api_server_edit.c

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/*****************************************************************************
 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 <fc_config.h>
#endif
 
/* utility */
#include "rand.h"
 
/* common */
#include "citizens.h"
#include "map.h"
#include "movement.h"
#include "research.h"
#include "unittype.h"
 
/* common/scriptcore */
#include "api_game_find.h"
#include "luascript.h"
 
/* server */
#include "aiiface.h"
#include "barbarian.h"
#include "citytools.h"
#include "cityturn.h" /* city_refresh() auto_arrange_workers() */
#include "console.h" /* enum rfc_status */
#include "gamehand.h"
#include "maphand.h"
#include "notify.h"
#include "plrhand.h"
#include "srv_main.h" /* game_was_started() */
#include "stdinhand.h"
#include "techtools.h"
#include "unithand.h"
#include "unittools.h"
 
/* server/scripting */
#include "script_server.h"
 
/* server/generator */
#include "mapgen_utils.h"
 
#include "api_server_edit.h"
 
 
/**********************************************************************/
bool api_edit_unleash_barbarians(lua_State *L, Tile *ptile)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 2, Tile, FALSE);
 
  return unleash_barbarians(ptile);
}
 
/**********************************************************************/
static bool
ur_transform_unit(struct unit *punit, const struct unit_type *to_unit,
                  int vet_loss)
{
  if (UU_OK == unit_transform_result(&(wld.map), punit, to_unit)) {
    /* Avoid getting overt veteranship if a user requests increasing it */
    if (vet_loss < 0) {
      int vl = utype_veteran_levels(to_unit);
 
      vl = punit->veteran - vl + 1;
      if (vl >= 0) {
        vet_loss = 0;
      } else {
        vet_loss = MAX(vet_loss, vl);
      }
    }
    transform_unit(punit, to_unit, vet_loss);
 
    return TRUE;
  } else {
    return FALSE;
  }
}
 
/**********************************************************************/
void api_edit_place_partisans(lua_State *L, Tile *ptile, Player *pplayer,
                              int count, int sq_radius)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 2, Tile);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 3, Player);
  LUASCRIPT_CHECK_ARG(L, 0 <= sq_radius, 5, "radius must be positive");
  LUASCRIPT_CHECK(L, 0 < num_role_units(L_PARTISAN),
                  "no partisans in ruleset");
 
  return place_partisans(ptile, pplayer, count, sq_radius);
}
 
/**********************************************************************/
Unit *api_edit_create_unit(lua_State *L, Player *pplayer, Tile *ptile,
                           Unit_Type *ptype, int veteran_level,
                           City *homecity, int moves_left)
{
  return api_edit_create_unit_full(L, pplayer, ptile, ptype, veteran_level,
                                   homecity, moves_left, -1, nullptr);
}
 
/**********************************************************************/
Unit *api_edit_create_unit_full(lua_State *L, Player *pplayer,
                                Tile *ptile,
                                Unit_Type *ptype, int veteran_level,
                                City *homecity, int moves_left,
                                int hp_left,
                                Unit *ptransport)
{
  struct fc_lua *fcl;
  struct city *pcity;
  struct unit *punit;
#ifndef FREECIV_NDEBUG
  bool placed;
#endif
 
  LUASCRIPT_CHECK_STATE(L, nullptr);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player, nullptr);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 3, Tile, nullptr);
 
  fcl = luascript_get_fcl(L);
 
  LUASCRIPT_CHECK(L, fcl != nullptr, "Undefined Freeciv lua state!", nullptr);
 
  if (ptype == nullptr
      || ptype < unit_type_array_first() || ptype > unit_type_array_last()) {
    return nullptr;
  }
 
  if (is_non_allied_unit_tile(ptile, pplayer,
                              utype_has_flag(ptype, UTYF_FLAGLESS))) {
    luascript_log(fcl, LOG_ERROR, "create_unit_full: tile is occupied by "
                                  "enemy unit");
    return nullptr;
  }
 
  pcity = tile_city(ptile);
  if (pcity != nullptr && !pplayers_allied(pplayer, city_owner(pcity))) {
    luascript_log(fcl, LOG_ERROR, "create_unit_full: tile is occupied by "
                                  "enemy city");
    return nullptr;
  }
 
  if (utype_player_already_has_this_unique(pplayer, ptype)) {
    luascript_log(fcl, LOG_ERROR,
                  "create_unit_full: player already has unique unit");
    return nullptr;
  }
 
  punit = unit_virtual_prepare(pplayer, ptile, ptype, veteran_level,
                               homecity ? homecity->id : 0,
                               moves_left, hp_left);
  if (ptransport) {
    /* The unit maybe can't freely load into the transport
     * but must be able to be in it, see can_unit_load() */
    int ret = same_pos(ptile, unit_tile(ptransport))
       && could_unit_be_in_transport(punit, ptransport);
 
    if (!ret) {
      unit_virtual_destroy(punit);
      luascript_log(fcl, LOG_ERROR, "create_unit_full: '%s' cannot transport "
                                    "'%s' here",
                    utype_rule_name(unit_type_get(ptransport)),
                    utype_rule_name(ptype));
      return nullptr;
    }
  } else if (!can_exist_at_tile(&(wld.map), ptype, ptile)) {
    unit_virtual_destroy(punit);
    luascript_log(fcl, LOG_ERROR, "create_unit_full: '%s' cannot exist at "
                                  "tile", utype_rule_name(ptype));
    return nullptr;
  }
 
