/**
 * @fileoverview Defines types and interfaces for the DuckDB service.
 * @module services/duck-db/types
 */
import * as duckdb from "@duckdb/node-api";
/**
 * Configuration options for initializing the DuckDB service.
 */
export interface DuckDBServiceConfig {
    /**
     * The path to the database file.
     * Use ':memory:' for an in-memory database.
     * If undefined, defaults to an in-memory database.
     */
    dbPath?: string;
    /**
     * Optional DuckDB launch configurations.
     * Refer to DuckDB documentation for available options.
     * Example: { allow_unsigned_extensions: 'true' }
     */
    launchConfig?: Record<string, string>;
    /**
     * List of extensions to install and load upon initialization.
     * Example: ['httpfs', 'json']
     */
    extensions?: string[];
}
/**
 * Represents a query to be executed.
 */
export interface DuckDBQuery {
    sql: string;
    params?: unknown[];
}
/**
 * Represents the result of a query execution.
 */
export interface DuckDBQueryResult<T = Record<string, unknown>> {
    rows: T[];
    columnNames: string[];
    columnTypes: duckdb.DuckDBTypeId[];
    rowCount: number;
}
/**
 * Interface for the DuckDB service.
 */
export interface IDuckDBService {
    /**
     * Initializes the DuckDB service with the given configuration.
     * Must be called before any other operations.
     * @param {DuckDBServiceConfig} config - The configuration for the DuckDB service.
     * @returns {Promise<void>}
     * @throws {McpError} If initialization fails.
     */
    initialize(config?: DuckDBServiceConfig): Promise<void>;
    /**
     * Executes a SQL query that does not return a large result set (e.g., CREATE, INSERT, UPDATE, DELETE).
     * @param {string} sql - The SQL query string.
     * @param {unknown[]} [params] - Optional parameters for the query.
     * @returns {Promise<void>}
     * @throws {McpError} If the query fails or the service is not initialized.
     */
    run(sql: string, params?: unknown[]): Promise<void>;
    /**
     * Executes a SQL query and returns all resulting rows.
     * Suitable for queries that return a manageable number of rows.
     * @template T - The expected type of the row objects.
     * @param {string} sql - The SQL query string.
     * @param {unknown[]} [params] - Optional parameters for the query.
     * @returns {Promise<DuckDBQueryResult<T>>} The query result.
     * @throws {McpError} If the query fails or the service is not initialized.
     */
    query<T = Record<string, unknown>>(sql: string, params?: unknown[]): Promise<DuckDBQueryResult<T>>;
    /**
     * Executes a SQL query and provides a streaming result reader.
     * Suitable for queries that return very large result sets.
     * The caller is responsible for closing the stream.
     * @param {string} sql - The SQL query string.
     * @param {unknown[]} [params] - Optional parameters for the query.
     * @returns {Promise<duckdb.DuckDBStreamingResult>} A streaming result object.
     * @throws {McpError} If the query fails or the service is not initialized.
     */
    stream(sql: string, params?: unknown[]): Promise<duckdb.DuckDBResult>;
    /**
     * Creates a prepared statement.
     * @param {string} sql - The SQL query string for the prepared statement.
     * @returns {Promise<duckdb.DuckDBPreparedStatement>} The prepared statement object.
     * @throws {McpError} If preparing the statement fails or the service is not initialized.
     */
    prepare(sql: string): Promise<duckdb.DuckDBPreparedStatement>;
    /**
     * Begins a new transaction.
     * @returns {Promise<void>}
     * @throws {McpError} If starting the transaction fails or the service is not initialized.
     */
    beginTransaction(): Promise<void>;
    /**
     * Commits the current transaction.
     * @returns {Promise<void>}
     * @throws {McpError} If committing the transaction fails or the service is not initialized.
     */
    commitTransaction(): Promise<void>;
    /**
     * Rolls back the current transaction.
     * @returns {Promise<void>}
     * @throws {McpError} If rolling back the transaction fails or the service is not initialized.
     */
    rollbackTransaction(): Promise<void>;
    /**
     * Installs and loads a DuckDB extension.
     * @param {string} extensionName - The name of the extension to install and load.
     * @returns {Promise<void>}
     * @throws {McpError} If installing or loading the extension fails or the service is not initialized.
     */
    loadExtension(extensionName: string): Promise<void>;
    /**
     * Closes the DuckDB connection and instance.
     * @returns {Promise<void>}
     * @throws {McpError} If closing fails.
     */
    close(): Promise<void>;
    /**
     * Gets the underlying DuckDB connection object.
     * Use with caution, primarily for advanced scenarios not covered by the service interface.
     * @returns {duckdb.DuckDBConnection | null} The connection object, or null if not initialized.
     */
    getRawConnection(): duckdb.DuckDBConnection | null;
    /**
     * Gets the underlying DuckDB instance object.
     * Use with caution, primarily for advanced scenarios not covered by the service interface.
     * @returns {duckdb.DuckDBInstance | null} The instance object, or null if not initialized.
     */
    getRawInstance(): duckdb.DuckDBInstance | null;
}