hexabot/api/src/channel/lib/Handler.ts
2025-01-21 14:25:47 +01:00

386 lines
12 KiB
TypeScript

/*
* Copyright © 2025 Hexastack. All rights reserved.
*
* Licensed under the GNU Affero General Public License v3.0 (AGPLv3) with the following additional terms:
* 1. The name "Hexabot" is a trademark of Hexastack. You may not use this name in derivative works without express written permission.
* 2. All derivative works must include clear attribution to the original creator and software, Hexastack and Hexabot, in a prominent location (e.g., in the software's "About" section, documentation, and README file).
*/
import path from 'path';
import {
ForbiddenException,
Inject,
Injectable,
NotFoundException,
OnModuleInit,
} from '@nestjs/common';
import { JwtService, JwtSignOptions } from '@nestjs/jwt';
import { plainToClass } from 'class-transformer';
import { NextFunction, Request, Response } from 'express';
import mime from 'mime';
import { v4 as uuidv4 } from 'uuid';
import { Attachment } from '@/attachment/schemas/attachment.schema';
import { AttachmentService } from '@/attachment/services/attachment.service';
import {
AttachmentAccess,
AttachmentCreatedByRef,
AttachmentFile,
AttachmentResourceRef,
} from '@/attachment/types';
import { SubscriberCreateDto } from '@/chat/dto/subscriber.dto';
import { AttachmentRef } from '@/chat/schemas/types/attachment';
import {
IncomingMessageType,
StdEventType,
StdOutgoingEnvelope,
StdOutgoingMessage,
} from '@/chat/schemas/types/message';
import { config } from '@/config';
import { LoggerService } from '@/logger/logger.service';
import { SettingService } from '@/setting/services/setting.service';
import { Extension } from '@/utils/generics/extension';
import { buildURL } from '@/utils/helpers/URL';
import { HyphenToUnderscore } from '@/utils/types/extension';
import { SocketRequest } from '@/websocket/utils/socket-request';
import { SocketResponse } from '@/websocket/utils/socket-response';
import { ChannelService } from '../channel.service';
import { ChannelName, ChannelSetting } from '../types';
import EventWrapper from './EventWrapper';
@Injectable()
export default abstract class ChannelHandler<
N extends ChannelName = ChannelName,
>
extends Extension
implements OnModuleInit
{
private readonly settings: ChannelSetting<N>[];
@Inject(AttachmentService)
public readonly attachmentService: AttachmentService;
@Inject(JwtService)
protected readonly jwtService: JwtService;
protected readonly jwtSignOptions: JwtSignOptions = {
secret: config.parameters.signedUrl.secret,
expiresIn: config.parameters.signedUrl.expiresIn,
algorithm: 'HS256',
encoding: 'utf-8',
};
constructor(
name: N,
protected readonly settingService: SettingService,
private readonly channelService: ChannelService,
protected readonly logger: LoggerService,
) {
super(name);
// eslint-disable-next-line @typescript-eslint/no-var-requires
this.settings = require(path.join(this.getPath(), 'settings')).default;
}
getName() {
return this.name as N;
}
async onModuleInit() {
await super.onModuleInit();
this.channelService.setChannel(
this.getName(),
this as unknown as ChannelHandler<N>,
);
this.setup();
}
async setup() {
await this.settingService.seedIfNotExist(
this.getName(),
this.settings.map((s, i) => ({
...s,
weight: i + 1,
})),
);
this.init();
}
/**
* Returns the channel's settings
* @returns Channel's settings
*/
async getSettings<S extends string = HyphenToUnderscore<N>>() {
const settings = await this.settingService.getSettings();
// @ts-expect-error workaround typing
return settings[this.getNamespace() as keyof Settings] as Settings[S];
}
/**
* Perform any initialization needed
*/
abstract init(): void;
/**
* Process incoming channel data via POST/GET methods
*
* @param {module:Controller.req} req
* @param {module:Controller.res} res
*/
abstract handle(
req: Request | SocketRequest,
res: Response | SocketResponse,
): any;
/**
* Format a text message that will be sent to the channel
*
* @param message - A text to be sent to the end user
* @param options - might contain additional settings
* @returns {Object} - A text message in the channel specific format
*/
