shop.c

Go to the documentation of this file.

/*
 * static char *rcsid_shop_c =
 *   "$Id: shop.c 11578 2009-02-23 22:02:27Z lalo $";
 */

/*
  CrossFire, A Multiplayer game for X-windows

  Copyright (C) 2002 Mark Wedel & Crossfire Development Team
  Copyright (C) 1992 Frank Tore Johansen

  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 of the License, 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.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

  The authors can be reached via e-mail at crossfire-devel@real-time.com
*/

#include <assert.h>
#include <global.h>
#include <spells.h>
#include <skills.h>
#include <living.h>
#include <newclient.h>
#ifndef __CEXTRACT__
#include <sproto.h>
#endif
#include <math.h>

#define SPECIALISATION_EFFECT 0.5

#define DISAPPROVAL_RATIO 0.2

#define NEUTRAL_RATIO 0.8

static uint64 pay_from_container(object *pl, object *pouch, uint64 to_pay);
static uint64 value_limit(uint64 val, int quantity, const object *who, int isshop);
static double shop_specialisation_ratio(const object *item, const mapstruct *map);
static double shop_greed(const mapstruct *map);

#define NUM_COINS 5     
#define LARGEST_COIN_GIVEN 2 
static const char *const coins[] = {
    "ambercoin",
    "jadecoin",
    "platinacoin",
    "goldcoin",
    "silvercoin",
    NULL
};

uint64 query_cost(const object *tmp, object *who, int flag) {
    uint64 val;
    int number; /* used to better calculate value */
    int no_bargain;
    int identified;
    int not_cursed;
    int approximate;
    int shop;
    float diff;
    float ratio;
    const char *key;

    no_bargain = flag&F_NO_BARGAIN;
    identified = flag&F_IDENTIFIED;
    not_cursed = flag&F_NOT_CURSED;
    approximate = flag&F_APPROX;
    shop = flag&F_SHOP;
    flag &= ~(F_NO_BARGAIN|F_IDENTIFIED|F_NOT_CURSED|F_APPROX|F_SHOP);

    number = tmp->nrof;
    if (number == 0)
        number = 1;

    if ((key = get_ob_key_value(tmp, "price_adjustment")) != NULL) {
        ratio = atof(key);
        return tmp->value*number*ratio;
    }
    if ((flag == F_BUY) && ((key = get_ob_key_value(tmp, "price_adjustment_buy")) != NULL)) {
        ratio = atof(key);
        return tmp->value*number*ratio;
    }
    if ((flag == F_SELL) && ((key = get_ob_key_value(tmp, "price_adjustment_sell")) != NULL)) {
        ratio = atof(key);
        return tmp->value*number*ratio;
    }

    if (tmp->type == MONEY)
        return (tmp->nrof*tmp->value);
    if (tmp->type == GEM) {
        if (flag == F_TRUE)
            return number*tmp->value;
        if (flag == F_BUY)
            return (1.03*tmp->nrof*tmp->value);
        if (flag == F_SELL)
            return (0.97*tmp->nrof*tmp->value);
        LOG(llevError, "Query_cost: Gem type with unknown flag : %d\n", flag);
        return 0;
    }
    if (QUERY_FLAG(tmp, FLAG_IDENTIFIED)
    || !need_identify(tmp)
    || identified) {
        if (!not_cursed
        && (QUERY_FLAG(tmp, FLAG_CURSED) || QUERY_FLAG(tmp, FLAG_DAMNED)))
            return 0;
        else
            val = tmp->value*number;
    /* This area deals with objects that are not identified, but can be */
    } else {
        if (tmp->arch != NULL) {
            if (flag == F_BUY) {
                LOG(llevError, "Asking for buy-value of unidentified object.\n");
                val = tmp->arch->clone.value*50*number;
            } else {     /* Trying to sell something, or get true value */
                if (tmp->type == POTION)
                    val = number*1000; /* Don't want to give anything away */
                else {
                    /* Get 2/3 value for applied objects, 1/3 for totally
                     * unknown objects
                     */
                    if (QUERY_FLAG(tmp, FLAG_BEEN_APPLIED))
                        val = number*tmp->arch->clone.value*2/3;
                    else
                        val = number*tmp->arch->clone.value/3;
                }
            }
        } else { /* No archetype with this object */
            LOG(llevDebug, "In sell item: Have object with no archetype: %s\n", tmp->name);
            if (flag == F_BUY) {
                LOG(llevError, "Asking for buy-value of unidentified object without arch.\n");
                val = number*tmp->value*10;
            } else
                val = number*tmp->value/5;
        }
    }