#ifndef FREECIV_NDEBUG
  placed =
#endif
  place_unit(punit, pplayer, homecity, ptransport, TRUE);
  fc_assert_action(placed, unit_virtual_destroy(punit); punit = nullptr);
 
  return punit;
}
 
/**********************************************************************/
bool api_edit_unit_teleport(lua_State *L, Unit *punit, Tile *dest,
                            Unit *embark_to, bool allow_disembark,
                            bool conquer_city, bool conquer_extra,
                            bool enter_hut, bool frighten_hut)
{
  bool alive;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, dest, 3, Tile, FALSE);
 
  LUASCRIPT_CHECK(L, !(enter_hut && frighten_hut),
                  "Can't both enter and frighten a hut at the same time",
                  TRUE);
 
  if (!allow_disembark && unit_transported(punit)) {
    /* Can't leave the transport. */
    return TRUE;
  }
 
  if (unit_teleport_to_tile_test(&(wld.map), punit, ACTIVITY_IDLE,
                                 unit_tile(punit), dest, FALSE,
                                 embark_to, TRUE) != MR_OK) {
    /* Can't teleport to target. Return that unit is still alive. */
    return TRUE;
  }
 
  /* Teleport first so destination is revealed even if unit dies */
  alive = unit_move(punit, dest, 0,
                    embark_to, embark_to != nullptr,
                    conquer_city, conquer_extra,
                    enter_hut, frighten_hut);
  if (alive) {
    struct player *owner = unit_owner(punit);
    struct city *pcity = tile_city(dest);
 
    if (!can_unit_exist_at_tile(&(wld.map), punit, dest)
        && !unit_transported(punit)) {
      wipe_unit(punit, ULR_NONNATIVE_TERR, nullptr);
      return FALSE;
    }
    if (is_non_allied_unit_tile(dest, owner,
                                unit_has_type_flag(punit, UTYF_FLAGLESS))
        || (pcity != nullptr
            && !pplayers_allied(city_owner(pcity), owner))) {
      wipe_unit(punit, ULR_STACK_CONFLICT, nullptr);
      return FALSE;
    }
  }
 
  return alive;
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_city(lua_State *L, Unit *punit,
                                          Action *paction, City *tgt)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) == ATK_CITY, 3,
                      "Not a city-targeted action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, City, FALSE);
 
  fc_assert_ret_val(!action_has_result(paction, ACTRES_FOUND_CITY), FALSE);
  if (is_action_enabled_unit_on_city(&(wld.map), paction->id, punit, tgt)) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tgt->id, IDENTITY_NUMBER_ZERO, "",
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_city_impr(lua_State *L, Unit *punit,
                                               Action *paction, City *tgt,
                                               Building_Type *sub_tgt)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) == ATK_CITY, 3,
                      "Not a city-targeted action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, City, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, sub_tgt, 5, Building_Type, FALSE);
 
  fc_assert_ret_val(!action_has_result(paction, ACTRES_FOUND_CITY), FALSE);
  if (is_action_enabled_unit_on_city(&(wld.map), paction->id, punit, tgt)) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tgt->id, sub_tgt->item_number, "",
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_city_tech(lua_State *L, Unit *punit,
                                               Action *paction, City *tgt,
                                               Tech_Type *sub_tgt)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) == ATK_CITY, 3,
                      "Not a city-targeted action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, City, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, sub_tgt, 5, Tech_Type, FALSE);
 
  fc_assert_ret_val(!action_has_result(paction, ACTRES_FOUND_CITY), FALSE);
  if (is_action_enabled_unit_on_city(&(wld.map), paction->id, punit, tgt)) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tgt->id, sub_tgt->item_number, "",
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_unit(lua_State *L, Unit *punit,
                                          Action *paction, Unit *tgt)
{
  const struct civ_map *nmap = &(wld.map);
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) == ATK_UNIT, 3,
                      "Not a unit-targeted action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, Unit, FALSE);
 
