gamehand.c

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/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   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
 
#include <stdio.h> /* for remove() */ 
 
/* utility */
#include "capability.h"
#include "fcintl.h"
#include "log.h"
#include "mem.h"
#include "rand.h"
#include "registry.h"
#include "shared.h"
#include "string_vector.h"
#include "support.h"
 
/* common */
#include "ai.h"
#include "calendar.h"
#include "events.h"
#include "game.h"
#include "improvement.h"
#include "modpack.h"
#include "movement.h"
#include "nation.h"
#include "packets.h"
 
/* server */
#include "citytools.h"
#include "connecthand.h"
#include "maphand.h"
#include "notify.h"
#include "plrhand.h"
#include "srv_main.h"
#include "stdinhand.h"
#include "unittools.h"
 
/* server/advisors */
#include "advdata.h"
 
#include "gamehand.h"
 
#define CHALLENGE_ROOT "challenge"
 
#define SPECLIST_TAG startpos
#define SPECLIST_TYPE struct startpos
#include "speclist.h"
#define startpos_list_iterate(list, plink, psp)                             \
  TYPED_LIST_BOTH_ITERATE(struct startpos_list_link, struct startpos,       \
                          list, plink, psp)
#define startpos_list_iterate_end LIST_BOTH_ITERATE_END
 
struct team_placement_config {
  struct tile **startpos;
  int flexible_startpos_num;
  int usable_startpos_num;
  int total_startpos_num;
};
 
struct team_placement_state {
  int *startpos;
  long score;
};
 
#define SPECPQ_TAG team_placement
#define SPECPQ_DATA_TYPE struct team_placement_state *
#define SPECPQ_PRIORITY_TYPE long
#include "specpq.h"
 
/************************************************************************/
enum unit_role_id crole_to_role_id(char crole)
{
  switch (crole) {
  case 'c':
    return L_START_CITIES;
  case 'w':
    return L_START_WORKER;
  case 'x':
    return L_START_EXPLORER;
  case 'k':
    return L_START_KING;
  case 's':
    return L_START_DIPLOMAT;
  case 'f':
    return L_START_FERRY;
  case 'd':
    return L_START_DEFEND_OK;
  case 'D':
    return L_START_DEFEND_GOOD;
  case 'a':
    return L_START_ATTACK_FAST;
  case 'A':
    return L_START_ATTACK_STRONG;
  default: 
    return 0;
  }
}
 
/************************************************************************/
struct unit_type *crole_to_unit_type(char crole, struct player *pplayer)
{
  struct unit_type *utype = NULL;
  enum unit_role_id role = crole_to_role_id(crole);
  int num;
 
  if (role == 0) {
    fc_assert_ret_val(FALSE, NULL);
    return NULL;
  }
 
  /* Create the unit of an appropriate type, if it exists */
  num = num_role_units(role);
  if (num > 0) {
    if (pplayer != NULL) {
      int i;
 
      utype = first_role_unit_for_player(pplayer, role);
      for (i = 0; utype == NULL && i < num; i++) {
        struct unit_type *ntype = get_role_unit(role, i);
 
        if (!utype_player_already_has_this_unique(pplayer, ntype)) {
          utype = ntype;
        }
      }
    } else {
      utype = get_role_unit(role, 0);
    }
  }
 
  return utype;
}
 
/************************************************************************/
static struct tile *place_starting_unit(struct tile *starttile,
                                        struct player *pplayer,
                                        struct unit_type *ptype, char crole)
{
  struct tile *ptile = NULL;
  struct unit_type *utype;
  bool hut_present = FALSE;
 
  if (ptype != NULL) {
    utype = ptype;
  } else {
    utype = crole_to_unit_type(crole, pplayer);
  }
 
  if (utype != NULL) {
    iterate_outward(&(wld.map), starttile,
                    MAP_NATIVE_WIDTH + MAP_NATIVE_HEIGHT, itertile) {
      if (!is_non_allied_unit_tile(itertile, pplayer,
                                   utype_has_flag(utype, UTYF_FLAGLESS))
          && is_native_tile(utype, itertile)) {
        ptile = itertile;
        break;
      }
    } iterate_outward_end;
  }
 
  if (ptile == NULL) {
    /* No place where unit may exist. */
    return NULL;
  }
 
  fc_assert_ret_val(!is_non_allied_unit_tile(ptile, pplayer,
                                             utype_has_flag(utype, UTYF_FLAGLESS)),
                    NULL);
 
  /* For scenarios or dispersion, huts may coincide with player starts (in 
   * other cases, huts are avoided as start positions). Remove any such hut,
   * and make sure to tell the client, since we may have already sent this
   * tile (with the hut) earlier: */
  /* FIXME: Don't remove under a unit that can't enter or frighten hut */
  extra_type_by_rmcause_iterate(ERM_ENTER, pextra) {
    if (tile_has_extra(ptile, pextra)) {
      tile_extra_rm_apply(ptile, pextra);
      hut_present = TRUE;
    }
  } extra_type_by_rmcause_iterate_end;
 
  if (hut_present) {
    update_tile_knowledge(ptile);
    log_verbose("Removed hut on start position for %s",
                player_name(pplayer));
  }
 
