/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2014 - Daniel De Matteis
 *
 *  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/>.
 */

static void menu_common_shader_manager_init(menu_handle_t *menu)
{
   char cgp_path[PATH_MAX];
   config_file_t *conf = NULL;
   const char *config_path = NULL;
   struct gfx_shader *shader = (struct gfx_shader*)menu->shader;

   if (*g_extern.core_specific_config_path && g_settings.core_specific_config)
      config_path = g_extern.core_specific_config_path;
   else if (*g_extern.config_path)
      config_path = g_extern.config_path;

   // In a multi-config setting, we can't have conflicts on menu.cgp/menu.glslp.
   if (config_path)
   {
      fill_pathname_base(menu->default_glslp, config_path,
            sizeof(menu->default_glslp));
      path_remove_extension(menu->default_glslp);
      strlcat(menu->default_glslp, ".glslp", sizeof(menu->default_glslp));
      fill_pathname_base(menu->default_cgp, config_path,
            sizeof(menu->default_cgp));
      path_remove_extension(menu->default_cgp);
      strlcat(menu->default_cgp, ".cgp", sizeof(menu->default_cgp));
   }
   else
   {
      strlcpy(menu->default_glslp, "menu.glslp", sizeof(menu->default_glslp));
      strlcpy(menu->default_cgp, "menu.cgp", sizeof(menu->default_cgp));
   }


   const char *ext = path_get_extension(g_settings.video.shader_path);
   if (strcmp(ext, "glslp") == 0 || strcmp(ext, "cgp") == 0)
   {
      conf = config_file_new(g_settings.video.shader_path);
      if (conf)
      {
         if (gfx_shader_read_conf_cgp(conf, shader))
         {
            gfx_shader_resolve_relative(shader, g_settings.video.shader_path);
            gfx_shader_resolve_parameters(conf, shader);
         }
         config_file_free(conf);
      }
   }
   else if (strcmp(ext, "glsl") == 0 || strcmp(ext, "cg") == 0)
   {
      strlcpy(shader->pass[0].source.path, g_settings.video.shader_path,
            sizeof(shader->pass[0].source.path));
      shader->passes = 1;
   }
   else
   {
      const char *shader_dir = *g_settings.video.shader_dir ?
         g_settings.video.shader_dir : g_settings.system_directory;

      fill_pathname_join(cgp_path, shader_dir, "menu.glslp", sizeof(cgp_path));
      conf = config_file_new(cgp_path);

      if (!conf)
      {
         fill_pathname_join(cgp_path, shader_dir, "menu.cgp", sizeof(cgp_path));
         conf = config_file_new(cgp_path);
      }

      if (conf)
      {
         if (gfx_shader_read_conf_cgp(conf, shader))
         {
            gfx_shader_resolve_relative(shader, cgp_path);
            gfx_shader_resolve_parameters(conf, shader);
         }
         config_file_free(conf);
      }
   }
}

static void menu_common_shader_manager_set_preset(struct gfx_shader *shader,
      unsigned type, const char *cgp_path)
{
   RARCH_LOG("Setting Menu shader: %s.\n", cgp_path ? cgp_path : "N/A (stock)");

   if (driver.video->set_shader && driver.video->set_shader(driver.video_data,
            (enum rarch_shader_type)type, cgp_path))
   {
      /* Makes sure that we use Menu CGP shader on driver reinit.
       * Only do this when the cgp actually works to avoid potential errors. */
      strlcpy(g_settings.video.shader_path, cgp_path ? cgp_path : "",
            sizeof(g_settings.video.shader_path));
      g_settings.video.shader_enable = true;

      if (cgp_path && shader)
      {
         /* Load stored CGP into menu on success.
          * Used when a preset is directly loaded.
          * No point in updating when the CGP was 
          * created from the menu itself. */
         config_file_t *conf = config_file_new(cgp_path);

         if (conf)
         {
            if (gfx_shader_read_conf_cgp(conf, shader))
            {
               gfx_shader_resolve_relative(shader, cgp_path);
               gfx_shader_resolve_parameters(conf, shader);
            }
            config_file_free(conf);
         }

         driver.menu->need_refresh = true;
      }
   }
   else
   {
      RARCH_ERR("Setting Menu CGP failed.\n");
      g_settings.video.shader_enable = false;
   }
}

static void menu_common_shader_manager_get_str(struct gfx_shader *shader,
      char *type_str, size_t type_str_size, unsigned type)
{
   *type_str = '\0';

