import { AssistantLanguage } from './languages';
export interface AssistantLanguagePair {
    /** What the user speaks or types. Drives the recogniser. */
    input: AssistantLanguage;
    /** What the assistant answers in. Drives the prompt directive and the voice. */
    reply: AssistantLanguage;
    /**
     * A human chose this reply language, rather than it being guessed.
     *
     * `buildLanguagePreamble` uses this to decide whether the language the user
     * WROTE IN overrides their setting. For a guess it should — what they typed is
     * better evidence than the interface language. For a choice it must not, or
     * the preference is inert for everyone who types rather than dictates.
     *
     * ★ True when EITHER field was pinned, not only the reply field. Someone who
     * picked Tamil before this setting existed has `replyLanguage` null and means
     * "answer me in Tamil"; reading only the reply field would decide they never
     * chose anything and hand their setting back to the mirror clause — silently
     * re-breaking, for every existing user, the exact bug that clause was written
     * to fix.
     *
     * False only when NOTHING was pinned and the language came from the interface.
     *
     * Resolved rather than merely non-null, so a stale persisted code from a build
     * that offered more languages is not mistaken for a decision.
     */
    replyIsExplicit: boolean;
}
export declare function resolveLanguagePair(inputCode: string | null | undefined, replyCode: string | null | undefined, appLocale: string): AssistantLanguagePair;
/**
 * Does the reply language follow the input, or has it been pinned?
 *
 * The selector shows "Match my language" for the former, and it is the default.
 */
export declare function replyFollowsInput(replyCode: string | null | undefined): boolean;
//# sourceMappingURL=languagePair.d.ts.map