/* vi: set ts=2:
+-------------------+
|                   |  Enno Rehling <enno@eressea.de>
| Eressea PBEM host |  Christian Schlittchen <corwin@amber.kn-bremen.de>
| (c) 1998 - 2008   |  Katja Zedel <katze@felidae.kn-bremen.de>
|                   |  Henning Peters <faroul@beyond.kn-bremen.de>
+-------------------+

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

#include "helpers.h"
#include <platform.h>

#include <util/attrib.h>
#include <util/base36.h>
#include <util/functions.h>
#include <util/log.h>

#include <kernel/config.h>
#include <kernel/equipment.h>
#include <kernel/faction.h>
#include <kernel/magic.h>
#include <kernel/race.h>
#include <kernel/unit.h>
#include <kernel/building.h>
#include <kernel/item.h>
#include <kernel/region.h>

#include <gamecode/archetype.h>

#include <lua.h>
#include <tolua.h>

#include <assert.h>

static int
lua_giveitem(unit * s, unit * d, const item_type * itype, int n, struct order * ord)
{
  lua_State * L = (lua_State *)global.vm_state;
  char fname[64];
  int result = -1;
  const char * iname = itype->rtype->_name[0];

  assert(s!=NULL);
  strcat(strcpy(fname, iname), "_give");

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, s, TOLUA_CAST "unit");
    tolua_pushusertype(L, d, TOLUA_CAST "unit");
    tolua_pushstring(L, iname);
    tolua_pushnumber(L, (lua_Number)n);

    if (lua_pcall(L, 4, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("unit %s calling '%s': %s.\n",
        unitname(s), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("unit %s trying to call '%s' : not a function.\n",
      unitname(s), fname));
    lua_pop(L, 1);
  }

  return result;
}

static int
limit_resource(const region * r, const resource_type * rtype)
{
  char fname[64];
  int result = -1;
  lua_State * L = (lua_State *)global.vm_state;

  snprintf(fname, sizeof(fname), "%s_limit", rtype->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)r, TOLUA_CAST "region");

    if (lua_pcall(L, 1, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("limit(%s) calling '%s': %s.\n",
        regionname(r, NULL), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("limit(%s) calling '%s': not a function.\n",
      regionname(r, NULL), fname));
    lua_pop(L, 1);
  }

  return result;
}

static void
produce_resource(region * r, const resource_type * rtype, int norders)
{
  lua_State * L = (lua_State *)global.vm_state;
  char fname[64];
  snprintf(fname, sizeof(fname), "%s_produce", rtype->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)r, TOLUA_CAST "region");
    tolua_pushnumber(L, (lua_Number)norders);

    if (lua_pcall(L, 2, 0, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("produce(%s) calling '%s': %s.\n",
        regionname(r, NULL), fname, error));
      lua_pop(L, 1);
    }
  } else {
    log_error(("produce(%s) calling '%s': not a function.\n",
      regionname(r, NULL), fname));
    lua_pop(L, 1);
  }
}


static int
lc_age(struct attrib * a)
{
  building_action * data = (building_action*)a->data.v;
  const char * fname = data->fname;
  const char * fparam = data->param;
  building * b = data->b;
  int result = -1;

  assert(b!=NULL);
  if (fname!=NULL) {
    lua_State * L = (lua_State *)global.vm_state;

    lua_pushstring(L, fname);
    lua_rawget(L, LUA_GLOBALSINDEX);
    if (lua_isfunction(L, 1)) {
      tolua_pushusertype(L, (void *)b, TOLUA_CAST "building");
      if (fparam) {
        tolua_pushstring(L, fparam);
      }