  /* Expose visible area. */
  map_show_circle(pplayer, ptile, game.server.init_vis_radius_sq);
 
  if (utype != NULL) {
    (void) create_unit(pplayer, ptile, utype, FALSE, 0, 0);
    return ptile;
  }
 
  return NULL;
}
 
/************************************************************************/
static struct tile *find_dispersed_position(struct player *pplayer,
                                            struct tile *pcenter)
{
  struct tile *ptile;
  int x, y;
  int bailout;
 
  if (game.server.dispersion == 0) {
    bailout = 1; /* One attempt is guaranteed to cover single tile */
  } else {
    bailout = game.server.dispersion * 2 + 1; /* Side of the area */
    bailout *= bailout;                       /* Area */
    bailout *= 5;                             /* Likely to hit each tile at least once */
  }
 
  do {
    if (!bailout--) {
      return NULL;
    }
    index_to_map_pos(&x, &y, tile_index(pcenter));
    x += fc_rand(2 * game.server.dispersion + 1) - game.server.dispersion;
    y += fc_rand(2 * game.server.dispersion + 1) - game.server.dispersion;
  } while (!((ptile = map_pos_to_tile(&(wld.map), x, y))
             && tile_continent(pcenter) == tile_continent(ptile)
             && !is_ocean_tile(ptile)
             && real_map_distance(pcenter, ptile) < game.server.dispersion
                + 1
             && !is_non_allied_unit_tile(ptile, pplayer, TRUE)));
 
  return ptile;
}
 
/* Calculate the distance between tiles, according to the 'teamplacement'
 * setting set to 'CLOSEST'. */
#define team_placement_closest sq_map_distance
 
/************************************************************************/
static int team_placement_continent(const struct tile *ptile1,
                                    const struct tile *ptile2)
{
  return (ptile1->continent == ptile2->continent
          ? sq_map_distance(ptile1, ptile2)
          : sq_map_distance(ptile1, ptile2) + MAP_INDEX_SIZE);
}
 
/************************************************************************/
static int team_placement_horizontal(const struct tile *ptile1,
                                     const struct tile *ptile2)
{
  int dx, dy;
 
  map_distance_vector(&dx, &dy, ptile1, ptile2);
  /* Map vector to natural vector (Y axis). */
  return abs(MAP_IS_ISOMETRIC ? dx + dy : dy);
}
 
/************************************************************************/
static int team_placement_vertical(const struct tile *ptile1,
                                   const struct tile *ptile2)
{
  int dx, dy;
 
  map_distance_vector(&dx, &dy, ptile1, ptile2);
  /* Map vector to natural vector (X axis). */
  return abs(MAP_IS_ISOMETRIC ? dx - dy : dy);
}
 
/************************************************************************/
static void team_placement_state_destroy(struct team_placement_state *pstate)
{
  free(pstate->startpos);
  free(pstate);
}
 
/************************************************************************/
static void do_team_placement(const struct team_placement_config *pconfig,
                              struct team_placement_state *pbest_state,
                              int iter_max)
{
  const size_t state_array_size = (sizeof(*pbest_state->startpos)
                                   * pconfig->total_startpos_num);
  struct team_placement_pq *pqueue =
      team_placement_pq_new(pconfig->total_startpos_num * 4);
  int (*distance)(const struct tile *, const struct tile *) = NULL;
  struct team_placement_state *pstate, *pnew;
  const struct tile *ptile1, *ptile2;
  long base_delta, delta;
  bool base_delta_calculated;
  int iter = 0;
  bool repeat;
  int i, j, k, t1, t2;
 
  switch (wld.map.server.team_placement) {
  case TEAM_PLACEMENT_CLOSEST:
    distance = team_placement_closest;
    break;
  case TEAM_PLACEMENT_CONTINENT:
    distance = team_placement_continent;
    break;
  case TEAM_PLACEMENT_HORIZONTAL:
    distance = team_placement_horizontal;
    break;
  case TEAM_PLACEMENT_VERTICAL:
    distance = team_placement_vertical;
    break;
  case TEAM_PLACEMENT_DISABLED:
    break;
  }
  fc_assert_ret_msg(distance != NULL, "Wrong team_placement variant (%d)",
                    wld.map.server.team_placement);
 