    /* If the item has been applied or identifed or does not need to be
     * identified, AND the object is magical and the archetype is non
     * magical, then change values accordingly.  The tmp->arch==NULL is
     * really just a check to prevent core dumps for when it checks
     * tmp->arch->clone.magic for any magic.  The check for archetype
     * magic is to not give extra money for archetypes that are by
     * default magical.  This is because the archetype value should have
     * already figured in that value.
     */
    if ((QUERY_FLAG(tmp, FLAG_IDENTIFIED) || !need_identify(tmp) || identified || QUERY_FLAG(tmp, FLAG_BEEN_APPLIED))
    && tmp->magic
    && (tmp->arch == NULL || !tmp->arch->clone.magic)) {
        if (tmp->magic > 0)
            val *= (3*tmp->magic*tmp->magic*tmp->magic);
        else
            /* Note that tmp->magic is negative, so that this
             * will actually be something like val /=2, /=3, etc.
             */
            val /= (1-tmp->magic);
    }

    if (tmp->type == WAND) {
        /* Value of the wand is multiplied by the number of
         * charges.  the treasure code already sets up the value
         * 50 charges is used as the baseline.
         */
        if (QUERY_FLAG(tmp, FLAG_IDENTIFIED)
        || !need_identify(tmp)
        || identified)
            val = (val*tmp->stats.food)/50;
        else /* if not identified, presume one charge */
            val /= 50;
    }

    /* Limit amount of money you can get for really great items. */
    if (flag == F_TRUE || flag == F_SELL)
        val = value_limit(val, number, who, shop);

    /* we need to multiply these by 4.0 to keep buy costs roughly the same
     * (otherwise, you could buy a potion of charisma for around 400 pp.
     * Arguable, the costs in the archetypes should be updated to better
     * reflect values (potion charisma list for 1250 gold)
     */
    val *= 4;

    /* This modification is for bargaining skill.
     * Now only players with max level in bargaining
     * AND Cha = 30 will get optimal price.
     * Thus charisma will never get useless.
     * -b.e. edler@heydernet.de
     */

    if (who != NULL && who->type == PLAYER) {
        int lev_bargain = 0;
        int lev_identify = 0;
        int idskill1 = 0;
        int idskill2 = 0;
        const typedata *tmptype;

        /* ratio determines how much of the price modification
         * will come from the basic stat charisma
         * the rest will come from the level in bargaining skill
         */
        ratio = 0.5;
        tmptype = get_typedata(tmp->type);

        if (find_skill_by_number(who, SK_BARGAINING)) {
            lev_bargain = find_skill_by_number(who, SK_BARGAINING)->level;
        }
        if (tmptype) {
            idskill1 = tmptype->identifyskill;
            if (idskill1) {
                idskill2 = tmptype->identifyskill2;
                if (find_skill_by_number(who, idskill1)) {
                    lev_identify = find_skill_by_number(who, idskill1)->level;
                }
                if (idskill2 && find_skill_by_number(who, idskill2)) {
                    lev_identify += find_skill_by_number(who, idskill2)->level;
                }
            }
        } else
            LOG(llevError, "Query_cost: item %s hasn't got a valid type\n", tmp->name);
        if (!no_bargain && (lev_bargain > 0))
            diff = (0.8-0.6*((lev_bargain+settings.max_level*0.05)/(settings.max_level*1.05)));
        else
            diff = 0.8;

        diff *= 1-ratio;

        /* Diff is now a float between 0.2 and 0.8 */
        diff += (cha_bonus[who->stats.Cha]-1)/(1+cha_bonus[who->stats.Cha])*ratio;

        if (flag == F_BUY)
            val = (val*(long)(1000*(1+diff)))/1000;
        else if (flag == F_SELL)
            val = (val*(long)(1000*(1-diff)))/1000;

        /* If we are approximating, then the value returned should
         * be allowed to be wrong however merely using a random number
         * each time will not be sufficient, as then multiple examinations
         * would give different answers, so we'll use the count instead.
         * By taking the sine of the count, a value between -1 and 1 is
         * generated, we then divide by the square root of the bargaining
         * skill and the appropriate identification skills, so that higher
         * level players get better estimates. (We need a +1 there to
         * prevent dividing by zero.)
         */
        if (approximate)
            val = (sint64)val+(sint64)((sint64)val*(sin(tmp->count)/sqrt(lev_bargain+lev_identify*2+1.0)));
    }

    /* I don't think this should really happen - if it does,
     * it indicates an overflow of diff above.  That should only
     * happen if we are selling objects - in that case, the person
     * just gets no money.
     */
    if ((sint64)val < 0)
        val = 0;

    /* Unidentified stuff won't sell for more than 60gp */
    if (flag == F_SELL
    && !QUERY_FLAG(tmp, FLAG_IDENTIFIED)
    && need_identify(tmp)
    && !identified) {
        val = MIN(val, 600);
    }