      if (lua_pcall(L, fparam?2:1, 1, 0)!=0) {
        const char* error = lua_tostring(L, -1);
        log_error(("lc_age(%s) calling '%s': %s.\n",
          buildingname(b), fname, error));
        lua_pop(L, 1);
      } else {
        result = (int)lua_tonumber(L, -1);
        lua_pop(L, 1);
      }
    } else {
      log_error(("lc_age(%s) calling '%s': not a function.\n",
        buildingname(b), fname));
      lua_pop(L, 1);
    }
  }
  return (result!=0)?AT_AGE_KEEP:AT_AGE_REMOVE;
}

static void push_param(lua_State * L, char c, spllprm * param)
{
  if (c=='u') tolua_pushusertype(L, param->data.u, "unit");
  else if (c=='b') tolua_pushusertype(L, param->data.b, "building");
  else if (c=='s') tolua_pushusertype(L, param->data.sh, "ship");
  else if (c=='r') tolua_pushusertype(L, param->data.sh, "region");
  else if (c=='c') tolua_pushstring(L, param->data.s);
  else {
    log_error(("unsupported syntax %c.\n", c));
    lua_pushnil(L);
  }
}

/** callback to use lua for spell functions */
static int
lua_callspell(castorder *co)
{
  lua_State * L = (lua_State *)global.vm_state;
  const char * fname = co->sp->sname;
  unit * mage = co->familiar?co->familiar:co->magician.u;
  int result = -1;
  const char * hashpos = strchr(fname, '#');
  char fbuf[64];

  if (hashpos!=NULL) {
    ptrdiff_t len = hashpos - fname;
    assert(len<(ptrdiff_t)sizeof(fbuf));
    strncpy(fbuf, fname, len);
    fbuf[len] = '\0';
    fname = fbuf;
  }

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    int nparam = 4;
    tolua_pushusertype(L, co->rt, TOLUA_CAST "region");
    tolua_pushusertype(L, mage, TOLUA_CAST "unit");
    tolua_pushnumber(L, (lua_Number)co->level);
    tolua_pushnumber(L, (lua_Number)co->force);
    if (co->sp->parameter && co->par->length) {
      const char * synp = co->sp->parameter;
      int i = 0;
      ++nparam;
      lua_newtable(L);
      while (*synp&&i<co->par->length) {
        spllprm * param = co->par->param[i];
        char c = *synp;
        if (c=='+') {
          push_param(L, *(synp-1), param);
        } else {
          push_param(L, c, param);
          ++synp;
        }
        lua_rawseti(L, -2, ++i);
      }
    }

    if (lua_pcall(L, nparam, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("spell(%s) calling '%s': %s.\n",
        unitname(mage), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("spell(%s) calling '%s': not a function.\n",
      unitname(mage), fname));
    lua_pop(L, 1);
  }

  return result;
}

/** callback to initialize a familiar from lua. */
static void
lua_initfamiliar(unit * u)
{
  lua_State * L = (lua_State *)global.vm_state;
  char fname[64];
  int result = -1;
  snprintf(fname, sizeof(fname), "initfamiliar_%s", u->race->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, u, TOLUA_CAST "unit");

    if (lua_pcall(L, 1, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("familiar(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_warning(("familiar(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }

  create_mage(u, M_GRAY);

  snprintf(fname, sizeof(fname), "%s_familiar", u->race->_name[0]);
  equip_unit(u, get_equipment(fname));
}

static int
lua_changeresource(unit * u, const struct resource_type * rtype, int delta)
{
  lua_State * L = (lua_State *)global.vm_state;
  int result = -1;
  char fname[64];
  snprintf(fname, sizeof(fname), "%s_changeresource", rtype->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, u, TOLUA_CAST "unit");
    tolua_pushnumber(L, (lua_Number)delta);

    if (lua_pcall(L, 2, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("change(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("change(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }

  return result;
}

static int
lua_getresource(unit * u, const struct resource_type * rtype)
{
  lua_State * L = (lua_State *)global.vm_state;
  int result = -1;
  char fname[64];
  snprintf(fname, sizeof(fname), "%s_getresource", rtype->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, u, TOLUA_CAST "unit");

