/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2013 - Hans-Kristian Arntzen
 * 
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "shader_parse.h"
#include "../compat/posix_string.h"
#include "../msvc/msvc_compat.h"
#include "../file.h"
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_LIBXML2
#include <libxml/parser.h>
#include <libxml/tree.h>
#else
#define RXML_LIBXML2_COMPAT
#include "../compat/rxml/rxml.h"
#endif

#define print_buf(buf, ...) snprintf(buf, sizeof(buf), __VA_ARGS__)

static const char *wrap_mode_to_str(enum gfx_wrap_type type)
{
   switch (type)
   {
      case RARCH_WRAP_BORDER:
         return "clamp_to_border";
      case RARCH_WRAP_EDGE:
         return "clamp_to_edge";
      case RARCH_WRAP_REPEAT:
         return "repeat";
      case RARCH_WRAP_MIRRORED_REPEAT:
         return "mirrored_repeat";
      default:
         return "???";
   }
}

static enum gfx_wrap_type wrap_str_to_mode(const char *wrap_mode)
{
   if (strcmp(wrap_mode, "clamp_to_border") == 0)
      return RARCH_WRAP_BORDER;
   else if (strcmp(wrap_mode, "clamp_to_edge") == 0)
      return RARCH_WRAP_EDGE;
   else if (strcmp(wrap_mode, "repeat") == 0)
      return RARCH_WRAP_REPEAT;
   else if (strcmp(wrap_mode, "mirrored_repeat") == 0)
      return RARCH_WRAP_MIRRORED_REPEAT;
   else
   {
      RARCH_WARN("Invalid wrapping type %s. Valid ones are: clamp_to_border (default), clamp_to_edge, repeat and mirrored_repeat. Falling back to default.\n",
            wrap_mode);
      return RARCH_WRAP_DEFAULT;
   }
}

// CGP
static bool shader_parse_pass(config_file_t *conf, struct gfx_shader_pass *pass, unsigned i)
{
   // Source
   char shader_name[64];
   print_buf(shader_name, "shader%u", i);
   if (!config_get_path(conf, shader_name, pass->source.cg, sizeof(pass->source.cg)))
   {
      RARCH_ERR("Couldn't parse shader source (%s).\n", shader_name);
      return false;
   }
   
   // Smooth
   char filter_name_buf[64];
   print_buf(filter_name_buf, "filter_linear%u", i);

   bool smooth = false;
   if (config_get_bool(conf, filter_name_buf, &smooth))
      pass->filter = smooth ? RARCH_FILTER_LINEAR : RARCH_FILTER_NEAREST;
   else
      pass->filter = RARCH_FILTER_UNSPEC;

   // Wrapping mode
   char wrap_name_buf[64];
   print_buf(wrap_name_buf, "wrap_mode%u", i);
   char wrap_mode[64];
   if (config_get_array(conf, wrap_name_buf, wrap_mode, sizeof(wrap_mode)))
      pass->wrap = wrap_str_to_mode(wrap_mode);

   // Frame count mod
   char frame_count_mod[64] = {0};
   char frame_count_mod_buf[64];
   print_buf(frame_count_mod_buf, "frame_count_mod%u", i);
   if (config_get_array(conf, frame_count_mod_buf, frame_count_mod, sizeof(frame_count_mod)))
      pass->frame_count_mod = strtoul(frame_count_mod, NULL, 0);

   // Scale
   struct gfx_fbo_scale *scale = &pass->fbo;
   char scale_type[64] = {0};
   char scale_type_x[64] = {0};
   char scale_type_y[64] = {0};
   char scale_name_buf[64];
   print_buf(scale_name_buf, "scale_type%u", i);
   config_get_array(conf, scale_name_buf, scale_type, sizeof(scale_type));

   print_buf(scale_name_buf, "scale_type_x%u", i);
   config_get_array(conf, scale_name_buf, scale_type_x, sizeof(scale_type_x));

   print_buf(scale_name_buf, "scale_type_y%u", i);
   config_get_array(conf, scale_name_buf, scale_type_y, sizeof(scale_type_y));

   if (!*scale_type && !*scale_type_x && !*scale_type_y)
      return true;

   if (*scale_type)
   {
      strlcpy(scale_type_x, scale_type, sizeof(scale_type_x));
      strlcpy(scale_type_y, scale_type, sizeof(scale_type_y));
   }

   char attr_name_buf[64];
   float fattr = 0.0f;
   int iattr = 0;

   scale->valid = true;
   scale->type_x = RARCH_SCALE_INPUT;
   scale->type_y = RARCH_SCALE_INPUT;
   scale->scale_x = 1.0;
   scale->scale_y = 1.0;

