/* 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 <util/rng.h>

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

#include <tests.h>

static unsigned int
get_markets(region * r, unit ** results, size_t size)
{
  unsigned int n = 0;
  building * b;
  static building_type * btype;
  if (!btype) 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)
{
  unit_list * 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) {
              unit_list * ulist = malloc(sizeof(unit_list));
              a = a_add(&u->attribs, a_new(&at_market));
              ulist->next = traders;
              ulist->data = u;
              traders = ulist;
            }
            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) {
              unit_list * ulist = malloc(sizeof(unit_list));
              a = a_add(&u->attribs, a_new(&at_market));
              ulist->next = traders;
              ulist->data = u;
              traders = ulist;
            }
            items = (item *)a->data.v;
            i_change(&items, herb, 1);
            a->data.v = items;
            /* give 1 herb */
          }
        }
      }
    }
  }

  while (traders) {
    unit_list * trade = traders;
    unit * u = trade->data;
    attrib * a = a_find(u->attribs, &at_market);
    item * items = 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);
      }
    }

    traders = trade->next;

    a_remove(&u->attribs, a);
    free(trade);
  }
}
#ifndef DISABLE_TESTS
#include "market_test.c"
#endif