/**
 * Centralised feature keys for the whole application.
 *
 * Every gateable thing in the app — module, screen, tab, menu entry, button and
 * action — has exactly one key here. UI code must never pass a raw string to the
 * feature service; always reference a member of this enum so renames and typos
 * are caught by the compiler.
 *
 * Keys use dot notation and the hierarchy is encoded in the key itself:
 *
 *   loans            → parent of
 *   loans.apply      → parent of
 *   loans.apply.submit
 *
 * The feature service derives parent/child relationships from this path, so a
 * disabled parent automatically disables everything beneath it. Adding a child
 * key therefore only requires that its parent key also exists.
 */
export enum FeatureKey {
  // ---------------------------------------------------------------- Auth ----
  AUTH = 'auth',
  AUTH_LOGIN = 'auth.login',
  AUTH_LOGIN_USER_ROLE = 'auth.login.userRole',
  AUTH_LOGIN_AGENT_ROLE = 'auth.login.agentRole',
  AUTH_LOGIN_BIOMETRIC = 'auth.login.biometric',
  AUTH_LOGIN_FORGOT_PASSWORD = 'auth.login.forgotPassword',
  AUTH_REGISTER = 'auth.register',
  AUTH_LOGIN_CREATE_ACCOUNT = 'auth.login.createAccount',
  AUTH_LOGOUT = 'auth.logout',

  // ---------------------------------------------------------------- Home ----
  HOME = 'home',
  HOME_ACCOUNTS = 'home.accounts',
  HOME_ACCOUNTS_CAROUSEL = 'home.accounts.carousel',
  HOME_ACCOUNTS_BALANCE_TOGGLE = 'home.accounts.balanceToggle',
  HOME_ACCOUNTS_MINI_STATEMENT = 'home.accounts.miniStatement',
  HOME_ACCOUNTS_DETAILS = 'home.accounts.details',
  HOME_ACCOUNTS_EPASSBOOK = 'home.accounts.ePassbook',
  HOME_ACCOUNTS_REKYC = 'home.accounts.reKyc',
  HOME_ACCOUNTS_VIDEO_KYC = 'home.accounts.videoKyc',
  HOME_ACCOUNTS_MMID = 'home.accounts.mmid',

  HOME_QUICK_ACTIONS = 'home.quickActions',
  HOME_QUICK_ACTIONS_TRANSFER = 'home.quickActions.transfer',
  HOME_QUICK_ACTIONS_BILL_PAY = 'home.quickActions.billPay',
  HOME_QUICK_ACTIONS_AIRTIME = 'home.quickActions.airtime',
  HOME_QUICK_ACTIONS_LOANS = 'home.quickActions.loans',
  HOME_QUICK_ACTIONS_CARDS = 'home.quickActions.cards',
  HOME_QUICK_ACTIONS_STATS = 'home.quickActions.stats',

  HOME_SERVICES = 'home.services',
  HOME_SERVICES_TRANSFER = 'home.services.transfer',
  HOME_SERVICES_SELF_TRANSFER = 'home.services.selfTransfer',
  HOME_SERVICES_BILL_PAY = 'home.services.billPay',
  HOME_SERVICES_COLLECT_REQUEST = 'home.services.collectRequest',
  HOME_SERVICES_MANAGE_PAYEE = 'home.services.managePayee',
  HOME_SERVICES_SUPPORT = 'home.services.support',
  HOME_SERVICES_INSURANCE = 'home.services.insurance',
  HOME_SERVICES_DEPOSITS = 'home.services.deposits',
  HOME_SERVICES_GOLD_LOAN = 'home.services.goldLoan',

  HOME_INSIGHTS = 'home.insights',
  HOME_PROMO_BANNER = 'home.promoBanner',

  // -------------------------------------------------------------- Search ----
  SEARCH = 'search',
  SEARCH_GLOBAL = 'search.global',

  // ------------------------------------------------------- Notifications ----
  NOTIFICATIONS = 'notifications',
  NOTIFICATIONS_LIST = 'notifications.list',
  NOTIFICATIONS_MARK_READ = 'notifications.markRead',