   char fp_fbo_buf[64];
   print_buf(fp_fbo_buf, "float_framebuffer%u", i);
   config_get_bool(conf, fp_fbo_buf, &scale->fp_fbo);

   if (*scale_type_x)
   {
      if (strcmp(scale_type_x, "source") == 0)
         scale->type_x = RARCH_SCALE_INPUT;
      else if (strcmp(scale_type_x, "viewport") == 0)
         scale->type_x = RARCH_SCALE_VIEWPORT;
      else if (strcmp(scale_type_x, "absolute") == 0)
         scale->type_x = RARCH_SCALE_ABSOLUTE;
      else
      {
         RARCH_ERR("Invalid attribute.\n");
         return false;
      }
   }

   if (*scale_type_y)
   {
      if (strcmp(scale_type_y, "source") == 0)
         scale->type_y = RARCH_SCALE_INPUT;
      else if (strcmp(scale_type_y, "viewport") == 0)
         scale->type_y = RARCH_SCALE_VIEWPORT;
      else if (strcmp(scale_type_y, "absolute") == 0)
         scale->type_y = RARCH_SCALE_ABSOLUTE;
      else
      {
         RARCH_ERR("Invalid attribute.\n");
         return false;
      }
   }

   if (scale->type_x == RARCH_SCALE_ABSOLUTE)
   {
      print_buf(attr_name_buf, "scale%u", i);
      if (config_get_int(conf, attr_name_buf, &iattr))
         scale->abs_x = iattr;
      else
      {
         print_buf(attr_name_buf, "scale_x%u", i);
         if (config_get_int(conf, attr_name_buf, &iattr))
            scale->abs_x = iattr;
      }
   }
   else
   {
      print_buf(attr_name_buf, "scale%u", i);
      if (config_get_float(conf, attr_name_buf, &fattr))
         scale->scale_x = fattr;
      else
      {
         print_buf(attr_name_buf, "scale_x%u", i);
         if (config_get_float(conf, attr_name_buf, &fattr))
            scale->scale_x = fattr;
      }
   }

   if (scale->type_y == RARCH_SCALE_ABSOLUTE)
   {
      print_buf(attr_name_buf, "scale%u", i);
      if (config_get_int(conf, attr_name_buf, &iattr))
         scale->abs_y = iattr;
      else
      {
         print_buf(attr_name_buf, "scale_y%u", i);
         if (config_get_int(conf, attr_name_buf, &iattr))
            scale->abs_y = iattr;
      }
   }
   else
   {
      print_buf(attr_name_buf, "scale%u", i);
      if (config_get_float(conf, attr_name_buf, &fattr))
         scale->scale_y = fattr;
      else
      {
         print_buf(attr_name_buf, "scale_y%u", i);
         if (config_get_float(conf, attr_name_buf, &fattr))
            scale->scale_y = fattr;
      }
   }

   return true;
}

static bool shader_parse_textures(config_file_t *conf, struct gfx_shader *shader)
{
   const char *id;
   char *save;
   char textures[1024];
   if (!config_get_array(conf, "textures", textures, sizeof(textures)))
      return true;

   for (id = strtok_r(textures, ";", &save);
         id && shader->luts < GFX_MAX_TEXTURES;
         shader->luts++, id = strtok_r(NULL, ";", &save))
   {
      if (!config_get_array(conf, id, shader->lut[shader->luts].path, sizeof(shader->lut[shader->luts].path)))
      {
         RARCH_ERR("Cannot find path to texture \"%s\" ...\n", id);
         return false;
      }

      strlcpy(shader->lut[shader->luts].id, id, sizeof(shader->lut[shader->luts].id));

      char id_filter[64];
      print_buf(id_filter, "%s_linear", id);

      bool smooth = false;
      if (config_get_bool(conf, id_filter, &smooth))
         shader->lut[shader->luts].filter = smooth ? RARCH_FILTER_LINEAR : RARCH_FILTER_NEAREST;
      else
         shader->lut[shader->luts].filter = RARCH_FILTER_UNSPEC;

      char id_wrap[64];
      print_buf(id_wrap, "%s_wrap_mode", id);
      char wrap_mode[64];
      if (config_get_array(conf, id_wrap, wrap_mode, sizeof(wrap_mode)))
         shader->lut[shader->luts].wrap = wrap_str_to_mode(wrap_mode);
   }

   return true;
}

static bool shader_parse_imports(config_file_t *conf, struct gfx_shader *shader)
{
   char imports[1024];
   char *save;
   const char *id;
   if (!config_get_array(conf, "imports", imports, sizeof(imports)))
      return true;

