export type TimerHandle = ReturnType<typeof globalThis.setTimeout> | number;

export interface Clock {
	clearInterval(handle: TimerHandle): void;
	clearTimeout(handle: TimerHandle): void;
	now(): number;
	setInterval(fn: () => void, delayMs: number): TimerHandle;
	setTimeout(fn: () => void, delayMs: number): TimerHandle;
}

export class SystemClock implements Clock {
	public now(): number {
		if (
			!globalThis.performance ||
			typeof globalThis.performance.now !== "function"
		) {
			throw new Error("SystemClock requires globalThis.performance.now()");
		}

		return globalThis.performance.now();
	}

	public setTimeout(fn: () => void, delayMs: number): TimerHandle {
		return globalThis.setTimeout(fn, delayMs);
	}

	public clearTimeout(handle: TimerHandle): void {
		globalThis.clearTimeout(handle as ReturnType<typeof globalThis.setTimeout>);
	}

	public setInterval(fn: () => void, delayMs: number): TimerHandle {
		return globalThis.setInterval(fn, delayMs);
	}

	public clearInterval(handle: TimerHandle): void {
		globalThis.clearInterval(
			handle as ReturnType<typeof globalThis.setTimeout>,
		);
	}
}