  /* Initialize starting state. */
  pstate = fc_malloc(sizeof(*pstate));
  pstate->startpos = fc_malloc(state_array_size);
  memcpy(pstate->startpos, pbest_state->startpos, state_array_size);
  pstate->score = pbest_state->score;
 
  do {
    repeat = FALSE;
    for (i = 0; i < pconfig->usable_startpos_num; i++) {
      t1 = pstate->startpos[i];
      if (t1 == -1) {
        continue; /* Not used. */
      }
      ptile1 = pconfig->startpos[i];
      base_delta_calculated = FALSE;
      for (j = i + 1; j < (i >= pconfig->flexible_startpos_num
                           ? pconfig->usable_startpos_num
                           : pconfig->flexible_startpos_num); j++) {
        t2 = pstate->startpos[j];
        if (t2 == -1) {
          /* Not assigned yet. */
          ptile2 = pconfig->startpos[j];
          if (base_delta_calculated) {
            delta = base_delta;
            for (k = 0; k < pconfig->total_startpos_num; k++) {
              if (k != i && t1 == pstate->startpos[k]) {
                delta += distance(ptile2, pconfig->startpos[k]);
              }
            }
          } else {
            delta = 0;
            base_delta = 0;
            for (k = 0; k < pconfig->total_startpos_num; k++) {
              if (k != i && t1 == pstate->startpos[k]) {
                base_delta -= distance(ptile1, pconfig->startpos[k]);
                delta += distance(ptile2, pconfig->startpos[k]);
              }
            }
            delta += base_delta;
            base_delta_calculated = TRUE;
          }
        } else if (t1 < t2) {
          ptile2 = pconfig->startpos[j];
          if (base_delta_calculated) {
            delta = base_delta;
            for (k = 0; k < pconfig->total_startpos_num; k++) {
              if (k != i && t1 == pstate->startpos[k]) {
                delta += distance(ptile2, pconfig->startpos[k]);
              } else if (k != j && t2 == pstate->startpos[k]) {
                delta -= distance(ptile2, pconfig->startpos[k]);
                delta += distance(ptile1, pconfig->startpos[k]);
              }
            }
          } else {
            delta = 0;
            base_delta = 0;
            for (k = 0; k < pconfig->total_startpos_num; k++) {
              if (k != i && t1 == pstate->startpos[k]) {
                base_delta -= distance(ptile1, pconfig->startpos[k]);
                delta += distance(ptile2, pconfig->startpos[k]);
              } else if (k != j && t2 == pstate->startpos[k]) {
                delta -= distance(ptile2, pconfig->startpos[k]);
                delta += distance(ptile1, pconfig->startpos[k]);
              }
            }
            delta += base_delta;
            base_delta_calculated = TRUE;
          }
        } else {
          continue;
        }
 
        if (delta <= 0) {
          repeat = TRUE;
          pnew = fc_malloc(sizeof(*pnew));
          pnew->startpos = fc_malloc(state_array_size);
          memcpy(pnew->startpos, pstate->startpos, state_array_size);
          pnew->startpos[i] = t2;
          pnew->startpos[j] = t1;
          pnew->score = pstate->score + delta;
          team_placement_pq_insert(pqueue, pnew, -pnew->score);
 
          if (pnew->score < pbest_state->score) {
            memcpy(pbest_state->startpos, pnew->startpos, state_array_size);
            pbest_state->score = pnew->score;
          }
        }
      }
    }
 
    team_placement_state_destroy(pstate);
    if (iter++ >= iter_max) {
      log_normal(_("Didn't find optimal solution for team placement "
                   "in %d iterations."), iter);
      break;
    }
 
  } while (repeat && team_placement_pq_remove(pqueue, &pstate));
 
  team_placement_pq_destroy_full(pqueue, team_placement_state_destroy);
}
 
/************************************************************************/
void init_new_game(void)
{
  struct startpos_list *impossible_list, *targeted_list, *flexible_list;
  struct tile *player_startpos[player_slot_count()];
  int placed_units[player_slot_count()];
  int players_to_place = player_count();
  int sulen;
 
  randomize_base64url_string(server.game_identifier,
                             sizeof(server.game_identifier));
 
  /* Assign players to starting positions on the map.
   * (In scenarios with restrictions on which nations can use which predefined
   * start positions, this process tries to satisfy those restrictions, but
   * does not guarantee to. Even if there is a solution to the matching
   * problem, this algorithm may not find it.) */
 
  fc_assert(player_count() <= map_startpos_count());
 
  /* Convert the startposition hash table in a linked lists, as we mostly
   * need now to iterate it now. And then, we will be able to remove the
   * assigned start positions one by one. */
  impossible_list = startpos_list_new();
  targeted_list = startpos_list_new();
  flexible_list = startpos_list_new();
 
  map_startpos_iterate(psp) {
    if (startpos_allows_all(psp)) {
      startpos_list_append(flexible_list, psp);
    } else {
      startpos_list_append(targeted_list, psp);
    }
  } map_startpos_iterate_end;
 
  fc_assert(startpos_list_size(targeted_list)
            + startpos_list_size(flexible_list) == map_startpos_count());
 
  memset(player_startpos, 0, sizeof(player_startpos));
  log_verbose("Placing players at start positions.");
 