   for (id = strtok_r(imports, ";", &save);
         id && shader->variables < GFX_MAX_VARIABLES;
         shader->variables++, id = strtok_r(NULL, ";", &save))
   {
      struct state_tracker_uniform_info *var = &shader->variable[shader->variables];

      strlcpy(var->id, id, sizeof(var->id));

      char semantic_buf[64];
      char wram_buf[64];
      char input_slot_buf[64];
      char mask_buf[64];
      char equal_buf[64];

      print_buf(semantic_buf, "%s_semantic", id);
      print_buf(wram_buf, "%s_wram", id);
      print_buf(input_slot_buf, "%s_input_slot", id);
      print_buf(mask_buf, "%s_mask", id);
      print_buf(equal_buf, "%s_equal", id);

      char semantic[64];
      if (!config_get_array(conf, semantic_buf, semantic, sizeof(semantic)))
      {
         RARCH_ERR("No semantic for import variable.\n");
         return false;
      }

      if (strcmp(semantic, "capture") == 0)
         var->type = RARCH_STATE_CAPTURE;
      else if (strcmp(semantic, "transition") == 0)
         var->type = RARCH_STATE_TRANSITION;
      else if (strcmp(semantic, "transition_count") == 0)
         var->type = RARCH_STATE_TRANSITION_COUNT;
      else if (strcmp(semantic, "capture_previous") == 0)
         var->type = RARCH_STATE_CAPTURE_PREV;
      else if (strcmp(semantic, "transition_previous") == 0)
         var->type = RARCH_STATE_TRANSITION_PREV;
      else if (strcmp(semantic, "python") == 0)
         var->type = RARCH_STATE_PYTHON;
      else
      {
         RARCH_ERR("Invalid semantic.\n");
         return false;
      }

      unsigned addr = 0, mask = 0, equal = 0;
      if (var->type != RARCH_STATE_PYTHON)
      {
         unsigned input_slot = 0;
         if (config_get_uint(conf, input_slot_buf, &input_slot))
         {
            switch (input_slot)
            {
               case 1:
                  var->ram_type = RARCH_STATE_INPUT_SLOT1;
                  break;

               case 2:
                  var->ram_type = RARCH_STATE_INPUT_SLOT2;
                  break;

               default:
                  RARCH_ERR("Invalid input slot for import.\n");
                  return false;
            }
         }
         else if (config_get_hex(conf, wram_buf, &addr))
         {
            var->ram_type = RARCH_STATE_WRAM;
            var->addr = addr;
         }
         else
         {
            RARCH_ERR("No address assigned to semantic.\n");
            return false;
         }
      }

      if (config_get_hex(conf, mask_buf, &mask))
         var->mask = mask;
      if (config_get_hex(conf, equal_buf, &equal))
         var->equal = equal;
   }

   config_get_path(conf, "import_script", shader->script_path, sizeof(shader->script_path));
   config_get_array(conf, "import_script_class", shader->script_class, sizeof(shader->script_class));

   return true;
}

bool gfx_shader_read_conf_cgp(config_file_t *conf, struct gfx_shader *shader)
{
   unsigned shaders, i;
   memset(shader, 0, sizeof(*shader));

   shader->type = RARCH_SHADER_CG;

   shaders = 0;
   if (!config_get_uint(conf, "shaders", &shaders))
   {
      RARCH_ERR("Cannot find \"shaders\" param.\n");
      return false;
   }

   if (!shaders)
   {
      RARCH_ERR("Need to define at least 1 shader.\n");
      return false;
   }

   shader->passes = min(shaders, GFX_MAX_SHADERS);
   for (i = 0; i < shader->passes; i++)
   {
      if (!shader_parse_pass(conf, &shader->pass[i], i))
         return false;
   }

   if (!shader_parse_textures(conf, shader))
      return false;

   if (!shader_parse_imports(conf, shader))
      return false;

   return true;
}

// XML shaders
static bool xml_get_prop(char *buf, size_t size, xmlNodePtr node, const char *prop)
{
   if (!size)
      return false;

   xmlChar *p = xmlGetProp(node, (const xmlChar*)prop);
   if (p)
   {
      bool ret = strlcpy(buf, (const char*)p, size) < size;
      xmlFree(p);
      return ret;
   }
   else
   {
      *buf = '\0';
      return false;
   }
}

static char *xml_get_content(xmlNodePtr node)
{
   xmlChar *content = xmlNodeGetContent(node);
   if (!content)
      return NULL;

   char *ret = strdup((const char*)content);
   xmlFree(content);
   return ret;
}

static char *xml_replace_if_file(char *content, const char *path, xmlNodePtr node, const char *src_prop)
{
   char prop[PATH_MAX];
   if (!xml_get_prop(prop, sizeof(prop), node, src_prop))
      return content;

   free(content);
   content = NULL;

   char shader_path[PATH_MAX];
   fill_pathname_resolve_relative(shader_path, path, prop, sizeof(shader_path));