    if (lua_pcall(L, 1, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("get(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("get(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }

  return result;
}

static boolean
lua_canuse_item(const unit * u, const struct item_type * itype)
{
  static int function_exists = 1;
  boolean result = true;

  if (function_exists) {
    lua_State * L = (lua_State *)global.vm_state;
    const char * fname = "item_canuse";

    lua_pushstring(L, fname);
    lua_rawget(L, LUA_GLOBALSINDEX);
    if (lua_isfunction(L, 1)) {
      tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");
      tolua_pushstring(L, itype->rtype->_name[0]);

      if (lua_pcall(L, 2, 1, 0)!=0) {
        const char* error = lua_tostring(L, -1);
        log_error(("get(%s) calling '%s': %s.\n",
          unitname(u), fname, error));
        lua_pop(L, 1);
      } else {
        result = lua_toboolean(L, -1);
        lua_pop(L, 1);
      }
    } else {
      function_exists = 0;
      log_error(("get(%s) calling '%s': not a function.\n",
        unitname(u), fname));
      lua_pop(L, 1);
    }
  }
  return result;
}

static int
lua_wage(const region * r, const faction * f, const race * rc, int in_turn)
{
  lua_State * L = (lua_State *)global.vm_state;
  const char * fname = "wage";
  int result = -1;

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)r, TOLUA_CAST "region");
    tolua_pushusertype(L, (void *)f, TOLUA_CAST "faction");
    tolua_pushstring(L, rc?rc->_name[0]:0);
    tolua_pushnumber(L, (lua_Number)in_turn);

    if (lua_pcall(L, 3, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("wage(%s) calling '%s': %s.\n",
        regionname(r, NULL), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("wage(%s) calling '%s': not a function.\n",
      regionname(r, NULL), fname));
    lua_pop(L, 1);
  }

  return result;
}

static void
lua_agebuilding(building * b)
{
  lua_State * L = (lua_State *)global.vm_state;
  char fname[64];

  snprintf(fname, sizeof(fname), "age_%s", b->type->_name);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)b, TOLUA_CAST "building");

    if (lua_pcall(L, 1, 0, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("agebuilding(%s) calling '%s': %s.\n",
        buildingname(b), fname, error));
      lua_pop(L, 1);
    }
  } else {
    log_error(("agebuilding(%s) calling '%s': not a function.\n",
      buildingname(b), fname));
    lua_pop(L, 1);
  }
}

static int
lua_building_protection(building * b, unit * u)
{
  lua_State * L = (lua_State *)global.vm_state;
  const char * fname = "building_protection";
  int result = 0;

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)b, TOLUA_CAST "building");
    tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");

    if (lua_pcall(L, 2, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("building_protection(%s, %s) calling '%s': %s.\n",
        buildingname(b), unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("building_protection(%s, %s) calling '%s': not a function.\n",
      buildingname(b), unitname(u), fname));
    lua_pop(L, 1);
  }
  return result;
}

static double
lua_building_taxes(building * b, int level)
{
  lua_State * L = (lua_State *)global.vm_state;
  const char * fname = "building_taxes";
  double result = 0.0F;
  int type;

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  type=lua_type(L, 1);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)b, TOLUA_CAST "building");
    tolua_pushnumber(L, level);

    if (lua_pcall(L, 2, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("building_taxes(%s) calling '%s': %s.\n",
        buildingname(b), fname, error));
      lua_pop(L, 1);
    } else {
      result = (double)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("building_taxes(%s) calling '%s': not a function.\n",
      buildingname(b), fname));
    lua_pop(L, 1);
  }
  return result;
}

static int
lua_maintenance(const unit * u)
{
  lua_State * L = (lua_State *)global.vm_state;
  const char * fname = "maintenance";
  int result = -1;