    /* if in a shop, check how the type of shop should affect the price */
    if (shop && who) {
        if (flag == F_SELL)
            val = (sint64)val*shop_specialisation_ratio(tmp, who->map)
                *shopkeeper_approval(who->map, who)/shop_greed(who->map);
        else if (flag == F_BUY) {
            /*
             * When buying, if the item was sold by another player, it is
             * ok to let the item be sold cheaper, according to the
             * specialisation of the shop. If a player sold an item here,
             * then his sale price was multiplied by the specialisation
             * ratio, to do the same to the buy price will not generate
             * extra money. However, the same is not true of generated
             * items, these have to /divide/ by the specialisation, so
             * that the price is never less than what they could
             * be sold for (otherwise players could camp map resets to
             * make money).
             * In game terms, a non-specialist shop might not recognise
             * the true value of the items it sells (much like how people
             * sometimes find antiques in a junk shop in real life).
             */
            if (QUERY_FLAG(tmp, FLAG_PLAYER_SOLD))
                val = (sint64)val*shop_greed(who->map)
                    *shop_specialisation_ratio(tmp, who->map)
                    /shopkeeper_approval(who->map, who);
            else
                val = (sint64)val*shop_greed(who->map)
                    /(shop_specialisation_ratio(tmp, who->map)
                      *shopkeeper_approval(who->map, who));
        }
        /* We will also have an extra 0-5% variation between shops of
         * the same type for valuable items (below a value of 50 this
         * effect wouldn't be very meaningful, and could give fun with
         * rounding.
         */
        if (who->map->path != NULL && val > 50)
            val = (sint64)val+0.05*(sint64)val*cos(tmp->count+strlen(who->map->path));
    }
    return val;
}

static archetype *find_next_coin(uint64 c, int *cointype) {
    archetype *coin;

    do {
        if (coins[*cointype] == NULL)
            return NULL;
        coin = find_archetype(coins[*cointype]);
        if (coin == NULL)
            return NULL;
        *cointype += 1;
    } while (coin->clone.value > c);

    return coin;
}

static StringBuffer *cost_string_from_value(uint64 cost, StringBuffer *buf) {
    archetype *coin, *next_coin;
    uint32 num;
    int cointype = LARGEST_COIN_GIVEN;

    if (!buf)
        buf = stringbuffer_new();

    coin = find_next_coin(cost, &cointype);
    if (coin == NULL) {
        stringbuffer_append_string(buf, "nothing");
        return buf;
    }

    num = cost/coin->clone.value;
    /* so long as nrof is 32 bit, this is true.
     * If it takes more coins than a person can possibly carry, this
     * is basically true.
     */
    if ((cost/coin->clone.value) > UINT32_MAX) {
        stringbuffer_append_string(buf, "an unimaginable sum of money.");
        return buf;
    }

    cost -= (uint64)num*(uint64)coin->clone.value;
    if (num == 1)
        stringbuffer_append_printf(buf, "1 %s", coin->clone.name);
    else
        stringbuffer_append_printf(buf, "%u %ss", num, coin->clone.name);

    next_coin = find_next_coin(cost, &cointype);
    if (next_coin == NULL)
        return buf;

    do {
        coin = next_coin;
        num = cost/coin->clone.value;
        cost -= (uint64)num*(uint64)coin->clone.value;

        if (cost == 0)
            next_coin = NULL;
        else
            next_coin = find_next_coin(cost, &cointype);

        if (next_coin) {
            /* There will be at least one more string to add to the list,
             * use a comma.
             */
            stringbuffer_append_string(buf, ", ");
        } else {
            stringbuffer_append_string(buf, " and ");
        }
        if (num == 1)
            stringbuffer_append_printf(buf, "1 %s", coin->clone.name);
        else
            stringbuffer_append_printf(buf, "%u %ss", num, coin->clone.name);
    } while (next_coin);

    return buf;
}

static StringBuffer *real_money_value(const object *coin, StringBuffer *buf) {
    assert(coin->type == MONEY);
    assert(buf);

    stringbuffer_append_printf(buf, "%ld %s", coin->nrof, coin->nrof == 1 ? coin->name : coin->name_pl);
    return buf;
}

StringBuffer *query_cost_string(const object *tmp, object *who, int flag, StringBuffer *buf) {
    uint64 real_value = query_cost(tmp, who, flag);
    int idskill1 = 0;
    int idskill2 = 0;
    const typedata *tmptype;

    if (!buf)
        buf = stringbuffer_new();

    /* money it's pretty hard to not give the exact price, so skip all logic and just return the real value. */
    if (tmp->type == MONEY) {
        return real_money_value(tmp, buf);
    }

    tmptype = get_typedata(tmp->type);
    if (tmptype) {
        idskill1 = tmptype->identifyskill;
        idskill2 = tmptype->identifyskill2;
    }