   RARCH_LOG("Loading external source from \"%s\".\n", shader_path);
   if (read_file(shader_path, (void**)&content) >= 0)
      return content;
   else
      return NULL;
}

static bool get_xml_attrs(struct gfx_shader_pass *pass, xmlNodePtr ptr)
{
   struct gfx_fbo_scale *fbo = &pass->fbo;
   pass->frame_count_mod = 0;
   pass->filter = RARCH_FILTER_UNSPEC;
   fbo->fp_fbo = false;
   fbo->scale_x = 1.0;
   fbo->scale_y = 1.0;
   fbo->type_x = pass->fbo.type_y = RARCH_SCALE_INPUT;
   fbo->valid = false;

   // Check if shader forces a certain texture filtering.
   char attr[64];
   if (xml_get_prop(attr, sizeof(attr), ptr, "filter"))
   {
      if (strcmp(attr, "nearest") == 0)
      {
         pass->filter = RARCH_FILTER_NEAREST;
         RARCH_LOG("XML: Shader forces GL_NEAREST.\n");
      }
      else if (strcmp(attr, "linear") == 0)
      {
         pass->filter = RARCH_FILTER_LINEAR;
         RARCH_LOG("XML: Shader forces GL_LINEAR.\n");
      }
      else
      {
         RARCH_WARN("XML: Invalid property for filter.\n");
         return false;
      }
   }

   // Check for scaling attributes *lots of code <_<*
   char attr_scale[64], attr_scale_x[64], attr_scale_y[64];
   char attr_size[64], attr_size_x[64], attr_size_y[64];
   char attr_outscale[64], attr_outscale_x[64], attr_outscale_y[64];
   char frame_count_mod[64], fp_fbo[64];

   xml_get_prop(attr_scale, sizeof(attr_scale), ptr, "scale");
   xml_get_prop(attr_scale_x, sizeof(attr_scale_x), ptr, "scale_x");
   xml_get_prop(attr_scale_y, sizeof(attr_scale_y), ptr, "scale_y");
   xml_get_prop(attr_size, sizeof(attr_size), ptr, "size");
   xml_get_prop(attr_size_x, sizeof(attr_size_x), ptr, "size_x");
   xml_get_prop(attr_size_y, sizeof(attr_size_y), ptr, "size_y");
   xml_get_prop(attr_outscale, sizeof(attr_outscale), ptr, "outscale");
   xml_get_prop(attr_outscale_x, sizeof(attr_outscale_x), ptr, "outscale_x");
   xml_get_prop(attr_outscale_y, sizeof(attr_outscale_y), ptr, "outscale_y");
   xml_get_prop(frame_count_mod, sizeof(frame_count_mod), ptr, "frame_count_mod");
   xml_get_prop(fp_fbo, sizeof(fp_fbo), ptr, "float_framebuffer");

   fbo->fp_fbo = strcmp(fp_fbo, "true") == 0;

   unsigned x_attr_cnt = 0, y_attr_cnt = 0;

   if (*frame_count_mod)
   {
      pass->frame_count_mod = strtoul(frame_count_mod, NULL, 0);
      RARCH_LOG("Got frame count mod attr: %u\n", pass->frame_count_mod);
   }

   if (*attr_scale)
   {
      float scale = strtod(attr_scale, NULL);
      fbo->scale_x = scale;
      fbo->scale_y = scale;
      fbo->valid = true;
      RARCH_LOG("Got scale attr: %.1f\n", scale);
      x_attr_cnt++;
      y_attr_cnt++;
   }

   if (*attr_scale_x)
   {
      float scale = strtod(attr_scale_x, NULL);
      fbo->scale_x = scale;
      fbo->valid = true;
      RARCH_LOG("Got scale_x attr: %.1f\n", scale);
      x_attr_cnt++;
   }

   if (*attr_scale_y)
   {
      float scale = strtod(attr_scale_y, NULL);
      fbo->scale_y = scale;
      fbo->valid = true;
      RARCH_LOG("Got scale_y attr: %.1f\n", scale);
      y_attr_cnt++;
   }
   
   if (*attr_size)
   {
      fbo->abs_x = fbo->abs_y = strtoul(attr_size, NULL, 0);
      fbo->valid = true;
      fbo->type_x = fbo->type_y = RARCH_SCALE_ABSOLUTE;
      RARCH_LOG("Got size attr: %u\n", fbo->abs_x);
      x_attr_cnt++;
      y_attr_cnt++;
   }

