/**
 * Lightweight hash router for the app's tab views.
 *
 * Tabs are routable via the URL hash so a user can share/copy a URL for a
 * specific tab (e.g. #/radar) and use browser back/forward between tabs.
 * There is no nested route structure — just a single top-level view segment.
 */

export const VALID_VIEWS = ['current', 'hourly', 'daily', 'detail', 'radar']
export const DEFAULT_VIEW = 'current'

/**
 * Parse a location hash into a view id, falling back to the default view.
 * Accepts '#/hourly', 'hourly', '#hourly', '', '#/unknown', etc.
 *
 * @param {string} [hash] - window.location.hash
 * @returns {string} one of VALID_VIEWS
 */
export function parseHash(hash = '') {
  const clean = String(hash).replace(/^#\/?/, '')
  const seg = clean.split('/')[0]
  return VALID_VIEWS.includes(seg) ? seg : DEFAULT_VIEW
}

/**
 * Convert a view id into its URL hash representation.
 * @param {string} view - one of VALID_VIEWS
 * @returns {string} e.g. '#/radar'
 */
export function viewToHash(view) {
  return `#/${view}`
}