    /* we show an approximate price if
     * 1) we are approximating
     * 2) there either is no id skill(s) for the item, or we don't have them
     * 3) we don't have bargaining skill either
     */
    if (flag&F_APPROX) {
        if (!idskill1 || !find_skill_by_number(who, idskill1)) {
            if (!idskill2 || !find_skill_by_number(who, idskill2)) {
                if (!find_skill_by_number(who, SK_BARGAINING)) {
                    int num;
                    int cointype = LARGEST_COIN_GIVEN;
                    archetype *coin = find_next_coin(real_value, &cointype);

                    if (coin == NULL) {
                        stringbuffer_append_string(buf, "nothing");
                        return buf;
                    }

                    num = real_value/coin->clone.value;
                    if (num == 1)
                        stringbuffer_append_printf(buf, "about one %s", coin->clone.name);
                    else if (num < 5)
                        stringbuffer_append_printf(buf, "a few %s", coin->clone.name_pl);
                    else if (num < 10)
                        stringbuffer_append_printf(buf, "several %s", coin->clone.name_pl);
                    else if (num < 25)
                        stringbuffer_append_printf(buf, "a moderate amount of %s", coin->clone.name_pl);
                    else if (num < 100)
                        stringbuffer_append_printf(buf, "lots of %s", coin->clone.name_pl);
                    else if (num < 1000)
                        stringbuffer_append_printf(buf, "a great many %s", coin->clone.name_pl);
                    else
                        stringbuffer_append_printf(buf, "a vast quantity of %s", coin->clone.name_pl);
                    return buf;
                }
            }
        }
    }
    return cost_string_from_value(real_value, buf);
}

uint64 query_money(const object *op) {
    object *tmp;
    uint64 total = 0;

    if (op->type != PLAYER && op->type != CONTAINER) {
        LOG(llevError, "Query money called with non player/container\n");
        return 0;
    }
    for (tmp = op->inv; tmp; tmp = tmp->below) {
        if (tmp->type == MONEY) {
            total += (uint64)tmp->nrof*(uint64)tmp->value;
        } else if (tmp->type == CONTAINER
        && QUERY_FLAG(tmp, FLAG_APPLIED)
        && (tmp->race == NULL || strstr(tmp->race, "gold"))) {
            total += query_money(tmp);
        }
    }
    return total;
}

int pay_for_amount(uint64 to_pay, object *pl) {
    object *pouch;

    if (to_pay == 0)
        return 1;
    if (to_pay > query_money(pl))
        return 0;

    to_pay = pay_from_container(pl, pl, to_pay);

    for (pouch = pl->inv; (pouch != NULL) && (to_pay > 0); pouch = pouch->below) {
        if (pouch->type == CONTAINER
        && QUERY_FLAG(pouch, FLAG_APPLIED)
        && (pouch->race == NULL || strstr(pouch->race, "gold"))) {
            to_pay = pay_from_container(pl, pouch, to_pay);
        }
    }
    if (to_pay > 0) {
        LOG(llevError, "pay_for_amount: Cannot remove enough money -- %"FMT64U" remains\n", to_pay);
    }

    fix_object(pl);
    return 1;
}

int pay_for_item(object *op, object *pl) {
    uint64 to_pay = query_cost(op, pl, F_BUY|F_SHOP);
    object *pouch;
    uint64 saved_money;

    if (to_pay == 0)
        return 1;
    if (to_pay > query_money(pl))
        return 0;

    /* We compare the paid price with the one for a player
     * without bargaining skill.
     * This determins the amount of exp (if any) gained for bargaining.
     */
    saved_money = query_cost(op, pl, F_BUY|F_NO_BARGAIN|F_SHOP)-to_pay;

    if (saved_money > 0)
        change_exp(pl, saved_money, "bargaining", SK_EXP_NONE);

    to_pay = pay_from_container(pl, pl, to_pay);

    for (pouch = pl->inv; (pouch != NULL) && (to_pay > 0); pouch = pouch->below) {
        if (pouch->type == CONTAINER
        && QUERY_FLAG(pouch, FLAG_APPLIED)
        && (pouch->race == NULL || strstr(pouch->race, "gold"))) {
            to_pay = pay_from_container(pl, pouch, to_pay);
        }
    }
    if (to_pay > 0) {
        LOG(llevError, "pay_for_item: Cannot remove enough money -- %"FMT64U" remains\n", to_pay);
    }
    if (settings.real_wiz == FALSE && QUERY_FLAG(pl, FLAG_WAS_WIZ))
        SET_FLAG(op, FLAG_WAS_WIZ);
    fix_object(pl);
    return 1;
}

static sint64 remove_value(object *coin_objs[], sint64 remain) {
    int i;

    for (i = 0; i < NUM_COINS; i++) {
        int count;
        sint64 num_coins;