  fc_assert_ret_val(!action_has_result(paction, ACTRES_FOUND_CITY), FALSE);
  if (is_action_enabled_unit_on_unit(nmap, paction->id, punit, tgt)) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tgt->id, IDENTITY_NUMBER_ZERO, "",
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_tile(lua_State *L, Unit *punit,
                                          Action *paction, Tile *tgt)
{
  bool enabled = FALSE;
  const struct civ_map *nmap = &(wld.map);
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, Tile, FALSE);
 
  switch (action_get_target_kind(paction)) {
  case ATK_STACK:
    enabled = is_action_enabled_unit_on_stack(nmap, paction->id, punit, tgt);
    break;
  case ATK_TILE:
    enabled = is_action_enabled_unit_on_tile(nmap, paction->id, punit,
                                             tgt, nullptr);
    break;
  case ATK_EXTRAS:
    enabled = is_action_enabled_unit_on_extras(nmap, paction->id, punit,
                                               tgt, nullptr);
    break;
  case ATK_CITY:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_CITY, 3,
                        "City-targeted action applied to tile", FALSE);
    break;
  case ATK_UNIT:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_UNIT, 3,
                        "Unit-targeted action applied to tile", FALSE);
    break;
  case ATK_SELF:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_SELF, 3,
                        "Self-targeted action applied to tile", FALSE);
    break;
  case ATK_COUNT:
    /* Should not exist */
    fc_assert(action_get_target_kind(paction) != ATK_COUNT);
    break;
  }
 
  if (enabled) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tile_index(tgt), IDENTITY_NUMBER_ZERO,
                               city_name_suggestion(unit_owner(punit), tgt),
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_tile_extra(lua_State *L, Unit *punit,
                                                Action *paction, Tile *tgt,
                                                const char *sub_tgt)
{
  struct extra_type *sub_target;
  bool enabled = FALSE;
  const struct civ_map *nmap = &(wld.map);
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tgt, 4, Tile, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, sub_tgt, 5, string, FALSE);
 
  sub_target = extra_type_by_rule_name(sub_tgt);
  LUASCRIPT_CHECK_ARG(L, sub_target != nullptr, 5, "No such extra", FALSE);
 
  switch (action_get_target_kind(paction)) {
  case ATK_STACK:
    enabled = is_action_enabled_unit_on_stack(nmap, paction->id, punit, tgt);
    break;
  case ATK_TILE:
    enabled = is_action_enabled_unit_on_tile(nmap, paction->id, punit,
                                             tgt, sub_target);
    break;
  case ATK_EXTRAS:
    enabled = is_action_enabled_unit_on_extras(nmap, paction->id, punit,
                                               tgt, sub_target);
    break;
  case ATK_CITY:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_CITY, 3,
                        "City-targeted action applied to tile", FALSE);
    break;
  case ATK_UNIT:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_UNIT, 3,
                        "Unit-targeted action applied to tile", FALSE);
    break;
  case ATK_SELF:
    /* Not handled here. */
    LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) != ATK_SELF, 3,
                        "Self-targeted action applied to tile", FALSE);
    break;
  case ATK_COUNT:
    /* Should not exist */
    fc_assert(action_get_target_kind(paction) != ATK_COUNT);
    break;
  }
 
  if (enabled) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               tile_index(tgt), sub_target->id,
                               city_name_suggestion(unit_owner(punit), tgt),
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/***********************************************************************/
bool api_edit_perform_action_unit_vs_self(lua_State *L, Unit *punit,
                                          Action *paction)
{
  const struct civ_map *nmap = &(wld.map);
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, paction, 3, Action, FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_actor_kind(paction) == AAK_UNIT, 3,
                      "Not a unit-performed action", FALSE);
  LUASCRIPT_CHECK_ARG(L, action_get_target_kind(paction) == ATK_SELF, 3,
                      "Not a self-targeted action", FALSE);
  fc_assert_ret_val(!action_has_result(paction, ACTRES_FOUND_CITY), FALSE);
  if (is_action_enabled_unit_on_self(nmap, paction->id, punit)) {
    return unit_perform_action(unit_owner(punit), punit->id,
                               IDENTITY_NUMBER_ZERO, IDENTITY_NUMBER_ZERO,
                               "",
                               paction->id, ACT_REQ_RULES);
  } else {
    /* Action not enabled */
    return FALSE;
  }
}
 
/**********************************************************************/
void api_edit_unit_turn(lua_State *L, Unit *punit, Direction dir)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit);
 
  if (direction8_is_valid(dir)) {
    punit->facing = dir;
 
    send_unit_info(nullptr, punit);
  } else {
    log_error("Illegal direction %d for unit from lua script", dir);
  }
}
 
/**********************************************************************/
bool api_edit_unit_upgrade(lua_State *L, Unit *punit, int vet_loss)
{
  const struct unit_type *ptype;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, punit, FALSE);
 
  ptype = can_upgrade_unittype(unit_owner(punit), unit_type_get(punit));
  if (!ptype) {
    return FALSE;
  }
  return ur_transform_unit(punit, ptype, vet_loss);
}
 
