import { IChannel, IMessage, Channel, IContent, ILoggerInstance, IClientOptions } from '../../types';
import { Logger } from '../../utils/logger';
/**
 * Implementation of base channel.
 */
export declare abstract class AbstractChannel implements IChannel {
    private options;
    private token;
    private channel;
    protected logger: Logger;
    constructor(token: string, channel: Channel, loggerInstance: ILoggerInstance, options: IClientOptions);
    /**
     * This method sends the message to the channel.
     *
     * @param from The sender identifier of the message.
     * @param to The recipient identifier of the message.
     * @param contents An array of [[IContent]] object that will be sent.
     * @returns A promise that resolves to an [[IMessage]] object.
     */
    sendMessage(from: string, to: string, ...contents: IContent[]): Promise<IMessage>;
    /**
     * This method creates a message.
     *
     * @param from The sender identifier of the message.
     * @param to The recipient identifier of the message.
     * @param contents An array of [[IContent]] object that will be sent.
     * @returns An [[IMessageRequest]] object.
     */
    private createMessage;
    /**
     * This method requests to the endpoint.
     *
     * @param message An [[IMessageRequest]] object.
     * @returns A promise that resolves to an [[IMessage]] object.
     */
    private request;
    protected abstract contentSupportValidation(content: IContent): void | never;
}