  // ------------------------------------------------------------ Payments ----
  PAYMENTS = 'payments',
  PAYMENTS_HUB = 'payments.hub',
  PAYMENTS_BENEFICIARIES = 'payments.beneficiaries',
  PAYMENTS_BENEFICIARIES_LIST = 'payments.beneficiaries.list',
  PAYMENTS_BENEFICIARIES_ADD = 'payments.beneficiaries.add',
  PAYMENTS_BENEFICIARIES_DELETE = 'payments.beneficiaries.delete',
  PAYMENTS_TRANSFER = 'payments.transfer',
  PAYMENTS_TRANSFER_IMPS = 'payments.transfer.imps',
  PAYMENTS_TRANSFER_NEFT = 'payments.transfer.neft',
  PAYMENTS_TRANSFER_RTGS = 'payments.transfer.rtgs',
  PAYMENTS_TRANSFER_INTERNAL = 'payments.transfer.internal',
  PAYMENTS_TRANSFER_SUBMIT = 'payments.transfer.submit',
  /**
   * The three fund-transfer entry points on the payments hub. Each is a
   * destination in its own right rather than a rail: `mobile` collects a
   * mobile number and MMID, `account` an account number and IFSC, and `own`
   * moves money
   * between the customer's own accounts. The rail keys above still decide how
   * the resulting transfer settles.
   */
  PAYMENTS_TRANSFER_MOBILE = 'payments.transfer.mobile',
  PAYMENTS_TRANSFER_ACCOUNT = 'payments.transfer.account',
  PAYMENTS_TRANSFER_OWN = 'payments.transfer.own',
  PAYMENTS_UPI = 'payments.upi',
  PAYMENTS_UPI_SCAN = 'payments.upi.scan',

  /** This customer's own MMIDs, for receiving money over IMPS. */
  PAYMENTS_MMID = 'payments.mmid',
  PAYMENTS_MMID_CANCEL = 'payments.mmid.cancel',
  PAYMENTS_MMID_GENERATE = 'payments.mmid.generate',

  // --------------------------------------------------------------- Cards ----
  CARDS = 'cards',
  CARDS_OVERVIEW = 'cards.overview',
  CARDS_DETAILS = 'cards.details',
  CARDS_TRANSACTIONS = 'cards.transactions',
  CARDS_CONTROLS = 'cards.controls',
  CARDS_CONTROLS_FREEZE = 'cards.controls.freeze',
  CARDS_CONTROLS_ONLINE = 'cards.controls.online',
  CARDS_CONTROLS_INTERNATIONAL = 'cards.controls.international',
  CARDS_CONTROLS_CONTACTLESS = 'cards.controls.contactless',
  CARDS_CONTROLS_ATM = 'cards.controls.atm',
  CARDS_CONTROLS_LIMITS = 'cards.controls.limits',
  CARDS_CONTROLS_BLOCK = 'cards.controls.block',
  CARDS_APPLY_CREDIT = 'cards.applyCredit',
  CARDS_REQUEST_PHYSICAL = 'cards.requestPhysical',

  // ------------------------------------------------------------ Services ----
  SERVICES = 'services',
  SERVICES_HUB = 'services.hub',

  SERVICES_DEPOSITS = 'services.deposits',
  SERVICES_DEPOSITS_OVERVIEW = 'services.deposits.overview',
  SERVICES_DEPOSITS_DETAILS = 'services.deposits.details',
  SERVICES_DEPOSITS_OPEN_FD = 'services.deposits.openFd',
  SERVICES_DEPOSITS_OPEN_RD = 'services.deposits.openRd',
  SERVICES_DEPOSITS_CALCULATOR = 'services.deposits.calculator',

  SERVICES_CHEQUE = 'services.cheque',
  SERVICES_CHEQUE_HUB = 'services.cheque.hub',
  SERVICES_CHEQUE_BOOK_REQUEST = 'services.cheque.bookRequest',
  SERVICES_CHEQUE_STOP_PAYMENT = 'services.cheque.stopPayment',
  SERVICES_CHEQUE_TRACKING = 'services.cheque.tracking',
  SERVICES_CHEQUE_POSITIVE_PAY = 'services.cheque.positivePay',

  SERVICES_CERTIFICATES = 'services.certificates',
  SERVICES_CERTIFICATES_HUB = 'services.certificates.hub',
  SERVICES_CERTIFICATES_LIST = 'services.certificates.list',
  SERVICES_CERTIFICATES_BALANCE = 'services.certificates.balance',
  SERVICES_CERTIFICATES_INTEREST = 'services.certificates.interest',
  SERVICES_CERTIFICATES_SHARE = 'services.certificates.share',
  SERVICES_CERTIFICATES_HYPOTHECATION = 'services.certificates.hypothecation',
  SERVICES_CERTIFICATES_INSURANCE = 'services.certificates.insurance',
  SERVICES_CERTIFICATES_TAX = 'services.certificates.tax',
  SERVICES_CERTIFICATES_LOAN = 'services.certificates.loan',

