import type { SaveStatus } from './state';

/** When a snapshot was made, in the local time of the browser: `2026-09-25 17:39`. */
export function snapshotTime(at: Date): string {
  const two = (n: number) => String(n).padStart(2, '0');
  return `${at.getFullYear()}-${two(at.getMonth() + 1)}-${two(at.getDate())} ${two(at.getHours())}:${two(at.getMinutes())}`;
}

/**
 * Why a snapshot cannot be made or restored right now, or null when it can (#231). The server copies
 * what it has stored, so the editor has to have saved everything first: a snapshot without the
 * last edits would be a stand nobody ever saw. A release is a copy as well (#266) and asks the same.
 */
export function snapshotBlocker(
  status: SaveStatus,
  copy: 'snapshot' | 'release' = 'snapshot',
): string | null {
  switch (status) {
    case 'saved':
      return null;
    case 'conflict':
      return 'This project was changed elsewhere. Reload to continue.';
    case 'error':
      return `The project could not be saved, so there is nothing current to ${copy === 'release' ? 'release' : 'take a snapshot of'}`;
    default:
      return 'The latest changes are not saved yet – stop the game or wait a moment';
  }
}