import { createHash } from 'node:crypto';

import { IdentifierType } from './types';
import {
  normalizeEmail,
  normalizePhone,
  normalizeLegalName,
  normalizeCardNumber,
  normalizePaymentAppId,
  normalizeCanvasFp,
  normalizeWebglFp,
  normalizeAudioFp,
  normalizeWebrtcLocalIp,
  normalizeScreenGeometry,
  normalizeTimezoneLocale,
  normalizeFontSet,
  normalizeHardwareProfile,
  normalizeTypingCadence,
  normalizeMouseDynamics,
} from './normalizers';

/**
 * Normalize an identifier value according to its type before hashing.
 *
 * Dispatches to the appropriate type-specific normalizer, ensuring
 * consistent matching regardless of input formatting.
 */
export function normalizeIdentifier(type: IdentifierType, value: string): string {
  switch (type) {
    case IdentifierType.EMAIL:
      return normalizeEmail(value);
    case IdentifierType.PHONE:
      return normalizePhone(value);
    case IdentifierType.LEGAL_NAME:
      return normalizeLegalName(value);
    case IdentifierType.CARD_HASH:
      return normalizeCardNumber(value);
    case IdentifierType.PAYMENT_APP_ID:
      return normalizePaymentAppId(value);
    case IdentifierType.DEVICE_FP:
    case IdentifierType.IP_ADDRESS:
    case IdentifierType.USERNAME:
      return value.trim().toLowerCase();
    case IdentifierType.CANVAS_FP:
      return normalizeCanvasFp(value);
    case IdentifierType.WEBGL_FP:
      return normalizeWebglFp(value);
    case IdentifierType.AUDIO_FP:
      return normalizeAudioFp(value);
    case IdentifierType.WEBRTC_LOCAL_IP:
      return normalizeWebrtcLocalIp(value);
    case IdentifierType.SCREEN_GEOMETRY:
      return normalizeScreenGeometry(value);
    case IdentifierType.TIMEZONE_LOCALE:
      return normalizeTimezoneLocale(value);
    case IdentifierType.FONT_SET:
      return normalizeFontSet(value);
    case IdentifierType.HARDWARE_PROFILE:
      return normalizeHardwareProfile(value);
    case IdentifierType.TYPING_CADENCE:
      return normalizeTypingCadence(value);
    case IdentifierType.MOUSE_DYNAMICS:
      return normalizeMouseDynamics(value);
  }
}

/**
 * Hash an identifier value using SHA-256 after normalization.
 *
 * The pepper MUST be provided as a parameter — this function has
 * no dependency on environment variables or NestJS config.
 *
 * @param type - The identifier type (determines normalization strategy)
 * @param value - The raw identifier value
 * @param pepper - Secret pepper value for hash salting
 * @returns Hex-encoded SHA-256 hash of the normalized value + pepper
 */
export function hashIdentifier(type: IdentifierType, value: string, pepper: string): string {
  const normalized = normalizeIdentifier(type, value);
  return createHash('sha256')
    .update(normalized + pepper)
    .digest('hex');
}