// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
import type { SemVer } from "./types.ts";
import {
  checkIdentifier,
  compareIdentifier,
  compareNumber,
} from "./_shared.ts";

/**
 * Compare two semantic version objects.
 *
 * Returns `0` if `v1 === v2`, or `1` if `v1` is greater, or `-1` if `v2` is
 * greater.
 *
 * Sorts in ascending order if passed to `Array.sort()`,
 */
export function compare(
  s0: SemVer,
  s1: SemVer,
): 1 | 0 | -1 {
  if (s0 === s1) return 0;
  return (
    compareNumber(s0.major, s1.major) ||
    compareNumber(s0.minor, s1.minor) ||
    compareNumber(s0.patch, s1.patch) ||
    checkIdentifier(s0.prerelease, s1.prerelease) ||
    compareIdentifier(s0.prerelease, s1.prerelease)
  );
}