import * as pg from "pg";

declare class Pool<T extends pg.Client> extends pg.Pool {
    readonly Client: Pool.ClientLikeCtr<T>;

    constructor(config?: Pool.Config<T>, client?: Pool.ClientLikeCtr<T>);

    connect(): Promise<T & pg.PoolClient>;
    connect(callback: (err?: Error, client?: T & pg.PoolClient, done?: (release?: any) => void) => void): void;

    on<K extends "error" | "release" | "connect" | "acquire" | "remove">(
        event: K,
        listener: K extends "error" | "release" ? (err: Error, client: T & pg.PoolClient) => void
            : (client: T & pg.PoolClient) => void,
    ): this;
}

declare namespace Pool {
    type ClientLikeCtr<T extends pg.Client> = new(config?: string | pg.ClientConfig) => T;

    interface Config<T extends pg.Client> extends pg.PoolConfig {
        Client?: ClientLikeCtr<T> | undefined;
    }
}

export = Pool;