  SERVICES_REQUESTS = 'services.requests',
  SERVICES_REQUESTS_HUB = 'services.requests.hub',

  SERVICES_STANDING_INSTRUCTIONS = 'services.standingInstructions',
  SERVICES_FORM_15G15H = 'services.form15g15h',
  SERVICES_NOMINATION = 'services.nomination',
  SERVICES_BRANCH_LOCATOR = 'services.branchLocator',

  SERVICES_AWARENESS = 'services.awareness',
  SERVICES_AWARENESS_LIST = 'services.awareness.list',
  SERVICES_AWARENESS_DETAIL = 'services.awareness.detail',

  SERVICES_PROTECTION = 'services.protection',
  SERVICES_PROTECTION_HUB = 'services.protection.hub',
  SERVICES_PROTECTION_SCHEME_DETAIL = 'services.protection.schemeDetail',
  SERVICES_PROTECTION_ENROLLMENT = 'services.protection.enrollment',
  SERVICES_PROTECTION_DEAF = 'services.protection.deaf',
  SERVICES_PROTECTION_DEAF_CLAIM = 'services.protection.deafClaim',
  SERVICES_PROTECTION_DICGC = 'services.protection.dicgc',

  SERVICES_SUPPORT_CHAT = 'services.supportChat',
  SERVICES_HELP_CENTER = 'services.helpCenter',

  /**
   * Enquiry desk: the entries that answer a question outright, or change a PIN,
   * rather than opening a journey.
   *
   * `mpinChange` and `miniStatement` gate entry points rather than screens —
   * those screens live in the profile and home stacks and keep their own keys.
   * Having a key here lets the bank take the tile off the service desk without
   * also removing the screen from where it already was.
   */
  SERVICES_BALANCE_ENQUIRY = 'services.balanceEnquiry',
  SERVICES_MINI_STATEMENT = 'services.miniStatement',
  SERVICES_MPIN_CHANGE = 'services.mpinChange',
  SERVICES_TPIN_CHANGE = 'services.tpinChange',
  SERVICES_FATE_OF_CHEQUE = 'services.fateOfCheque',

  // --------------------------------------------------------------- Loans ----
  LOANS = 'loans',
  LOANS_DASHBOARD = 'loans.dashboard',
  LOANS_TYPES = 'loans.types',
  LOANS_ELIGIBILITY = 'loans.eligibility',
  LOANS_CALCULATOR = 'loans.calculator',
  LOANS_APPLY = 'loans.apply',
  LOANS_TRACKING = 'loans.tracking',
  LOANS_ACTIVE_DETAILS = 'loans.activeDetails',
  LOANS_EMI_PAYMENT = 'loans.emiPayment',
  LOANS_FORECLOSURE = 'loans.foreclosure',
  LOANS_HISTORY = 'loans.history',
  LOANS_DOCUMENTS = 'loans.documents',

  // ----------------------------------------------------------- Insurance ----
  INSURANCE = 'insurance',
  INSURANCE_DASHBOARD = 'insurance.dashboard',
  INSURANCE_BUY = 'insurance.buy',
  INSURANCE_POLICIES = 'insurance.policies',
  INSURANCE_POLICY_DETAILS = 'insurance.policyDetails',
  INSURANCE_RENEWALS = 'insurance.renewals',
  INSURANCE_CLAIMS = 'insurance.claims',
  INSURANCE_DOCUMENTS = 'insurance.documents',
  INSURANCE_CALCULATOR = 'insurance.calculator',
  INSURANCE_COMPARISON = 'insurance.comparison',
  INSURANCE_NOTIFICATIONS = 'insurance.notifications',

  // ------------------------------------------------------------- Profile ----
  PROFILE = 'profile',
  PROFILE_MAIN = 'profile.main',
  PROFILE_EDIT = 'profile.edit',
  PROFILE_ACCOUNTS = 'profile.accounts',
  PROFILE_ACCOUNTS_ADD = 'profile.accounts.add',
  PROFILE_BENEFICIARIES_SHORTCUT = 'profile.beneficiariesShortcut',
  PROFILE_STATEMENTS_SHORTCUT = 'profile.statementsShortcut',

  PROFILE_SETTINGS = 'profile.settings',
  PROFILE_SETTINGS_LANGUAGE = 'profile.settings.language',
  PROFILE_SETTINGS_NOTIFICATIONS = 'profile.settings.notifications',
  PROFILE_SETTINGS_PRIVACY = 'profile.settings.privacy',

