/**
 * Shared utilities for querying per-stream per-device data presence
 * via the analytics SQL backend.
 *
 * Uses a UNION ALL across all telemetry tables to discover what data
 * exists, grouped by (device_id, stream_name, stream_type).
 */
/**
 * Escape a string for safe interpolation into a SQL single-quoted literal.
 * Replaces single quotes with two single quotes.
 */
export declare function escapeSQL(value: string): string;
export interface StreamPresenceRow {
    data_points: number;
    device_id: string;
    first_seen: string;
    last_seen: string;
    stream_name: string;
    stream_type: string;
}
/**
 * Build a SQL query that returns per-stream per-device data presence.
 *
 * Returns columns: device_id, stream_name, stream_type, data_points, first_seen, last_seen
 */
export declare function buildPresenceSQL(options: {
    days?: number;
    deviceIds?: string[];
    limit?: number;
    streamNames?: string[];
    streamTypes?: string[];
}): string;
/**
 * Build a SQL query that returns the last time any data was seen per device.
 *
 * Returns columns: device_id, last_seen, total_points, stream_count
 */
export declare function buildLastSeenSQL(options: {
    days?: number;
    deviceIds?: string[];
}): string;
/**
 * Normalize a timestamp string from analytics SQL (e.g. "2026-02-19 23:37:04.747")
 * to ISO 8601 format ("2026-02-19T23:37:04.747Z").
 */
export declare function toIsoDateTime(sqlTimestamp: string): string;
/**
 * Freshness label based on how recently data was seen.
 */
export type FreshnessLevel = 'active' | 'dormant' | 'recent' | 'stale';
export declare function getFreshness(lastSeenIso: string): FreshnessLevel;