function normalizeText(value: unknown): string | null {
  if (typeof value !== 'string') {
    return null
  }
  const trimmed = value.trim()
  return trimmed ? trimmed : null
}

function normalizeURLPath(pathname: string): string {
  const normalized = pathname.replace(/\/+$/, '')
  return normalized === '/' ? '' : normalized
}

function safeParseURL(input: string): URL | null {
  try {
    return new URL(input)
  } catch {
    return null
  }
}

function genericAIConversationPath(pathname: string): boolean {
  return /^\/(?:chat|c|conversation)(?:\/|$)/i.test(pathname)
}

export interface GenericAIPageState {
  displayName: string | null
  avatarUrl: string | null
  fingerprint: string | null
  credentialFingerprint: string | null
  currentPath: string | null
  strongAuthSignalCount: number
  loginSignalCount: number
  loggedOutSignalCount: number
  challengeSignalCount: number
}

export function isLikelyGenericAICredentialName(name: string): boolean {
  const normalized = name.trim().toLowerCase()
  if (!normalized) {
    return false
  }

  if (/(?:^|[-_.])(?:x[-_]?csrf|xsrf|csrf)(?:[-_]?token)?(?:$|[-_.])/.test(normalized)) {
    return false
  }

  if (
    /(?:^|[-_.])(?:slardar|analytics|monitor|telemetry|trace|tracing|log|logger|sentry|rum|perf|performance|abtest|experiment|visitor|guest|anonymous|device|webid|web_id|ttwid|hook|mstoken|ms_token|odin_tt|s_v_web_id|__ac_nonce|__ac_signature)(?:$|[-_.])/i.test(
      normalized,
    )
  ) {
    return false
  }

  return /(token|session|auth|login|passport|ticket|jwt|refresh|access|sso)/i.test(normalized)
}

export function isLikelyGenericAICredentialValue(value: string | null | undefined): boolean {
  const normalized = normalizeText(value)
  if (!normalized) {
    return false
  }

  if (/^(true|false|null|undefined|0|1)$/i.test(normalized)) {
    return false
  }

  return normalized.length >= 8
}

export function genericAIHasVisibleAccountSignal(pageState: GenericAIPageState | null): boolean {
  return (
    Boolean(pageState?.displayName || pageState?.avatarUrl) ||
    (pageState?.strongAuthSignalCount ?? 0) >= 2
  )
}

export function genericAIPlatformRequiresVisibleCredentialSignal(platformId: string): boolean {
  const normalizedPlatformId = platformId.trim().toLowerCase()
  return normalizedPlatformId === 'qwen'
}

export function isLikelyPlatformAICredentialCookie(
  platformId: string,
  name: string,
  value: string | null | undefined,
  pageState?: GenericAIPageState | null,
): boolean {
  const normalizedPlatformId = platformId.trim().toLowerCase()
  const hasVisibleAccountSignal = genericAIHasVisibleAccountSignal(pageState ?? null)

  if (normalizedPlatformId === 'doubao' || normalizedPlatformId === 'kimi') {
    return false
  }

  if (!isLikelyGenericAICredentialName(name) || !isLikelyGenericAICredentialValue(value)) {
    return false
  }

  if (
    genericAIPlatformRequiresVisibleCredentialSignal(platformId) &&
    !hasVisibleAccountSignal
  ) {
    return false
  }

  return true
}

export function genericAIPageLooksAuthenticated(
  currentURL: string,
  pageState: GenericAIPageState | null,
): boolean {
  const current = safeParseURL(currentURL)
  const currentPath = normalizeURLPath(current?.pathname ?? pageState?.currentPath ?? '')
  const strongAuthSignalCount = pageState?.strongAuthSignalCount ?? 0
  const loginSignalCount = pageState?.loginSignalCount ?? 0
  const loggedOutSignalCount = pageState?.loggedOutSignalCount ?? 0
  const challengeSignalCount = pageState?.challengeSignalCount ?? 0
  const hasCredentialFingerprint = Boolean(normalizeText(pageState?.credentialFingerprint))
  const onConversationPath = genericAIConversationPath(currentPath)

  if (challengeSignalCount > 0) {
    return false
  }

  if (loggedOutSignalCount > 0) {
    return false
  }

  if (
    loginSignalCount > 0 &&
    strongAuthSignalCount === 0 &&
    !onConversationPath &&
    !hasCredentialFingerprint
  ) {
    return false
  }

  if (loginSignalCount > 0) {
    return (strongAuthSignalCount >= 2 || hasCredentialFingerprint) && !onConversationPath
  }

  return strongAuthSignalCount > 0 || hasCredentialFingerprint
}