/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2021 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2021 - Daniel De Matteis
 *  Copyright (C) 2019-2021 - James Leaver
 *
 *  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 <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include <string/stdstring.h>

#include "tasks_internal.h"

#include "../menu/menu_entries.h"
#include "../menu/menu_driver.h"

typedef struct menu_explore_init_handle
{
   explore_state_t *state;
   char *directory_playlist;
   char *directory_database;
} menu_explore_init_handle_t;

/*********************/
/* Utility Functions */
/*********************/

static void free_menu_explore_init_handle(
      menu_explore_init_handle_t *menu_explore)
{
   if (!menu_explore)
      return;

   if (menu_explore->directory_playlist)
   {
      free(menu_explore->directory_playlist);
      menu_explore->directory_playlist = NULL;
   }

   if (menu_explore->directory_database)
   {
      free(menu_explore->directory_database);
      menu_explore->directory_database = NULL;
   }

   if (menu_explore->state)
   {
      menu_explore_free_state(menu_explore->state);
      free(menu_explore->state);
      menu_explore->state = NULL;
   }

   free(menu_explore);
   menu_explore = NULL;
}

static void cb_task_menu_explore_init(
      retro_task_t *task, void *task_data,
      void *user_data, const char *err)
{
   menu_explore_init_handle_t *menu_explore = NULL;
   unsigned menu_type                       = 0;

   if (!task)
      return;

   menu_explore = (menu_explore_init_handle_t*)task->state;

   if (!menu_explore)
      return;

   /* Assign global menu explore state object */
   menu_explore_set_state(menu_explore->state);
   menu_explore->state = NULL;

   /* If the explore menu is currently displayed,
    * it must be refreshed */
   menu_entries_get_last_stack(NULL, NULL, &menu_type, NULL, NULL);

   /* check if we are opening a saved view from the horizontal/tabs menu */
   if (menu_type == MENU_SETTING_HORIZONTAL_MENU)
   {
      size_t selection = menu_driver_list_get_selection();
      size_t size      = menu_driver_list_get_size(MENU_LIST_TABS);
      if (selection > 0 && size > 0)
      {
         menu_ctx_list_t horizontal;
         horizontal.type = MENU_LIST_HORIZONTAL;
         horizontal.idx  = selection - (size + 1);
         if (menu_driver_list_get_entry(&horizontal))
            menu_type = ((struct item_file*)horizontal.entry)->type;
      }
   }

   if (menu_type == MENU_EXPLORE_TAB)
   {
      struct menu_state *menu_st = menu_state_get_ptr();
      menu_st->flags            |=  MENU_ST_FLAG_ENTRIES_NEED_REFRESH
                                 |  MENU_ST_FLAG_PREVENT_POPULATE;
   }
}

static void task_menu_explore_init_free(retro_task_t *task)
{
   menu_explore_init_handle_t *menu_explore = NULL;

   if (!task)
      return;

   menu_explore = (menu_explore_init_handle_t*)task->state;

   free_menu_explore_init_handle(menu_explore);
}

/*******************************/
/* Explore Menu Initialisation */
/*******************************/

static void task_menu_explore_init_handler(retro_task_t *task)
{
   menu_explore_init_handle_t *menu_explore = NULL;

   if (!task)
      goto task_finished;

   menu_explore = (menu_explore_init_handle_t*)task->state;

   if (!menu_explore)
      goto task_finished;

   if (task_get_cancelled(task))
      goto task_finished;

   /* TODO/FIXME: It could be beneficial to
    * initialise the explore menu iteratively,
    * but this would require a non-trivial rewrite
    * of the menu_explore code. For now, we will
    * do it in a single shot (the most important
    * consideration here is to place this
    * initialisation on a background thread) */
   menu_explore->state = menu_explore_build_list(
         menu_explore->directory_playlist,
         menu_explore->directory_database);

   task_set_progress(task, 100);

task_finished:

   if (task)
      task_set_finished(task, true);
}

static bool task_menu_explore_init_finder(
      retro_task_t *task, void *user_data)
{
   if (!task)
      return false;

   if (task->handler == task_menu_explore_init_handler)
      return true;

   return false;
}

bool task_push_menu_explore_init(const char *directory_playlist,
      const char *directory_database)
{
   task_finder_data_t find_data;
   retro_task_t *task                       = NULL;
   menu_explore_init_handle_t *menu_explore = NULL;

   if (string_is_empty(directory_playlist) ||
       string_is_empty(directory_database))
      goto error;

   task         = task_init();
   menu_explore = (menu_explore_init_handle_t*)calloc(1,
         sizeof(menu_explore_init_handle_t));

   if (!task || !menu_explore)
      goto error;

   /* Explore menu is singular - cannot perform
    * multiple initialisations simultaneously */
   find_data.func     = task_menu_explore_init_finder;
   find_data.userdata = NULL;

   if (task_queue_find(&find_data))
      goto error;

   /* Configure handle */
   menu_explore->state              = NULL;
   menu_explore->directory_playlist = strdup(directory_playlist);
   menu_explore->directory_database = strdup(directory_database);

   /* Configure task
    * > Note: This is silent task, with no title
    *   and no user notification messages */
   task->handler  = task_menu_explore_init_handler;
   task->state    = menu_explore;
   task->mute     = true;
   task->title    = NULL;
   task->progress = 0;
   task->callback = cb_task_menu_explore_init;
   task->cleanup  = task_menu_explore_init_free;

   task_queue_push(task);

   return true;

error:

   if (task)
   {
      free(task);
      task = NULL;
   }

   free_menu_explore_init_handle(menu_explore);
   menu_explore = NULL;

   return false;
}

bool menu_explore_init_in_progress(void *data)
{
   task_finder_data_t find_data;

   find_data.func     = task_menu_explore_init_finder;
   find_data.userdata = NULL;

   if (task_queue_find(&find_data))
      return true;

   return false;
}

void menu_explore_wait_for_init_task(void)
{
   task_queue_wait(menu_explore_init_in_progress, NULL);
}
