#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <X11/Xlib.h>

#include <Imlib2.h>
#include <Evas.h>
#include <Ecore.h>
#include <Ecore_X.h>
#include <Ecore_Evas.h>
#include <Edje.h>

#define DATA_PATH "data"

typedef struct _E_Band E_Band;

void _eg_band_show();
void _eg_band_hide();
void _eg_band_resize(int w, int h);
void _eg_band_move(int x, int y);

void _eg_init();

static int _eg_event_mouse_move_cb(void *data, int type, void *event);
static int _eg_event_mouse_up_cb(void *data, int type, void *event);

/* initial coords of region to grab */
int grab_x, grab_y;

/* the rubber band object */
static E_Band *band = NULL;

/* mouse move event */
static Ecore_Event_Handler *event_mouse_move = NULL;

/* mouse button up event */
static Ecore_Event_Handler *event_mouse_up = NULL;

/* input window that us used to get X events */
static Ecore_X_Window input_window;

/* rubber band structure */
struct _E_Band
{
  /* gui components */
  Ecore_Evas *ee;
  Evas *evas;
  Evas_Object *edj;
};

/**
 * Grab a part of the screen and return as an Evas object
 */
Evas_Object *_eg_screen_area_grab(int x, int y, int w, int h)
{
  Imlib_Image im;
  Evas_Object *ob;  

  imlib_context_set_display(ecore_x_display_get());
  imlib_context_set_drawable(RootWindow(ecore_x_display_get(),0));
  imlib_context_set_visual( DefaultVisual(ecore_x_display_get(), DefaultScreen(ecore_x_display_get() ) ));
  im = imlib_create_image_from_drawable(0, x,y,w,h,0);
  imlib_context_set_image(im);	     	     
  imlib_image_set_format("argb");

  ob = evas_object_image_add(band->evas);
  evas_object_image_size_set(ob, w, h);
  evas_object_image_data_copy_set(ob, imlib_image_get_data_for_reading_only());
  evas_object_image_fill_set(ob, 0, 0,  w, h);
  evas_object_resize(ob, w, h);	
  evas_object_image_alpha_set(ob, 0);
  imlib_free_image();

  return ob;
}

/**
 * Show rubber band
 */
void _eg_band_show()
{
  /* create rubber band if it doesnt exist */
  if (!band)
  {
    /* allocate memory, create Ecore_Evas, create Edje object */
    band = calloc(1, sizeof(E_Band));
    band->ee = ecore_evas_software_x11_new(NULL, 0, 0, 0, 0, 0);
    band->evas = ecore_evas_get(band->ee);


    /* check if we have composite, if we do, use translucency */
    if (ecore_x_composite_query() && 
        ecore_x_screen_is_composited(0))
    {
      ecore_evas_alpha_set(band->ee, 1);
    }
    else
    {
      /* we dont have composite, use shaped windows */
      ecore_evas_shaped_set(band->ee, 1);
    }
  
    band->edj = evas_object_image_add(band->evas);
    evas_object_image_file_set(band->edj, "data/images/rect.png", NULL);
    evas_object_image_border_set(band->edj, 3, 3, 3, 3);
    evas_object_move(band->edj, 0, 0);

    /* if we dont put these here, Evas messes up */
    evas_object_resize(band->edj, 50, 50);
    evas_object_image_fill_set(band->edj, 0, 0, 50, 50);

    /* let the window manager ignore this window, and make it borderless */
    ecore_evas_override_set(band->ee, 1);
    ecore_evas_borderless_set(band->ee, 1);
  }

  ecore_evas_show(band->ee);
  evas_object_show(band->edj);
}

/**
 * Hide rubber band
 */
void _eg_band_hide()
{
  if (!band)
    return;

  ecore_evas_hide(band->ee);
}

/**
 * Resize rubber band
 */
void _eg_band_resize(int w, int h)
{
  if (!band)
    return;

  ecore_evas_resize(band->ee, w, h);
  /* this is also the same problem with Evas as above */
  if (w >= 6 && h >= 6)
  {
    evas_object_resize(band->edj, w, h);
    evas_object_image_fill_set(band->edj, 0, 0, w, h);
  }
  _eg_band_show();
}

/**
 * Move the rubber band
 */
void _eg_band_move(int x, int y)
{
  if (!band)
    return;

  ecore_evas_move(band->ee, x, y);
}

/**
 * Start the selection of a region to grab
 */
void _eg_grab_region_start()
{
  int px, py;
  int sw, sh;

