/**
 * Pure version-comparison logic for the mobile update check (issue #66) —
 * no Capacitor/network/DOM dependency, kept separate from
 * `useAppUpdateCheck.ts` so it's testable in isolation (same
 * pure-logic/effectful-hook split this repo uses everywhere else, e.g.
 * `ingredient-matcher.ts`'s `matchIngredientName` vs `loadIngredientCatalog`).
 *
 * Release tags in this repo are always `vX.Y.Z` (see `.github/workflows/release.yml`'s
 * `on: push: tags: ["v*.*.*"]`) — a hand-rolled comparison for exactly that
 * shape is simpler than pulling in a semver library for three integers.
 */

/** One `vX.Y.Z` tag parsed into its three integer components. */
export interface ParsedVersion {
  major: number;
  minor: number;
  patch: number;
}

/**
 * Parses a `vX.Y.Z` (or bare `X.Y.Z`) string into its components — `null`
 * if it doesn't match that exact shape (a malformed tag, an empty string, a
 * pre-release suffix this app doesn't publish). Callers treat `null` as
 * "can't compare, assume no update" rather than throwing — a version check
 * is never allowed to be the reason the app breaks.
 */
export function parseVersion(raw: string): ParsedVersion | null {
  const match = /^v?(\d+)\.(\d+)\.(\d+)$/.exec(raw.trim());
  if (!match) return null;
  const [, major, minor, patch] = match;
  return { major: Number(major), minor: Number(minor), patch: Number(patch) };
}

/**
 * `true` when `latest` is a genuinely newer version than `current` —
 * `false` for equal, older, or unparseable input on either side (fails
 * closed: "don't nag" is always the safe default for a background check).
 */
export function isNewerVersion(current: string, latest: string): boolean {
  const currentParsed = parseVersion(current);
  const latestParsed = parseVersion(latest);
  if (!currentParsed || !latestParsed) return false;

  if (latestParsed.major !== currentParsed.major) {
    return latestParsed.major > currentParsed.major;
  }
  if (latestParsed.minor !== currentParsed.minor) {
    return latestParsed.minor > currentParsed.minor;
  }
  return latestParsed.patch > currentParsed.patch;
}