/* GStreamer
 * Copyright (C) 2019 Seungha Yang <seungha.yang@navercorp.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 "d3d11config.h"

#include "gstd3d11utils.h"
#include "gstd3d11device.h"

#include <windows.h>
#include <versionhelpers.h>

GST_DEBUG_CATEGORY_STATIC (GST_CAT_CONTEXT);
GST_DEBUG_CATEGORY_EXTERN (gst_d3d11_utils_debug);
#define GST_CAT_DEFAULT gst_d3d11_utils_debug

static void
_init_context_debug (void)
{
  static volatile gsize _init = 0;

  if (g_once_init_enter (&_init)) {
    GST_DEBUG_CATEGORY_GET (GST_CAT_CONTEXT, "GST_CONTEXT");
    g_once_init_leave (&_init, 1);
  }
}

/**
 * gst_d3d11_handle_set_context:
 * @element: a #GstElement
 * @context: a #GstContext
 * @device: (inout) (transfer full): location of a #GstD3DDevice
 *
 * Helper function for implementing #GstElementClass.set_context() in
 * D3D11 capable elements.
 *
 * Retrieve's the #GstD3D11Device in @context and places the result in @device.
 *
 * Returns: whether the @device could be set successfully
 */
gboolean
gst_d3d11_handle_set_context (GstElement * element, GstContext * context,
    gint adapter, GstD3D11Device ** device)
{
  const gchar *context_type;

  g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
  g_return_val_if_fail (device != NULL, FALSE);

  _init_context_debug ();

  if (!context)
    return FALSE;

  context_type = gst_context_get_context_type (context);
  if (g_strcmp0 (context_type, GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE) == 0) {
    const GstStructure *str;
    GstD3D11Device *other_device = NULL;
    gint other_adapter = 0;

    /* If we had device already, will not replace it */
    if (*device)
      return TRUE;

    str = gst_context_get_structure (context);

    if (gst_structure_get (str, "device", GST_TYPE_D3D11_DEVICE,
            &other_device, "adapter", G_TYPE_INT, &other_adapter, NULL)) {
      if (adapter == -1 || adapter == other_adapter) {
        GST_CAT_DEBUG_OBJECT (GST_CAT_CONTEXT,
            element, "Found D3D11 device context");
        *device = other_device;

        return TRUE;
      }

      gst_object_unref (other_device);
    }
  }

  return FALSE;
}

static void
context_set_d3d11_device (GstContext * context, GstD3D11Device * device)
{
  GstStructure *s;
  gint adapter;

  g_return_if_fail (context != NULL);

  g_object_get (G_OBJECT (device), "adapter", &adapter, NULL);

  GST_CAT_LOG (GST_CAT_CONTEXT,
      "setting GstD3D11Device(%" GST_PTR_FORMAT
      ") with adapter %d on context(%" GST_PTR_FORMAT ")",
      device, adapter, context);

  s = gst_context_writable_structure (context);
  gst_structure_set (s, "device", GST_TYPE_D3D11_DEVICE,
      device, "adapter", G_TYPE_INT, adapter, NULL);
}

/**
 * gst_d3d11_handle_context_query:
 * @element: a #GstElement
 * @query: a #GstQuery of type %GST_QUERY_CONTEXT
 * @device: (transfer none) (nullable): a #GstD3D11Device
 *
 * Returns: Whether the @query was successfully responded to from the passed
 *          @device.
 */
gboolean
gst_d3d11_handle_context_query (GstElement * element, GstQuery * query,
    GstD3D11Device * device)
{
  const gchar *context_type;
  GstContext *context, *old_context;

  g_return_val_if_fail (GST_IS_ELEMENT (element), FALSE);
  g_return_val_if_fail (GST_IS_QUERY (query), FALSE);

  _init_context_debug ();

  GST_LOG_OBJECT (element, "handle context query %" GST_PTR_FORMAT, query);

  if (!device)
    return FALSE;

  gst_query_parse_context_type (query, &context_type);
  if (g_strcmp0 (context_type, GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE) != 0)
    return FALSE;

  gst_query_parse_context (query, &old_context);
  if (old_context)
    context = gst_context_copy (old_context);
  else
    context = gst_context_new (GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE, TRUE);

  context_set_d3d11_device (context, device);
  gst_query_set_context (query, context);
  gst_context_unref (context);