  /* attach callbacks to mouse movement and click so
   * we can resize the rubber band and hide it on a click
   */
  event_mouse_move = ecore_event_handler_add(ECORE_X_EVENT_MOUSE_MOVE,
                      _eg_event_mouse_move_cb, NULL);
  event_mouse_up = ecore_event_handler_add(ECORE_X_EVENT_MOUSE_BUTTON_UP,
                    _eg_event_mouse_up_cb, NULL);
   
  /* get our desktop's width and height */
  ecore_x_window_geometry_get(0, NULL, NULL, &sw, &sh);

  /* set up our input window to grab X events */
  input_window = ecore_x_window_input_new(0, 0, 0, sw, sh);
  ecore_x_window_show(input_window);

  /* get our mouse cursor's curret x and y coords */
  ecore_x_pointer_xy_get(input_window, &px, &py);
  
  /* set initial grabbing coords */
  grab_x = px;
  grab_y = py;

  /* show the rubber band */
  _eg_band_show();

/* move the rubber band */
  _eg_band_move(grab_x, grab_y);
}

/**
 * End the selection of a region
 */
void _eg_grab_region_end()
{
  int x, y, w, h;
  Evas_Object *shot;

  /* detach the events we added to move movement and click */
  ecore_event_handler_del(event_mouse_move);
  ecore_event_handler_del(event_mouse_up);

  /* hide and delete our input window */
  ecore_x_window_hide(input_window);
  ecore_x_window_delete_request_send(input_window);

  /* get the proper coords */
  ecore_evas_geometry_get(band->ee, &x, &y, &w, &h);

  /* hide the rubber band */
  _eg_band_hide();

  /* grab and save the shot to disk */
  shot = _eg_screen_area_grab(x, y, w, h);
  if (!evas_object_image_save(shot, "/tmp/egrab_tmp.jpg", NULL, NULL))
  {
    fprintf(stderr, "WARNING: Could not save screenshot to disk!\n");
  }
  evas_object_del(shot);

  /* quit the application */
  ecore_main_loop_quit();
}

/**
 * Called when a region grab is in progress and the mouse is moving
 */
static int _eg_event_mouse_move_cb(void *data, int type, void *event)
{
  int w, h;
  Ecore_X_Event_Mouse_Move *ev = event;

  w = ev->root.x - grab_x;
  h = ev->root.y - grab_y;
  
  /* figure out how to move the band */
  if (w < 0 && h < 0)
  {
    int x, y;
    ecore_x_pointer_xy_get(input_window, &x, &y);
    
    _eg_band_move(x, y);
    _eg_band_resize(-w, -h);
  }
  else if (w < 0 &&  h > 0)
  {
    int x, y;
    ecore_x_pointer_xy_get(input_window, &x, &y);
    
    _eg_band_move(x, grab_y);
    _eg_band_resize(-w, h);
  }
  else if (w > 0 && h < 0)
  {
    int x, y;
    ecore_x_pointer_xy_get(input_window, &x, &y);
    
    _eg_band_move(grab_x, y);
    _eg_band_resize(w, -h);

  }
  else
  {
    _eg_band_resize(w, h);
  }

  return 1;
}

/**
 * Called when a region grab is in progress and the mouse button is depressed
 */
static int _eg_event_mouse_up_cb(void *data, int type, void *event)
{
  _eg_grab_region_end();
  
  return 1;
}

/**
 * Initialize Ecore_X with proper display
 * FIXME: This is segfaulting. Cant call ecore_x_window_root_list if not
 * init'ed.
 */
void _eg_init()
{
  Ecore_X_Window *roots;
  int screens, i;
  char *dispstr, *subdisp;
  char newdisp[255];

  roots = ecore_x_window_root_list(&screens);
  dispstr = DisplayString(ecore_x_display_get());
  subdisp = strdup(dispstr);

  for (i = 0; i < screens; i++) 
  {
    dispstr = strchr(subdisp, ':');
    if (dispstr) 
    {
      dispstr = strchr(dispstr, '.');
      if (NULL != dispstr)
        *dispstr = '\0';
    }

    snprintf(newdisp, sizeof(newdisp), "%s.%d", subdisp, i);
    ecore_x_init(newdisp);
  }
}

int main(char *argc, char **argv)
{
  ecore_init();
  ecore_evas_init();
  ecore_x_init(NULL);
  edje_init();

  _eg_grab_region_start();

  ecore_main_loop_begin();

  edje_shutdown();
  ecore_x_shutdown();
  ecore_evas_shutdown();
  ecore_shutdown();
  return 0;
}