//> include: ./lua
//> lib: ./lua
//> link: -Wl,-Bstatic -llua54 -Wl,-Bdynamic -lm -ldl
//> cflags: -Ofast

import "lua.h";
import "lauxlib.h";
import "lualib.h";

fn l_zenc_hello(L: lua_State*) -> int {
    const name: string = (string)luaL_optstring(L, 1, "world");
    println "hello from Zen-C, {name}"
    return 0;
}

fn main() {
    let L: lua_State* = luaL_newstate();

    if (!L) return !"Could not initialize LUA.";

    // Opens standard libs
    luaL_openlibs(L);
    defer lua_close(L);

    // Expose a Zen-C function to Lua as global "zenc_hello"
    lua_pushcfunction(L, l_zenc_hello);
    lua_setglobal(L, "zenc_hello");

    // Run some Lua from a Zen-C variable
    const script = "print('hello from lua')\nzenc_hello('test')\n";

    if (luaL_dostring(L, script) != LUA_OK) {
        const err: string = (string)lua_tostring(L, -1);
        !"lua error: {err}"
        lua_pop(L, 1);
    }

    // Run some Lua from a script file
    if (luaL_loadfile(L, "script.lua") != LUA_OK) {
        const err: string = (string)lua_tostring(L, -1);
        !"lua load-error: {err}"
        lua_pop(L, 1);
    } else if (lua_pcall(L, 0, 0, 0) != LUA_OK) {
         const err: string = (string)lua_tostring(L, -1);
        !"lua error: {err}"
        lua_pop(L, 1);
    }
}