  GST_DEBUG_OBJECT (element, "successfully set %" GST_PTR_FORMAT
      " on %" GST_PTR_FORMAT, device, query);

  return TRUE;
}

static gboolean
pad_query (const GValue * item, GValue * value, gpointer user_data)
{
  GstPad *pad = g_value_get_object (item);
  GstQuery *query = user_data;
  gboolean res;

  res = gst_pad_peer_query (pad, query);

  if (res) {
    g_value_set_boolean (value, TRUE);
    return FALSE;
  }

  GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, pad, "pad peer query failed");
  return TRUE;
}

static gboolean
run_query (GstElement * element, GstQuery * query, GstPadDirection direction)
{
  GstIterator *it;
  GstIteratorFoldFunction func = pad_query;
  GValue res = { 0 };

  g_value_init (&res, G_TYPE_BOOLEAN);
  g_value_set_boolean (&res, FALSE);

  /* Ask neighbor */
  if (direction == GST_PAD_SRC)
    it = gst_element_iterate_src_pads (element);
  else
    it = gst_element_iterate_sink_pads (element);

  while (gst_iterator_fold (it, func, &res, query) == GST_ITERATOR_RESYNC)
    gst_iterator_resync (it);

  gst_iterator_free (it);

  return g_value_get_boolean (&res);
}

static void
run_d3d11_context_query (GstElement * element, GstD3D11Device ** device)
{
  GstQuery *query;
  GstContext *ctxt;

  /* 1) Query downstream with GST_QUERY_CONTEXT for the context and
   *    check if downstream already has a context of the specific type
   */
  query = gst_query_new_context (GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE);
  if (run_query (element, query, GST_PAD_SRC)) {
    gst_query_parse_context (query, &ctxt);
    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
        "found context (%" GST_PTR_FORMAT ") in downstream query", ctxt);
    gst_element_set_context (element, ctxt);
  }

  /* 2) although we found d3d11 device context above, the element does not want
   *    to use the context. Then try to find from the other direction */
  if (*device == NULL && run_query (element, query, GST_PAD_SINK)) {
    gst_query_parse_context (query, &ctxt);
    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
        "found context (%" GST_PTR_FORMAT ") in upstream query", ctxt);
    gst_element_set_context (element, ctxt);
  }

  if (*device == NULL) {
    /* 3) Post a GST_MESSAGE_NEED_CONTEXT message on the bus with
     *    the required context type and afterwards check if a
     *    usable context was set now as in 1). The message could
     *    be handled by the parent bins of the element and the
     *    application.
     */
    GstMessage *msg;

    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
        "posting need context message");
    msg = gst_message_new_need_context (GST_OBJECT_CAST (element),
        GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE);
    gst_element_post_message (element, msg);
  }

  /*
   * Whomever responds to the need-context message performs a
   * GstElement::set_context() with the required context in which the element
   * is required to update the display_ptr or call gst_gl_handle_set_context().
   */

  gst_query_unref (query);
}

/**
 * gst_d3d11_ensure_element_data:
 * @element: the #GstElement running the query
 * @adapter: prefered adapter index, pass adapter >=0 when
 *           the adapter explicitly required. Otherwise, set -1.
 * @device: (inout): the resulting #GstD3D11Device
 *
 * Perform the steps necessary for retrieving a #GstD3D11Device
 * from the surrounding elements or from the application using the #GstContext mechanism.
 *
 * If the contents of @device is not %NULL, then no #GstContext query is
 * necessary for #GstD3D11Device retrieval is performed.
 *
 * Returns: whether a #GstD3D11Device exists in @device
 */
gboolean
gst_d3d11_ensure_element_data (GstElement * element, gint adapter,
    GstD3D11Device ** device)
{
  guint target_adapter = 0;

  g_return_val_if_fail (element != NULL, FALSE);
  g_return_val_if_fail (device != NULL, FALSE);

  _init_context_debug ();

  if (*device) {
    GST_LOG_OBJECT (element, "already have a device %" GST_PTR_FORMAT, *device);
    return TRUE;
  }

  run_d3d11_context_query (element, device);
  if (*device)
    return TRUE;

  if (adapter > 0)
    target_adapter = adapter;

  *device = gst_d3d11_device_new (target_adapter);

  if (*device == NULL) {
    GST_ERROR_OBJECT (element,
        "Couldn't create new device with adapter index %d", target_adapter);
    return FALSE;
  } else {
    GstContext *context;
    GstMessage *msg;

