/**
 * @file llua_space.c
 *
 * @brief Handle the Lua space bindings.
 *
 * These bindings control the planets and systems.
 */

#include "lauxlib.h"
#include "lephisto.h"
#include "llua.h"
#include "lluadef.h"
#include "llua_space.h"
#include "llua_faction.h"
#include "rng.h"
#include "pilot.h"
#include "player.h"
#include "llua_pilot.h"

/* From pilot.c */
extern Pilot** pilot_stack;
extern int pilot_nstack;

static int pilotL_createmetatable(lua_State* L);
/* Pilots. */
static int pilot_getPlayer(lua_State* L);
static int pilot_addFleet(lua_State* L);
static int pilot_clear(lua_State* L);
static int pilot_toggleSpawn(lua_State* L);
static int pilot_getPilots(lua_State* L);
static const luaL_reg pilot_methods[] = {
  { "player",       pilot_getPlayer   },
  { "add",          pilot_addFleet    },
  { "clear",        pilot_clear       },
  { "toggleSpawn",  pilot_toggleSpawn },
  { "get",          pilot_getPilots   },
  { 0, 0 }
}; /**< Pilot lua methods. */

/* Pilot metatable methods. */
static int pilotL_eq(lua_State* L);
static int pilotL_name(lua_State* L);
static int pilotL_alive(lua_State* L);
static int pilotL_rename(lua_State* L);
static int pilotL_position(lua_State* L);
static int pilotL_velocity(lua_State* L);
static int pilotL_warp(lua_State* L);
static int pilotL_broadcast(lua_State* L);
static int pilotL_setFaction(lua_State* L);
static int pilotL_setHostile(lua_State* L);
static const luaL_reg pilotL_methods[] = {
  { "__eq",       pilotL_eq         },
  { "name",       pilotL_name       },
  { "alive",      pilotL_alive      },
  { "rename",     pilotL_rename     },
  { "pos",        pilotL_position   },
  { "vel",        pilotL_velocity   },
  { "warp",       pilotL_warp       },
  { "broadcast",  pilotL_broadcast  },
  { "setFaction", pilotL_setFaction },
  { "setHostile", pilotL_setHostile },
  { 0, 0 }
}; /**< Pilot metatable methods. */

/**
 * @fn int lua_loadPilot(lua_State* L, int readonly)
 *
 * @brief Load the space library.
 *    @param L State to load space library into.
 *    @return 0 on success.
 */
int lua_loadPilot(lua_State* L, int readonly) {
  if(readonly) /* Nothing is read only. */
    return 0;

  /* Register the functions. */
  luaL_register(L, "pilot", pilot_methods);

  /* Register the metatables. */
  pilotL_createmetatable(L);

  return 0;
}

/**
 * @fn static int pilotL_createmetatable(lua_State* L)
 *
 * @brief Registers the pilot metatable.
 *    @param L Lua state to register metatable in.
 *    @return 0 on success.
 */
static int pilotL_createmetatable(lua_State* L) {
  /* Create the metatable. */
  luaL_newmetatable(L, PILOT_METATABLE);

  /* Create the access table. */
  lua_pushvalue(L, -1);
  lua_setfield(L, -2, "__index");

  /* Register the values. */
  luaL_register(L, NULL, pilotL_methods);

  return 0;
}

/**
 * @defgroup PILOT Pilot Lua bindings.
 *
 * @brief Lua bindings to interact with pilots.
 *
 * @luamod pilot
 * Functions should be called like:
 *
 * @code
 * pilot.function(parameters)
 * @endcode
 */
/**
 * @defgroup META_PILOT Pilot Metatable
 *
 * @brief Represents a pilot in Lua.
 *
 * To call members of the metatable always use:
 *
 * @code
 * pilot:function(param)
 * @endcode
 */

/**
 * @fn LuaPilot* lua_topilot(lua_State* L, int ind)
 *
 * @brief Get pilot at index.
 *    @param L Lua state to get pilot from.
 *    @param ind Index position to find the pilot.
 *    @return Pilot found at the index in the state.
 */
LuaPilot* lua_topilot(lua_State* L, int ind) {
  if(lua_isuserdata(L, ind)) {
    return (LuaPilot*)lua_touserdata(L, ind);
  }
  luaL_typerror(L, ind, PILOT_METATABLE);
  return NULL;
}

/**
 * @fn LuaPilot* lua_pushpilot(lua_State* L, LuaPilot pilot)
 *
 * @brief Push a pilot on the stack.
 *    @param L Lua state to push pilot into.
 *    @param pilot Pilot to push.
 *    @return Newly pushed pilot.
 */
LuaPilot* lua_pushpilot(lua_State* L, LuaPilot pilot) {
  LuaPilot* p;
  p = (LuaPilot*)lua_newuserdata(L, sizeof(LuaPilot));
  *p = pilot;
  luaL_getmetatable(L, PILOT_METATABLE);
  lua_setmetatable(L, -2);
  return p;
}

