/* Copyright (c) 2010-2020. The SimGrid Team.
 * All rights reserved.                                                     */

/* This program is free software; you can redistribute it and/or modify it
 * under the terms of the license (GNU LGPL) which comes with this package. */

/* SimGrid Lua bindings                                                     */

#include "lua_private.hpp"
#include "lua_utils.hpp"
#include "src/surf/xml/platf.hpp"
#include <lauxlib.h>

XBT_LOG_NEW_DEFAULT_CATEGORY(lua, "Lua Bindings");

extern "C" int luaopen_simgrid(lua_State* L);

/* ********************************************************************************* */
/*                                  simgrid API                                      */
/* ********************************************************************************* */

/**
 * @brief Prints a log string with debug level.
 * @param L a Lua state
 * @return number of values returned to Lua
 *
 * - Argument 1 (string): the text to print
 */
static int debug(lua_State* L)
{
  const char* str = luaL_checkstring(L, 1);
  XBT_DEBUG("%s", str);
  return 0;
}

/**
 * @brief Prints a log string with info level.
 * @param L a Lua state
 * @return number of values returned to Lua
 *
 * - Argument 1 (string): the text to print
 */
static int info(lua_State* L)
{
  const char* str = luaL_checkstring(L, 1);
  XBT_INFO("%s", str);
  return 0;
}

static int error(lua_State* L)
{
  const char* str = luaL_checkstring(L, 1);
  XBT_ERROR("%s", str);
  return 0;
}

static int critical(lua_State* L)
{
  const char* str = luaL_checkstring(L, 1);
  XBT_CRITICAL("%s", str);
  return 0;
}

/**
 * @brief Dumps a lua table with XBT_DEBUG
 *
 * This function can be called from within lua via "simgrid.dump(table)". It will
 * then dump the table via XBT_DEBUG
 */
static int dump(lua_State* L)
{
  int argc = lua_gettop(L);

  for (int i = 1; i <= argc; i++) {
    if (lua_istable(L, i)) {
      lua_pushnil(L); /* table nil */

      //lua_next pops the topmost element from the stack and
      //gets the next pair from the table at the specified index
      while (lua_next(L, i)) { /* table key val  */
        // we need to copy here, as a cast from "Number" to "String"
        // could happen in Lua.
        // see remark in the lua manual, function "lua_tolstring"
        // http://www.lua.org/manual/5.3/manual.html#lua_tolstring

        lua_pushvalue(L, -2); /* table key val key */

        XBT_DEBUG("%s", sglua_keyvalue_tostring(L, -1, -2));
      }

      lua_settop(L, argc); // Remove everything except the initial arguments
    }
  }

  return 0;
}

static const luaL_Reg simgrid_functions[] = {
  {"dump", dump},
  {"debug", debug},
  {"info", info},
  {"critical", critical},
  {"error", error},
  {nullptr, nullptr}
};

/* ********************************************************************************* */
/*                           module management functions                             */
/* ********************************************************************************* */

/**
 * @brief Makes the core functions available to the Lua world.
 * @param L a Lua world
 */
static void sglua_register_core_functions(lua_State *L)
{
  /* register the core C functions to lua */
  luaL_newlib(L, simgrid_functions); /* simgrid */
  lua_pushvalue(L, -1);              /* simgrid simgrid */
  lua_setglobal(L, "simgrid");       /* simgrid */
}

/**
 * @brief Opens the simgrid Lua module.
 *
 * This function is called automatically by the Lua interpreter when some
 * Lua code requires the "simgrid" module.
 *
 * @param L the Lua state
 */
int luaopen_simgrid(lua_State *L)
{
  XBT_DEBUG("luaopen_simgrid *****");

  sglua_register_core_functions(L);
  sglua_register_host_functions(L);
  sglua_register_platf_functions(L);

  return 1;
}