    /* Propagate new D3D11 device context */

    context = gst_context_new (GST_D3D11_DEVICE_HANDLE_CONTEXT_TYPE, TRUE);
    context_set_d3d11_device (context, *device);

    gst_element_set_context (element, context);

    GST_CAT_INFO_OBJECT (GST_CAT_CONTEXT, element,
        "posting have context (%p) message with D3D11 device context (%p)",
        context, *device);
    msg = gst_message_new_have_context (GST_OBJECT_CAST (element), context);
    gst_element_post_message (GST_ELEMENT_CAST (element), msg);
  }

  return TRUE;
}

gboolean
gst_d3d11_is_windows_8_or_greater (void)
{
  static gsize version_once = 0;
  static gboolean ret = FALSE;

  if (g_once_init_enter (&version_once)) {
    if (IsWindows8OrGreater ())
      ret = TRUE;

    g_once_init_leave (&version_once, 1);
  }

  return ret;
}

GstQuery *
gst_query_new_d3d11_usage (GstD3D11Device * device, D3D11_USAGE usage)
{
  GstQuery *query;
  GstStructure *structure;

  g_return_val_if_fail (GST_IS_D3D11_DEVICE (device), NULL);

  structure = gst_structure_new ("GstQueryD3D11Usage",
      "device", GST_TYPE_D3D11_DEVICE, device,
      "usage", G_TYPE_INT, usage, "result", G_TYPE_BOOLEAN, FALSE, NULL);
  query = gst_query_new_custom (GST_QUERY_CUSTOM, structure);

  return query;
}

void
gst_query_parse_d3d11_usage (GstQuery * query, GstD3D11Device ** device,
    D3D11_USAGE * usage)
{
  const GstStructure *structure;

  g_return_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CUSTOM);

  if (!gst_query_is_d3d11_usage (query))
    return;

  structure = gst_query_get_structure (query);

  gst_structure_get (structure, "device", GST_TYPE_D3D11_DEVICE, device,
      "usage", G_TYPE_INT, usage, NULL);
}

void
gst_query_set_d3d11_usage_result (GstQuery * query, gboolean result)
{
  GstStructure *structure;
  const gchar *name;

  g_return_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CUSTOM);
  g_return_if_fail (gst_query_is_writable (query));

  structure = gst_query_writable_structure (query);
  name = gst_structure_get_name (structure);

  g_return_if_fail (g_strcmp0 (name, "GstQueryD3D11Usage") == 0);
  gst_structure_set (structure, "result", G_TYPE_BOOLEAN, result, NULL);
}

void
gst_query_parse_d3d11_usage_result (GstQuery * query, gboolean * result)
{
  const GstStructure *structure;
  const gchar *name;

  g_return_if_fail (GST_QUERY_TYPE (query) == GST_QUERY_CUSTOM);
  g_return_if_fail (gst_query_is_writable (query));
  g_return_if_fail (result != NULL);

  structure = gst_query_get_structure (query);
  name = gst_structure_get_name (structure);

  g_return_if_fail (g_strcmp0 (name, "GstQueryD3D11Usage") == 0);

  gst_structure_get (structure, "result", G_TYPE_BOOLEAN, result, NULL);
}

gboolean
gst_query_is_d3d11_usage (GstQuery * query)
{
  const GstStructure *structure;

  g_return_val_if_fail (GST_IS_QUERY (query), FALSE);

  if (GST_QUERY_TYPE (query) != GST_QUERY_CUSTOM)
    return FALSE;

  structure = gst_query_get_structure (query);

  if (!structure ||
      g_strcmp0 (gst_structure_get_name (structure), "GstQueryD3D11Usage"))
    return FALSE;