/**
 * @fn int lua_ispilot(lua_State* L, int ind)
 *
 * @brief Check to see if ind is a pilot.
 *    @param L Lua state to check.
 *    @param ind Index position to check.
 *    @return 1 if ind is a pilot.
 */
int lua_ispilot(lua_State* L, int ind) {
  int ret;

  if(lua_getmetatable(L, ind)==0)
    return 0;
  lua_getfield(L, LUA_REGISTRYINDEX, PILOT_METATABLE);
  
  ret = 0;
  if(lua_rawequal(L, -1, -2)) /* Does it have the correct mt?*/
    ret = 1;

  lua_pop(L, 2); /* Remove both metatables. */
  return ret;
}

/**
 * @ingroup PILOT
 *
 * @brief Get the players pilot.
 *    @return Pilot pointing to the player.
 * @luafunc player()
 */
static int pilot_getPlayer(lua_State* L) {
  LuaPilot lp;

  if(player == NULL) {
    lua_pushnil(L);
    return 1;
  }

  lp.pilot = player->id;
  lua_pushpilot(L, lp);
  return 1;
}

/**
 * @ingroup PILOT
 *
 * @brief Adds a fleet to the system.
 *    @luaparam fleetname Name of the fleet to add.
 *    @luaparam ai If set will override the standard fleet AI. "def" means use default.
 *    @luaparam pos Position to create pilots around instead of choosing randomly.
 *    @return Table populated with all the identifiers of the pilots created.
 * @luafunc add(fleetname, ai, pos)
 */
static int pilot_addFleet(lua_State* L) {
  LLUA_MIN_ARGS(1);
  Fleet* flt;
  char* fltname, *fltai;
  int i, j;
  unsigned int p;
  double a;
  double d;
  Vec2 vv, vp, vn;
  FleetPilot* plt;
  LuaPilot lp;
  LuaVector* lv;


  /* Parse first argument - Fleet name */
  if(lua_isstring(L, 1)) fltname = (char*) lua_tostring(L, 1);
  else LLUA_INVALID_PARAMETER();

  /* Parse second argument - Fleet IA override. */
  if(lua_gettop(L) > 1) {
    if(lua_isstring(L, 2)) {
      fltai = (char*)lua_tostring(L, 2);
      if(strcmp(fltai, "def")==0) /* Check if set to default. */
        fltai = NULL;
    }
    else LLUA_INVALID_PARAMETER();
  }
  else fltai = NULL;

  /* Parse third argument - Position. */
  if(lua_gettop(L) > 2) {
    if(lua_isvector(L,3))
      lv = lua_tovector(L,3);
    else LLUA_INVALID_PARAMETER();
  }
  else lv = NULL;

  /* Needed to determine angle. */
  vectnull(&vn);

  /* Pull the fleet. */
  flt = fleet_get(fltname);
  if(flt == NULL) {
    LLUA_DEBUG("Fleet not found!");
    return 0;
  }

  /* Use position passed if possible. */
  if(lv != NULL)
    vectcpy(&vp, &lv->vec);
  else {
    d = RNGF()*(HYPERSPACE_ENTER_MAX-HYPERSPACE_ENTER_MIN) + HYPERSPACE_ENTER_MIN;
  }

  j = 0;
  lua_newtable(L);
  for(i = 0; i < flt->npilots; i++) {
    plt = &flt->pilots[i];

    if(RNG(0, 100) <= plt->chance) {
      /* Fleet displacement. */
      vect_cadd(&vp, RNG(75, 150) * (RNG(0,1) ? 1 : -1),
          RNG(75, 150) * (RNG(0,1) ? 1 : -1));

      /* Set velocity only if no position is set.. */
      if(lv != NULL) {
        if(VMOD(lv->vec) > HYPERSPACE_ENTER_MIN*0.9) {
          a = vect_angle(&vp, &vn);
          vect_pset(&vv, HYPERSPACE_VEL, a);
        }
        else vectnull(&vv);
      }
      else { /* Enterting via hyperspace. */
        a = vect_angle(&vp, &vn);
        vect_pset(&vv, HYPERSPACE_VEL, a);
      }

      /* Create the pilot. */
      p = pilot_create(plt->ship,
          plt->name,
          flt->faction,
          (fltai != NULL) ? /* Lua AI override. */
            fltai :
            (plt->ai != NULL) ? /* Pilot AI override */
            plt->ai : flt->ai,
          a,
          &vp,
          &vv,
          0);