/**********************************************************************/
bool api_edit_unit_transform(lua_State *L, Unit *punit, Unit_Type *ptype,
                             int vet_loss)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, punit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, ptype, 3, Unit_Type, FALSE);
 
  return ur_transform_unit(punit, ptype, vet_loss);
}
 
/**********************************************************************/
void api_edit_unit_kill(lua_State *L, Unit *punit, const char *reason,
                        Player *killer)
{
  enum unit_loss_reason loss_reason;
 
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, punit, 2, Unit);
  LUASCRIPT_CHECK_ARG_NIL(L, reason, 3, string);
 
  loss_reason = unit_loss_reason_by_name(reason, fc_strcasecmp);
 
  LUASCRIPT_CHECK_ARG(L, unit_loss_reason_is_valid(loss_reason), 3,
                      "Invalid unit loss reason");
 
  wipe_unit(punit, loss_reason, killer);
}
 
/**********************************************************************/
bool api_edit_unit_hitpoints(lua_State *L, Unit *self, int change,
                             const char *reason, Player *killer)
{
  LUASCRIPT_CHECK_STATE(L, TRUE);
  LUASCRIPT_CHECK_ARG_NIL(L, self, 2, Unit, TRUE);
 
  self->hp += change;
 
  if (self->hp <= 0) {
    enum unit_loss_reason loss_reason
      = unit_loss_reason_by_name(reason, fc_strcasecmp);
 
    wipe_unit(self, loss_reason, killer);
 
    /* Intentionally only after wiping, so that unit is never left with
     * zero or less hit points. */
    LUASCRIPT_CHECK_ARG(L, unit_loss_reason_is_valid(loss_reason), 4,
                        "Invalid unit loss reason", FALSE);
 
    return FALSE;
  } else {
    int max = unit_type_get(self)->hp;
 
    if (self->hp > max) {
      self->hp = max;
    }
  }
 
  send_unit_info(nullptr, self);
 
  return TRUE;
}
 
/**********************************************************************/
void api_edit_unit_movepoints(lua_State *L, Unit *self, int change)
{
  bool was_exhausted = FALSE;
 
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, self, 2, Unit);
 
  if (self->moves_left == 0 && self->done_moving) {
    was_exhausted = TRUE;
  }
 
  self->moves_left += change;
 
  if (self->moves_left <= 0) {
    self->moves_left = 0;
  } else if (was_exhausted && !unit_has_orders(self)) {
    /* Unit has regained ability to move. */
    self->done_moving = FALSE;
  }
 
  send_unit_info(nullptr, self);
}
 
/**********************************************************************/
bool api_edit_change_terrain(lua_State *L, Tile *ptile, Terrain *pterr)
{
  struct terrain *old_terrain;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 2, Tile, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, pterr, 3, Terrain, FALSE);
 
  old_terrain = tile_terrain(ptile);
 
  if (old_terrain == pterr
      || (terrain_has_flag(pterr, TER_NO_CITIES)
          && tile_city(ptile) != nullptr)) {
    return FALSE;
  }
 
  tile_change_terrain(ptile, pterr);
  fix_tile_on_terrain_change(ptile, old_terrain, FALSE);
  if (need_to_reassign_continents(old_terrain, pterr)) {
    assign_continent_numbers();
 
    /* FIXME: adv / ai phase handling like in check_terrain_change() */
 
    send_all_known_tiles(nullptr);
  }
 
  update_tile_knowledge(ptile);
 
  tile_change_side_effects(ptile, TRUE);
 
  return TRUE;
}
 
/**********************************************************************/
bool api_edit_create_city(lua_State *L, Player *pplayer, Tile *ptile,
                          const char *name, Player *nationality)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 3, Tile, FALSE);
 
  return create_city_for_player(pplayer, ptile, name, nationality);
}
 
/**********************************************************************/
void api_edit_remove_city(lua_State *L, City *pcity)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City);
 
  remove_city(pcity);
}
 
/**********************************************************************/
bool api_edit_transfer_city(lua_State *L, City *pcity, Player *new_owner)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, new_owner, 3, Player, FALSE);
 
  return transfer_city(new_owner, pcity, FALSE, FALSE, FALSE, FALSE, FALSE);
}
 
/**********************************************************************/
void api_edit_create_building(lua_State *L, City *pcity, Building_Type *impr)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City);
  LUASCRIPT_CHECK_ARG_NIL(L, impr, 3, Building_Type);
  /* FIXME: may "Special" impr be buildable? */
  LUASCRIPT_CHECK_ARG(L, !is_special_improvement(impr), 3,
                      "It is a special item, not a city building");
 