   if (*attr_size_x)
   {
      fbo->abs_x = strtoul(attr_size_x, NULL, 0);
      fbo->valid = true;
      fbo->type_x = RARCH_SCALE_ABSOLUTE;
      RARCH_LOG("Got size_x attr: %u\n", fbo->abs_x);
      x_attr_cnt++;
   }

   if (*attr_size_y)
   {
      fbo->abs_y = strtoul(attr_size_y, NULL, 0);
      fbo->valid = true;
      fbo->type_y = RARCH_SCALE_ABSOLUTE;
      RARCH_LOG("Got size_y attr: %u\n", fbo->abs_y);
      y_attr_cnt++;
   }

   if (*attr_outscale)
   {
      float scale = strtod(attr_outscale, NULL);
      fbo->scale_x = fbo->scale_y = scale;
      fbo->valid = true;
      fbo->type_x = fbo->type_y = RARCH_SCALE_VIEWPORT;
      RARCH_LOG("Got outscale attr: %.1f\n", scale);
      x_attr_cnt++;
      y_attr_cnt++;
   }

   if (*attr_outscale_x)
   {
      float scale = strtod(attr_outscale_x, NULL);
      fbo->scale_x = scale;
      fbo->valid = true;
      fbo->type_x = RARCH_SCALE_VIEWPORT;
      RARCH_LOG("Got outscale_x attr: %.1f\n", scale);
      x_attr_cnt++;
   }

   if (*attr_outscale_y)
   {
      float scale = strtod(attr_outscale_y, NULL);
      fbo->scale_y = scale;
      fbo->valid = true;
      fbo->type_y = RARCH_SCALE_VIEWPORT;
      RARCH_LOG("Got outscale_y attr: %.1f\n", scale);
      y_attr_cnt++;
   }

   if (x_attr_cnt > 1)
      return false;
   if (y_attr_cnt > 1)
      return false;

   return true;
}

static bool add_texture_image(struct gfx_shader *shader,
      xmlNodePtr ptr)
{
   if (shader->luts >= GFX_MAX_TEXTURES)
   {
      RARCH_WARN("Too many texture images. Ignoring ...\n");
      return true;
   }

   struct gfx_shader_lut *lut = &shader->lut[shader->luts];

   xml_get_prop(lut->id, sizeof(lut->id), ptr, "id");
   xml_get_prop(lut->path, sizeof(lut->path), ptr, "file");

   char filter[64] = {0};
   xml_get_prop(filter, sizeof(filter), ptr, "filter");

   if (!*lut->id)
   {
      RARCH_ERR("Could not find ID in texture.\n");
      return false;
   }

   if (!*lut->path)
   {
      RARCH_ERR("Could not find filename in texture.\n");
      return false;
   }

   if (strcmp(filter, "linear") == 0)
      lut->filter = RARCH_FILTER_LINEAR;
   else if (strcmp(filter, "nearest") == 0)
      lut->filter = RARCH_FILTER_NEAREST;
   else if (!*filter)
      lut->filter = RARCH_FILTER_UNSPEC;
   else
   {
      RARCH_ERR("Invalid LUT filter type.\n");
      return false;
   }

   shader->luts++;
   return true;
}

static bool add_import_value(struct gfx_shader *shader, xmlNodePtr ptr)
{
   if (shader->variables >= GFX_MAX_VARIABLES)
   {
      RARCH_ERR("Too many import variables ...\n");
      return false;
   }

   struct state_tracker_uniform_info *var = &shader->variable[shader->variables];

   char semantic[64], wram[64], input[64], bitmask[64], bitequal[64];
   xml_get_prop(var->id, sizeof(var->id), ptr, "id");
   xml_get_prop(semantic, sizeof(semantic), ptr, "semantic");
   xml_get_prop(wram, sizeof(wram), ptr, "wram");
   xml_get_prop(input, sizeof(input), ptr, "input_slot");
   xml_get_prop(bitmask, sizeof(bitmask), ptr, "mask");
   xml_get_prop(bitequal, sizeof(bitequal), ptr, "equal");

   if (!*semantic || !*var->id)
   {
      RARCH_ERR("No semantic or ID for import value.\n");
      return false;
   }

   if (strcmp(semantic, "capture") == 0)
      var->type = RARCH_STATE_CAPTURE;
   else if (strcmp(semantic, "capture_previous") == 0)
      var->type = RARCH_STATE_CAPTURE_PREV;
   else if (strcmp(semantic, "transition") == 0)
      var->type = RARCH_STATE_TRANSITION;
   else if (strcmp(semantic, "transition_count") == 0)
      var->type = RARCH_STATE_TRANSITION_COUNT;
   else if (strcmp(semantic, "transition_previous") == 0)
      var->type = RARCH_STATE_TRANSITION_PREV;
   else if (strcmp(semantic, "python") == 0)
      var->type = RARCH_STATE_PYTHON;
   else
   {
      RARCH_ERR("Invalid semantic for import value.\n");
      return false;
   }

