// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.

#ifndef toolx_Xt_sg_viewer
#define toolx_Xt_sg_viewer

#include "session"

#ifndef GL_GLEXT_LEGACY
#define GL_GLEXT_LEGACY
#endif
#include <GL/gl.h>

#ifdef TOOLS_USE_GL_VERSION_3_2
  #ifndef GL_GLEXT_PROTOTYPES
  #define GL_GLEXT_PROTOTYPES
  #endif
  #include <GL/glext.h>
#endif

#include "../GL/gl_functions"

#include "../sg/GL_action"
#include "../sg/GL_viewer"

namespace toolx {
namespace sg {
  using GL_action = GL_action_T<GL::gl_functions>;
  using GL_manager = GL_manager_T<GL::gl_functions>;
  using GL_viewer = GL_viewer_T<GL_manager,GL_action>;
}}

#include "OpenGLArea"

#include <X11/Shell.h>
#include <X11/StringDefs.h>
#include <X11/IntrinsicP.h>

#include <tools/num2s>
#include <tools/sg/device_interactor>
#include <tools/sg/keys>

namespace toolx {
namespace Xt {

class sg_viewer : public sg::GL_viewer {
  typedef sg::GL_viewer parent;
public:
  sg_viewer(session& a_session,
            int a_x = 0,int a_y = 0,
            unsigned int a_width = 500,unsigned int a_height = 500,
            const std::string& a_win_title = "")
  :parent(a_session.out(),a_width,a_height)
  ,m_session(a_session)
  ,m_shell(0)
  ,m_glarea(0)
  ,m_interactor(0)
  {
    Widget app_widget = a_session.get_app_widget();
    if(!app_widget) return;

    std::string sgeom;
    tools::numas(a_width,sgeom);
    sgeom += "x";
    tools::numas(a_height,sgeom);
    sgeom += "+";
    tools::numas(a_x,sgeom);
    sgeom += "+";
    tools::numas(a_y,sgeom);

    Arg args[2];
    XtSetArg(args[0],XtNgeometry,XtNewString(sgeom.c_str()));
    XtSetArg(args[1],XtNborderWidth,0);

    m_shell = ::XtAppCreateShell((char*)a_win_title.c_str(),
                                 (char*)"sg_viewer_shell",
                                 topLevelShellWidgetClass,XtDisplay(app_widget),args,2);
    ::XtSetMappedWhenManaged(m_shell,True);
  
    m_glarea = ::XtCreateManagedWidget("glarea",OpenGLArea::widget_class(),m_shell,args,0);
    ::XtAddCallback(m_glarea,XoNpaintCallback,paint_cbk,(XtPointer)this);
    ::XtAddCallback(m_glarea,XoNeventCallback,event_cbk,(XtPointer)this);

    ::XtAddCallback(m_shell,XtNdestroyCallback,destroy_shell_callback,(XtPointer)this);
    
    ::XtRealizeWidget(m_shell);
  }
  virtual ~sg_viewer() {
    if(m_shell) {
      ::XtRemoveCallback(m_glarea,XoNpaintCallback,paint_cbk,(XtPointer)this);
      ::XtRemoveCallback(m_shell,XtNdestroyCallback,destroy_shell_callback,(XtPointer)this);
      ::XtDestroyWidget(m_shell);
    }
    m_shell = 0;
    m_glarea = 0;
  }
protected:
  sg_viewer(const sg_viewer& a_from)
  :parent(a_from)
  ,m_session(a_from.m_session)
  ,m_shell(0)
  ,m_glarea(0)
  ,m_interactor(0)
  {}
  sg_viewer& operator=(const sg_viewer& a_from){
    parent::operator=(a_from);
    return *this;
  }
public:
  bool has_window() const {return m_glarea?true:false;}

  bool show() {
    if(!m_shell) return false;
    ::XtRealizeWidget(m_shell);
    ::XtMapWidget(m_shell);
    // Raise window :
    if(XtIsWidget(m_shell) && XtIsRealized(m_shell) ) {
      Display* display = XtDisplay(m_shell);
      Atom atom = ::XInternAtom(display,"WM_DELETE_WINDOW",False);
      ::XSetWMProtocols(display,XtWindow(m_shell),&atom,1);
      ::XRaiseWindow(display,XtWindow(m_shell));
    }
    return true;
  }

  void win_render() {
    if(!m_glarea) return;
    OpenGLArea::paint(m_glarea);
    m_session.sync();
  }