        if (coin_objs[i]->nrof*coin_objs[i]->value > remain) {
            num_coins = remain/coin_objs[i]->value;
            if ((uint64)num_coins*(uint64)coin_objs[i]->value < remain) {
                num_coins++;
            }
        } else {
            num_coins = coin_objs[i]->nrof;
        }
        remain -= (sint64)num_coins*(sint64)coin_objs[i]->value;
        coin_objs[i]->nrof -= num_coins;
        /* Now start making change.  Start at the coin value
         * below the one we just did, and work down to
         * the lowest value.
         */
        count = i-1;
        while (remain < 0 && count >= 0) {
            num_coins = -remain/coin_objs[count]->value;
            coin_objs[count]->nrof += num_coins;
            remain += num_coins*coin_objs[count]->value;
            count--;
        }
    }

    return remain;
}

static void add_value(object *coin_objs[], sint64 value) {
    int i;

    for (i = NUM_COINS-LARGEST_COIN_GIVEN-1; i >= 0; i--) {
        uint32 nrof;

        nrof = (uint32)(value/coin_objs[i]->value);
        value -= nrof*coin_objs[i]->value;
        coin_objs[i]->nrof += nrof;
    }
}

static void insert_objects(object *pl, object *container, object *objects[], int objects_len) {
    int i, one = 0;

    for (i = 0; i < objects_len; i++) {
        if (objects[i]->nrof > 0) {
            insert_ob_in_ob(objects[i], container);
            one = 1;
        } else {
            free_object(objects[i]);
        }
    }
    if (one)
        esrv_update_item(UPD_WEIGHT, pl, container);
}

static uint64 pay_from_container(object *pl, object *pouch, uint64 to_pay) {
    int i;
    sint64 remain;
    object *tmp, *coin_objs[NUM_COINS], *next;
    object *other_money[16]; /* collects MONEY objects not matching coins[] */
    size_t other_money_len; /* number of allocated entries in other_money[] */
    archetype *at;

    if (pouch->type != PLAYER && pouch->type != CONTAINER)
        return to_pay;

    remain = to_pay;
    for (i = 0; i < NUM_COINS; i++)
        coin_objs[i] = NULL;

    /* This hunk should remove all the money objects from the player/container */
    other_money_len = 0;
    for (tmp = pouch->inv; tmp; tmp = next) {
        next = tmp->below;
        if (tmp->type == MONEY) {
            for (i = 0; i < NUM_COINS; i++) {
                if (!strcmp(coins[NUM_COINS-1-i], tmp->arch->name)
                && (tmp->value == tmp->arch->clone.value)) {

                    /* This should not happen, but if it does, just
                     * merge the two.
                     */
                    if (coin_objs[i] != NULL) {
                        LOG(llevError, "%s has two money entries of (%s)\n", pouch->name, coins[NUM_COINS-1-i]);
                        remove_ob(tmp);
                        coin_objs[i]->nrof += tmp->nrof;
                        free_object(tmp);
                    } else {
                        remove_ob(tmp);
                        coin_objs[i] = tmp;
                    }
                    break;
                }
            }
            if (i == NUM_COINS) {
                if (other_money_len >= sizeof(other_money)/sizeof(*other_money)) {
                    LOG(llevError, "pay_for_item: Cannot store non-standard money object %s\n", tmp->arch->name);
                } else {
                    remove_ob(tmp);
                    other_money[other_money_len++] = tmp;
                }
            }
        }
    }

    /* Fill in any gaps in the coin_objs array - needed to make change.      */
    /* Note that the coin_objs array goes from least value to greatest value */
    for (i = 0; i < NUM_COINS; i++)
        if (coin_objs[i] == NULL) {
            at = find_archetype(coins[NUM_COINS-1-i]);
            if (at == NULL)
                LOG(llevError, "Could not find %s archetype\n", coins[NUM_COINS-1-i]);
            coin_objs[i] = get_object();
            copy_object(&at->clone, coin_objs[i]);
            coin_objs[i]->nrof = 0;
        }

    /* Try to pay from standard coins first. */
    remain = remove_value(coin_objs, remain);

    /* Now pay from non-standard coins until all is paid. */
    for (i = 0; i < other_money_len && remain > 0; i++) {
        uint32 nrof;
        object *coin;

        coin = other_money[i];

        /* Find the minimal number of coins to use. This prevents converting
         * excess non-standard coins to standard money.
         */
        nrof = (remain+coin->value-1)/coin->value;
        if (nrof > coin->nrof) {
            nrof = coin->nrof;
        }
        coin->nrof -= nrof;
        add_value(coin_objs, nrof*coin->value);

        remain = remove_value(coin_objs, remain);
    }

    /* re-insert remaining coins into player */
    insert_objects(pl, pouch, coin_objs, NUM_COINS);
    insert_objects(pl, pouch, other_money, other_money_len);

    return(remain);
}

static void count_unpaid(object *pl, object *item, int *unpaid_count, uint64 *unpaid_price, uint32 *coincount) {
    int i;

