import { type Locale } from './i18n.js';
/** Pure decision: is the user pinned to the bottom of a scroll container?
 *  Threshold defaults to 80px — small enough that a user who has genuinely
 *  scrolled up to read history is not jolted, large enough that subpixel
 *  rounding (font-size, line-height, scrollbar gutter) does not flip the
 *  decision frame-to-frame. */
export interface ShouldAutoScrollArgs {
    readonly scrollTop: number;
    readonly scrollHeight: number;
    readonly clientHeight: number;
    readonly thresholdPx?: number;
}
export declare function shouldAutoScroll(args: ShouldAutoScrollArgs): boolean;
/** Short, stable display fallback when a peer didn't claim a nick.
 *  Last 6 chars of the peerId — UUIDs end in random hex so the suffix
 *  distinguishes peers in a small room without leaking the full
 *  identifier into the transcript. */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function shortFromPeerId(peerId: string): string;
export interface MessageLike {
    from: string;
    nick?: string;
    ts: number;
}
/** Author-chain detection — consecutive messages from the same peer/nick
 *  within a short window collapse the from-label and tighten vertical
 *  spacing, mirroring iMessage / Telegram desktop. */
export declare function isChained(prev: MessageLike | undefined, curr: MessageLike): boolean;
export declare function formatTime(ts: number): string;
/** Format a millisecond duration as mm:ss (e.g. 0:00). */
export declare function formatDuration(ms: number): string;
/** Format remaining time until a wall-clock expiry timestamp.
 *  - >= 1h: `Hh Mm` (e.g. `2h 15m`)
 *  - >= 1m: `Mm Ss` (e.g. `15m 30s`)
 *  - <= 1m, > 0:  `Ss` (e.g. `30s`)
 *  - <= 0: `expired`
 *  Pure — exported so unit tests can pin every boundary. */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function formatTimeRemaining(remainMs: number): string;
/** Tombstone replacement text — same wording for both scopes
 *  (see Task 5 spec; scope is informational, identical visuals).
 *  i18n follow-up: `lang` defaults to 'en' so every existing call site (and
 *  the direct-import unit tests) keeps working without a signature change. */
export declare function tombstoneText(_scope: "self" | "everyone", lang?: Locale): string;
/** U2: Failed-decrypt placeholder text (visible) — same wording regardless of
 *  the SDK's unsealError reason ('replay' | 'auth' | 'unknown'). Mirrors
 *  tombstoneText's one-wording-for-all-cases precedent: the UI doesn't need
 *  to expose crypto failure-class detail to the end user, only that the
 *  content is unavailable. Lock glyph gives a visual cue distinct from the
 *  plain-italic tombstone. i18n follow-up: routed through the widget's
 *  locale table (see ./i18n.ts) — `lang` defaults to 'en'. */
export declare function unsealErrorText(lang?: Locale): string;
/** U2 review-fix: aria/screen-reader variant of unsealErrorText() — same
 *  wording, no lock glyph. VoiceOver/NVDA announce U+1F512 as "locked", so
 *  the glyph-bearing string would read as "locked This message couldn't be
 *  decrypted" — redundant once the words themselves are spoken. The glyph is
 *  a visual-only affordance; keep it out of the announced text. */
export declare function unsealErrorAriaText(lang?: Locale): string;
/**
 * Guarded self/other identity compare — the single source of truth for every
 * self-identity check in message-list.ts (bubble alignment, aria-label,
 * reaction "own" state). Returns false whenever selfUid is unresolved (empty
 * string), so a row can never false-positive as "self" merely because both
 * senderUid and selfUid happen to be empty — mirrors hasOwnHeart's non-empty
 * guard below. Extracted after an independent audit found 4 separate inline
 * `===`/`includes` compares in message-list.ts that could drift (sibling gap
 * to PR #39's selfUidFromJwt fix).
 */
export declare function isSelf(senderUid: string, selfUid: string): boolean;
/** Does the current user have a ❤️ reaction on the given message?
 *  Pure helper so the heart-fill state is unit-testable without
 *  mounting Svelte. Tuple shape mirrors the hook view. */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function hasOwnHeart(reactions: ReadonlyArray<readonly [string, ReadonlyArray<string>]> | undefined, selfPeerId: string): boolean;
/** Defense-in-depth on the render boundary. Images ride inline as
 *  `data:image/...` URLs; the schema only types `url: string.min(1)`
 *  so a hostile peer could substitute an https:// URL and weaponize
 *  the renderer into a tracking pixel that leaks the receiver's IP
 *  past whatever TURN relay was protecting it. We refuse anything
 *  but a data:image/ URL on display. */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function isSafeImageUrl(url: string | undefined): boolean;
/** Same threat-model guard for voice attachments. Only data:audio/ URLs
 *  are rendered — https:// would leak the receiver's IP to a tracking
 *  server past the TURN relay (same concern as isSafeImageUrl). */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function isSafeAudioUrl(url: string | undefined): boolean;
/** CSS.escape with a conservative regex fallback for older test runtimes
 *  that may not expose `CSS.escape`. msgIds are UUIDs in practice so this
 *  is a defense-in-depth path. */
/** @internal Not part of the package's public API surface; not re-exported from index.ts. Kept exported for cross-file use within the package. */
export declare function cssEscape(s: string): string;
//# sourceMappingURL=list-helpers.d.ts.map