import {
  ObjectCreate,
  TypeError,
  WeakMap,
  WeakMapPrototypeSet as set,
} from "ext:core/primordials";
import { onRuntimeStart } from "ext:core/bootstrap";
import {
  op_timer_now as timerNow,
  op_timer_time_origin as timerTimeOrigin,
} from "ext:core/ops";
import { EventTarget } from "./events.js";
import { state } from "./idl.js";

const secret = ObjectCreate(null) as {
  readonly performanceToken: unique symbol;
};
const performances = new WeakMap<object, number>();
const floor = Math.floor;

class Performance extends EventTarget {
  constructor(key: typeof secret);
  constructor() {
    if (arguments[0] !== secret) throw new TypeError("Illegal constructor");
    super();
  }
  now(): number {
    state(performances, this);
    return floor(timerNow(null) * 10) / 10;
  }
  get timeOrigin(): number {
    return state(performances, this);
  }
  toJSON(): { timeOrigin: number } {
    return { timeOrigin: state(performances, this) };
  }
}

const performance = new Performance(secret);
onRuntimeStart(() => {
  set(performances, performance, floor(timerTimeOrigin(null) * 10) / 10);
});
export { Performance, performance };