    for (; item; item = item->below) {
        if QUERY_FLAG(item, FLAG_UNPAID) {
            (*unpaid_count)++;
            (*unpaid_price) += query_cost(item, pl, F_BUY|F_SHOP);
        }
        /* Merely converting the player's monetary wealth won't do.
         * If we did that, we could print the wrong numbers for the
         * coins, so we count the money instead.
         */
        for (i = 0; i < NUM_COINS; i++)
            if (!strcmp(coins[i], item->arch->name)) {
                coincount[i] += item->nrof;
                break;
            }
        if (item->inv)
            count_unpaid(pl, item->inv, unpaid_count, unpaid_price, coincount);
    }
}

int can_pay(object *pl) {
    int unpaid_count = 0, i;
    uint64 unpaid_price = 0;
    uint64 player_wealth = query_money(pl);
    uint32 coincount[NUM_COINS];

    if (!pl || pl->type != PLAYER) {
        LOG(llevError, "can_pay(): called against something that isn't a player\n");
        return 0;
    }

    for (i = 0; i < NUM_COINS; i++)
        coincount[i] = 0;

    count_unpaid(pl, pl->inv, &unpaid_count, &unpaid_price, coincount);

    if (unpaid_price > player_wealth) {
        char buf[MAX_BUF], coinbuf[MAX_BUF];
        int denominations = 0;
        char *value = stringbuffer_finish(cost_string_from_value(unpaid_price, NULL));

        snprintf(buf, sizeof(buf), "You have %d unpaid items that would cost you %s, ", unpaid_count, value);
        free(value);
        for (i = 0; i < NUM_COINS; i++) {
            if (coincount[i] > 0 && coins[i]) {
                if (denominations == 0)
                    snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "but you only have");
                denominations++;
                snprintf(coinbuf, sizeof(coinbuf), " %u %s,", coincount[i], find_archetype(coins[i])->clone.name_pl);
                snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "%s", coinbuf);
            }
        }
        if (denominations == 0)
            snprintf(buf+strlen(buf), sizeof(buf)-strlen(buf), "but you don't have any money.");
        else if (denominations > 1)
            make_list_like(buf);
        draw_ext_info(NDI_UNIQUE, 0, pl, MSG_TYPE_SHOP,
                      MSG_TYPE_SHOP_PAYMENT, buf, NULL);
        return 0;
    } else
        return 1;
}

int get_payment(object *pl, object *op) {
    char name_op[MAX_BUF];
    int ret = 1;

    if (op != NULL && op->inv)
        ret = get_payment(pl, op->inv);

    if (!ret)
        return 0;

    if (op != NULL && op->below)
        ret = get_payment(pl, op->below);

    if (!ret)
        return 0;

    if (op != NULL && QUERY_FLAG(op, FLAG_UNPAID)) {
        if (!pay_for_item(op, pl)) {
            uint64 i = query_cost(op, pl, F_BUY|F_SHOP)-query_money(pl);
            char *missing = stringbuffer_finish(cost_string_from_value(i, NULL));

            CLEAR_FLAG(op, FLAG_UNPAID);
            query_name(op, name_op, MAX_BUF);
            draw_ext_info_format(NDI_UNIQUE, 0, pl,
                                 MSG_TYPE_SHOP, MSG_TYPE_SHOP_PAYMENT,
                                 "You lack %s to buy %s.",
                                 "You lack %s to buy %s.",
                                 missing, name_op);
            free(missing);
            SET_FLAG(op, FLAG_UNPAID);
            return 0;
        } else {
            object *tmp;
            char *value = stringbuffer_finish(query_cost_string(op, pl, F_BUY|F_SHOP, NULL));

            CLEAR_FLAG(op, FLAG_UNPAID);
            CLEAR_FLAG(op, FLAG_PLAYER_SOLD);
            query_name(op, name_op, MAX_BUF);
            draw_ext_info_format(NDI_UNIQUE, 0, pl,
                                 MSG_TYPE_SHOP, MSG_TYPE_SHOP_PAYMENT,
                                 "You paid %s for %s.",
                                 "You paid %s for %s.",
                                 value, name_op);
            free(value);
            tmp = merge_ob(op, NULL);
            if (pl->type == PLAYER && !tmp) {
                /* If item wasn't merged we update it. If merged, merge_ob handled everything for us. */
                esrv_update_item(UPD_FLAGS|UPD_NAME, pl, op);
            }
        }
    }
    return 1;
}

void sell_item(object *op, object *pl) {
    uint64 i = query_cost(op, pl, F_SELL|F_SHOP), extra_gain;
    int count;
    object *tmp, *pouch;
    archetype *at;
    char name_op[MAX_BUF], *value;

    if (pl == NULL || pl->type != PLAYER) {
        LOG(llevDebug, "Object other than player tried to sell something.\n");
        return;
    }

    if (op->custom_name)
        FREE_AND_CLEAR_STR(op->custom_name);

    if (!i) {
        query_name(op, name_op, MAX_BUF);
        draw_ext_info_format(NDI_UNIQUE, 0, pl,
                             MSG_TYPE_SHOP, MSG_TYPE_SHOP_SELL,
                             "We're not interested in %s.",
                             "We're not interested in %s.",
                             name_op);

