/**********************************************************************
 Freeciv - Copyright (C) 2005 - The Freeciv Project
   This program 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 Foundation; either version 2, or (at your option)
   any later version.

   This program 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.
***********************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/* common */
#include "idex.h"
#include "movement.h"

/* server/scripting */
#include "api_find.h"
#include "script.h"


/**************************************************************************
  Return a player with the given player_id.
**************************************************************************/
Player *api_find_player(int player_id)
{
  return player_by_number(player_id);
}

/**************************************************************************
  Return a player city with the given city_id.
**************************************************************************/
City *api_find_city(Player *pplayer, int city_id)
{
  if (pplayer) {
    return player_city_by_number(pplayer, city_id);
  } else {
    return idex_lookup_city(city_id);
  }
}

/**************************************************************************
  Return a player unit with the given unit_id.
**************************************************************************/
Unit *api_find_unit(Player *pplayer, int unit_id)
{
  if (pplayer) {
    return player_unit_by_number(pplayer, unit_id);
  } else {
    return idex_lookup_unit(unit_id);
  }
}

/**************************************************************************
  Return a unit that can transport ptype at a given ptile.
**************************************************************************/
Unit *api_find_transport_unit(Player *pplayer, Unit_Type *ptype,
                              Tile *ptile)
{
  SCRIPT_CHECK_ARG_NIL(pplayer, 1, Player, NULL);
  SCRIPT_CHECK_ARG_NIL(ptype, 2, Unit_Type, NULL);
  SCRIPT_CHECK_ARG_NIL(ptile, 3, Tile, NULL);

  {
    struct unit *ptransport;
    struct unit *pvirt = create_unit_virtual(pplayer, NULL, ptype, 0);
    pvirt->tile = ptile;
    pvirt->homecity = 0;
    ptransport = transport_from_tile(pvirt, ptile);
    destroy_unit_virtual(pvirt);
    return ptransport;
  }
}

/************************************************************************** 
  Return a unit type for given role.
**************************************************************************/
Unit_Type *api_find_role_unit_type(const char *role_name, Player *pplayer)
{
  enum unit_role_id role;
  SCRIPT_CHECK_ARG_NIL(role_name, 1, string, NULL);

  role = unit_role_by_rule_name(role_name);

  if (role == L_LAST) {
    return NULL;
  }

  if (pplayer) {
    return best_role_unit_for_player(pplayer, role);
  } else if (num_role_units(role) > 0) {
    return get_role_unit(role, 0);
  } else {
    return NULL;
  }
}

/**************************************************************************
  Return the tile at the given native coordinates.
**************************************************************************/
Tile *api_find_tile(int nat_x, int nat_y)
{
  return native_pos_to_tile(nat_x, nat_y);
}

/**************************************************************************
  Return the tile at the given index.
**************************************************************************/
Tile *api_find_tile_by_index(int index)
{
  return index_to_tile(index);
}

/**************************************************************************
  Return the government with the given government_id index.
**************************************************************************/
Government *api_find_government(int government_id)
{
  return government_by_number(government_id);
}

/**************************************************************************
  Return the governmet with the given name_orig.
**************************************************************************/
Government *api_find_government_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return government_by_rule_name(name_orig);
}

/**************************************************************************
  Return the nation type with the given nation_type_id index.
**************************************************************************/
Nation_Type *api_find_nation_type(int nation_type_id)
{
  return nation_by_number(nation_type_id);
}

/**************************************************************************
  Return the nation type with the given name_orig.
**************************************************************************/
Nation_Type *api_find_nation_type_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return nation_by_rule_name(name_orig);
}

/**************************************************************************
  Return the improvement type with the given impr_type_id index.
**************************************************************************/
Building_Type *api_find_building_type(int building_type_id)
{
  return improvement_by_number(building_type_id);
}

/**************************************************************************
  Return the improvement type with the given name_orig.
**************************************************************************/
Building_Type *api_find_building_type_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return improvement_by_rule_name(name_orig);
}

/**************************************************************************
  Return the unit type with the given unit_type_id index.
**************************************************************************/
Unit_Type *api_find_unit_type(int unit_type_id)
{
  return utype_by_number(unit_type_id);
}

/**************************************************************************
  Return the unit type with the given name_orig.
**************************************************************************/
Unit_Type *api_find_unit_type_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return unit_type_by_rule_name(name_orig);
}

/**************************************************************************
  Return the tech type with the given tech_type_id index.
**************************************************************************/
Tech_Type *api_find_tech_type(int tech_type_id)
{
  return advance_by_number(tech_type_id);
}

/**************************************************************************
  Return the tech type with the given name_orig.
**************************************************************************/
Tech_Type *api_find_tech_type_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return advance_by_rule_name(name_orig);
}

/**************************************************************************
  Return the terrain with the given terrain_id index.
**************************************************************************/
Terrain *api_find_terrain(int terrain_id)
{
  return terrain_by_number(terrain_id);
}

/**************************************************************************
  Return the terrain with the given name_orig.
**************************************************************************/
Terrain *api_find_terrain_by_name(const char *name_orig)
{
  SCRIPT_CHECK_ARG_NIL(name_orig, 1, string, NULL);
  return terrain_by_rule_name(name_orig);
}

/**************************************************************************
  Return a dummy pointer.
**************************************************************************/
Nonexistent *api_find_nonexistent()
{
  static char *p = "";
  return p;
}