/* vi: set ts=2:
+-------------------+  Christian Schlittchen <corwin@amber.kn-bremen.de>
|                   |  Enno Rehling <enno@eressea.de>
| Eressea PBEM host |  Katja Zedel <katze@felidae.kn-bremen.de>
| (c) 1998 - 2003   |  Henning Peters <faroul@beyond.kn-bremen.de>
|                   |  Ingo Wilken <Ingo.Wilken@informatik.uni-oldenburg.de>
+-------------------+  Stefan Reich <reich@halbling.de>

This program may not be used, modified or distributed 
without prior permission by the authors of Eressea.

*/
#include <platform.h>
#include <kernel/config.h>
#include "market.h"

#include <assert.h>

#include <util/attrib.h>
#include <quicklist.h>
#include <util/rng.h>

#include <kernel/building.h>
#include <kernel/faction.h>
#include <kernel/item.h>
#include <kernel/messages.h>
#include <kernel/race.h>
#include <kernel/region.h>
#include <kernel/unit.h>

static unsigned int get_markets(region * r, unit ** results, size_t size)
{
  unsigned int n = 0;
  building *b;
  const building_type *btype = bt_find("market");
  if (!btype)
        return 0;
  for (b = r->buildings; n < size && b; b = b->next) {
    if (b->type == btype && (b->flags & BLD_WORKING)
      && b->size >= b->type->maxsize) {
      unit *u = building_owner(b);
      unsigned int i;
      for (i = 0; u && i != n; ++i) {
        /* only one market per faction */
        if (results[i]->faction == u->faction)
          u = NULL;
      }
      if (u) {
        results[n++] = u;
      }
    }
  }
  return n;
}

static void free_market(attrib * a)
{
  item *items = (item *) a->data.v;
  i_freeall(&items);
  a->data.v = 0;
}

attrib_type at_market = {
  "script",
  NULL, free_market, NULL,
  NULL, NULL, ATF_UNIQUE
};

static int rc_luxury_trade(const struct race *rc)
{
  if (rc) {
    return get_param_int(rc->parameters, "luxury_trade", 1000);
  }
  return 1000;
}

static int rc_herb_trade(const struct race *rc)
{
  if (rc) {
    return get_param_int(rc->parameters, "herb_trade", 500);
  }
  return 500;
}

#define MAX_MARKETS 128
#define MIN_PEASANTS 50         /* if there are at least this many peasants, you will get 1 good */

void do_markets(void)
{
  quicklist *traders = 0;
  unit *markets[MAX_MARKETS];
  region *r;
  for (r = regions; r; r = r->next) {
    if (r->land) {
      faction *f = region_get_owner(r);
      const struct race *rc = f ? f->race : NULL;
      int p = rpeasants(r);
      int numlux = rc_luxury_trade(rc), numherbs = rc_herb_trade(rc);
      numlux = (p + numlux - MIN_PEASANTS) / numlux;
      numherbs = (p + numherbs - MIN_PEASANTS) / numherbs;
      if (numlux > 0 || numherbs > 0) {
        int d, nmarkets = 0;
        const item_type *lux = r_luxury(r);
        const item_type *herb = r->land->herbtype;

        nmarkets += get_markets(r, markets + nmarkets, MAX_MARKETS - nmarkets);
        for (d = 0; d != MAXDIRECTIONS; ++d) {
          region *r2 = rconnect(r, d);
          if (r2 && r2->buildings) {
            nmarkets +=
              get_markets(r2, markets + nmarkets, MAX_MARKETS - nmarkets);
          }
        }
        if (nmarkets) {
          while (lux && numlux--) {
            int n = rng_int() % nmarkets;
            unit *u = markets[n];
            item *items;
            attrib *a = a_find(u->attribs, &at_market);
            if (a == NULL) {
              a = a_add(&u->attribs, a_new(&at_market));
              ql_push(&traders, u);
            }
            items = (item *) a->data.v;
            i_change(&items, lux, 1);
            a->data.v = items;
            /* give 1 luxury */
          }
          while (herb && numherbs--) {
            int n = rng_int() % nmarkets;
            unit *u = markets[n];
            item *items;
            attrib *a = a_find(u->attribs, &at_market);
            if (a == NULL) {
              a = a_add(&u->attribs, a_new(&at_market));
              ql_push(&traders, u);
            }
            items = (item *) a->data.v;
            i_change(&items, herb, 1);
            a->data.v = items;
            /* give 1 herb */
          }
        }
      }
    }
  }

  if (traders) {
    quicklist *qliter = traders;
    int qli = 0;
    for (qli = 0; qliter; ql_advance(&qliter, &qli, 1)) {
      unit *u = (unit *) ql_get(qliter, qli);
      attrib *a = a_find(u->attribs, &at_market);
      item *items = (item *) a->data.v;

      a->data.v = NULL;
      while (items) {
        item *itm = items;
        items = itm->next;

        if (itm->number) {
          ADDMSG(&u->faction->msgs, msg_message("buyamount",
              "unit amount resource", u, itm->number, itm->type->rtype));
          itm->next = NULL;
          i_add(&u->items, itm);
        } else {
          i_free(itm);
        }
      }

      a_remove(&u->attribs, a);
    }
    ql_free(traders);
  }
}