      /* We push each pilot created into a table and return it. */
      lua_pushnumber(L, ++j); /* Index, starts with 1. */
      lp.pilot = p;
      lua_pushpilot(L, lp);   /* value = LuaPilot */
      lua_rawset(L, -3);      /* Store the value in the table. */
    }
  }

  return 1;

}

/**
 * @ingroup PILOT
 * @brief Clears the current system of pilots. Used for epic battles and such.
 * @luafunc clear()
 */
static int pilot_clear(lua_State* L) {
  (void) L;
  pilots_clean();
  return 0;
}

/**
 * @ingroup PILOT
 *
 * @brief Disable or enable pilot spawning in the current system. If player jumps
 * the spawn is enabled again automatically.
 *    @luaparam enable true enables spawn, false disables it.
 *    @return The current spawn state.
 * @luafunc togglespawn(enable)
 */
static int pilot_toggleSpawn(lua_State* L) {
  /* Setting it directly. */
  if((lua_gettop(L) > 0) && lua_isboolean(L, 1))
      space_spawn = lua_toboolean(L, 1);
    /* Toggling. */
  else
    space_spawn = !space_spawn;

  lua_pushboolean(L, space_spawn);
  return 1;
}

/**
 * @ingroup PILOT
 */
static int pilot_getPilots(lua_State* L) {
  int i, j, k;
  int* factions;
  int nfactions;
  LuaFaction* f;
  LuaPilot p;

  /* Check for belonging to faction. */
  if(lua_istable(L, 1)) {
    /* get table length and preallocate. */
    nfactions = (int)lua_objlen(L, 1);
    factions = malloc(sizeof(int) * nfactions);
    /* Load up the table. */
    lua_pushnil(L);
    i = 0;
    while(lua_next(L, -2) != 0) {
      f = lua_tofaction(L, -1);
      factions[i++] = f->f;
      lua_pop(L, 1);
    }

    /* Now put all the matching pilots in a table. */
    lua_newtable(L);
    k = 1;
    for(i = 0; i < pilot_nstack; i++) {
      for(j = 0; j < nfactions; j++) {
        if((pilot_stack[i]->faction == factions[j]) &&
          !pilot_isDisabled(pilot_stack[i])) {
          lua_pushnumber(L, k++); /* key. */
          p.pilot = pilot_stack[i]->id;
          lua_pushpilot(L, p); /* Value. */
          lua_rawset(L, -3); /* table[key] = value */
          break; /* Continue to next pilot. */
        }
      }
    }

    /* Clean up. */
    free(factions);
  } else
    LLUA_INVALID_PARAMETER();

  return 1;
}

/**
 * @brief Check to see if pilot and p are the same.
 *    @luaparam p Pilot to compare against.
 *    @return true if they are the same.
 * @luafunc __eq(pilot)
 */
static int pilotL_eq(lua_State* L) {
  LLUA_MIN_ARGS(2);
  LuaPilot* p1, *p2;

  /* Get parameters. */
  p1 = lua_topilot(L, 1);
  if(lua_ispilot(L, 2))
    p2 = lua_topilot(L, 2);
  else LLUA_INVALID_PARAMETER();

  /* Push result. */
  lua_pushboolean(L, p1->pilot == p2->pilot);
  return 1;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Get the pilots current name.
 *    @return The current name of the pilot.
 * @luafunc name()
 */
static int pilotL_name(lua_State* L) {
  LLUA_MIN_ARGS(1);
  LuaPilot* p1;
  Pilot* p;

  /* Parse parameters. */
  p1 = lua_topilot(L, 1);
  p = pilot_get(p1->pilot);

  /* Pilot must exist. */
  if(p == NULL) return 0;

  /* Get name. */
  lua_pushstring(L, p->name);
  return 1;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Checks to see if pilot is still alive.
 *    @return true if pilot is still alive.
 * @luafunc alive()
 */
static int pilotL_alive(lua_State* L) {
  LLUA_MIN_ARGS(1);
  LuaPilot* lp;
  Pilot* p;

  /* Parse parameters. */
  lp = lua_topilot(L, 1);
  p = pilot_get(lp->pilot);

  /* Check if is alive. */
  lua_pushboolean(L, p != NULL);
  return 1;
}

/**
 * @brief Changes the pilots name.
 *    @param name Name to change to.
 * @luafunc rename(name)
 */
static int pilotL_rename(lua_State* L) {
  LLUA_MIN_ARGS(2);
  LuaPilot* p1;
  char* name;
  Pilot* p;

