Rocket.Chat/packages/apps/deno-runtime/handlers/slashcommand-handler.ts

import type { IRoom } from '@rocket.chat/apps-engine/definition/rooms/IRoom';
import type { ISlashCommand } from '@rocket.chat/apps-engine/definition/slashcommands/ISlashCommand';
import { SlashCommandContext  } from '@rocket.chat/apps-engine/definition/slashcommands/SlashCommandContext';
import { Defined, JsonRpcError } from 'jsonrpc-lite';

import { AppObjectRegistry } from '../AppObjectRegistry.ts';
import { AppAccessors, AppAccessorsInstance } from '../lib/accessors/mod.ts';
import createRoom from '../lib/roomFactory.ts';
import { RequestContext } from '../lib/requestContext.ts';
import { wrapComposedApp } from '../lib/wrapAppForRequest.ts';

export default async function slashCommandHandler(request: RequestContext): Promise<JsonRpcError | Defined> {
	const { method: call, params } = request;
	const { logger } = request.context;

	const [, commandName, method] = call.split(':');

	const command = AppObjectRegistry.get<ISlashCommand>(`slashcommand:${commandName}`);

	if (!command) {
		return new JsonRpcError(`Slashcommand ${commandName} not found`, -32000);
	}

	let result: Awaited<ReturnType<typeof handleExecutor>> | Awaited<ReturnType<typeof handlePreviewItem>>;

	logger.debug({ msg: `Command is being executed...`, commandName, method, params });

	try {
		if (method === 'executor' || method === 'previewer') {
			result = await handleExecutor({ AppAccessorsInstance, request }, command, method, params);
		} else if (method === 'executePreviewItem') {
			result = await handlePreviewItem({ AppAccessorsInstance, request }, command, params);
		} else {
			return new JsonRpcError(`Method ${method} not found on slashcommand ${commandName}`, -32000);
		}

		logger.debug({ msg: `Command was successfully executed.`, commandName, method });
	} catch (error) {
		logger.debug({ msg: `Command was unsuccessful.`, commandName, method, err: error });

		return new JsonRpcError(error.message, -32000);
	}

	return result;
}

type Deps = {
	AppAccessorsInstance: AppAccessors,
	request: RequestContext;
}

/**
 * @param deps Dependencies that need to be injected into the slashcommand
 * @param command The slashcommand that is being executed
 * @param method The method that is being executed
 * @param params The parameters that are being passed to the method
 */
export function handleExecutor(deps: Deps, command: ISlashCommand, method: 'executor' | 'previewer', params: unknown) {
	const executor = command[method];

	if (typeof executor !== 'function') {
		throw new Error(`Method ${method} not found on slashcommand ${command.command}`);
	}

	if (!Array.isArray(params) || typeof params[0] !== 'object' || !params[0]) {
		throw new Error(`First parameter must be an object`);
	}

	const { sender, room, params: args, threadId, triggerId } = params[0] as Record<string, unknown>;

	const context = new SlashCommandContext(
		sender as SlashCommandContext['sender'],
		createRoom(room as IRoom, deps.AppAccessorsInstance.getSenderFn()),
		args as SlashCommandContext['params'],
		threadId as SlashCommandContext['threadId'],
		triggerId as SlashCommandContext['triggerId'],
	);

	return executor.apply(wrapComposedApp(command, deps.request), [
		context,
		deps.AppAccessorsInstance.getReader(),
		deps.AppAccessorsInstance.getModifier(),
		deps.AppAccessorsInstance.getHttp(),
		deps.AppAccessorsInstance.getPersistence(),
	]);
}

/**
 * @param deps Dependencies that need to be injected into the slashcommand
 * @param command The slashcommand that is being executed
 * @param params The parameters that are being passed to the method
 */
export function handlePreviewItem(deps: Deps, command: ISlashCommand, params: unknown) {
	if (typeof command.executePreviewItem !== 'function') {
		throw new Error(`Method  not found on slashcommand ${command.command}`);
	}

	if (!Array.isArray(params) || typeof params[0] !== 'object' || !params[0]) {
		throw new Error(`First parameter must be an object`);
	}

	const [previewItem, { sender, room, params: args, threadId, triggerId }] = params as [Record<string, unknown>, Record<string, unknown>];

	const context = new SlashCommandContext(
		sender as SlashCommandContext['sender'],
		createRoom(room as IRoom, deps.AppAccessorsInstance.getSenderFn()),
		args as SlashCommandContext['params'],
		threadId as SlashCommandContext['threadId'],
		triggerId as SlashCommandContext['triggerId'],
	);

	return command.executePreviewItem.call(
		wrapComposedApp(command, deps.request),
		previewItem,
		context,
		deps.AppAccessorsInstance.getReader(),
		deps.AppAccessorsInstance.getModifier(),
		deps.AppAccessorsInstance.getHttp(),
		deps.AppAccessorsInstance.getPersistence(),
	);
}