  void emit_win_render() {
    if(!m_glarea) return;
    if(!post_expose(m_glarea)) {}
  }

  bool window_size(unsigned int& a_w,unsigned int& a_h) {
    if(!m_glarea) {a_w = 0;a_h = 0;return false;}
    a_w = (unsigned int)m_glarea->core.width;
    a_h = (unsigned int)m_glarea->core.height;
    return true;
  }
  void render_area_size(unsigned int& a_w,unsigned int& a_h) {
    a_w = parent::width();
    a_h = parent::height();
  }

public:
  void set_device_interactor(tools::sg::device_interactor* a_interactor) {m_interactor = a_interactor;} //we do not have ownership.
protected:
  static void paint_cbk(Widget a_widget,XtPointer a_tag,XtPointer){
    unsigned int width = a_widget->core.width;
    unsigned int height = a_widget->core.height;
    sg_viewer* _this = (sg_viewer*)a_tag;
    _this->set_size(width,height);
    _this->render();
  }
  static void event_cbk(Widget,XtPointer a_tag,XtPointer a_data){
    sg_viewer* _this = (sg_viewer*)a_tag;
    if(!_this->m_interactor) return;
    XoAnyCallbackStruct* data = (XoAnyCallbackStruct*)a_data;
    XEvent* xevent = data->event;
    switch( xevent->type ) {
    case KeyPress:{
      KeySym key_sym;
      ::XLookupString(&(xevent->xkey),NULL,0,&key_sym,NULL);
      tools::sg::key_down_event event(_this->convert(key_sym));
      _this->m_interactor->key_press(event);
    }return;
    case KeyRelease:{
      KeySym key_sym;
      ::XLookupString(&(xevent->xkey),NULL,0,&key_sym,NULL);
      tools::sg::key_up_event event(_this->convert(key_sym));
      _this->m_interactor->key_release(event);
    }return;
    case ButtonPress:{
      bool shift_modifier = xevent->xkey.state & ShiftMask;
      bool control_modifier = xevent->xkey.state & ControlMask;
      if(xevent->xbutton.button==Button4) {  //4=wheel down, or move down double touch on trackpad = zoom in.
        tools::sg::wheel_rotate_event event(8,xevent->xbutton.x,xevent->xbutton.y,shift_modifier,control_modifier);  //8=cooking.
        _this->m_interactor->wheel_rotate(event);
      } else if(xevent->xbutton.button==Button5) {  //5=wheel up, or move up double touch on trackpad = zoom out.
        tools::sg::wheel_rotate_event event(-8,xevent->xbutton.x,xevent->xbutton.y,shift_modifier,control_modifier);  //8=cooking.
        _this->m_interactor->wheel_rotate(event);
      } else if(xevent->xbutton.button==Button1) {
        tools::sg::mouse_down_event event(xevent->xbutton.x,xevent->xbutton.y,shift_modifier,control_modifier);
        _this->m_interactor->mouse_press(event);
      }
    }return;
    case ButtonRelease:{
      if(xevent->xbutton.button==Button1) {
        bool shift_modifier = xevent->xkey.state & ShiftMask;
        bool control_modifier = xevent->xkey.state & ControlMask;
        tools::sg::mouse_up_event event(xevent->xbutton.x,xevent->xbutton.y,shift_modifier,control_modifier);
        _this->m_interactor->mouse_release(event);
      }
    }return;
    case MotionNotify:{
      if((xevent->xmotion.state & Button1MotionMask)==Button1MotionMask) {
        bool shift_modifier = xevent->xkey.state & ShiftMask;
        bool control_modifier = xevent->xkey.state & ControlMask;
        tools::sg::mouse_move_event event(xevent->xmotion.x,xevent->xmotion.y,shift_modifier,control_modifier,0,0,false);
        _this->m_interactor->mouse_move(event);
      }
    }return;
    default:return;}
  }
  static void destroy_shell_callback(Widget,XtPointer a_tag,XtPointer) {
    sg_viewer* _this = (sg_viewer*)a_tag;
    _this->m_shell = 0;
    _this->m_glarea = 0;
  }
protected:
  tools::key_code convert(KeySym a_key) {
    if(a_key==XK_Shift_L) return tools::sg::key_shift();
    if(a_key==XK_Shift_R) return tools::sg::key_shift();
    return (tools::key_code)a_key;
  }
protected:
  session& m_session;
  Widget m_shell;
  Widget m_glarea;
  tools::sg::device_interactor* m_interactor;
};

}}

#endif