  /* Parse parameters. */
  p1 = lua_topilot(L, 1);
  p = pilot_get(p1->pilot);
  if(lua_isstring(L, 2))
    name = (char*)lua_tostring(L, 2);
  else LLUA_INVALID_PARAMETER();

  /* Pilot must exist. */
  if(p == NULL) return 0;

  /* Change name. */
  if(p->name != NULL)
    free(p->name);
  p->name = strdup(name);

  return 0;
}

/**
 * @brief Get the pilots position.
 *    @return The pilots current position.
 * @luafunc pos()
 */
static int pilotL_position(lua_State* L) {
  LLUA_MIN_ARGS(1);
  LuaPilot* p1;
  Pilot* p;
  LuaVector v;

  /* Parse parameters */
  p1 = lua_topilot(L, 1);
  p = pilot_get(p1->pilot);

  /* Pilot must exist. */
  if(p == NULL) return 0;

  /* Push position. */
  vectcpy(&v.vec, &p->solid->pos);
  lua_pushvector(L, v);
  return 1;
}

/**
 * @fn static int pilotL_velocity(lua_State* L)
 * @ingroup META_PILOT
 *
 * @brief Gets the pilots velocity.
 *    @return The pilots current velocity.
 * @luafunc vel()
 */
static int pilotL_velocity(lua_State* L) {
  LLUA_MIN_ARGS(1);
  LuaPilot* p1;
  Pilot* p;
  LuaVector v;

  /* Parse parameters. */
  p1 = lua_topilot(L, 1);
  p = pilot_get(p1->pilot);

  /* Pilot must exist.. */
  if(p == NULL) return 0;

  /* Push velocity. */
  vectcpy(&v.vec, &p->solid->vel);
  lua_pushvector(L, v);
  return 1;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Set the pilots position.
 *    @luaparam pos Position to set.
 * @luafunc warp( pos )
 */
static int pilotL_warp(lua_State* L) {
  LLUA_MIN_ARGS(2);
  LuaPilot* p1;
  Pilot* p;
  LuaVector* v;

  /* Parse parameters. */
  p1 = lua_topilot(L, 1);
  p = pilot_get(p1->pilot);
  if(lua_isvector(L,2))
    v = lua_tovector(L, 2);
  else LLUA_INVALID_PARAMETER();

  /* Pilot must exist. */
  if(p == NULL) return 0;

  /* Warp pilot to new position. */
  vectcpy(&p->solid->pos, &v->vec);
  vectnull(&p->solid->vel);  /* Clear velocity otherwise it's a bit weird. */
  return 0;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Make the pilot broadcast a message.
 *    @luaparam msg Message to broadcast.
 * @luafunc broadcast(msg)
 */
static int pilotL_broadcast(lua_State* L) {
  LLUA_MIN_ARGS(2);
  Pilot* p;
  LuaPilot* lp;
  char* msg;

  /* Parse arguments. */
  lp = lua_topilot(L, 1);
  if(lua_isstring(L, 2))
    msg = (char*)lua_tostring(L, 2);
  else LLUA_INVALID_PARAMETER();

  /* Check to see if pilot is valid. */
  p = pilot_get(lp->pilot);
  if(p == NULL)
    return 0;

  /* Broadcast message. */
  player_message("Broadcast %s> \"%s\"", p->name, msg);
  return 0;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Set the pilots faction.
 *    @luaparam faction Faction to set by name or faction.
 * @luafunc setFaction( faction )
 */
static int pilotL_setFaction(lua_State* L) {
  LLUA_MIN_ARGS(2);
  Pilot* p;
  LuaPilot* lp;
  LuaFaction* f;
  int fid;
  char* faction;

  /* Parse parameters. */
  lp = lua_topilot(L, 1);
  if(lua_isstring(L, 2)) {
    faction = (char*)lua_tostring(L,2);
    fid = faction_get(faction);
  }
  else if(lua_isfaction(L, 2)) {
    f = lua_tofaction(L, 2);
    fid = f->f;
  }
  else LLUA_INVALID_PARAMETER();

  /* Get pilot/faction. */
  p = pilot_get(lp->pilot);
  if(p == NULL) return 0;

  /* Set the new faction. */
  p->faction = fid;

  return 0;
}

/**
 * @ingroup META_PILOT
 *
 * @brief Set the pilot as hostile to player.
 * @luafunc setHostile()
 */
static int pilotL_setHostile(lua_State* L) {
  LuaPilot* lp;
  Pilot* p;

  /* Get the pilot. */
  lp = lua_topilot(L, 1);
  p = pilot_get(lp->pilot);
  if(p == NULL) return 0;

  /* Set as hostile. */
  pilot_setHostile(p);

  return 0;
}