  if (!city_has_building(pcity, impr)) {
    bool need_game_info = FALSE;
    bool need_plr_info = FALSE;
    struct player *old_owner = nullptr, *pplayer = city_owner(pcity);
    struct city *oldcity;
 
    oldcity = build_or_move_building(pcity, impr, &old_owner);
    if (oldcity) {
      need_plr_info = TRUE;
    }
    if (old_owner && old_owner != pplayer) {
      /* Great wonders make more changes. */
      need_game_info = TRUE;
    }
 
    if (oldcity) {
      if (city_refresh(oldcity)) {
        auto_arrange_workers(oldcity);
      }
      send_city_info(nullptr, oldcity);
    }
 
    if (city_refresh(pcity)) {
      auto_arrange_workers(pcity);
    }
    send_city_info(nullptr, pcity);
    if (need_game_info) {
      send_game_info(nullptr);
      send_player_info_c(old_owner, nullptr);
    }
    if (need_plr_info) {
      send_player_info_c(pplayer, nullptr);
    }
  }
}
 
/**********************************************************************/
void api_edit_remove_building(lua_State *L, City *pcity, Building_Type *impr)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City);
  LUASCRIPT_CHECK_ARG_NIL(L, impr, 3, Building_Type);
 
  if (city_has_building(pcity, impr)) {
    city_remove_improvement(pcity, impr);
    send_city_info(nullptr, pcity);
 
    if (is_wonder(impr)) {
      if (is_great_wonder(impr)) {
        send_game_info(nullptr);
      }
      send_player_info_c(city_owner(pcity), nullptr);
    }
  }
}
 
/**********************************************************************/
bool api_edit_city_reduce_specialists(lua_State *L, City *pcity,
                                      Specialist *s, int amount)
{
  Specialist_type_id from;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, pcity, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, s, 2, Specialist, FALSE);
  LUASCRIPT_CHECK_ARG(L, amount >= 0, 3, "must be non-negative", FALSE);
 
  from = specialist_index(s);
  if (pcity->specialists[from] < amount) {
    return FALSE;
  }
 
  if (is_super_specialist_id(from)) {
    /* Just reduce superspecialists */
    pcity->specialists[from] -= amount;
  } else {
    /* Toggle normal specialist */
    Specialist_type_id to = from;
 
    do {
      to = (to + 1) % normal_specialist_count();
    } while (to != from && !city_can_use_specialist(pcity, to));
 
    if (to == from) {
      /* We can use only the default specialist */
      return FALSE;
    } else {
      /* City population must be correct */
      fc_assert_ret_val_msg(pcity->specialists[to] <= amount - MAX_CITY_SIZE,
                            FALSE, "Wrong specialist number in %s",
                            city_name_get(pcity));
      pcity->specialists[from] -= amount;
      pcity->specialists[to] += amount;
    }
  }
 
  city_refresh(pcity);
  /* sanity_check_city(pcity); -- hopefully we don't break things here? */
  send_city_info(city_owner(pcity), pcity);
 
  return TRUE;
}
 
/**********************************************************************/
bool api_edit_city_add_specialist(lua_State *L, City *pcity,
                                  Specialist *s, int amount)
{
  Specialist_type_id sid;
  int csize = 0;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, pcity, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, s, 2, Specialist, FALSE);
  LUASCRIPT_CHECK_ARG(L, amount >= 0, 3, "must be non-negative", FALSE);
 
  sid = specialist_index(s);
 
  if (!city_can_use_specialist(pcity, sid)) {
    /* Can't employ this one */
    return FALSE;
  }
  if (is_super_specialist(s)) {
    if (pcity->specialists[sid] > MAX_CITY_SIZE - amount) {
      /* No place for the specialist */
      return FALSE;
    }
    pcity->specialists[sid] += amount;
    city_refresh(pcity);
    send_city_info(city_owner(pcity), pcity);
  } else {
    csize = city_size_get(pcity);
 
    if (csize > MAX_CITY_SIZE - amount) {
      /* No place for the specialist */
      return FALSE;
    }
    city_change_size(pcity, csize + amount, city_owner(pcity), sid, "script");
    city_refresh(pcity);
    send_city_info(nullptr, pcity);
  }
 
  return TRUE;
}
 
/**********************************************************************/
Player *api_edit_create_player(lua_State *L, const char *username,
                               Nation_Type *pnation, const char *ai)
{
  struct player *pplayer = nullptr;
  char buf[128] = "";
  struct fc_lua *fcl;
 
  LUASCRIPT_CHECK_STATE(L, nullptr);
  LUASCRIPT_CHECK_ARG_NIL(L, username, 2, string, nullptr);
 
  if (!ai) {
    ai = default_ai_type_name();
  }
 
  fcl = luascript_get_fcl(L);
 