        /* Even if the character doesn't get anything for it, it may still be
         * worth something.  If so, make it unpaid
         */
        if (op->value) {
            SET_FLAG(op, FLAG_UNPAID);
            SET_FLAG(op, FLAG_PLAYER_SOLD);
        }
        identify(op);
        return;
    }

    /* We compare the price with the one for a player
     * without bargaining skill.
     * This determins the amount of exp (if any) gained for bargaining.
     * exp/10 -> 1 for each gold coin
     */
    extra_gain = i-query_cost(op, pl, F_SELL|F_NO_BARGAIN|F_SHOP);

    if (extra_gain > 0)
        change_exp(pl, extra_gain/10, "bargaining", SK_EXP_NONE);

    for (count = LARGEST_COIN_GIVEN; coins[count] != NULL; count++) {
        at = find_archetype(coins[count]);
        if (at == NULL)
            LOG(llevError, "Could not find %s archetype\n", coins[count]);
        else if ((i/at->clone.value) > 0) {
            for (pouch = pl->inv; pouch; pouch = pouch->below) {
                if (pouch->type == CONTAINER
                && QUERY_FLAG(pouch, FLAG_APPLIED)
                && pouch->race
                && strstr(pouch->race, "gold")) {
                    int w = at->clone.weight*(100-pouch->stats.Str)/100;
                    int n = i/at->clone.value;

                    if (w == 0)
                        w = 1;    /* Prevent divide by zero */
                    if (n > 0
                    && (!pouch->weight_limit || pouch->carrying+w <= pouch->weight_limit)) {
                        if (pouch->weight_limit
                        && (pouch->weight_limit-pouch->carrying)/w < n)
                            n = (pouch->weight_limit-pouch->carrying)/w;

                        tmp = get_object();
                        copy_object(&at->clone, tmp);
                        tmp->nrof = n;
                        i -= (uint64)tmp->nrof*(uint64)tmp->value;
                        tmp = insert_ob_in_ob(tmp, pouch);
                        esrv_update_item(UPD_WEIGHT, pl, pl);
                    }
                }
            }
            if (i/at->clone.value > 0) {
                tmp = get_object();
                copy_object(&at->clone, tmp);
                tmp->nrof = i/tmp->value;
                i -= (uint64)tmp->nrof*(uint64)tmp->value;
                tmp = insert_ob_in_ob(tmp, pl);
                esrv_update_item(UPD_WEIGHT, pl, pl);
            }
        }
    }

    if (i != 0)
#ifndef WIN32
        LOG(llevError, "Warning - payment not zero: %llu\n", i);
#else
        LOG(llevError, "Warning - payment not zero: %I64u\n", i);
#endif

    query_name(op, name_op, MAX_BUF);
    value = stringbuffer_finish(query_cost_string(op, pl, F_SELL|F_SHOP, NULL));

    draw_ext_info_format(NDI_UNIQUE, 0, pl, MSG_TYPE_SHOP, MSG_TYPE_SHOP_SELL,
                         "You receive %s for %s.",
                         "You receive %s for %s.",
                         value,
                         name_op);

    free(value);

    SET_FLAG(op, FLAG_UNPAID);
    identify(op);
}

static double shop_specialisation_ratio(const object *item, const mapstruct *map) {
    shopitems *items = map->shopitems;
    double ratio = SPECIALISATION_EFFECT, likedness = 0.001;
    int i;

    if (item == NULL) {
        LOG(llevError, "shop_specialisation_ratio: passed a NULL item for map %s\n", map->path);
        return 0;
    }
    if (!item->type) {
        LOG(llevError, "shop_specialisation_ratio: passed an item with an invalid type\n");
        /*
         * I'm not really sure what the /right/ thing to do here is,
         * these types of item shouldn't exist anyway, but returning
         * the ratio is probably the best bet.."
         */
        return ratio;
    }
    if (map->shopitems) {
        for (i = 0; i < items[0].index; i++)
            if (items[i].typenum == item->type || (!items[i].typenum && likedness == 0.001))
                likedness = items[i].strength/100.0;
    }
    if (likedness > 1.0) { /* someone has been rather silly with the map headers. */
        LOG(llevDebug, "shop_specialisation ratio: item type %d on map %s is above 100%%\n", item->type, map->path);
        likedness = 1.0;
    }
    if (likedness < -1.0) {
        LOG(llevDebug, "shop_specialisation ratio: item type %d on map %s is below -100%%\n", item->type, map->path);
        likedness = -1.0;
    }
    ratio = ratio+(1.0-ratio)*likedness;
    if (ratio <= 0.1)
        ratio = 0.1; /* if the ratio were much lower than this, we would get silly prices */
    return ratio;
}

