import { type Configuration, type ConnectionOptions } from '../utils/Configuration.js';
import type { LogContext, Logger } from '../logging/Logger.js';
import type { MetadataStorage } from '../metadata/MetadataStorage.js';
import type { ConnectionType, Dictionary, MaybePromise, Primary, RoutineProperty } from '../typings.js';
import type { Routine } from '../metadata/Routine.js';
import type { Platform } from '../platforms/Platform.js';
import type { Type } from '../types/Type.js';
import type { TransactionEventBroadcaster } from '../events/TransactionEventBroadcaster.js';
import type { IsolationLevel } from '../enums.js';
/** Abstract base class for database connections, providing transaction and query execution support. */
export declare abstract class Connection {
    #private;
    protected readonly config: Configuration;
    protected readonly type: ConnectionType;
    protected metadata: MetadataStorage;
    protected platform: Platform;
    protected readonly options: ConnectionOptions;
    protected readonly logger: Logger;
    protected connected: boolean;
    constructor(config: Configuration, options?: ConnectionOptions, type?: ConnectionType);
    /**
     * Establishes connection to database
     */
    abstract connect(options?: {
        skipOnConnect?: boolean;
    }): void | Promise<void>;
    /**
     * Are we connected to the database
     */
    abstract isConnected(): Promise<boolean>;
    /**
     * Are we connected to the database
     */
    abstract checkConnection(): Promise<{
        ok: true;
    } | {
        ok: false;
        reason: string;
        error?: Error;
    }>;
    /**
     * Closes the database connection (aka disconnect)
     */
    close(force?: boolean): Promise<void>;
    /**
     * Ensure the connection exists, this is used to support lazy connect when using `new MikroORM()` instead of the async `init` method.
     */
    ensureConnection(): Promise<void>;
    /**
     * Execute raw SQL queries, handy from running schema dump loaded from a file.
     * This method doesn't support transactions, as opposed to `orm.schema.execute()`, which is used internally.
     */
    executeDump(dump: string): Promise<void>;
    protected onConnect(): Promise<void>;
    /** Executes a callback inside a transaction, committing on success and rolling back on failure. */
    transactional<T>(cb: (trx: Transaction) => Promise<T>, options?: {
        isolationLevel?: IsolationLevel | `${IsolationLevel}`;
        readOnly?: boolean;
        ctx?: Transaction;
        eventBroadcaster?: TransactionEventBroadcaster;
        loggerContext?: LogContext;
    }): Promise<T>;
    /** Begins a new database transaction and returns the transaction context. */
    begin(options?: {
        isolationLevel?: IsolationLevel | `${IsolationLevel}`;
        readOnly?: boolean;
        ctx?: Transaction;
        eventBroadcaster?: TransactionEventBroadcaster;
        loggerContext?: LogContext;
    }): Promise<Transaction>;
    /** Commits the given transaction. */
    commit(ctx: Transaction, eventBroadcaster?: TransactionEventBroadcaster, loggerContext?: LogContext): Promise<void>;
    /** Rolls back the given transaction. */
    rollback(ctx: Transaction, eventBroadcaster?: TransactionEventBroadcaster, loggerContext?: LogContext): Promise<void>;
    /** Executes a raw query and returns the result. */
    abstract execute<T>(query: string, params?: any[], method?: 'all' | 'get' | 'run', ctx?: Transaction): Promise<QueryResult<T> | any | any[]>;
    /** @internal — public callers go through {@link EntityManager.callRoutine}. */
    callRoutine<T>(routine: Routine, args: Record<string, unknown>, ctx?: Transaction): Promise<T>;
    /**
     * Unwraps a routine argument (resolving any `ScalarReference` wrapper) and, when the param
     * declares a `customType`, marshals it through `convertToDatabaseValue`. `undefined` is
     * normalised to `null` so every driver sees the same shape.