  /* First assign start positions which have restrictions on which nations
   * can use them. */
  if (0 < startpos_list_size(targeted_list)) {
    log_verbose("Assigning matching nations.");
 
    startpos_list_shuffle(targeted_list); /* Randomize. */
    do {
      struct nation_type *pnation;
      struct startpos_list_link *choice;
      bool removed = FALSE;
 
      /* Assign first players which can pick only one start position. */
      players_iterate(pplayer) {
        if (NULL != player_startpos[player_index(pplayer)]) {
          /* Already assigned. */
          continue;
        }
 
        pnation = nation_of_player(pplayer);
        choice = NULL;
        startpos_list_iterate(targeted_list, plink, psp) {
          if (startpos_nation_allowed(psp, pnation)) {
            if (NULL != choice) {
              choice = NULL;
              break; /* Many choices. */
            } else {
              choice = plink;
            }
          }
        } startpos_list_iterate_end;
 
        if (NULL != choice) {
          /* Assign this start position to this player and remove
           * both from consideration. */
          struct tile *ptile =
              startpos_tile(startpos_list_link_data(choice));
 
          player_startpos[player_index(pplayer)] = ptile;
          startpos_list_erase(targeted_list, choice);
          players_to_place--;
          removed = TRUE;
          log_verbose("Start position (%d, %d) exactly matches player %s (%s).",
                      TILE_XY(ptile), player_name(pplayer),
                      nation_rule_name(pnation));
        }
      } players_iterate_end;
 
      if (!removed) {
        /* Didn't find any 1:1 matches. For the next restricted start
         * position, assign a random matching player. (This may create
         * restrictions such that more 1:1 matches are possible.) */
        struct startpos *psp = startpos_list_back(targeted_list);
        struct tile *ptile = startpos_tile(psp);
        struct player *rand_plr = NULL;
        int i = 0;
 
        startpos_list_pop_back(targeted_list); /* Detach 'psp'. */
        players_iterate(pplayer) {
          if (NULL != player_startpos[player_index(pplayer)]) {
            /* Already assigned. */
            continue;
          }
 
          pnation = nation_of_player(pplayer);
          if (startpos_nation_allowed(psp, pnation) && 0 == fc_rand(++i)) {
            rand_plr = pplayer;
          }
        } players_iterate_end;
 
        if (NULL != rand_plr) {
          player_startpos[player_index(rand_plr)] = ptile;
          players_to_place--;
          log_verbose("Start position (%d, %d) matches player %s (%s).",
                      TILE_XY(ptile), player_name(rand_plr),
                      nation_rule_name(nation_of_player(rand_plr)));
        } else {
          /* This start position cannot be assigned, given the assignments
           * made so far. We may have to fall back to mismatched
           * assignments. */
          log_verbose("Start position (%d, %d) cannot be assigned for "
                      "any player, keeping for the moment...",
                      TILE_XY(ptile));
          /* Keep it for later, we may need it. */
          startpos_list_append(impossible_list, psp);
        }
      }
    } while (0 < players_to_place && 0 < startpos_list_size(targeted_list));
  }
 
  /* Now try to assign with regard to the 'teamplacement' setting. */
  if (players_to_place > 0
      && wld.map.server.team_placement != TEAM_PLACEMENT_DISABLED
      && player_count() > team_count()) {
    const struct player_list *members;
    int team_placement_players_to_place = 0;
    int real_team_count = 0;
 
    teams_iterate(pteam) {
      members = team_members(pteam);
      fc_assert(0 < player_list_size(members));
      real_team_count++;
      if (player_list_size(members) == 1) {
        /* Single player teams, doesn't count for team placement. */
        continue;
      }
      player_list_iterate(members, pplayer) {
        if (player_startpos[player_index(pplayer)] == NULL) {
          team_placement_players_to_place++;
        }
      } player_list_iterate_end;
    } teams_iterate_end;
 
    if (real_team_count > 1 && team_placement_players_to_place > 0) {
      /* We really can do something to improve team placement. */
      struct team_placement_config config;
      struct team_placement_state state;
      int i, j, t;
 
      log_verbose("Do team placement for %d players, using %s variant.",
                  team_placement_players_to_place,
                  team_placement_name(wld.map.server.team_placement));
 
