import { IHttp, IMessageExtender, IPersistence, IRead } from '../accessors';
import { IMessage } from './IMessage';

/** Handler called when an App wants to enrich a message update. */
export interface IPreMessageUpdatedExtend {
    /**
     * Enables the handler to signal to the Apps framework whether
     * this handler should actually be executed for the message
     * about to be updated.
     *
     * @param message The message which is being updated
     * @param read An accessor to the environment
     * @param http An accessor to the outside world
     * @returns whether to run the execute or not
     */
    checkPreMessageUpdatedExtend?(message: IMessage, read: IRead, http: IHttp): Promise<boolean>;

    /**
     * Method which is to be used to non-destructively enrich the updated message.
     *
     * @param message The message about to be updated
     * @param extend An accessor for modifying the message non-destructively
     * @param read An accessor to the environment
     * @param http An accessor to the outside world
     * @param persistence An accessor to the App's persistence storage
     * @returns the resulting message
     */
    executePreMessageUpdatedExtend(message: IMessage, extend: IMessageExtender, read: IRead, http: IHttp, persistence: IPersistence): Promise<IMessage>;
}