  PROFILE_SECURITY = 'profile.security',
  PROFILE_SECURITY_CHANGE_PIN = 'profile.security.changePin',
  PROFILE_SECURITY_CHANGE_PASSWORD = 'profile.security.changePassword',
  PROFILE_SECURITY_BIOMETRIC = 'profile.security.biometric',
  PROFILE_SECURITY_TWO_FACTOR = 'profile.security.twoFactor',
  PROFILE_SECURITY_DEVICES = 'profile.security.devices',
  PROFILE_SECURITY_LOGOUT_ALL = 'profile.security.logoutAll',
  PROFILE_SECURITY_HIDE_BALANCE = 'profile.security.hideBalance',

  PROFILE_SUPPORT = 'profile.support',
  PROFILE_LEGAL = 'profile.legal',
  PROFILE_ABOUT = 'profile.about',
  /**
   * In-app switchboard for the curated operational features.
   *
   * Ships disabled and is meant to be turned on through remote config for the
   * tenants whose staff need it — so the bank decides which installs expose it,
   * rather than it being present for every customer.
   */
  PROFILE_FEATURE_FLAGS = 'profile.featureFlags',

  // --------------------------------------------------------------- Agent ----
  AGENT = 'agent',

  AGENT_DASHBOARD = 'agent.dashboard',
  AGENT_DASHBOARD_MAIN = 'agent.dashboard.main',
  AGENT_DASHBOARD_ROUTE = 'agent.dashboard.route',

  AGENT_CUSTOMERS = 'agent.customers',
  AGENT_CUSTOMERS_LIST = 'agent.customers.list',
  AGENT_CUSTOMERS_DETAIL = 'agent.customers.detail',
  AGENT_CUSTOMERS_CREATE = 'agent.customers.create',
  AGENT_CUSTOMERS_EDIT = 'agent.customers.edit',
  AGENT_CUSTOMERS_DELETE = 'agent.customers.delete',
  AGENT_CUSTOMERS_INSTALLMENT_HISTORY = 'agent.customers.installmentHistory',

  AGENT_COLLECTIONS = 'agent.collections',
  AGENT_COLLECTIONS_DAILY = 'agent.collections.daily',
  AGENT_COLLECTIONS_HISTORY = 'agent.collections.history',
  AGENT_COLLECTIONS_RECEIPT = 'agent.collections.receipt',

  AGENT_LOANS = 'agent.loans',
  AGENT_LOANS_LIST = 'agent.loans.list',
  AGENT_LOANS_CREATE_REQUEST = 'agent.loans.createRequest',
  AGENT_LOANS_ACCOUNT_OPENING = 'agent.loans.accountOpening',
  AGENT_LOANS_COMMISSION = 'agent.loans.commission',

  AGENT_PROFILE = 'agent.profile',
  AGENT_PROFILE_MAIN = 'agent.profile.main',
  AGENT_PROFILE_SMS_HISTORY = 'agent.profile.smsHistory',
  AGENT_PROFILE_CHANGE_PASSWORD = 'agent.profile.changePassword',
}

/** Every declared feature key, in declaration order. */
export const ALL_FEATURE_KEYS = Object.values(FeatureKey) as FeatureKey[];

/** Set form, for O(1) membership checks when validating untrusted strings. */
const FEATURE_KEY_SET: ReadonlySet<string> = new Set<string>(ALL_FEATURE_KEYS);

/**
 * Narrows an arbitrary string (remote config, JSON-driven UI, deep link) to a
 * known FeatureKey. Returns `undefined` when the string is not a declared key,
 * which callers must treat as "not enabled".
 */
export const toFeatureKey = (value: string | null | undefined): FeatureKey | undefined =>
  typeof value === 'string' && FEATURE_KEY_SET.has(value) ? (value as FeatureKey) : undefined;

/**
 * Parent key of a feature, derived from its dot path.
 * `loans.apply.submit` → `loans.apply`; a root key → `undefined`.
 */
export const getParentFeatureKey = (key: FeatureKey): FeatureKey | undefined => {
  const lastDot = key.lastIndexOf('.');

  if (lastDot === -1) {
    return undefined;
  }

  return toFeatureKey(key.slice(0, lastDot));
};

/**
 * All ancestors of a key, nearest parent first.
 * `loans.apply.submit` → [`loans.apply`, `loans`].
 */
export const getFeatureAncestors = (key: FeatureKey): FeatureKey[] => {
  const ancestors: FeatureKey[] = [];
  let current = getParentFeatureKey(key);

  while (current) {
    ancestors.push(current);
    current = getParentFeatureKey(current);
  }

  return ancestors;
};