/* GStreamer
 *
 * Copyright (C) 2016 Igalia
 *
 * Authors:
 *  Víctor Manuel Jáquez Leal <vjaquez@igalia.com>
 *  Javier Martin <javiermartin@by.com.es>
 *
 * 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 <drm_fourcc.h>

#include "gstkmsutils.h"

/* *INDENT-OFF* */
static const struct
{
  guint32 fourcc;
  GstVideoFormat format;
} format_map[] = {
#define DEF_FMT(fourcc, fmt) \
  { DRM_FORMAT_##fourcc,GST_VIDEO_FORMAT_##fmt }

  /* DEF_FMT (XRGB1555, ???), */
  /* DEF_FMT (XBGR1555, ???), */
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
  DEF_FMT (ARGB8888, BGRA),
  DEF_FMT (XRGB8888, BGRx),
  DEF_FMT (ABGR8888, RGBA),
  DEF_FMT (XBGR8888, RGBx),
#else
  DEF_FMT (ARGB8888, ARGB),
  DEF_FMT (XRGB8888, xRGB),
  DEF_FMT (ABGR8888, ABGR),
  DEF_FMT (XBGR8888, xBGR),
#endif
  DEF_FMT (UYVY, UYVY),
  DEF_FMT (YUYV, YUY2),
  DEF_FMT (YVYU, YVYU),
  DEF_FMT (YUV420, I420),
  DEF_FMT (YVU420, YV12),
  DEF_FMT (YUV422, Y42B),
  DEF_FMT (NV12, NV12),
  DEF_FMT (NV21, NV21),
  DEF_FMT (NV16, NV16),

#undef DEF_FMT
};
/* *INDENT-ON* */

GstVideoFormat
gst_video_format_from_drm (guint32 drmfmt)
{
  gint i;

  for (i = 0; i < G_N_ELEMENTS (format_map); i++) {
    if (format_map[i].fourcc == drmfmt)
      return format_map[i].format;
  }

  return GST_VIDEO_FORMAT_UNKNOWN;
}

guint32
gst_drm_format_from_video (GstVideoFormat fmt)
{
  gint i;

  for (i = 0; i < G_N_ELEMENTS (format_map); i++) {
    if (format_map[i].format == fmt)
      return format_map[i].fourcc;
  }

  return 0;
}

static GstStructure *
gst_video_format_to_structure (GstVideoFormat format)
{
  GstStructure *structure;

  structure = NULL;
  if (format != GST_VIDEO_FORMAT_UNKNOWN)
    structure = gst_structure_new ("video/x-raw", "format", G_TYPE_STRING,
        gst_video_format_to_string (format), NULL);

  return structure;
}

GstCaps *
gst_kms_sink_caps_template_fill (void)
{
  gint i;
  GstCaps *caps;
  GstStructure *template;

  caps = gst_caps_new_empty ();
  for (i = 0; i < G_N_ELEMENTS (format_map); i++) {
    template = gst_video_format_to_structure (format_map[i].format);
    gst_structure_set (template,
        "width", GST_TYPE_INT_RANGE, 1, G_MAXINT,
        "height", GST_TYPE_INT_RANGE, 1, G_MAXINT,
        "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL);
    gst_caps_append_structure (caps, template);
  }
  return gst_caps_simplify (caps);
}

static const gint device_par_map[][2] = {
  {1, 1},                       /* regular screen */
  {16, 15},                     /* PAL TV */
  {11, 10},                     /* 525 line Rec.601 video */
  {54, 59},                     /* 625 line Rec.601 video */
  {64, 45},                     /* 1280x1024 on 16:9 display */
  {5, 3},                       /* 1280x1024 on 4:3 display */
  {4, 3}                        /* 800x600 on 16:9 display */
};

#define DELTA(ratio, idx, w) \
  (ABS(ratio - ((gdouble)device_par_map[idx][w] / device_par_map[idx][!(w)])))

void
gst_video_calculate_device_ratio (guint dev_width, guint dev_height,
    guint dev_width_mm, guint dev_height_mm,
    guint * dpy_par_n, guint * dpy_par_d)
{
  gdouble ratio, delta, cur_delta;
  gint i, j, index, windex;

  /* First, calculate the "real" ratio based on the X values; which is
   * the "physical" w/h divided by the w/h in pixels of the display */
  if (dev_width == 0 || dev_height == 0
      || dev_width_mm == 0 || dev_height_mm == 0)
    ratio = 1.0;
  else
    ratio = (gdouble) (dev_width_mm * dev_height) / (dev_height_mm * dev_width);

  /* Now, find the one from device_par_map[][2] with the lowest delta
   * to the real one */
  delta = DELTA (ratio, 0, 0);
  index = 0;
  windex = 0;

  for (i = 1; i < G_N_ELEMENTS (device_par_map); i++) {
    for (j = 0; j < 2; j++) {
      cur_delta = DELTA (ratio, i, j);
      if (cur_delta < delta) {
        index = i;
        windex = j;
        delta = cur_delta;
      }
    }
  }

  if (dpy_par_n)
    *dpy_par_n = device_par_map[index][windex];

  if (dpy_par_d)
    *dpy_par_d = device_par_map[index][windex ^ 1];
}