  return TRUE;
}

/*
 * This is an incomplete matrix of in formats and a score for the prefered output
 * format.
 *
 *         out: RGB24   RGB16  ARGB  AYUV  YUV444  YUV422 YUV420 YUV411 YUV410  PAL  GRAY
 *  in
 * RGB24          0      2       1     2     2       3      4      5      6      7    8
 * RGB16          1      0       1     2     2       3      4      5      6      7    8
 * ARGB           2      3       0     1     4       5      6      7      8      9    10
 * AYUV           3      4       1     0     2       5      6      7      8      9    10
 * YUV444         2      4       3     1     0       5      6      7      8      9    10
 * YUV422         3      5       4     2     1       0      6      7      8      9    10
 * YUV420         4      6       5     3     2       1      0      7      8      9    10
 * YUV411         4      6       5     3     2       1      7      0      8      9    10
 * YUV410         6      8       7     5     4       3      2      1      0      9    10
 * PAL            1      3       2     6     4       6      7      8      9      0    10
 * GRAY           1      4       3     2     1       5      6      7      8      9    0
 *
 * PAL or GRAY are never prefered, if we can we would convert to PAL instead
 * of GRAY, though
 * less subsampling is prefered and if any, preferably horizontal
 * We would like to keep the alpha, even if we would need to to colorspace conversion
 * or lose depth.
 */
#define SCORE_FORMAT_CHANGE       1
#define SCORE_DEPTH_CHANGE        1
#define SCORE_ALPHA_CHANGE        1
#define SCORE_CHROMA_W_CHANGE     1
#define SCORE_CHROMA_H_CHANGE     1
#define SCORE_PALETTE_CHANGE      1

#define SCORE_COLORSPACE_LOSS     2     /* RGB <-> YUV */
#define SCORE_DEPTH_LOSS          4     /* change bit depth */
#define SCORE_ALPHA_LOSS          8     /* lose the alpha channel */
#define SCORE_CHROMA_W_LOSS      16     /* vertical subsample */
#define SCORE_CHROMA_H_LOSS      32     /* horizontal subsample */
#define SCORE_PALETTE_LOSS       64     /* convert to palette format */
#define SCORE_COLOR_LOSS        128     /* convert to GRAY */

#define COLORSPACE_MASK (GST_VIDEO_FORMAT_FLAG_YUV | \
                         GST_VIDEO_FORMAT_FLAG_RGB | GST_VIDEO_FORMAT_FLAG_GRAY)
#define ALPHA_MASK      (GST_VIDEO_FORMAT_FLAG_ALPHA)
#define PALETTE_MASK    (GST_VIDEO_FORMAT_FLAG_PALETTE)

/* calculate how much loss a conversion would be */
static void
score_value (const GstVideoFormatInfo * in_info,
    const GValue * val, gint * min_loss, const GstVideoFormatInfo ** out_info)
{
  const gchar *fname;
  const GstVideoFormatInfo *t_info;
  GstVideoFormatFlags in_flags, t_flags;
  gint loss;

  fname = g_value_get_string (val);
  t_info = gst_video_format_get_info (gst_video_format_from_string (fname));
  if (!t_info)
    return;

  /* accept input format immediately without loss */
  if (in_info == t_info) {
    *min_loss = 0;
    *out_info = t_info;
    return;
  }

  loss = SCORE_FORMAT_CHANGE;

  in_flags = GST_VIDEO_FORMAT_INFO_FLAGS (in_info);
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
  in_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;

  t_flags = GST_VIDEO_FORMAT_INFO_FLAGS (t_info);
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_LE;
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_COMPLEX;
  t_flags &= ~GST_VIDEO_FORMAT_FLAG_UNPACK;

  if ((t_flags & PALETTE_MASK) != (in_flags & PALETTE_MASK)) {
    loss += SCORE_PALETTE_CHANGE;
    if (t_flags & PALETTE_MASK)
      loss += SCORE_PALETTE_LOSS;
  }

  if ((t_flags & COLORSPACE_MASK) != (in_flags & COLORSPACE_MASK)) {
    loss += SCORE_COLORSPACE_LOSS;
    if (t_flags & GST_VIDEO_FORMAT_FLAG_GRAY)
      loss += SCORE_COLOR_LOSS;
  }

  if ((t_flags & ALPHA_MASK) != (in_flags & ALPHA_MASK)) {
    loss += SCORE_ALPHA_CHANGE;
    if (in_flags & ALPHA_MASK)
      loss += SCORE_ALPHA_LOSS;
  }

  if ((in_info->h_sub[1]) != (t_info->h_sub[1])) {
    loss += SCORE_CHROMA_H_CHANGE;
    if ((in_info->h_sub[1]) < (t_info->h_sub[1]))
      loss += SCORE_CHROMA_H_LOSS;
  }
  if ((in_info->w_sub[1]) != (t_info->w_sub[1])) {
    loss += SCORE_CHROMA_W_CHANGE;
    if ((in_info->w_sub[1]) < (t_info->w_sub[1]))
      loss += SCORE_CHROMA_W_LOSS;
  }

  if ((in_info->bits) != (t_info->bits)) {
    loss += SCORE_DEPTH_CHANGE;
    if ((in_info->bits) > (t_info->bits))
      loss += SCORE_DEPTH_LOSS + (in_info->bits - t_info->bits);
  }

