#include "lua.h"
#include "lauxlib.h"

#include "hook.h"
#include "mission.h"
#include "log.h"
#include "lephisto.h"
#include "rng.h"
#include "space.h"
#include "misn_lua.h"

// FUCK LUA!!!                                                                  
#define luaL_register(L,n,l) (luaL_openlib(L, (n),(l), 0))

#define MIN_ARGS(n) if(lua_gettop(L) < n) return 0

static Mission* cur_mission = NULL;

// -- Libraries. --

// Mission.
static int misn_setTitle(lua_State* L);
static int misn_setDesc(lua_State* L);
static int misn_setReward(lua_State* L);
static const luaL_Reg misn_methods[] = {
  { "setTitle",     misn_setTitle   },
  { "setDesc",      misn_setDesc    },
  { "setReward",    misn_setReward  },
  { 0, 0 }
};

// Space.
static int space_getPlanet(lua_State* L);
static const luaL_Reg space_methods[] = {
  { "getPlanet",    space_getPlanet },
  { 0, 0 }
};

// RNG.
static int rnd_int(lua_State*L);
static const luaL_Reg rnd_methods[] = {
  { "int",    rnd_int },
  { 0, 0 }
};

static int hook_land(lua_State* L);
static const luaL_Reg hook_methods[] = {
  { "land", hook_land },
  { 0, 0 },
};

// Register all the libaries.
int misn_loadLibs(lua_State* L) {
  luaL_register(L, "misn",    misn_methods);
  luaL_register(L, "space",   space_methods);
  luaL_register(L, "rnd",     rnd_methods);
  luaL_register(L, "hook",    hook_methods);
  return 0;
}

// Run a mission function.
int misn_run(Mission* misn, char* func) {
  int ret;

  cur_mission = misn;

  lua_getglobal(misn->L, func);
  if((ret = lua_pcall(misn->L, 0, 0, 0)))
    // Did an oops.
    WARN("Mission '%s' -> '%s' : %s",
         cur_mission->data->name, func, lua_tostring(misn->L, -1));

  cur_mission = NULL;

  return ret;
}

// -- Mission. --

static int misn_setTitle(lua_State* L) {
  MIN_ARGS(1);
  if(lua_isstring(L, -1)) {
    if(cur_mission->title)
      // Cleanup the old title.
      free(cur_mission->title);
    cur_mission->title = strdup(lua_tostring(L, -1));
  }
  return 0;
}

static int misn_setDesc(lua_State* L) {
  MIN_ARGS(1);
  if(lua_isstring(L, -1)) {
    if(cur_mission->title)
      // Cleanup the old description.
      free(cur_mission->desc);
    cur_mission->desc = strdup(lua_tostring(L, -1));
  }
  return 0;
}

static int misn_setReward(lua_State* L) {
  MIN_ARGS(1);
  if(lua_isstring(L, -1)) {
    if(cur_mission->reward)
      // Cleanup the old reward.
      free(cur_mission->reward);
    cur_mission->reward = strdup(lua_tostring(L, -1));
  }
  return 0;
}

static int space_getPlanet(lua_State* L) {
  (void)L;
  return 0;
}

static rnd_int(lua_State* L) {
  int o;

  o = lua_gettop(L);

  if(o == 0) lua_pushnumber(L, RNGF()); // Random double o <= x <= 1.
  else if(o == 1) {
    // Random int 0 <= x <= param.
    if(lua_isnumber(L, -1))
      lua_pushnumber(L, RNG(0, (int)lua_tonumber(L, -1)));
    else return 0;
  }
  else if(o >= 2) {
    // Random int param 1 <= x <= param 2.
    if(lua_isnumber(L, -1) && lua_isnumber(L, -2))
      lua_pushnumber(L, RNG((int)lua_tonumber(L, -2), (int)lua_tonumber(L,-1)));
    else return 0;
  }
  else return 0;
  
  // Unless it's returned 0 already it'll always return param.
  return 1;
}

// -- HOOK --
static int hook_land(lua_State* L) {
  char* func;
  
  MIN_ARGS(1);

  if(lua_isstring(L, -1)) func = (char*)lua_tostring(L, -1);
  else {
    WARN("Mission '%s': trying to push non-valid function hook",
        cur_mission->data->name);
    return 0;
  }
  hook_add(L, cur_mission->id, func, "land");
  return 0;
}