  LUASCRIPT_CHECK(L, fcl != nullptr, "Undefined Freeciv lua state!", nullptr);
 
  if (game_was_started()) {
    create_command_newcomer(username, ai, FALSE, pnation, &pplayer,
                            buf, sizeof(buf));
  } else {
    create_command_pregame(username, ai, FALSE, &pplayer,
                           buf, sizeof(buf));
  }
 
  if (strlen(buf) > 0) {
    luascript_log(fcl, LOG_NORMAL, "%s", buf);
  }
 
  return pplayer;
}
 
/**********************************************************************/
void api_edit_change_gold(lua_State *L, Player *pplayer, int amount)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player);
 
  pplayer->economic.gold = MAX(0, pplayer->economic.gold + amount);
 
  send_player_info_c(pplayer, nullptr);
}
 
/**********************************************************************/
void api_edit_change_infrapoints(lua_State *L, Player *pplayer, int amount)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player);
 
  pplayer->economic.infra_points
    = MAX(0, pplayer->economic.infra_points + amount);
 
  send_player_info_c(pplayer, nullptr);
}
 
/**********************************************************************/
Tech_Type *api_edit_give_technology(lua_State *L, Player *pplayer,
                                    Tech_Type *ptech, int cost,
                                    bool notify,
                                    const char *reason)
{
  struct research *presearch;
  Tech_type_id id;
  Tech_Type *result;
 
  LUASCRIPT_CHECK_STATE(L, nullptr);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player, nullptr);
  LUASCRIPT_CHECK_ARG(L, cost >= -3, 4, "Unknown give_tech() cost value", nullptr);
 
  presearch = research_get(pplayer);
  if (ptech) {
    id = advance_number(ptech);
  } else {
    id = pick_free_tech(presearch);
  }
 
  if (is_future_tech(id)
      || research_invention_state(presearch, id) != TECH_KNOWN) {
    if (cost < 0) {
      if (cost == -1) {
        cost = game.server.freecost;
      } else if (cost == -2) {
        cost = game.server.conquercost;
      } else if (cost == -3) {
        cost = game.server.diplbulbcost;
      } else {
        cost = 0;
      }
    }
    research_apply_penalty(presearch, id, cost);
    found_new_tech(presearch, id, FALSE, TRUE);
    result = advance_by_number(id);
    script_tech_learned(presearch, pplayer, result, reason);
 
    if (notify && result != nullptr) {
      const char *adv_name = research_advance_name_translation(presearch, id);
      char research_name[MAX_LEN_NAME * 2];
 
      research_pretty_name(presearch, research_name, sizeof(research_name));
 
      notify_player(pplayer, nullptr, E_TECH_GAIN, ftc_server,
                    Q_("?fromscript:You acquire %s."), adv_name);
      notify_research(presearch, pplayer, E_TECH_GAIN, ftc_server,
                      /* TRANS: "The Greeks ..." or "The members of
                       * team Red ..." */
                      Q_("?fromscript:The %s acquire %s and share this "
                         "advance with you."),
                      nation_plural_for_player(pplayer), adv_name);
      notify_research_embassies(presearch, nullptr, E_TECH_EMBASSY, ftc_server,
                                /* TRANS: "The Greeks ..." or "The members of
                                 * team Red ..." */
                                Q_("?fromscript:The %s acquire %s."),
                                research_name, adv_name);
    }
 
    return result;
  } else {
    return nullptr;
  }
}
 
/**********************************************************************/
bool api_edit_trait_mod_set(lua_State *L, Player *pplayer,
                            const char *tname, const int mod)
{
  enum trait tr;
 
  LUASCRIPT_CHECK_STATE(L, -1);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, tname, 3, string, FALSE);
 
  tr = trait_by_name(tname, fc_strcasecmp);
 
  LUASCRIPT_CHECK_ARG(L, trait_is_valid(tr), 3, "no such trait", 0);
 
  pplayer->ai_common.traits[tr].mod += mod;
 
  return TRUE;
}
 
/**********************************************************************/
void api_edit_create_owned_extra(lua_State *L, Tile *ptile,
                                 const char *name, Player *pplayer)
{
  struct extra_type *pextra;
 
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 2, Tile);
 
  if (name == nullptr) {
    return;
  }
 
  pextra = extra_type_by_rule_name(name);
 
  if (pextra != nullptr) {
    create_extra(ptile, pextra, pplayer);
    update_tile_knowledge(ptile);
    tile_change_side_effects(ptile, TRUE);
  }
}
 
/**********************************************************************/
void api_edit_create_extra(lua_State *L, Tile *ptile, const char *name)
{
  api_edit_create_owned_extra(L, ptile, name, nullptr);
}
 
/**********************************************************************/
void api_edit_create_base(lua_State *L, Tile *ptile, const char *name,
                          Player *pplayer)
{
  api_edit_create_owned_extra(L, ptile, name, pplayer);
}
 
