/**
 * Writing-style-matched draft reply composer.
 *
 * This module is PURE and DETERMINISTIC, no Date.now(), Math.random(),
 * or I/O.  It takes a corpus of prior sent messages and an inbound message
 * and produces a draft body that mirrors the user's writing style.
 *
 * BEFORE-SEND REVIEW BOUNDARY
 * ──────────────────────────────────────────────────────────────────────────
 * This composer produces a DRAFT only.  No send path is included here.
 * Delivery MUST go through the existing confirmed SMTP / connector send
 * route (EmailService.sendMail with confirm:true, or the equivalent MCP
 * connector action with explicit user confirmation).  The lane descriptor
 * in style-reply-lane.ts enforces this boundary at the Personal Ops level.
 *
 * The secret-like-text check is injected rather than imported: which strings
 * count as credentials is a product policy, and the composer must run against
 * whichever predicate the surface already uses on the rest of its text.
 */
import type { SecretLikeTextPredicate } from '../google/account-registry.js';
import type { EmailSummary } from './email-service.js';
export interface StyleProfile {
    /** Most common greeting prefix found in sent messages, e.g. 'Hi', 'Hello', 'Hey'. */
    readonly greeting: string;
    /** Most common sign-off found in sent messages, e.g. 'Thanks', 'Best', 'Cheers'. */
    readonly signOff: string;
    /** Median sentence count across sent messages (whole number, ≥1). */
    readonly medianSentenceCount: number;
    /** Dominant tone inferred from token analysis: 'formal' | 'casual' | 'neutral'. */
    readonly tone: 'formal' | 'casual' | 'neutral';
    /** True when the corpus is empty, all values are defaults. */
    readonly isDefault: boolean;
}
/**
 * Count how many sentences a text body contains.
 * Splits on '. ', '! ', '? ' and trailing punctuation.
 * Returns at least 1 for any non-empty string.
 */
export declare function countSentences(text: string): number;
/**
 * Compute the median of a sorted number array.
 * Returns `fallback` when the array is empty.
 */
export declare function median(sorted: readonly number[], fallback: number): number;
/**
 * Find the most frequently occurring token in a list.
 * When there are ties, the token appearing earliest in `candidates` wins.
 * Returns `fallback` when no candidates match.
 */
export declare function mostFrequent(corpus: readonly string[], candidates: readonly string[], fallback: string): string;
/**
 * Classify tone from a corpus of message bodies.
 * Returns 'formal', 'casual', or 'neutral'.
 */
export declare function classifyTone(bodies: readonly string[]): 'formal' | 'casual' | 'neutral';
/**
 * Extract a StyleProfile from a corpus of the user's prior sent messages.
 *
 * When `sentMessages` is empty, returns a neutral default profile.
 * Never reads the clock; fully deterministic.
 */
export declare function extractStyleProfile(sentMessages: readonly EmailSummary[]): StyleProfile;
export interface DraftReplyResult {
    /** Fully composed draft body. Never includes credentials or secret-looking text. */
    readonly body: string;
    /** The style profile used to compose this draft. */
    readonly profile: StyleProfile;
    /** Subject line for the reply, prefixed with 'Re: ' if not already. */
    readonly subject: string;
    /** BEFORE-SEND REVIEW BOUNDARY: always true, this is a draft, never auto-sent. */
    readonly requiresBeforeSendReview: true;
    /** Human-readable reminder of the review boundary. */
    readonly reviewBoundary: string;
}
/**
 * Compose a draft reply to `inbound` in the user's style as described by
 * `profile`.  An optional `context` string (e.g. key points the user wants
 * to include) is woven into the body.
 *
 * SAFETY GUARANTEES
 * - Throws if the composed body or context contains secret-like text.
 * - Never sends, returns a DraftReplyResult with requiresBeforeSendReview: true.
 * - No Date.now() / Math.random(), deterministic output for a given input.
 *
 * @param inbound   The email the user received and wants to reply to.
 * @param profile   Writing-style profile extracted from prior sent messages.
 * @param context   Key points / instructions to fold into the draft body; '' for none.
 * @param containsSecretLikeText  The surface's own credential-shaped-text
 *   predicate. Required rather than defaulted: a default would have to be
 *   permissive, and a permissive default here silently disables the check.
 */
export declare function composeDraftReply(inbound: EmailSummary, profile: StyleProfile, context: string, containsSecretLikeText: SecretLikeTextPredicate): DraftReplyResult;
/**
 * Extract a first name from an RFC-5322-style From header value.
 * Handles both "Display Name <addr>" and "addr" forms.
 * Returns empty string when no usable name is found.
 */
export declare function extractSenderName(from: string): string;
/** Ensure subject is prefixed with 'Re: ' exactly once. */
export declare function replySubject(subject: string): string;
//# sourceMappingURL=style-reply.d.ts.map