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");

    if (lua_pcall(L, 1, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("maintenance(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("maintenance(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }

  return result;
}

static void
lua_equipmentcallback(const struct equipment * eq, unit * u)
{
  lua_State * L = (lua_State *)global.vm_state;
  char fname[64];
  int result = -1;
  snprintf(fname, sizeof(fname), "equip_%s", eq->name);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");

    if (lua_pcall(L, 1, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("equip(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("equip(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }
}

/** callback for an item-use function written in lua. */
int
lua_useitem(struct unit * u, const struct item_type * itype, int amount, struct order * ord)
{
  lua_State * L = (lua_State *)global.vm_state;
  int result = 0;
  char fname[64];
  snprintf(fname, sizeof(fname), "use_%s", itype->rtype->_name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");
    tolua_pushnumber(L, (lua_Number)amount);

    if (lua_pcall(L, 2, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("use(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("use(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }

  return result;
}

static int
lua_recruit(struct unit * u, const struct archetype * arch, int amount)
{
  lua_State * L = (lua_State *)global.vm_state;
  int result = 0;
  char fname[64];
  snprintf(fname, sizeof(fname), "recruit_%s", arch->name[0]);

  lua_pushstring(L, fname);
  lua_rawget(L, LUA_GLOBALSINDEX);
  if (lua_isfunction(L, 1)) {
    tolua_pushusertype(L, (void *)u, TOLUA_CAST "unit");
    tolua_pushnumber(L, (lua_Number)amount);

    if (lua_pcall(L, 2, 1, 0)!=0) {
      const char* error = lua_tostring(L, -1);
      log_error(("use(%s) calling '%s': %s.\n",
        unitname(u), fname, error));
      lua_pop(L, 1);
    } else {
      result = (int)lua_tonumber(L, -1);
      lua_pop(L, 1);
    }
  } else {
    log_error(("use(%s) calling '%s': not a function.\n",
      unitname(u), fname));
    lua_pop(L, 1);
  }
  return result;
}

int
tolua_toid(lua_State* L, int idx, int def)
{
  int no = 0;
  int type = lua_type(L, idx);
  if (type==LUA_TNUMBER) {
    no = (int)tolua_tonumber(L, idx, def);
  } else {
    const char * str = tolua_tostring(L, idx, NULL);
    no = str?atoi36(str):def;
  }
  return no;
}

void
register_tolua_helpers(void)
{
  at_building_action.age = lc_age;

  register_function((pf_generic)&lua_building_protection, TOLUA_CAST "lua_building_protection");
  register_function((pf_generic)&lua_building_taxes, TOLUA_CAST "lua_building_taxes");
  register_function((pf_generic)&lua_agebuilding, TOLUA_CAST "lua_agebuilding");
  register_function((pf_generic)&lua_recruit, TOLUA_CAST "lua_recruit");
  register_function((pf_generic)&lua_callspell, TOLUA_CAST "lua_castspell");
  register_function((pf_generic)&lua_initfamiliar, TOLUA_CAST "lua_initfamiliar");
  register_item_use(&lua_useitem, TOLUA_CAST "lua_useitem");
  register_function((pf_generic)&lua_getresource, TOLUA_CAST "lua_getresource");
  register_function((pf_generic)&lua_canuse_item, TOLUA_CAST "lua_canuse_item");
  register_function((pf_generic)&lua_changeresource, TOLUA_CAST "lua_changeresource");
  register_function((pf_generic)&lua_equipmentcallback, TOLUA_CAST "lua_equip");

  register_function((pf_generic)&lua_wage, TOLUA_CAST "lua_wage");
  register_function((pf_generic)&lua_maintenance, TOLUA_CAST "lua_maintenance");


  register_function((pf_generic)produce_resource, TOLUA_CAST "lua_produceresource");
  register_function((pf_generic)limit_resource, TOLUA_CAST "lua_limitresource");
  register_item_give(lua_giveitem, TOLUA_CAST "lua_giveitem");
}