#include <lauxlib.h>
#include <lua.h>
#include <lualib.h>

// A simple C function to add two numbers
int c_add(lua_State *L) {
    double a = luaL_checknumber(L, 1);
    double b = luaL_checknumber(L, 2);
    lua_pushnumber(L, a + b);
    return 1; // one return value
}

int c_print(lua_State *L) {
    const char *c = luaL_checkstring(L, 1);
    printf("%s\n", c);
    return 0;
}

static int luaB_print(lua_State *L) {
    int n = lua_gettop(L); /* number of arguments */
    int i;
    for (i = 1; i <= n; i++) { /* for each argument */
        size_t      l;
        const char *s = luaL_tolstring(L, i, &l); /* convert it to string */
        if (i > 1)                                /* not the first element? */
            lua_writestring("\t", 1);             /* add a tab before it */
        lua_writestring(s, l);                    /* print it */
        lua_pop(L, 1);                            /* pop result */
    }
    lua_writeline();
    return 0;
}

static int luaB_type(lua_State *L) {
    int t = lua_type(L, 1);
    luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
    lua_pushstring(L, lua_typename(L, t));
    return 1;
}

int main(void) {
    lua_State *L = luaL_newstate();
    // luaL_openlibs(L); // Load Lua standard libraries

    const lua_Number ver = lua_version(NULL);

    printf("Lua version: %.2f\n", ver);
    printf("Lua version: %s\n", LUA_VERSION);

    // Register the C function as a global Lua function
    lua_register(L, "c_add", c_add);
    lua_register(L, "myprint", c_print);
    lua_register(L, "print", luaB_print);
    lua_register(L, "type", luaB_type);

    // Run the Lua script
    if (luaL_dofile(L, "script.lua") != LUA_OK) {
        fprintf(stderr, "Error: %s\n", lua_tostring(L, -1));
        lua_pop(L, 1); // remove error message
    }

    lua_close(L);
    return 0;
}