import { createMatcher } from "../../match/match.js";
import {
  type UuidV4,
  uuidV4Matcher,
  type UuidV4Matcher,
} from "./uuid-v4.type.js";

const uuidV4Regex =
  /^[\da-f]{8}-[\da-f]{4}-4[\da-f]{3}-[89ab][\da-f]{3}-[\da-f]{12}$/i;

/**
 * Matcher for a UUID v4 string value.
 */
export function uuidV4(): UuidV4Matcher {
  return {
    ...createMatcher(
      (value): value is UuidV4 =>
        typeof value === "string" && uuidV4Regex.test(value),
      () => "UUID v4 string",
      () => "uuidV4()",
    ),
    // Runtime marker used only to make the matcher type nominal for type-level
    // refinement dispatch. It is not part of the user-facing matcher behaviour.
    [uuidV4Matcher]: true,
  };
}