      /* Initialize configuration. */
      config.flexible_startpos_num = startpos_list_size(flexible_list);
      config.usable_startpos_num = config.flexible_startpos_num;
      if (config.flexible_startpos_num < team_placement_players_to_place) {
        config.usable_startpos_num += startpos_list_size(impossible_list);
      }
      config.total_startpos_num = (config.usable_startpos_num
                                   + player_count() - players_to_place);
      config.startpos = fc_malloc(sizeof(*config.startpos)
                                  * config.total_startpos_num);
      i = 0;
      startpos_list_iterate(flexible_list, plink, psp) {
        config.startpos[i++] = startpos_tile(psp);
      } startpos_list_iterate_end;
      fc_assert(i == config.flexible_startpos_num);
      if (i < config.usable_startpos_num) {
        startpos_list_iterate(impossible_list, plink, psp) {
          config.startpos[i++] = startpos_tile(psp);
        } startpos_list_iterate_end;
      }
      fc_assert(i == config.usable_startpos_num);
      while (i < config.total_startpos_num) {
        config.startpos[i++] = NULL;
      }
      fc_assert(i == config.total_startpos_num);
 
      /* Initialize state. */
      state.startpos = fc_malloc(sizeof(*state.startpos)
                                 * config.total_startpos_num);
      state.score = 0;
      i = 0;
      j = config.usable_startpos_num;
      teams_iterate(pteam) {
        members = team_members(pteam);
        if (player_list_size(members) <= 1) {
          /* Single player teams, doesn't count for team placement. */
          continue;
        }
        t = team_number(pteam);
        player_list_iterate(members, pplayer) {
          struct tile *ptile = player_startpos[player_index(pplayer)];
 
          if (ptile == NULL) {
            state.startpos[i++] = t;
          } else {
            state.startpos[j] = t;
            config.startpos[j] = ptile;
            j++;
          }
        } player_list_iterate_end;
      } teams_iterate_end;
      while (i < config.usable_startpos_num) {
        state.startpos[i++] = -1;
      }
      fc_assert(i == config.usable_startpos_num);
      while (j < config.total_startpos_num) {
        state.startpos[j++] = -1;
      }
      fc_assert(j == config.total_startpos_num);
 
      /* Look for best team placement. */
      do_team_placement(&config, &state, team_placement_players_to_place);
 
      /* Apply result. */
      for (i = 0; i < config.usable_startpos_num; i++) {
        t = state.startpos[i];
        if (t != -1) {
          const struct team *pteam = team_by_number(t);
          int candidate_index = -1;
          int candidate_num = 0;
 
          log_verbose("Start position (%d, %d) assigned to team %d (%s)",
                      TILE_XY(config.startpos[i]),
                      t, team_rule_name(pteam));
 
          player_list_iterate(team_members(pteam), member) {
            if (player_startpos[player_index(member)] == NULL
                && fc_rand(++candidate_num) == 0) {
              candidate_index = player_index(member);
            }
          } player_list_iterate_end;
          fc_assert(candidate_index >= 0);
          player_startpos[candidate_index] = config.startpos[i];
          team_placement_players_to_place--;
          players_to_place--;
        }
      }
      fc_assert(team_placement_players_to_place == 0);
 
      /* Free data. */
      if (players_to_place > 0) {
        /* We need to remove used startpos from the lists. */
        i = 0;
        startpos_list_iterate(flexible_list, plink, psp) {
          (void)psp; /* To avoid 'set but unused' compiler warning */
          fc_assert(config.startpos[i] == startpos_tile(psp));
          if (state.startpos[i] != -1) {
            startpos_list_erase(flexible_list, plink);
          }
          i++;
        } startpos_list_iterate_end;
        fc_assert(i == config.flexible_startpos_num);
        if (i < config.usable_startpos_num) {
          startpos_list_iterate(impossible_list, plink, psp) {
            (void)psp; /* To avoid 'set but unused' compiler warning */
            fc_assert(config.startpos[i] == startpos_tile(psp));
            if (state.startpos[i] != -1) {
              startpos_list_erase(impossible_list, plink);
            }
            i++;
          } startpos_list_iterate_end;
        }
        fc_assert(i == config.usable_startpos_num);
      }
 
      free(state.startpos);
      free(config.startpos);
    }
  }
 
  /* Now assign unrestricted start positions to any remaining players. */
  if (0 < players_to_place && 0 < startpos_list_size(flexible_list)) {
    struct tile *ptile;
 
    log_verbose("Assigning unrestricted start positions.");
 
    startpos_list_shuffle(flexible_list); /* Randomize. */
    players_iterate(pplayer) {
      if (NULL != player_startpos[player_index(pplayer)]) {
        /* Already assigned. */
        continue;
      }
 
      ptile = startpos_tile(startpos_list_front(flexible_list));
      player_startpos[player_index(pplayer)] = ptile;
      players_to_place--;
      startpos_list_pop_front(flexible_list);
      log_verbose("Start position (%d, %d) assigned randomly "
                  "to player %s (%s).", TILE_XY(ptile), player_name(pplayer),
                  nation_rule_name(nation_of_player(pplayer)));
      if (0 == startpos_list_size(flexible_list)) {
        break;
      }
    } players_iterate_end;
  }
 