   if (var->type != RARCH_STATE_PYTHON)
   {
      if (*input) 
      {
         unsigned slot = strtoul(input, NULL, 0);
         switch (slot)
         {
            case 1:
               var->ram_type = RARCH_STATE_INPUT_SLOT1;
               break;
            case 2:
               var->ram_type = RARCH_STATE_INPUT_SLOT2;
               break;

            default:
               RARCH_ERR("Invalid input slot for import.\n");
               return false;
         }
      }
      else if (*wram)
      {
         var->addr = strtoul(wram, NULL, 16);
         var->ram_type = RARCH_STATE_WRAM;
      }
      else
      {
         RARCH_ERR("No RAM address specificed for import value.\n");
         return false;
      }
   }

   if (*bitmask)
      var->mask = strtoul(bitmask, NULL, 16);
   if (*bitequal)
      var->equal = strtoul(bitequal, NULL, 16);

   shader->variables++;
   return true;
}

static bool get_script(struct gfx_shader *shader, const char *path,
      xmlNodePtr ptr)
{
   if (shader->script)
   {
      RARCH_ERR("Script already imported.\n");
      return false;
   }

   xml_get_prop(shader->script_class, sizeof(shader->script_class), ptr, "class");

   char language[64];
   xml_get_prop(language, sizeof(language), ptr, "language");
   if (strcmp(language, "python") != 0)
   {
      RARCH_ERR("Script language is not Python.\n");
      return false;
   }

   shader->script = xml_get_content(ptr);
   if (!shader->script)
      return false;

   shader->script = xml_replace_if_file(shader->script, path, ptr, "src"); 
   if (!shader->script)
   {
      RARCH_ERR("Cannot find Python script.\n");
      return false;
   }

   return true;
}

bool gfx_shader_read_xml(const char *path, struct gfx_shader *shader)
{
   LIBXML_TEST_VERSION;

   xmlParserCtxtPtr ctx = xmlNewParserCtxt();
   if (!ctx)
   {
      RARCH_ERR("Failed to load libxml2 context.\n");
      return false;
   }

   RARCH_LOG("Loading XML shader: %s\n", path);
   xmlDocPtr doc = xmlCtxtReadFile(ctx, path, NULL, 0);
   xmlNodePtr head = NULL;
   xmlNodePtr cur = NULL;

   if (!doc)
   {
      RARCH_ERR("Failed to parse XML file: %s\n", path);
      goto error;
   }

#ifdef HAVE_LIBXML2
   if (ctx->valid == 0)
   {
      RARCH_ERR("Cannot validate XML shader: %s\n", path);
      goto error;
   }
#endif

   head = xmlDocGetRootElement(doc);

   for (cur = head; cur; cur = cur->next)
   {
      if (cur->type != XML_ELEMENT_NODE)
         continue;
      if (strcmp((const char*)cur->name, "shader") != 0)
         continue;

      char attr[64];
      xml_get_prop(attr, sizeof(attr), cur, "language");

      if (strcmp(attr, "GLSL") == 0)
         shader->type = RARCH_SHADER_GLSL;
      else
         continue;

      xml_get_prop(attr, sizeof(attr), cur, "style");
      shader->modern = strcmp(attr, "GLES2") == 0;

      if (xml_get_prop(shader->prefix, sizeof(shader->prefix), cur, "prefix"))
         RARCH_LOG("[GL]: Using uniform and attrib prefix: %s\n", shader->prefix);

      if (shader->modern)
         RARCH_LOG("[GL]: Shader reports a GLES2 style shader.\n");
      else
         RARCH_WARN("[GL]: Legacy shaders are deprecated.\n");
      break;
   }

   if (!cur) // We couldn't find any GLSL shader :(
      goto error;

   // Iterate to check if we find fragment and/or vertex shaders.
   for (cur = cur->children; cur && shader->passes < GFX_MAX_SHADERS;
         cur = cur->next)
   {
      if (cur->type != XML_ELEMENT_NODE)
         continue;

      char *content = xml_get_content(cur);
      if (!content)
         continue;

      struct gfx_shader_pass *pass = &shader->pass[shader->passes];

      if (strcmp((const char*)cur->name, "vertex") == 0)
      {
         if (pass->source.xml.vertex)
         {
            RARCH_ERR("Cannot have more than one vertex shader in a program.\n");
            free(content);
            goto error;
         }

         content = xml_replace_if_file(content, path, cur, "src");
         if (!content)
         {
            RARCH_ERR("Shader source file was provided, but failed to read.\n");
            goto error;
         }