   if (type >= MENU_SETTINGS_SHADER_PARAMETER_0
         && type <= MENU_SETTINGS_SHADER_PARAMETER_LAST)
   {
      /* menu->parameter_shader here. */
      if (shader)
      {
         const struct gfx_shader_parameter *param =
            (const struct gfx_shader_parameter*)&shader->parameters
            [type - MENU_SETTINGS_SHADER_PARAMETER_0];
         snprintf(type_str, type_str_size, "%.2f [%.2f %.2f]",
               param->current, param->minimum, param->maximum);
      }
   }
   else if (type == MENU_SETTINGS_SHADER_PASSES)
      snprintf(type_str, type_str_size, "%u", shader->passes);
   else if (type >= MENU_SETTINGS_SHADER_0 && type <= MENU_SETTINGS_SHADER_LAST)
   {
      unsigned pass = (type - MENU_SETTINGS_SHADER_0) / 3;
      switch ((type - MENU_SETTINGS_SHADER_0) % 3)
      {
         case 0:
            if (*shader->pass[pass].source.path)
               fill_pathname_base(type_str,
                     shader->pass[pass].source.path, type_str_size);
            else
               strlcpy(type_str, "N/A", type_str_size);
            break;

         case 1:
            {
               static const char *modes[] = {
                  "Don't care",
                  "Linear",
                  "Nearest"
               };

               strlcpy(type_str, modes[shader->pass[pass].filter],
                     type_str_size);
            }
            break;

         case 2:
         {
            unsigned scale = shader->pass[pass].fbo.scale_x;
            if (!scale)
               strlcpy(type_str, "Don't care", type_str_size);
            else
               snprintf(type_str, type_str_size, "%ux", scale);
            break;
         }
      }
   }
}

static void menu_common_shader_manager_save_preset(
      const char *basename, bool apply)
{
   char buffer[PATH_MAX], config_directory[PATH_MAX], cgp_path[PATH_MAX];
   unsigned d, type = RARCH_SHADER_NONE;
   config_file_t *conf = NULL;
   const char *conf_path = NULL;
   bool ret = false;

   if (!driver.menu)
   {
      RARCH_ERR("Cannot save shader preset, menu handle is not initialized.\n");
      return;
   }

   if (driver.menu_ctx && driver.menu_ctx->backend
         && driver.menu_ctx->backend->shader_manager_get_type)
      type = driver.menu_ctx->backend->shader_manager_get_type
         (driver.menu->shader);

   if (type == RARCH_SHADER_NONE)
      return;

   conf_path = (type == RARCH_SHADER_GLSL) ?
      driver.menu->default_glslp : driver.menu->default_cgp;
   *config_directory = '\0';

   if (basename)
   {
      strlcpy(buffer, basename, sizeof(buffer));

      /* Append extension automatically as appropriate. */
      if (!strstr(basename, ".cgp") && !strstr(basename, ".glslp"))
      {
         if (type == RARCH_SHADER_GLSL)
            strlcat(buffer, ".glslp", sizeof(buffer));
         else if (type == RARCH_SHADER_CG)
            strlcat(buffer, ".cgp", sizeof(buffer));
      }
   }

   if (*g_extern.config_path)
      fill_pathname_basedir(config_directory,
            g_extern.config_path, sizeof(config_directory));

   const char *dirs[] = {
      g_settings.video.shader_dir,
      g_settings.menu_config_directory,
      config_directory,
   };

   if (!(conf = (config_file_t*)config_file_new(NULL)))
      return;
   gfx_shader_write_conf_cgp(conf, driver.menu->shader);

   for (d = 0; d < ARRAY_SIZE(dirs); d++)
   {
      if (!*dirs[d])
         continue;

      fill_pathname_join(cgp_path, dirs[d], conf_path, sizeof(cgp_path));
      if (config_file_write(conf, cgp_path))
      {
         RARCH_LOG("Saved shader preset to %s.\n", cgp_path);
         if (apply)
         {
            if (driver.menu_ctx && driver.menu_ctx->backend
                  && driver.menu_ctx->backend->shader_manager_set_preset)
               driver.menu_ctx->backend->shader_manager_set_preset(
                     NULL, type, cgp_path);
         }
         ret = true;
         break;
      }
      else
         RARCH_LOG("Failed writing shader preset to %s.\n", cgp_path);
   }

   config_file_free(conf);
   if (!ret)
      RARCH_ERR("Failed to save shader preset. Make sure config directory and/or shader dir are writable.\n");
}

static unsigned menu_common_shader_manager_get_type(
      const struct gfx_shader *shader)
{
   /* All shader types must be the same, or we cannot use it. */
   unsigned i;
   unsigned type = RARCH_SHADER_NONE;

   if (!shader)
   {
      RARCH_ERR("Cannot get shader type, shader handle is not initialized.\n");
      return RARCH_SHADER_NONE;
   }

   for (i = 0; i < shader->passes; i++)
   {
      enum rarch_shader_type pass_type = gfx_shader_parse_type(shader->pass[i].source.path,
            RARCH_SHADER_NONE);

      switch (pass_type)
      {
         case RARCH_SHADER_CG:
         case RARCH_SHADER_GLSL:
            if (type == RARCH_SHADER_NONE)
               type = pass_type;
            else if (type != pass_type)
               return RARCH_SHADER_NONE;
            break;
         default:
            return RARCH_SHADER_NONE;
      }
   }

