import type { PathParser } from './path-parser';

/**
 * Validates an A (arc-to) specific path command value.
 * Usually a `large-arc-flag` or `sweep-flag`.
 */
export function scanFlag(path: PathParser) {
  const { index, pathValue } = path;
  const code = pathValue.charCodeAt(index);

  if (code === 0x30 /* 0 */) {
    path.param = 0;
    path.index += 1;
    return;
  }

  if (code === 0x31 /* 1 */) {
    path.param = 1;
    path.index += 1;
    return;
  }

  path.err = `[path-util]: invalid Arc flag "${pathValue[index]}", expecting 0 or 1 at index ${index}`;
}