import { type ClickHouseClient, type ClickHouseClientConfigOptions } from "@clickhouse/client";
/**
 * Construction options for {@link createFjallClickHouseClient}.
 *
 * Every field is optional. `url` falls back to `process.env.CLICKHOUSE_URL`;
 * `caCert` falls back to `process.env.CLICKHOUSE_CA_CERT`. Empty strings
 * are treated identically to `undefined` on both — dev compose without a
 * CA cert injected boots transparently in plaintext, while prod ECS
 * containers receive the CA PEM via the secret-block on `secretsImport`
 * and run on `https://`.
 */
export interface CreateFjallClickHouseClientOptions {
    /** Defaults to env CLICKHOUSE_URL. Empty/undefined throws. */
    readonly url?: string;
    /**
     * Defaults to env CLICKHOUSE_CA_CERT (PEM string injected by the ECS
     * `secrets:` block from `ClickHouseDatabase.tlsCaSecret`). Absent/empty
     * disables the `tls:` config (plaintext fallback for dev compose).
     */
    readonly caCert?: string;
    readonly username?: string;
    readonly password?: string;
    /** Optional database name override. */
    readonly database?: string;
    /** Merged over {@link WIRE_FORMAT_CLICKHOUSE_SETTINGS}; caller keys win. */
    readonly clickhouse_settings?: ClickHouseClientConfigOptions["clickhouse_settings"];
    readonly compression?: ClickHouseClientConfigOptions["compression"];
    readonly request_timeout?: number;
    readonly max_open_connections?: number;
    readonly keep_alive?: ClickHouseClientConfigOptions["keep_alive"];
}
/**
 * The Fjall wire-format contract, applied to every client this factory
 * builds: DateTime/DateTime64 columns serialise as RFC3339 instants with a
 * timezone designator (`2026-08-23T01:23:45.678Z`), so consumers may
 * `new Date(value)` any timestamp the server returns — no bespoke parser.
 * Inputs stay tolerant (`best_effort` accepts both the ISO shape and the
 * legacy `YYYY-MM-DD hh:mm:ss` form).
 *
 * Asymmetry to know: typed query PARAMETERS (`{x:DateTime64(3)}`) are bound
 * by a separate parser that rejects a trailing `Z` regardless of
 * `date_time_input_format` — keep formatting bind parameters without the
 * designator (ClickHouse 26.3, verified).
 *
 * Caller-supplied `clickhouse_settings` spread AFTER these, so a caller can
 * override either setting deliberately.
 */
export declare const WIRE_FORMAT_CLICKHOUSE_SETTINGS: {
    readonly date_time_output_format: "iso";
    readonly date_time_input_format: "best_effort";
};
/**
 * Sync factory wrapping `@clickhouse/client`'s `createClient`. No AWS SDK
 * call, no `await`, no module-level cache — the CA PEM is already on
 * `process.env` when the container's user code runs because ECS resolves
 * the `secrets:` block during container bring-up.
 *
 * `tls.ca_cert` MUST be a `Buffer` per the `@clickhouse/client` contract.
 * Passing a raw string type-checks (the field accepts `Buffer | string`
 * structurally) but the underlying TLS stack silently skips the
 * trust-store add and the handshake fails downstream. Wrap explicitly
 * with `Buffer.from(pem, "utf8")`.
 */
export declare function createFjallClickHouseClient(opts?: CreateFjallClickHouseClientOptions): ClickHouseClient;