   return type;
}

static int menu_common_shader_manager_setting_toggle(
      unsigned id, unsigned action)
{
   if (!driver.menu)
   {
      RARCH_ERR("Cannot toggle shader setting, menu handle is not initialized.\n");
      return 0;
   }

   rarch_setting_t *current_setting = NULL;
   rarch_setting_t *setting_data = (rarch_setting_t *)setting_data_get_list();

   unsigned dist_shader = id - MENU_SETTINGS_SHADER_0;
   unsigned dist_filter = id - MENU_SETTINGS_SHADER_0_FILTER;
   unsigned dist_scale  = id - MENU_SETTINGS_SHADER_0_SCALE;

   if (id == MENU_SETTINGS_SHADER_FILTER)
   {
      if ((current_setting = setting_data_find_setting(
                  setting_data, "video_smooth")))
         menu_common_setting_set_current_boolean(current_setting, action);
   }
   else if ((id == MENU_SETTINGS_SHADER_PARAMETERS
            || id == MENU_SETTINGS_SHADER_PRESET_PARAMETERS)
         && action == MENU_ACTION_OK)
      menu_entries_push(driver.menu->menu_stack, "",
            "shader_parameters", id, driver.menu->selection_ptr);
   else if (id >= MENU_SETTINGS_SHADER_PARAMETER_0
         && id <= MENU_SETTINGS_SHADER_PARAMETER_LAST)
   {
      struct gfx_shader *shader = NULL;
      struct gfx_shader_parameter *param = NULL;

      if (!(shader = (struct gfx_shader*)driver.menu->parameter_shader))
         return 0;

      if (!(param = &shader->parameters[id - MENU_SETTINGS_SHADER_PARAMETER_0]))
         return 0;

      switch (action)
      {
         case MENU_ACTION_START:
            param->current = param->initial;
            break;

         case MENU_ACTION_LEFT:
            param->current -= param->step;
            break;

         case MENU_ACTION_RIGHT:
            param->current += param->step;
            break;

         default:
            break;
      }

      param->current = min(max(param->minimum, param->current), param->maximum);
   }
   else if ((id == MENU_SETTINGS_SHADER_APPLY ||
            id == MENU_SETTINGS_SHADER_PASSES))
      menu_setting_set(id, action);
   else if (((dist_shader % 3) == 0 || id == MENU_SETTINGS_SHADER_PRESET))
   {
      struct gfx_shader *shader = (struct gfx_shader*)driver.menu->shader;
      struct gfx_shader_pass *pass = NULL;

      dist_shader /= 3;
      if (shader && id == MENU_SETTINGS_SHADER_PRESET)
         pass = &shader->pass[dist_shader];

      switch (action)
      {
         case MENU_ACTION_OK:
            menu_entries_push(driver.menu->menu_stack,
                  g_settings.video.shader_dir, "video_shader_preset",
                  id, driver.menu->selection_ptr);
            break;

         case MENU_ACTION_START:
            if (pass)
               *pass->source.path = '\0';
            break;

         default:
            break;
      }
   }
   else if ((dist_filter % 3) == 0)
   {
      dist_filter /= 3;
      struct gfx_shader *shader = (struct gfx_shader*)driver.menu->shader;
      struct gfx_shader_pass *pass = (struct gfx_shader_pass*)
         &shader->pass[dist_filter];

      switch (action)
      {
         case MENU_ACTION_START:
            if (shader && shader->pass)
               shader->pass[dist_filter].filter = RARCH_FILTER_UNSPEC;
            break;

         case MENU_ACTION_LEFT:
         case MENU_ACTION_RIGHT:
         case MENU_ACTION_OK:
         {
            unsigned delta = (action == MENU_ACTION_LEFT) ? 2 : 1;
            if (pass)
               pass->filter = ((pass->filter + delta) % 3);
            break;
         }

         default:
         break;
      }
   }
   else if ((dist_scale % 3) == 0)
   {
      dist_scale /= 3;
      struct gfx_shader *shader = (struct gfx_shader*)driver.menu->shader;
      struct gfx_shader_pass *pass = (struct gfx_shader_pass*)
         &shader->pass[dist_scale];

      switch (action)
      {
         case MENU_ACTION_START:
            if (shader && shader->pass)
            {
               pass->fbo.scale_x = pass->fbo.scale_y = 0;
               pass->fbo.valid = false;
            }
            break;

         case MENU_ACTION_LEFT:
         case MENU_ACTION_RIGHT:
         case MENU_ACTION_OK:
         {
            unsigned current_scale = pass->fbo.scale_x;
            unsigned delta = action == MENU_ACTION_LEFT ? 5 : 1;
            current_scale = (current_scale + delta) % 6;

            if (pass)
            {
               pass->fbo.valid = current_scale;
               pass->fbo.scale_x = pass->fbo.scale_y = current_scale;
            }
            break;
         }

         default:
         break;
      }
   }

   return 0;
}