  if (0 < players_to_place && 0 < startpos_list_size(impossible_list)) {
    /* We still have players to place, and we have some restricted start
     * positions whose nation requirements can't be satisfied given existing
     * assignments. Fall back to making assignments ignoring the positions'
     * nation requirements. */
 
    struct tile *ptile;
 
    log_verbose("Ignoring nation restrictions on remaining start positions.");
 
    startpos_list_shuffle(impossible_list); /* Randomize. */
    players_iterate(pplayer) {
      if (NULL != player_startpos[player_index(pplayer)]) {
        /* Already assigned. */
        continue;
      }
 
      ptile = startpos_tile(startpos_list_front(impossible_list));
      player_startpos[player_index(pplayer)] = ptile;
      players_to_place--;
      startpos_list_pop_front(impossible_list);
      log_verbose("Start position (%d, %d) assigned to mismatched "
                  "player %s (%s).", TILE_XY(ptile), player_name(pplayer),
                  nation_rule_name(nation_of_player(pplayer)));
      if (0 == startpos_list_size(impossible_list)) {
        break;
      }
    } players_iterate_end;
  }
 
  fc_assert(0 == players_to_place);
 
  startpos_list_destroy(impossible_list);
  startpos_list_destroy(targeted_list);
  startpos_list_destroy(flexible_list);
 
  sulen = strlen(game.server.start_units);
 
  /* Loop over all players, creating their initial units... */
  shuffled_players_iterate(pplayer) {
    struct tile *ptile;
 
    /* We have to initialise the advisor and ai here as we could make contact
     * to other nations at this point. */
    adv_data_phase_init(pplayer, FALSE);
    CALL_PLR_AI_FUNC(phase_begin, pplayer, pplayer, FALSE);
 
    ptile = player_startpos[player_index(pplayer)];
 
    fc_assert_action(NULL != ptile, continue);
 
    /* Place first city */
    if (game.server.start_city) {
      create_city(pplayer, ptile, city_name_suggestion(pplayer, ptile),
                  NULL);
 
      /* Expose visible area. */
      map_show_circle(pplayer, ptile, game.server.init_vis_radius_sq);
    }
 
    if (sulen > 0) {
      /* Place the first unit. */
      if (place_starting_unit(ptile, pplayer, NULL,
                              game.server.start_units[0]) != NULL) {
        placed_units[player_index(pplayer)] = 1;
      } else {
        placed_units[player_index(pplayer)] = 0;
      }
    } else {
      placed_units[player_index(pplayer)] = 0;
    }
  } shuffled_players_iterate_end;
 
  /* Place all other units. */
  shuffled_players_iterate(pplayer) {
    int i;
    struct tile *const ptile = player_startpos[player_index(pplayer)];
    struct nation_type *nation = nation_of_player(pplayer);
 
    fc_assert_action(NULL != ptile, continue);
 
    /* Place global start units */
    for (i = 1; i < sulen; i++) {
      struct tile *rand_tile = find_dispersed_position(pplayer, ptile);
 
      /* Create the unit of an appropriate type. */
      if (rand_tile != NULL
          && place_starting_unit(rand_tile, pplayer, NULL,
                                 game.server.start_units[i]) != NULL) {
        placed_units[player_index(pplayer)]++;
      }
    }
 
    /* Place nation specific start units (not role based!) */
    i = 0;
    while (NULL != nation->init_units[i] && MAX_NUM_UNIT_LIST > i) {
      struct tile *rand_tile = find_dispersed_position(pplayer, ptile);
 
      if (rand_tile != NULL
          && place_starting_unit(rand_tile, pplayer,
                                 nation->init_units[i], '\0') != NULL) {
        placed_units[player_index(pplayer)]++;
      }
      i++;
    }
  } shuffled_players_iterate_end;
 
  players_iterate(pplayer) {
    /* Close the active phase for advisor and ai for all players; it was
     * opened in the first loop above. */
    adv_data_phase_done(pplayer);
    CALL_PLR_AI_FUNC(phase_finished, pplayer, pplayer);
 
    fc_assert_msg(game.server.start_city || 0 < placed_units[player_index(pplayer)],
                  _("No units placed for %s!"), player_name(pplayer));
  } players_iterate_end;
}
 
/************************************************************************/
void send_year_to_clients(void)
{
  struct packet_new_year apacket;
 
  players_iterate(pplayer) {
    pplayer->nturns_idle++;
  } players_iterate_end;
 
  apacket.year = game.info.year;
  apacket.fragments = game.info.fragment_count;
  apacket.turn = game.info.turn;
  lsend_packet_new_year(game.est_connections, &apacket);
 
  /* Hmm, clients could add this themselves based on above packet? */
  notify_conn(game.est_connections, NULL, E_NEXT_YEAR, ftc_any,
              _("Year: %s"), calendar_text());
}
 
