#include "eglcommon.h"


#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>
#include <VG/openvg.h>  /* using full OpenGL for now */
#include <EGL/egl.h>


static init_func    init = 0;
static draw_func    draw = 0;
static reshape_func reshape = 0;
static key_func     keyPress = 0;
static VGint width = 300, height = 300;
static EGLint alpha_size = 0;


void set_window_alpha_size(int size)
{
   alpha_size = size;
}

void set_window_size(int w, int h)
{
   width = w;
   height = h;
}

/*
 * Create an RGB, double-buffered X window.
 * Return the window and context handles.
 */
static void
make_x_window(Display *x_dpy, EGLDisplay egl_dpy,
              const char *name,
              int x, int y, int width, int height,
              Window *winRet,
              EGLContext *ctxRet,
              EGLSurface *surfRet)
{
   EGLint attribs[] = {
      EGL_RED_SIZE, 1,
      EGL_GREEN_SIZE, 1,
      EGL_BLUE_SIZE, 1,
      EGL_ALPHA_SIZE, alpha_size,
      EGL_RENDERABLE_TYPE, EGL_OPENVG_BIT,
      EGL_NONE
   };

   int scrnum;
   XSetWindowAttributes attr;
   unsigned long mask;
   Window root;
   Window win;
   XVisualInfo *visInfo, visTemplate;
   int num_visuals;
   EGLContext ctx;
   EGLConfig config;
   EGLint num_configs;
   EGLint vid;

   scrnum = DefaultScreen( x_dpy );
   root = RootWindow( x_dpy, scrnum );

   if (!eglChooseConfig( egl_dpy, attribs, &config, 1, &num_configs) ||
       !num_configs) {
      printf("Error: couldn't get an EGL visual config\n");
      exit(1);
   }

   assert(config);

   if (!eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
      printf("Error: eglGetConfigAttrib() failed\n");
      exit(1);
   }

   /* The X window visual must match the EGL config */
   visTemplate.visualid = vid;
   visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
   if (!visInfo) {
      printf("Error: couldn't get X visual\n");
      exit(1);
   }

   /* window attributes */
   attr.background_pixel = 0;
   attr.border_pixel = 0;
   attr.colormap = XCreateColormap( x_dpy, root, visInfo->visual, AllocNone);
   attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
   mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;

   win = XCreateWindow( x_dpy, root, 0, 0, width, height,
		        0, visInfo->depth, InputOutput,
		        visInfo->visual, mask, &attr );

   /* set hints and properties */
   {
      XSizeHints sizehints;
      sizehints.x = x;
      sizehints.y = y;
      sizehints.width  = width;
      sizehints.height = height;
      sizehints.flags = USSize | USPosition;
      XSetNormalHints(x_dpy, win, &sizehints);
      XSetStandardProperties(x_dpy, win, name, name,
                              None, (char **)NULL, 0, &sizehints);
   }

   eglBindAPI(EGL_OPENVG_API);

   ctx = eglCreateContext(egl_dpy, config, EGL_NO_CONTEXT, NULL );
   if (!ctx) {
      printf("Error: eglCreateContext failed\n");
      exit(1);
   }

   *surfRet = eglCreateWindowSurface(egl_dpy, config, win, NULL);

   if (!*surfRet) {
      printf("Error: eglCreateWindowSurface failed\n");
      exit(1);
   }

   XFree(visInfo);

   *winRet = win;
   *ctxRet = ctx;
}

static void
event_loop(Display *dpy, Window win,
           EGLDisplay egl_dpy, EGLSurface egl_surf)
{
   while (1) {
      int redraw = 0;
      XEvent event;

      XNextEvent(dpy, &event);

      switch (event.type) {
      case Expose:
         redraw = 1;
         break;
      case ConfigureNotify:
         if (reshape) {
            width = event.xconfigure.width;
            height = event.xconfigure.height;
            reshape(event.xconfigure.width, event.xconfigure.height);
         }
         break;
      case KeyPress:
      {
         char buffer[10];
         int r, code;
         code = XLookupKeysym(&event.xkey, 0);
         if (!keyPress || !keyPress(code)) {
            r = XLookupString(&event.xkey, buffer, sizeof(buffer),
                              NULL, NULL);
            if (buffer[0] == 27) {
               /* escape */
               return;
            }
         }
      }
      redraw = 1;
      break;
      default:
         ; /*no-op*/
      }

      if (redraw) {
         draw();
         eglSwapBuffers(egl_dpy, egl_surf);
      }
   }
}

int window_width(void)
{
   return width;
}

int window_height(void)
{
   return height;
}

static void
usage(void)
{
   printf("Usage:\n");
   printf("  -display <displayname>  set the display to run on\n");
   printf("  -info                   display OpenGL renderer info\n");
}

int run(int argc, char **argv,
        init_func init_f,
        reshape_func resh_f,
        draw_func draw_f,
        key_func key_f)
{
   const int winWidth = width, winHeight = height;
   Display *x_dpy;
   Window win;
   EGLSurface egl_surf;
   EGLContext egl_ctx;
   EGLDisplay egl_dpy;
   char *dpyName = NULL;
   EGLBoolean printInfo = EGL_FALSE;
   EGLint egl_major, egl_minor;
   int i;
   const char *s;

   init = init_f;
   draw = draw_f;
   reshape = resh_f;
   keyPress = key_f;

   for (i = 1; i < argc; i++) {
      if (strcmp(argv[i], "-display") == 0) {
         dpyName = argv[i+1];
         i++;
      }
      else if (strcmp(argv[i], "-info") == 0) {
         printInfo = EGL_TRUE;
      }
   }

   x_dpy = XOpenDisplay(dpyName);
   if (!x_dpy) {
      printf("Error: couldn't open display %s\n",
	     dpyName ? dpyName : getenv("DISPLAY"));
      return -1;
   }

   egl_dpy = eglGetDisplay(x_dpy);
   if (!egl_dpy) {
      printf("Error: eglGetDisplay() failed\n");
      return -1;
   }

   if (!eglInitialize(egl_dpy, &egl_major, &egl_minor)) {
      printf("Error: eglInitialize() failed\n");
      return -1;
   }

   s = eglQueryString(egl_dpy, EGL_VERSION);
   printf("EGL_VERSION = %s\n", s);

   make_x_window(x_dpy, egl_dpy,
                 "OpenVG Example", 0, 0, winWidth, winHeight,
                 &win, &egl_ctx, &egl_surf);

   XMapWindow(x_dpy, win);
   if (!eglMakeCurrent(egl_dpy, egl_surf, egl_surf, egl_ctx)) {
      printf("Error: eglMakeCurrent() failed\n");
      return -1;
   }

   if (printInfo) {
      printf("VG_RENDERER   = %s\n", (char *) vgGetString(VG_RENDERER));
      printf("VG_VERSION    = %s\n", (char *) vgGetString(VG_VERSION));
      printf("VG_VENDOR     = %s\n", (char *) vgGetString(VG_VENDOR));
   }

   if (init)
      init();

   /* Set initial projection/viewing transformation.
    * We can't be sure we'll get a ConfigureNotify event when the window
    * first appears.
    */
   if (reshape)
      reshape(winWidth, winHeight);

   event_loop(x_dpy, win, egl_dpy, egl_surf);

   eglMakeCurrent(egl_dpy, 0, 0, 0);
   eglDestroyContext(egl_dpy, egl_ctx);
   eglDestroySurface(egl_dpy, egl_surf);
   eglTerminate(egl_dpy);


   XDestroyWindow(x_dpy, win);
   XCloseDisplay(x_dpy);

   return 0;
}