static double shop_greed(const mapstruct *map) {
    double greed = 1.0;

    if (map->shopgreed)
        return map->shopgreed;
    return greed;
}

double shopkeeper_approval(const mapstruct *map, const object *player) {
    double approval = 1.0;

    if (map->shoprace) {
        approval = NEUTRAL_RATIO;
        if (player->race && !strcmp(player->race, map->shoprace))
            approval = 1.0;
    }
    return approval;
}

static uint64 value_limit(uint64 val, int quantity, const object *who, int isshop) {
    uint64 newval, unit_price;
    mapstruct *map;

    unit_price = val/quantity;
    if (!isshop || !who) {
        if (unit_price > 10000)
            newval = 8000+isqrt(unit_price)*20;
        else
            newval = unit_price;
    } else {
        if (!who->map) {
            LOG(llevError, "value_limit: asked shop price for ob %s on NULL map\n", who->name);
            return val;
        }
        map = who->map;
        if (map->shopmin && unit_price < map->shopmin)
            return 0;
        else if (map->shopmax && unit_price > map->shopmax/2)
            newval = MIN((map->shopmax/2)+isqrt(unit_price-map->shopmax/2), map->shopmax);
        else if (unit_price > 10000)
            newval = 8000+isqrt(unit_price)*20;
        else
            newval = unit_price;
    }
    newval *= quantity;
    return newval;
}

int describe_shop(const object *op) {
    mapstruct *map = op->map;
    /*shopitems *items=map->shopitems;*/
    int pos = 0, i;
    double opinion = 0;
    char tmp[MAX_BUF] = "\0", *value;

    if (op->type != PLAYER)
        return 0;

    /*check if there is a shop specified for this map */
    if (map->shopitems
    || map->shopgreed
    || map->shoprace
    || map->shopmin
    || map->shopmax) {
        draw_ext_info(NDI_UNIQUE, 0, op, MSG_TYPE_SHOP, MSG_TYPE_SHOP_LISTING,
                      "From looking at the nearby shop you determine that it trades in:",
                      NULL);

        if (map->shopitems) {
            for (i = 0; i < map->shopitems[0].index; i++) {
                if (map->shopitems[i].name && map->shopitems[i].strength > 10) {
                    snprintf(tmp+pos, sizeof(tmp)-pos, "%s, ", map->shopitems[i].name_pl);
                    pos += strlen(tmp+pos);
                }
            }
        }
        if (!pos)
            strcpy(tmp, "a little of everything.");

        /* format the string into a list */
        make_list_like(tmp);
        draw_ext_info(NDI_UNIQUE, 0, op,
                      MSG_TYPE_SHOP, MSG_TYPE_SHOP_LISTING, tmp, NULL);

        if (map->shopmax) {
            value = stringbuffer_finish(cost_string_from_value(map->shopmax, NULL));
            draw_ext_info_format(NDI_UNIQUE, 0, op,
                                 MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                                 "It won't trade for items above %s.",
                                 "It won't trade for items above %s.",
                                 value);
            free(value);
        }

        if (map->shopmin) {
            value = stringbuffer_finish(cost_string_from_value(map->shopmin, NULL));
            draw_ext_info_format(NDI_UNIQUE, 0, op,
                                 MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                                 "It won't trade in items worth less than %s.",
                                 "It won't trade in items worth less than %s.",
                                 value);
            free(value);
        }

        if (map->shopgreed) {
            if (map->shopgreed > 2.0)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "It tends to overcharge massively.", NULL);
            else if (map->shopgreed > 1.5)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "It tends to overcharge substantially.", NULL);
            else if (map->shopgreed > 1.1)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "It tends to overcharge slightly.", NULL);
            else if (map->shopgreed < 0.9)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "It tends to undercharge.", NULL);
        }
        if (map->shoprace) {
            opinion = shopkeeper_approval(map, op);
            if (opinion > 0.8)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "You think the shopkeeper likes you.", NULL);
            else if (opinion > 0.5)
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "The shopkeeper seems unconcerned by you.", NULL);
            else
                draw_ext_info(NDI_UNIQUE, 0, op,
                              MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                              "The shopkeeper seems to have taken a dislike to you.", NULL);
        }
    } else draw_ext_info(NDI_UNIQUE, 0, op, MSG_TYPE_SHOP, MSG_TYPE_SHOP_MISC,
                             "There is no shop nearby.", NULL);

    return 1;
}

int is_in_shop(object *ob) {
    if (!ob->map)
        return 0;
    return coords_in_shop(ob->map, ob->x, ob->y);
}

int coords_in_shop(mapstruct *map, int x, int y) {
    object *floor;

    for (floor = GET_MAP_OB(map, x, y); floor; floor = floor->above)
        if (floor->type == SHOP_FLOOR)
            return 1;
    return 0;
}