         pass->source.xml.vertex = content;
      }
      else if (strcmp((const char*)cur->name, "fragment") == 0)
      {
         if (shader->modern && !pass->source.xml.vertex)
         {
            RARCH_ERR("Modern GLSL was chosen and vertex shader was not provided. This is an error.\n");
            free(content);
            goto error;
         }

         content = xml_replace_if_file(content, path, cur, "src");
         if (!content)
         {
            RARCH_ERR("Shader source file was provided, but failed to read.\n");
            goto error;
         }

         pass->source.xml.fragment = content;
         if (!get_xml_attrs(pass, cur))
         {
            RARCH_ERR("XML shader attributes do not comply with specifications.\n");
            goto error;
         }

         shader->passes++;
      }
      else if (strcmp((const char*)cur->name, "texture") == 0)
      {
         free(content);
         if (!add_texture_image(shader, cur))
         {
            RARCH_ERR("Texture image failed to load.\n");
            goto error;
         }
      }
      else if (strcmp((const char*)cur->name, "import") == 0)
      {
         free(content);
         if (!add_import_value(shader, cur))
         {
            RARCH_ERR("Import value is invalid.\n");
            goto error;
         }
      }
      else if (strcmp((const char*)cur->name, "script") == 0)
      {
         free(content);
         if (!get_script(shader, path, cur))
         {
            RARCH_ERR("Script is invalid.\n");
            goto error;
         }
      }
   }

   if (!shader->passes)
   {
      RARCH_ERR("Couldn't find vertex shader nor fragment shader in XML file.\n");
      goto error;
   }

   xmlFreeDoc(doc);
   xmlFreeParserCtxt(ctx);
   return true;

error:
   RARCH_ERR("Failed to load XML shader ...\n");
   if (doc)
      xmlFreeDoc(doc);
   xmlFreeParserCtxt(ctx);
   return false;
}


// CGP store
static const char *scale_type_to_str(enum gfx_scale_type type)
{
   switch (type)
   {
      case RARCH_SCALE_INPUT:
         return "source";
      case RARCH_SCALE_VIEWPORT:
         return "viewport";
      case RARCH_SCALE_ABSOLUTE:
         return "absolute";
      default:
         return "?";
   }
}

static void shader_write_scale_dim(config_file_t *conf, const char *dim,
      enum gfx_scale_type type, float scale, unsigned abs, unsigned i)
{
   char key[64];
   print_buf(key, "scale_type_%s%u", dim, i);
   config_set_string(conf, key, scale_type_to_str(type));

   print_buf(key, "scale_%s%u", dim, i);
   if (type == RARCH_SCALE_ABSOLUTE)
      config_set_int(conf, key, abs);
   else
      config_set_float(conf, key, scale);
}

static void shader_write_fbo(config_file_t *conf, const struct gfx_fbo_scale *fbo, unsigned i)
{
   char key[64];
   print_buf(key, "float_framebuffer%u", i);
   config_set_bool(conf, key, fbo->fp_fbo);

   if (!fbo->valid)
      return;

   shader_write_scale_dim(conf, "x", fbo->type_x, fbo->scale_x, fbo->abs_x, i);
   shader_write_scale_dim(conf, "y", fbo->type_y, fbo->scale_y, fbo->abs_y, i);
}

static const char *import_semantic_to_string(enum state_tracker_type type)
{
   switch (type)
   {
      case RARCH_STATE_CAPTURE:
         return "capture";
      case RARCH_STATE_TRANSITION:
         return "transition";
      case RARCH_STATE_TRANSITION_COUNT:
         return "transition_count";
      case RARCH_STATE_CAPTURE_PREV:
         return "capture_previous";
      case RARCH_STATE_TRANSITION_PREV:
         return "transition_previous";
      case RARCH_STATE_PYTHON:
         return "python";

      default:
         return "?";
   }
}

static void shader_write_variable(config_file_t *conf, const struct state_tracker_uniform_info *info)
{
   const char *id = info->id;

   char semantic_buf[64];
   char wram_buf[64];
   char input_slot_buf[64];
   char mask_buf[64];
   char equal_buf[64];

   print_buf(semantic_buf, "%s_semantic", id);
   print_buf(wram_buf, "%s_wram", id);
   print_buf(input_slot_buf, "%s_input_slot", id);
   print_buf(mask_buf, "%s_mask", id);
   print_buf(equal_buf, "%s_equal", id);

   config_set_string(conf, semantic_buf, import_semantic_to_string(info->type));
   config_set_hex(conf, mask_buf, info->mask);
   config_set_hex(conf, equal_buf, info->equal);

