// Version utility.
//
// NILE_ELEMENTS_VERSION is this package's own version and is still substituted
// at build time by scripts/replace-version.cjs.
//
// The tokens version is read from the loaded Nile stylesheet's --nile-version
// custom property (stamped by @aquera/nile's scripts/stamp-css-version.mjs),
// falling back to the @aquera/nile installed alongside this package.
//
// Reading the stylesheet is what makes a tokens-only release visible. The
// imported constant alone is not enough: rollup.config.js bundles
// @aquera/nile/lib/version.js into dist/index.js, so on the CDN build it is
// frozen at this package's build time. The stylesheet is the live source.
import { NILE_VERSION as BUILT_IN_NILE_VERSION } from '@aquera/nile/lib/version.js';

export const NILE_ELEMENTS_VERSION = '__NILE_ELEMENTS_VERSION__';

function readStylesheetNileVersion(): string | null {
  if (typeof window === 'undefined' || typeof getComputedStyle !== 'function') {
    return null;
  }

  try {
    const value = getComputedStyle(document.documentElement)
      .getPropertyValue('--nile-version')
      .trim()
      .replace(/^["']|["']$/g, '');

    return value || null;
  } catch {
    return null;
  }
}

/**
 * The version of @aquera/nile (tokens/stylesheets) whose CSS is loaded in the
 * page, falling back to the @aquera/nile bundled into this package when no
 * stamped stylesheet is present.
 *
 * This is the canonical runtime API. It resolves on every call rather than
 * caching, so it is correct even when the Nile stylesheet is added to the page
 * after this module evaluates - which is the common case, and why no
 * module-evaluation-time snapshot of it is exported.
 */
export function getNileVersion(): string {
  return readStylesheetNileVersion() ?? BUILT_IN_NILE_VERSION;
}

// Set global versions for runtime access
if (typeof window !== 'undefined') {
  (window as any).nileElementsVersion = NILE_ELEMENTS_VERSION;

  // A getter rather than a value, so window.nileVersion reflects whichever
  // stylesheet is loaded at read time regardless of script/style ordering.
  let override: string | null = null;
  Object.defineProperty(window, 'nileVersion', {
    configurable: true,
    get: () => override ?? getNileVersion(),
    set: (value: string) => {
      override = value;
    },
  });

  (window as any).process = (window as any).process || {
    env: { NODE_ENV: 'production' },
  };
}