/**********************************************************************/
void api_edit_create_road(lua_State *L, Tile *ptile, const char *name)
{
  api_edit_create_owned_extra(L, ptile, name, nullptr);
}
 
/**********************************************************************/
void api_edit_remove_extra(lua_State *L, Tile *ptile, const char *name)
{
  struct extra_type *pextra;
 
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 2, Tile);
 
  if (name == nullptr) {
    return;
  }
 
  pextra = extra_type_by_rule_name(name);
 
  if (pextra != nullptr && tile_has_extra(ptile, pextra)) {
    tile_extra_rm_apply(ptile, pextra);
    update_tile_knowledge(ptile);
    tile_change_side_effects(ptile, TRUE);
  }
}
 
/**********************************************************************/
void api_edit_tile_set_label(lua_State *L, Tile *ptile, const char *label)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, ptile);
  LUASCRIPT_CHECK_ARG_NIL(L, label, 3, string);
 
  tile_set_label(ptile, label);
  if (server_state() >= S_S_RUNNING) {
    send_tile_info(nullptr, ptile, FALSE);
  }
}
 
/**********************************************************************/
void api_edit_tile_show(lua_State *L, Tile *ptile, Player *pplayer)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, ptile);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 3, Player);
 
  map_show_tile(pplayer, ptile);
}
 
/**********************************************************************/
bool api_edit_tile_hide(lua_State *L, Tile *ptile, Player *pplayer)
{
  struct city *pcity;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, ptile, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 3, Player, FALSE);
 
  if (map_is_known_and_seen(ptile, pplayer, V_MAIN)) {
    /* Can't hide currently seen tile */
    return FALSE;
  }
 
  pcity = tile_city(ptile);
 
  if (pcity != nullptr) {
    trade_partners_iterate(pcity, partner) {
      if (really_gives_vision(pplayer, city_owner(partner))) {
        /* Can't remove vision about trade partner */
        return FALSE;
      }
    } trade_partners_iterate_end;
  }
 
  dbv_clr(&pplayer->tile_known, tile_index(ptile));
 
  send_tile_info(pplayer->connections, ptile, TRUE);
 
  return TRUE;
}
 
/**********************************************************************/
void api_edit_climate_change(lua_State *L, enum climate_change_type type,
                             int effect)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG(L, type == CLIMATE_CHANGE_GLOBAL_WARMING
                      || type == CLIMATE_CHANGE_NUCLEAR_WINTER,
                      2, "invalid climate change type");
  LUASCRIPT_CHECK_ARG(L, effect > 0, 3, "effect must be greater than zero");
 
  climate_change(type == CLIMATE_CHANGE_GLOBAL_WARMING, effect);
}
 
/**********************************************************************/
Player *api_edit_civil_war(lua_State *L, Player *pplayer, int probability)
{
  LUASCRIPT_CHECK_STATE(L, nullptr);
  LUASCRIPT_CHECK_ARG_NIL(L, pplayer, 2, Player, nullptr);
  LUASCRIPT_CHECK_ARG(L, probability >= 0 && probability <= 100,
                      3, "must be a percentage", nullptr);
 
  if (!civil_war_possible(pplayer, FALSE, FALSE)) {
    return nullptr;
  }
 
  if (probability == 0) {
    /* Calculate chance with normal rules */
    if (!civil_war_triggered(pplayer)) {
      return nullptr;
    }
  } else {
    /* Fixed chance specified by script */
    if (fc_rand(100) >= probability) {
      return nullptr;
    }
  }
 
  return civil_war(pplayer);
}
 
/**********************************************************************/
void api_edit_player_victory(lua_State *L, Player *pplayer)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, pplayer);
 
  player_status_add(pplayer, PSTATUS_WINNER);
}
 
/**********************************************************************/
bool api_edit_unit_move(lua_State *L, Unit *punit, Tile *ptile,
                        int movecost,
                        Unit *embark_to, bool disembark,
                        bool conquer_city, bool conquer_extra,
                        bool enter_hut, bool frighten_hut)
{
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_SELF(L, punit, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, ptile, 3, Tile, FALSE);
  LUASCRIPT_CHECK_ARG(L, movecost >= 0, 4, "Negative move cost!", FALSE);
 
  LUASCRIPT_CHECK(L, !(enter_hut && frighten_hut),
                  "Can't both enter and frighten a hut at the same time",
                  TRUE);
 
  if (!disembark && unit_transported(punit)) {
    /* Can't leave the transport. */
    return TRUE;
  }
 
  if (unit_move_to_tile_test(&(wld.map), punit, ACTIVITY_IDLE,
                             unit_tile(punit), ptile, TRUE,
                             FALSE, embark_to, TRUE) != MR_OK) {
    /* Can't move to target. Return that unit is still alive. */
    return TRUE;
  }
 
  return unit_move(punit, ptile, movecost,
                   embark_to, embark_to != nullptr,
                   conquer_city, conquer_extra,
                   enter_hut, frighten_hut);
}
 