   switch (info->ram_type)
   {
      case RARCH_STATE_INPUT_SLOT1:
         config_set_int(conf, input_slot_buf, 1);
         break;

      case RARCH_STATE_INPUT_SLOT2:
         config_set_int(conf, input_slot_buf, 2);
         break;

      case RARCH_STATE_WRAM:
         config_set_hex(conf, wram_buf, info->addr);
         break;

      default:
         break;
   }
}

void gfx_shader_write_conf_cgp(config_file_t *conf, const struct gfx_shader *shader)
{
   unsigned i;
   config_set_int(conf, "shaders", shader->passes);
   for (i = 0; i < shader->passes; i++)
   {
      const struct gfx_shader_pass *pass = &shader->pass[i];

      char key[64];
      print_buf(key, "shader%u", i);
      config_set_string(conf, key, pass->source.cg);

      if (pass->filter != RARCH_FILTER_UNSPEC)
      {
         print_buf(key, "filter_linear%u", i);
         config_set_bool(conf, key, pass->filter == RARCH_FILTER_LINEAR);
      }

      print_buf(key, "wrap_mode%u", i);
      config_set_string(conf, key, wrap_mode_to_str(pass->wrap));

      if (pass->frame_count_mod)
      {
         print_buf(key, "frame_count_mod%u", i);
         config_set_int(conf, key, pass->frame_count_mod);
      }

      shader_write_fbo(conf, &pass->fbo, i);
   }

   if (shader->luts)
   {
      char textures[4096] = {0};
      strlcpy(textures, shader->lut[0].id, sizeof(textures));
      for (i = 1; i < shader->luts; i++)
      {
         // O(n^2), but number of textures is very limited.
         strlcat(textures, ";", sizeof(textures));
         strlcat(textures, shader->lut[i].id, sizeof(textures));
      }

      config_set_string(conf, "textures", textures);

      for (i = 0; i < shader->luts; i++)
      {
         char key[64];

         config_set_string(conf, shader->lut[i].id, shader->lut[i].path);

         if (shader->lut[i].filter != RARCH_FILTER_UNSPEC)
         {
            print_buf(key, "%s_linear", shader->lut[i].id);
            config_set_bool(conf, key, shader->lut[i].filter != RARCH_FILTER_LINEAR);
         }

         print_buf(key, "%s_wrap_mode", shader->lut[i].id);
         config_set_string(conf, key, wrap_mode_to_str(shader->lut[i].wrap));
      }
   }

   if (*shader->script_path)
      config_set_string(conf, "import_script", shader->script_path);
   if (*shader->script_class)
      config_set_string(conf, "import_script_class", shader->script_class);

   if (shader->variables)
   {
      char variables[4096] = {0};
      strlcpy(variables, shader->variable[0].id, sizeof(variables));
      for (i = 1; i < shader->variables; i++)
      {
         strlcat(variables, ";", sizeof(variables));
         strlcat(variables, shader->variable[i].id, sizeof(variables));
      }

      config_set_string(conf, "imports", variables);

      for (i = 0; i < shader->variables; i++)
         shader_write_variable(conf, &shader->variable[i]);
   }
}

enum rarch_shader_type gfx_shader_parse_type(const char *path, enum rarch_shader_type fallback)
{
   if (!path)
      return fallback;

   const char *ext = path_get_extension(path);

   if (strcmp(ext, "cg") == 0 || strcmp(ext, "cgp") == 0)
      return RARCH_SHADER_CG;
   else if (strcmp(ext, "shader") == 0 || strcmp(ext, "glslp") == 0 || strcmp(ext, "glsl") == 0)
      return RARCH_SHADER_GLSL;

   return fallback;
}

void gfx_shader_resolve_relative(struct gfx_shader *shader, const char *ref_path)
{
   unsigned i;
   char tmp_path[PATH_MAX];
   for (i = 0; i < shader->passes; i++)
   {
      if (!*shader->pass[i].source.cg)
         continue;

      strlcpy(tmp_path, shader->pass[i].source.cg, sizeof(tmp_path));
      fill_pathname_resolve_relative(shader->pass[i].source.cg,
            ref_path, tmp_path, sizeof(shader->pass[i].source.cg));
   }

   for (i = 0; i < shader->luts; i++)
   {
      strlcpy(tmp_path, shader->lut[i].path, sizeof(tmp_path));
      fill_pathname_resolve_relative(shader->lut[i].path,
            ref_path, tmp_path, sizeof(shader->lut[i].path));
   }

   if (*shader->script_path)
   {
      strlcpy(tmp_path, shader->script_path, sizeof(tmp_path));
      fill_pathname_resolve_relative(shader->script_path,
            ref_path, tmp_path, sizeof(shader->script_path));
   }
}