     *
     * @internal
     */
    protected convertRoutineInbound(value: unknown, param: RoutineProperty | undefined): unknown;
    /**
     * Converts a raw database value to its JS representation via the supplied `customType`, when
     * one is declared. Used to marshal scalar function returns and OUT/INOUT values back to the
     * caller before they land in a `ScalarReference` or `em.callRoutine`'s return value.
     *
     * @internal
     */
    protected convertRoutineOutbound<T>(value: unknown, customType: Type<unknown> | undefined): T;
    /**
     * Executes a scalar function routine as `select <qualified>(?, ?, ...) as value`, marshalling
     * IN params on the way in and the return value on the way out. The qualified name is built
     * from `routine.schema`, falling back to the platform's default schema (e.g. `dbo` on MSSQL),
     * which gives MySQL/SQLite a bare name and MSSQL/Oracle the mandatory `schema.name` form.
     *
     * @internal
     */
    protected callRoutineFunction<T>(routine: Routine, args: Record<string, unknown>, ctx?: Transaction): Promise<T>;
    /**
     * Walks a result row produced by an OUT/INOUT-param SELECT and writes each value into the
     * caller's `ScalarReference` slot. Non-reference args are ignored (the user opted out of
     * receiving the OUT value).
     *
     * @internal
     */
    protected applyRoutineOutParams(row: Dictionary, outParams: RoutineProperty[], args: Record<string, unknown>): void;
    /** Parses and returns the resolved connection configuration (host, port, user, etc.). */
    getConnectionOptions(): ConnectionConfig;
    /** Sets the metadata storage on this connection. */
    setMetadata(metadata: MetadataStorage): void;
    /** Sets the platform abstraction on this connection. */
    setPlatform(platform: Platform): void;
    /** Returns the platform abstraction for this connection. */
    getPlatform(): Platform;
    protected executeQuery<T>(query: string, cb: () => Promise<T>, context?: LogContext): Promise<T>;
    protected logQuery(query: string, context?: LogContext): void;
}
/** Result of a native database query (insert, update, delete). */
export interface QueryResult<T = {
    id: number;
}> {
    affectedRows: number;
    insertId: Primary<T>;
    row?: Dictionary;
    rows?: Dictionary[];
    insertedIds?: Primary<T>[];
}
/** Resolved database connection parameters. */
export interface ConnectionConfig {
    host?: string;
    port?: number;
    user?: string;
    password?: string | (() => MaybePromise<string>);
    database?: string;
    schema?: string;
}
/** Opaque transaction context type, wrapping the driver-specific transaction object. */
export type Transaction<T = any> = T & {};
/**
 * Strategy applied when an `AbortSignal` fires while a query is in flight.
 *
 * - `'ignore query'` — stop awaiting; the query keeps running on the server until it settles
 *   (the connection returns to the pool only when the database replies).
 * - `'cancel query'` — ask the database to cancel the running query (e.g. `pg_cancel_backend`,
 *   `KILL QUERY`). Falls back to `'ignore query'` if the dialect cannot cancel.
 *   Most engines do not cancel writes; partial commits are possible.
 * - `'kill session'` — terminate the database session/process the query runs in
 *   (`pg_terminate_backend` etc.). Falls back to `'cancel query'` if not supported.
 *
 * Default: `'ignore query'`.
 *
 * **Streaming queries (`em.stream()` / `qb.stream()`):** the strategy is silently treated as
 * `'ignore query'` because the underlying driver only accepts a plain `AbortSignal` for
 * streamed reads — there is no server-side cancel for an open cursor. The MongoDB driver also
 * has no notion of strategies; only the signal is honored there.
 */
export type InflightQueryAbortStrategy = 'ignore query' | 'cancel query' | 'kill session';
/** Per-query cancellation controls forwarded to the underlying driver. */
export interface AbortQueryOptions {
    /** AbortSignal that cancels the query when fired. */
    signal?: AbortSignal;
    /**
     * Strategy used when the signal fires while the query is in flight. See
     * {@apilink InflightQueryAbortStrategy} for caveats around streams and MongoDB.
     */
    inflightQueryAbortStrategy?: InflightQueryAbortStrategy;
}