represented_object, target, point))
    return super::on_leave(target, point);
  return false;
}

#define TEXT_PADDING 5

void LayerAreaGroup::render(mdc::CairoCtx *cr)
{
  mdc::AreaGroup::render(cr);

  if (_extents_invalid)
  {
    cr->get_text_extents(_font, _title, _extents);
    _extents_invalid= false;
  }

  Size size= get_title_bounds().size;

  cr->save();
  cr->translate(get_position());
  cr->set_color(_title_back);
  cr->new_path();
  cr->move_to(Point(0, 0));
  cr->line_to(Point(size.width, 0));
  cr->line_to(Point(size.width, size.height-5));
  cr->line_to(Point(size.width-5, size.height));
  cr->line_to(Point(0, size.height));
  cr->close_path();
  cr->fill();

  cr->set_color(_title_fore);
  cr->move_to(Point(TEXT_PADDING + _extents.x_bearing, TEXT_PADDING - _extents.y_bearing));
  cr->set_font(_font);
  cr->show_text(_title);
  
  cr->restore();
}

//--------------------------------------------------------------------------------------------------

void LayerAreaGroup::render_gl(mdc::CairoCtx *cr) 
{ 
  mdc::AreaGroup::render_gl(cr); 
 
  if (_extents_invalid) 
  { 
    cr->get_text_extents(_font, _title, _extents); 
    _extents_invalid= false; 
  } 
 
  Size size= get_title_bounds().size; 
  Point text_position= Point(_extents.x_bearing, -_extents.y_bearing);
 
  // Render caption for the layer figure. This is done via Cairo and a texture.
  bool generate_display_list= _display_list == 0;

  // Check if we need to regenerate the cache. if so, do it and load it as a texture.
  Size texture_size= get_texture_size(size);
  if (_needs_render || _text_texture == 0)
  {
    generate_display_list= true;

    // Create a temporary surface we can render the text into.
    cairo_surface_t* surface= cairo_image_surface_create(CAIRO_FORMAT_ARGB32, (unsigned int) texture_size.width, (unsigned int) texture_size.height);
    _layer->get_view()->bookkeep_cache_mem(cairo_image_surface_get_stride(surface) * cairo_image_surface_get_height(surface));
    memset(cairo_image_surface_get_data(surface), 0,
           cairo_image_surface_get_stride(surface) * cairo_image_surface_get_height(surface));

    // Create a context for the temporary surface and render the text.
    mdc::CairoCtx texture_context(surface);
    texture_context.set_color(_title_fore); 
    texture_context.move_to(text_position); 
    texture_context.set_font(_font); 
    texture_context.show_text(_title); 
    _needs_render= false;

    if (_text_texture == 0)
      glGenTextures(1, &_text_texture);

    // setup the texture
    glBindTexture(GL_TEXTURE_2D, _text_texture);
    
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    // don't tile the image
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

    // load the texture into opengl
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, (int) texture_size.width,  (int) texture_size.height, 0,
      GL_BGRA, GL_UNSIGNED_BYTE, cairo_image_surface_get_data(surface));

    // Once we transferred the pixel data we don't need the cache anymore.
    _layer->get_view()->bookkeep_cache_mem(-cairo_image_surface_get_stride(surface) * cairo_image_surface_get_height(surface));
    cairo_surface_destroy(surface);
  }

  glMatrixMode(GL_MODELVIEW);
  glPushMatrix(); 
  glTranslated(get_position().x, get_position().y, 0); 

  if (generate_display_list)
  {
    if (_display_list == 0)
      _display_list= glGenLists(1);

    glNewList(_display_list, GL_COMPILE);

    mdc::gl_setcolor(_title_back); 
   
    glBegin(GL_POLYGON); 
      glVertex2f(0.0, 0.0); 
      glVertex2d(size.width, 0); 
      glVertex2d(size.width, size.height - 5); 
      glVertex2d(size.width - 5, size.height); 
      glVertex2d(0, size.height); 
    glEnd(); 
   
    glEnable(GL_TEXTURE_2D);
    
    // Render the texture.
    glBindTexture(GL_TEXTURE_2D, _text_texture);
    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
    glTranslated(TEXT_PADDING, TEXT_PADDING, 0);
    glBegin(GL_QUADS);

    // Due to round-up to power of two the actual texture coordinates are usually somewhere within the actual texture.
    cairo_user_to_device_distance(_layer->get_view()->cairoctx()->get_cr(), &size.width, &size.height);

    double max_x_coordinate= size.width / texture_size.width;
    double max_y_coordinate= size.height / texture_size.height;

    glTexCoord2d(0, 0);
    glVertex2d(0, 0);

    glTexCoord2d(max_x_coordinate, 0);
    glVertex2d(size.width, 0);

    glTexCoord2d(max_x_coordinate, max_y_coordinate);
    glVertex2d(size.width, size.height);

    glTexCoord2d(0, max_y_coordinate);
    glVertex2d(0, size.height);

    glEnd();
    glDisable(GL_TEXTURE_2D);

    glEndList();
  }

  glCallList(_display_list);

  glPopMatrix();
} 

Rect LayerAreaGroup::get_title_bounds() const
{
  Rect rect;
  
  double width= _extents.width + 10;
  if (width < MIN_LAYER_TITLE_WIDTH)
    width= MIN_LAYER_TITLE_WIDTH;
  
  Size size= get_size();

  if (width > size.width - _extents.height - 2 * TEXT_PADDING)
    width= size.width - _extents.height - 2 * TEXT_PADDING;

  rect.size.width= width + 2 * TEXT_PADDING;
  rect.size.height= _extents.height + 2 * TEXT_PADDING;

  return rect;
}