/************************************************************************/
void send_game_info(struct conn_list *dest)
{
  struct packet_timeout_info tinfo;
 
  if (!dest) {
    dest = game.est_connections;
  }
 
  tinfo = game.tinfo;
 
  /* the following values are computed every
     time a packet_game_info packet is created */
 
  /* Sometimes this function is called before the phase_timer is
   * initialized.  In that case we want to send the dummy value. */
  if (current_turn_timeout() > 0 && game.server.phase_timer) {
    /* Whenever the client sees this packet, it starts a new timer at 0;
     * but the server's timer is only ever reset at the start of a phase
     * (and game.tinfo.seconds_to_phasedone is relative to this).
     * Account for the difference. */
    tinfo.seconds_to_phasedone = game.tinfo.seconds_to_phasedone
      - timer_read_seconds(game.server.phase_timer)
      - game.server.additional_phase_seconds;
  } else {
    /* unused but at least initialized */
    tinfo.seconds_to_phasedone = -1.0;
  }
 
  conn_list_iterate(dest, pconn) {
    /* Timeout info is separate from other packets since it has to
     * be sent always (it's not 'is-info') while the others are 'is-info'
     * Calendar info has been split from Game info packet to make packet
     * size more tolerable when json protocol is in use. */
    send_packet_game_info(pconn, &(game.info));
    send_packet_calendar_info(pconn, &(game.calendar));
    send_packet_timeout_info(pconn, &tinfo);
  }
  conn_list_iterate_end;
}
 
/************************************************************************/
void send_scenario_info(struct conn_list *dest)
{
  if (!dest) {
    dest = game.est_connections;
  }
 
  conn_list_iterate(dest, pconn) {
    send_packet_scenario_info(pconn, &(game.scenario));
  } conn_list_iterate_end;
}
 
/************************************************************************/
void send_scenario_description(struct conn_list *dest)
{
  if (!dest) {
    dest = game.est_connections;
  }
 
  conn_list_iterate(dest, pconn) {
    send_packet_scenario_description(pconn, &(game.scenario_desc));
  } conn_list_iterate_end;
}
 
/************************************************************************/
int update_timeout(void)
{
  /* if there's no timer or we're doing autogame, do nothing */
  if (game.info.timeout < 1 || game.server.timeoutint == 0) {
    return game.info.timeout;
  }
 
  if (game.server.timeoutcounter >= game.server.timeoutint) {
    game.info.timeout += game.server.timeoutinc;
    game.server.timeoutinc *= game.server.timeoutincmult;
 
    game.server.timeoutcounter = 1;
    game.server.timeoutint += game.server.timeoutintinc;
 
    if (game.info.timeout > GAME_MAX_TIMEOUT) {
      notify_conn(game.est_connections, NULL, E_SETTING, ftc_server,
                  _("The turn timeout has exceeded its maximum value, "
                    "fixing at its maximum."));
      log_debug("game.info.timeout exceeded maximum value");
      game.info.timeout = GAME_MAX_TIMEOUT;
      game.server.timeoutint = 0;
      game.server.timeoutinc = 0;
    } else if (game.info.timeout < 0) {
      notify_conn(game.est_connections, NULL, E_SETTING, ftc_server,
                  _("The turn timeout is smaller than zero, "
                    "fixing at zero."));
      log_debug("game.info.timeout less than zero");
      game.info.timeout = 0;
    }
  } else {
    game.server.timeoutcounter++;
  }
 
  log_debug("timeout=%d, inc=%d incmult=%d\n   "
            "int=%d, intinc=%d, turns till next=%d",
            game.info.timeout, game.server.timeoutinc,
            game.server.timeoutincmult, game.server.timeoutint,
            game.server.timeoutintinc,
            game.server.timeoutint - game.server.timeoutcounter);
 
  return game.info.timeout;
}
 
/************************************************************************/
void increase_timeout_because_unit_moved(void)
{
  if (current_turn_timeout() > 0 && game.server.timeoutaddenemymove > 0) {
    double maxsec = (timer_read_seconds(game.server.phase_timer)
                     + (double) game.server.timeoutaddenemymove);
 
    if (maxsec > game.tinfo.seconds_to_phasedone) {
      game.tinfo.seconds_to_phasedone = maxsec;
      send_game_info(NULL);
    }   
  }
}
 
/************************************************************************/
static void gen_challenge_filename(struct connection *pc)
{
}
 
