/*
 * GStreamer
 * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <Cocoa/Cocoa.h>

#include "gstgl_cocoa_private.h"

@implementation GstGLCAOpenGLLayer
- (void)dealloc {
  GST_TRACE ("dealloc GstGLCAOpenGLLayer %p context %p", self, self->gst_gl_context);

  [super dealloc];
}

- (id)initWithGstGLContext:(GstGLContextCocoa *)parent_gl_context {
  [super init];

  GST_TRACE ("init CAOpenGLLayer");

  self->gst_gl_context = parent_gl_context;

  return self;
}

- (CGLPixelFormatObj)copyCGLPixelFormatForDisplayMask:(uint32_t)mask {
  CGLPixelFormatObj fmt = NULL;

  if (self->gst_gl_context)
    fmt = gst_gl_context_cocoa_get_pixel_format (self->gst_gl_context);

  if (!fmt) {
    CGLPixelFormatAttribute attribs[] = {
      kCGLPFADoubleBuffer,
      kCGLPFAAccumSize, 32,
      0
    };
    CGLError ret;
    gint npix = 0;

    GST_DEBUG ("creating new pixel format for CAOpenGLLayer %p", self);

    ret = CGLChoosePixelFormat (attribs, &fmt, &npix);
    if (ret != kCGLNoError) {
      GST_ERROR ("CAOpenGLLayer cannot choose a pixel format: %s", CGLErrorString (ret));
    }
  }

  return fmt;
}

- (CGLContextObj)copyCGLContextForPixelFormat:(CGLPixelFormatObj)pixelFormat {
  CGLContextObj external_context = NULL;
  CGLError ret;

  if (self->gst_gl_context)
    external_context = (CGLContextObj) gst_gl_context_get_gl_context (GST_GL_CONTEXT (self->gst_gl_context));

  GST_INFO ("attempting to create CGLContext for CAOpenGLLayer with "
      "share context %p", external_context);

  ret = CGLCreateContext (pixelFormat, external_context, &self->gl_context);
  if (ret != kCGLNoError) {
    GST_ERROR ("failed to create CGL context in CAOpenGLLayer with share context %p: %s", external_context, CGLErrorString(ret));
  }

  return self->gl_context;
}

- (void)resize:(NSRect)bounds {
  const GstGLFuncs *gl = ((GstGLContext *)self->gst_gl_context)->gl_vtable;

  gl->GetIntegerv (GL_VIEWPORT, self->expected_dims);
}

- (void)releaseCGLContext:(CGLContextObj)glContext {
  CGLReleaseContext (glContext);
}

- (void)drawInCGLContext:(CGLContextObj)glContext
               pixelFormat:(CGLPixelFormatObj)pixelFormat
            forLayerTime:(CFTimeInterval)interval
             displayTime:(const CVTimeStamp *)timeStamp {
  GstGLWindow *window = gst_gl_context_get_window (GST_GL_CONTEXT (self->gst_gl_context));
  const GstGLFuncs *gl = ((GstGLContext *)self->gst_gl_context)->gl_vtable;
  gint ca_viewport[4];

  GST_LOG ("CAOpenGLLayer drawing with window %p cgl context %p", window, glContext);

  /* attempt to get the correct viewport back due to CA being too smart
   * and messing around with it so center the expected viewport into
   * the CA viewport set up on entry to this function */
  gl->GetIntegerv (GL_VIEWPORT, ca_viewport);

  GstVideoRectangle src, dst, result;

  src.x = self->expected_dims[0];
  src.y = self->expected_dims[1];
  src.w = self->expected_dims[2];
  src.h = self->expected_dims[3];

  dst.x = ca_viewport[0];
  dst.y = ca_viewport[1];
  dst.w = ca_viewport[2];
  dst.h = ca_viewport[3];

  gst_video_sink_center_rect (src, dst, &result, TRUE);

  gl->Viewport (result.x, result.y, result.w, result.h);

  if (window) {
    gst_gl_window_cocoa_draw_thread (GST_GL_WINDOW_COCOA (window));

    gst_object_unref (window);
  }

  /* flushes the buffer */
  [super drawInCGLContext:glContext pixelFormat:pixelFormat forLayerTime:interval displayTime:timeStamp];
}

@end