import { lua, lauxlib, lualib, to_luastring } from "fengari";
import { ScriptSchedulerService } from "./ScriptSchedulerService.js";
import { Instance } from "./Instance.js"; // your engine's instance class

// Import interop from fengari-interop
import { push, luaopen_js } from "fengari-interop";

export class Script extends Instance {
  constructor(sourceCode) {
    super("Script");
    this.Source = sourceCode;
    this.LuaState = null;
  }

  Run() {
    const L = lauxlib.luaL_newstate();
    luaopen_js(L);
    lualib.luaL_openlibs(L);

    // Bridge all engine APIs
    this._registerGlobals(L);

    // Compile the source
    const status = lauxlib.luaL_loadstring(L, to_luastring(this.Source));
    if (status !== lua.LUA_OK) {
      const err = lua.lua_tojsstring(L, -1);
      throw new Error("Lua load error: " + err);
    }

    // Create a coroutine thread
    const thread = lua.lua_newthread(L);

    // Schedule with scheduler
    this._getScheduler().scheduleFengariCoroutine(thread, L);
    this.LuaState = L;
  }

  _registerGlobals(L) {
    // game global
    push(L,  globalThis.game);
    lua.lua_setglobal(L, to_luastring("game"));

    // task + wait bridge
    lua.lua_pushjsfunction(L, () => {
      const secs = lua.lua_isnumber(L, 1) ? lua.lua_tonumber(L, 1) : 0;
      const yieldVal = JSON.stringify({ wait: secs });
      lua.lua_pushstring(L, to_luastring(yieldVal));
      return lua.lua_yield(L, 1);
    });
    lua.lua_setglobal(L, to_luastring("task_wait"));

    // Lua API helpers
    lua.lua_pushjsfunction(L, () => {
      const inst = new Instance("Part"); // example
      return inst.LuaBridge(); // converts to Lua table/proxy
    });
    lua.lua_setglobal(L, to_luastring("Instance_new"));
  }

  _getScheduler() {
    return game.GetService("ScriptSchedulerService");
  }
}