/************************************************************************/
static const char *get_challenge_filename(struct connection *pc)
{
  static char filename[MAX_LEN_PATH];
 
  fc_snprintf(filename, sizeof(filename), "%s_%d_%d",
      CHALLENGE_ROOT, srvarg.port, pc->id);
 
  return filename;
}
 
/************************************************************************/
static const char *get_challenge_fullname(struct connection *pc)
{
  static char fullname[MAX_LEN_PATH];
  const char *sdir = freeciv_storage_dir();
  const char *cname;
 
  if (sdir == NULL) {
    return NULL;
  }
 
  cname = get_challenge_filename(pc);
 
  if (cname == NULL) {
    return NULL;
  }
 
  fc_snprintf(fullname, sizeof(fullname), "%s" DIR_SEPARATOR "%s", sdir, cname);
 
  return fullname;
}
 
/************************************************************************/
const char *new_challenge_filename(struct connection *pc)
{
  gen_challenge_filename(pc);
  return get_challenge_filename(pc);
}
 
struct mrc_sendclient_data {
  int count;
  struct packet_ruleset_choices *packet;
};
 
/************************************************************************/
static void ruleset_cache_sendclient_cb(const char *mp_name,
                                        const char *filename, void *data_in)
{
  struct mrc_sendclient_data *data = (struct mrc_sendclient_data *)data_in;
  const int maxlen = sizeof(data->packet->rulesets[data->count]);
 
  if (data->count >= MAX_NUM_RULESETS) {
    log_verbose("Can't send more than %d ruleset names to client, "
                "skipping some", MAX_NUM_RULESETS);
    return;
  }
 
  if (fc_strlcpy(data->packet->rulesets[data->count], mp_name, maxlen) < maxlen) {
    data->count++;
  } else {
    log_verbose("Modpack name '%s' too long to send to client, skipped",
                mp_name);
  }
}
 
/************************************************************************/
void cache_rulesets(void)
{
  static bool rulesets_cached = FALSE;
 
  if (!rulesets_cached) {
    struct fileinfo_list *ruleset_choices;
 
    ruleset_choices = get_modpacks_list();
 
    fileinfo_list_iterate(ruleset_choices, pfile) {
      struct section_file *sf;
 
      sf = secfile_load(pfile->fullname, FALSE);
 
      if (sf != NULL) {
        modpack_cache_ruleset(sf);
        secfile_destroy(sf);
      }
    } fileinfo_list_iterate_end;
 
    fileinfo_list_destroy(ruleset_choices);
 
    rulesets_cached = TRUE;
  }
}
 
/************************************************************************/
static void send_ruleset_choices(struct connection *pc)
{
  struct packet_ruleset_choices packet;
  struct mrc_sendclient_data data;
 
  cache_rulesets();
 
  data.count = 0;
  data.packet = &packet;
  modpack_ruleset_cache_iterate(ruleset_cache_sendclient_cb, &data);
 
  packet.ruleset_count = data.count;
 
  send_packet_ruleset_choices(pc, &packet);
}
 
/************************************************************************/
void handle_ruleset_select(struct connection *pc,
                           const struct packet_ruleset_select *packet)
{
  struct section_file *sf;
  const char *name;
 
  if (server_state() != S_S_INITIAL) {
    log_warn("Unexpected ruleset selection packet from client");
    return;
  }
 
  if (pc->access_level < ALLOW_HACK) {
    log_verbose("Attempt to set ruleset from non-hack level connection");
  }
 
  name = modpack_file_from_ruleset_cache(packet->modpack);
 
  if (name == NULL) {
    log_error("Modpack \"%s\" not in ruleset cache", packet->modpack);
    return;
  }
 
  sf = secfile_load(name, FALSE);
 
  if (sf == NULL) {
    log_error("Failed to load modpack file \"%s\"", name);
    return;
  }
 
  name = modpack_serv_file(sf);
 
  if (name != NULL) {
    read_init_script(pc, name, FALSE, FALSE);
  } else {
    name = modpack_rulesetdir(sf);
 
    if (name != NULL) {
      set_rulesetdir(pc, name, FALSE, 0);
    } else {
      log_error("Modpack \"%s\" does not contain ruleset at all",
                packet->modpack);
    }
  }
 
  secfile_destroy(sf);
}
 
/************************************************************************/
void handle_single_want_hack_req(struct connection *pc,
                                 const struct packet_single_want_hack_req *
                                 packet)
{
  struct section_file *secfile;
  const char *token = NULL;
  bool you_have_hack = FALSE;
 
  if ((secfile = secfile_load(get_challenge_fullname(pc), FALSE))) {
    token = secfile_lookup_str(secfile, "challenge.token");
    you_have_hack = (token && strcmp(token, packet->token) == 0);
    secfile_destroy(secfile);
  } else {
    log_debug("Error reading '%s':\n%s", get_challenge_fullname(pc),
              secfile_error());
  }
 
  if (!token) {
    log_debug("Failed to read authentication token");
  }
 
  if (you_have_hack) {
    conn_set_access(pc, ALLOW_HACK, TRUE);
  }
 
  dsend_packet_single_want_hack_reply(pc, you_have_hack);
 
  send_ruleset_choices(pc);
  send_conn_info(pc->self, NULL);
}