/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2015 - 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/>.
 */

#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>

#include <boolean.h>

#include "../configuration.h"

bool menu_navigation_ctl(enum menu_navigation_ctl_state state, void *data)
{
   const menu_ctx_driver_t *driver = menu_ctx_driver_get_ptr();
   settings_t          *settings   = config_get_ptr();
   menu_navigation_t        *nav   = menu_navigation_get_ptr();
   menu_list_t          *menu_list = menu_list_get_ptr();

   (void)menu_list;
   (void)settings;

   switch (state)
   {
      case MENU_NAVIGATION_CTL_CLEAR:
         {
            bool *pending_push = (bool*)data;

            if (!pending_push)
               return false;

            menu_navigation_set(nav, 0, true);
            if (driver->navigation_clear)
               driver->navigation_clear(*pending_push);
         }
         return true;
      case MENU_NAVIGATION_CTL_INCREMENT:
         {
            size_t selection       = nav->selection_ptr;
            unsigned *scroll_speed = (unsigned*)data;

            if (!scroll_speed)
               return false;

            if ((selection + (*scroll_speed)) < (menu_list_get_size(menu_list)))
            {
               menu_navigation_set(nav, selection + (*scroll_speed), true);
               menu_navigation_ctl(MENU_NAVIGATION_CTL_INCREMENT, NULL);
            }
            else
            {
               if (settings->menu.navigation.wraparound.vertical_enable)
               {
                  bool pending_push = false;
                  menu_navigation_ctl(MENU_NAVIGATION_CTL_CLEAR, &pending_push);
               }
               else
               {
                  if ((menu_list_get_size(menu_list) > 0))
                  {
                     menu_navigation_ctl(MENU_NAVIGATION_CTL_SET_LAST,  NULL);
                     menu_navigation_ctl(MENU_NAVIGATION_CTL_INCREMENT, NULL);
                  }
               }
            }
            if (driver->navigation_increment)
               driver->navigation_increment();
         }
         return true;
      case MENU_NAVIGATION_CTL_DECREMENT:
         {
            size_t selection       = nav->selection_ptr;
            unsigned *scroll_speed = (unsigned*)data;

            if (!scroll_speed)
               return false;

            if (selection >= *scroll_speed)
               menu_navigation_set(nav, selection - *scroll_speed, true);
            else
            {
               if (settings->menu.navigation.wraparound.vertical_enable)
                  menu_navigation_set(nav, 
                        menu_list_get_size(menu_list) - 1, true);
               else
                  menu_navigation_set(nav, 0, true);
            }

            menu_navigation_ctl(MENU_NAVIGATION_CTL_DECREMENT, NULL);
            if (driver->navigation_decrement)
               driver->navigation_decrement();
         }
         return true;
      case MENU_NAVIGATION_CTL_SET:
         {
            bool *scroll = (bool*)data;

            if (!scroll)
               return false;

            if (driver->navigation_set)
               driver->navigation_set(*scroll);
         }
         return true;
      case MENU_NAVIGATION_CTL_SET_LAST:
         nav->selection_ptr = menu_list_get_size(menu_list) - 1;
         if (driver->navigation_set_last)
            driver->navigation_set_last();
         return true;
      case MENU_NAVIGATION_CTL_ASCEND_ALPHABET:
         {
            size_t *ptr_out = (size_t*)data;

            if (!ptr_out)
               return false;

            if (driver->navigation_ascend_alphabet)
               driver->navigation_ascend_alphabet(ptr_out);
         }
         return true;
      case MENU_NAVIGATION_CTL_DESCEND_ALPHABET:
         {
            size_t *ptr_out = (size_t*)data;

            if (!ptr_out)
               return false;

            if (driver->navigation_descend_alphabet)
               driver->navigation_descend_alphabet(ptr_out);
         }
         return true;
      case MENU_NAVIGATION_CTL_GET_SELECTION:
         {
            size_t *sel = (size_t*)data;
            if (!nav || !sel)
               return false;
            *sel = nav->selection_ptr;
         }
         return true;
      case MENU_NAVIGATION_CTL_SET_SELECTION:
         {
            size_t *sel = (size_t*)data;
            if (!nav || !sel)
               return false;
            nav->selection_ptr = *sel;
         }
         return true;
   }

   return false;
}

/**
 * menu_navigation_set:      
 * @idx                   : index to set navigation pointer to.
 * @scroll                : should we scroll when needed?
 *
 * Sets navigation pointer to index @idx.
 **/
void menu_navigation_set(menu_navigation_t *nav,
      size_t idx, bool scroll)
{
   menu_navigation_ctl(MENU_NAVIGATION_CTL_SET_SELECTION, &idx);
   menu_navigation_ctl(MENU_NAVIGATION_CTL_SET, &scroll);
}

/**
 * menu_navigation_descend_alphabet:
 * @ptr_out               : Amount of indices to 'scroll' to get
 *                          to the next entry.
 *
 * Descends alphabet.
 * E.g.:
 * If navigation points to an entry called 'Beta',
 * navigation pointer will be set to an entry called 'Alpha'.
 **/
void menu_navigation_descend_alphabet(menu_navigation_t *nav, size_t *ptr_out)
{
   size_t i, ptr = *ptr_out;

   if (!nav || !nav->scroll.indices.size || ptr == 0)
      return;

   i = nav->scroll.indices.size - 1;

   while (i && nav->scroll.indices.list[i - 1] >= ptr)
      i--;
   *ptr_out = nav->scroll.indices.list[i - 1];

   menu_navigation_ctl(MENU_NAVIGATION_CTL_DESCEND_ALPHABET, ptr_out);
}

/**
 * menu_navigation_ascends_alphabet:
 * @ptr_out               : Amount of indices to 'scroll' to get
 *                          to the next entry.
 *
 * Ascends alphabet.
 * E.g.:
 * If navigation points to an entry called 'Alpha',
 * navigation pointer will be set to an entry called 'Beta'.
 **/
void menu_navigation_ascend_alphabet(menu_navigation_t *nav, size_t *ptr_out)
{
   size_t i = 0, ptr = *ptr_out;
   if (!nav || !nav->scroll.indices.size)
      return;

   if (ptr == nav->scroll.indices.list[nav->scroll.indices.size - 1])
      return;

   while (i < nav->scroll.indices.size - 1
         && nav->scroll.indices.list[i + 1] <= ptr)
      i++;
   *ptr_out = nav->scroll.indices.list[i + 1];

   menu_navigation_ctl(MENU_NAVIGATION_CTL_ASCEND_ALPHABET, ptr_out);
}