  GST_DEBUG ("score %s -> %s = %d",
      GST_VIDEO_FORMAT_INFO_NAME (in_info),
      GST_VIDEO_FORMAT_INFO_NAME (t_info), loss);

  if (loss < *min_loss) {
    GST_DEBUG ("found new best %d", loss);
    *out_info = t_info;
    *min_loss = loss;
  }
}

GstCaps *
gst_d3d11_caps_fixate_format (GstCaps * caps, GstCaps * othercaps)
{
  GstStructure *ins, *outs;
  const gchar *in_format;
  const GstVideoFormatInfo *in_info, *out_info = NULL;
  gint min_loss = G_MAXINT;
  guint i, capslen;
  GstCaps *result;

  result = gst_caps_intersect (othercaps, caps);
  if (gst_caps_is_empty (result)) {
    gst_caps_unref (result);
    result = othercaps;
  } else {
    gst_caps_unref (othercaps);
  }

  result = gst_caps_make_writable (result);

  ins = gst_caps_get_structure (caps, 0);
  in_format = gst_structure_get_string (ins, "format");
  if (!in_format) {
    gst_caps_unref (result);
    return NULL;
  }

  GST_DEBUG ("source format %s", in_format);

  in_info =
      gst_video_format_get_info (gst_video_format_from_string (in_format));
  if (!in_info) {
    gst_caps_unref (result);
    return NULL;
  }

  outs = gst_caps_get_structure (result, 0);

  capslen = gst_caps_get_size (result);
  GST_DEBUG ("iterate %d structures", capslen);
  for (i = 0; i < capslen; i++) {
    GstStructure *tests;
    const GValue *format;

    tests = gst_caps_get_structure (result, i);
    format = gst_structure_get_value (tests, "format");
    /* should not happen */
    if (format == NULL)
      continue;

    if (GST_VALUE_HOLDS_LIST (format)) {
      gint j, len;

      len = gst_value_list_get_size (format);
      GST_DEBUG ("have %d formats", len);
      for (j = 0; j < len; j++) {
        const GValue *val;

        val = gst_value_list_get_value (format, j);
        if (G_VALUE_HOLDS_STRING (val)) {
          score_value (in_info, val, &min_loss, &out_info);
          if (min_loss == 0)
            break;
        }
      }
    } else if (G_VALUE_HOLDS_STRING (format)) {
      score_value (in_info, format, &min_loss, &out_info);
    }
  }
  if (out_info)
    gst_structure_set (outs, "format", G_TYPE_STRING,
        GST_VIDEO_FORMAT_INFO_NAME (out_info), NULL);

  return result;
}

static gchar *
gst_d3d11_hres_to_string (HRESULT hr)
{
  DWORD flags;
  gchar *ret_text;
  LPTSTR error_text = NULL;

  flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER
      | FORMAT_MESSAGE_IGNORE_INSERTS;
  FormatMessage (flags, NULL, hr, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
      (LPTSTR) & error_text, 0, NULL);

#ifdef UNICODE
  /* If UNICODE is defined, LPTSTR is LPWSTR which is UTF-16 */
  ret_text = g_utf16_to_utf8 (error_text, 0, NULL, NULL, NULL);
#else
  ret_text = g_strdup (error_text);
#endif

  LocalFree (error_text);
  return ret_text;
}

gboolean
_gst_d3d11_result (HRESULT hr, GstD3D11Device * device, GstDebugCategory * cat,
    const gchar * file, const gchar * function, gint line)
{
#ifndef GST_DISABLE_GST_DEBUG
  gboolean ret = TRUE;

  if (FAILED (hr)) {
    gchar *error_text = NULL;

    error_text = gst_d3d11_hres_to_string (hr);
    gst_debug_log (cat, GST_LEVEL_WARNING, file, function, line,
        NULL, "D3D11 call failed: 0x%x, %s", (guint) hr, error_text);
    g_free (error_text);

    ret = FALSE;
  }
#if (HAVE_D3D11SDKLAYERS_H || HAVE_DXGIDEBUG_H)
  if (device) {
    gst_d3d11_device_d3d11_debug (device, file, function, line);
    gst_d3d11_device_dxgi_debug (device, file, function, line);
  }
#endif

  return ret;
#else
  return SUCCEEDED (hr);
#endif
}