/**********************************************************************/
void api_edit_unit_moving_disallow(lua_State *L, Unit *punit)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, punit);
 
  if (punit != nullptr) {
    punit->stay = TRUE;
  }
}
 
/**********************************************************************/
void api_edit_unit_moving_allow(lua_State *L, Unit *punit)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, punit);
 
  if (punit != nullptr) {
    punit->stay = FALSE;
  }
}
 
/**********************************************************************/
void api_edit_city_add_history(lua_State *L, City *pcity, int amount)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, pcity);
 
  pcity->history += amount;
}
 
/**********************************************************************/
void api_edit_player_add_history(lua_State *L, Player *pplayer, int amount)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, pplayer);
 
  pplayer->history += amount;
}
 
/**********************************************************************/
void api_edit_player_give_bulbs(lua_State *L, Player *pplayer, int amount,
                                Tech_Type *tech)
{
  struct research *presearch;
 
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_SELF(L, pplayer);
  presearch = research_get(pplayer);
  fc_assert_ret(presearch);
 
  if (!tech) {
    update_bulbs(pplayer, amount, TRUE, TRUE);
 
    send_research_info(presearch, nullptr);
  } else if (advance_number(tech) == presearch->researching) {
    update_bulbs(pplayer, amount, TRUE, FALSE);
    /* Clean the saved tech to get no surprises switching */
    presearch->researching_saved = A_UNKNOWN;
 
    send_research_info(presearch, nullptr);
  } else {
    /* Sometimes we may set negative bulbs, it's normal though lurking */
    if (game.server.multiresearch) {
      presearch->inventions[advance_number(tech)].bulbs_researched_saved
        += amount;
      /* Currently, multiresearch data are not sent to clients */
    } else {
      int oldb = presearch->bulbs_researched;
 
      /* NOTE: We can set a tech we already know / can't research here.
       * Probably it's safe as we can't switch into it any way. */
      if (presearch->researching_saved != advance_number(tech)) {
        presearch->researching_saved = advance_number(tech);
        presearch->bulbs_researching_saved
          = amount + presearch->free_bulbs;
      } else {
        presearch->bulbs_researching_saved
          += amount + presearch->free_bulbs;
      }
      /* For consistency, modify current bulbs alongside
       * (sometimes getting into "overresearch" situation, but ok) */
      presearch->bulbs_researched = amount
        - amount * game.server.techpenalty / 100 + presearch->free_bulbs;
      if (oldb != presearch->bulbs_researched) {
        send_research_info(presearch, nullptr);
      }
    }
  }
}
 
/**********************************************************************/
bool api_edit_create_trade_route(lua_State *L, City *from, City *to)
{
  struct player *pplayer, *partner_player;
 
  LUASCRIPT_CHECK_STATE(L, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, from, 2, City, FALSE);
  LUASCRIPT_CHECK_ARG_NIL(L, to, 3, City, FALSE);
 
  /* Priority zero -> never replace old routes. */
  if (!can_establish_trade_route(from, to, 0)) {
    return FALSE;
  }
 
  create_trade_route(from, to, goods_from_city_to_unit(from, nullptr));
 
  /* Refresh the cities. */
  city_refresh(from);
  city_refresh(to);
 
  pplayer = city_owner(from);
  partner_player = city_owner(to);
 
  send_city_info(pplayer, from);
  send_city_info(partner_player, to);
 
  /* Notify each player about the other's cities. */
  if (pplayer != partner_player && game.info.reveal_trade_partner) {
    map_show_tile(partner_player, city_tile(from));
    send_city_info(partner_player, from);
    map_show_tile(pplayer, city_tile(to));
    send_city_info(pplayer, to);
  }
 
  return TRUE;
}
 
/**********************************************************************/
void api_edit_change_city_size(lua_State *L, City *pcity, int change,
                               Player *nationality)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City);
 
  if (nationality == nullptr) {
    nationality = city_owner(pcity);
  }
 
  city_change_size(pcity, city_size_get(pcity) + change, nationality,
                   -1, "script");
}
 
/**********************************************************************/
void api_edit_change_citizen_nationality(lua_State *L, City *pcity,
                                         Player *from, Player *to, int amount)
{
  LUASCRIPT_CHECK_STATE(L);
  LUASCRIPT_CHECK_ARG_NIL(L, pcity, 2, City);
  LUASCRIPT_CHECK_ARG_NIL(L, from, 3, Player);
  LUASCRIPT_CHECK_ARG_NIL(L, to, 4, Player);
 
  citizens_nation_move(pcity, from->slot, to->slot, amount);
}