abstract _textFormat(message: StdOutgoingMessage, options?: any): any;
/**
* Format a text + quick replies message that can be sent to the channel
*
* @param message - A text + quick replies to be sent to the end user
* @param options - might contain additional settings
* @returns {Object} - A quick replies message in the channel specific format
*/
abstract _quickRepliesFormat(message: StdOutgoingMessage, options?: any): any;
/**
* From raw buttons, construct a channel understable message containing those buttons
*
* @param message - A text + buttons to be sent to the end user
* @param options - Might contain additional settings
* @returns {Object} - A buttons message in the format required by the channel
*/
abstract _buttonsFormat(
message: StdOutgoingMessage,
options?: any,
...args: any
): any;
/**
* Format an attachment + quick replies message that can be sent to the channel
*
* @param message - An attachment + quick replies to be sent to the end user
* @param options - Might contain additional settings
* @returns {Object} - An attachment message in the format required by the channel
*/
abstract _attachmentFormat(message: StdOutgoingMessage, options?: any): any;
/**
* Format a list of elements
*
* @param message - Contains elements to be sent to the end user
* @param options - Might contain additional settings
* @returns {Object} - A ready to be sent list template message in the format required by the channel
*/
abstract _listFormat(
message: StdOutgoingMessage,
options: any,
...args: any
): any;
/**
* Format a carousel message
* @param message - Contains elements to be sent to the end user
* @param options - Might contain additional settings
* @returns {Object} - A carousel ready to be sent in the format required by the channel
*/
abstract _carouselFormat(
message: StdOutgoingMessage,
options: any,
...args: any
): any;
/**
* Send a channel Message to the end user
* @param event - Incoming event/message being responded to
* @param envelope - The message to be sent {format, message}
* @param options - Might contain additional settings
* @param context - Contextual data
* @returns {Promise} - The channel's response, otherwise an error
*/
abstract sendMessage(
event: EventWrapper<any, any, N>,
envelope: StdOutgoingEnvelope,
options: any,
context: any,
): Promise<{ mid: string }>;
/**
* Calls the channel handler to fetch attachments and stores them
*
* @param event
* @returns An attachment array
*/
getMessageAttachments?(
event: EventWrapper<any, any, N>,
): Promise<AttachmentFile[]>;
/**
* Fetch the subscriber profile data
* @param event - The message event received
* @returns {Promise<Subscriber>} - The channel's response, otherwise an error
*/
getSubscriberAvatar?(
event: EventWrapper<any, any, N>,
): Promise<AttachmentFile | undefined>;
/**
* Fetch the subscriber profile data
*
* @deprecated
* @param event - The message event received
* @returns {Promise<Subscriber>} - The channel's response, otherwise an error
*/
async getUserData(
event: EventWrapper<any, any, N>,
): Promise<SubscriberCreateDto> {
return await this.getSubscriberData(event);
}
/**
* Fetch the subscriber profile data
*
* @param event - The message event received
* @returns {Promise<Subscriber>} - The channel's response, otherwise an error
*/
abstract getSubscriberData(
event: EventWrapper<any, any, N>,
): Promise<SubscriberCreateDto>;
/**
* Persist Message attachments
*
* @returns Resolves the promise once attachments are fetched and stored
*/
async persistMessageAttachments(event: EventWrapper<any, any, N>) {
if (
event._adapter.eventType === StdEventType.message &&
event._adapter.messageType === IncomingMessageType.attachments &&
this.getMessageAttachments
) {
const metadatas = await this.getMessageAttachments(event);
const subscriber = event.getSender();
event._adapter.attachments = await Promise.all(
metadatas.map(({ file, name, type, size }) => {
return this.attachmentService.store(file, {
name: `${name ? `${name}-` : ''}${uuidv4()}.${mime.extension(type)}`,
type,
size,
resourceRef: AttachmentResourceRef.MessageAttachment,
access: AttachmentAccess.Private,
createdByRef: AttachmentCreatedByRef.Subscriber,
createdBy: subscriber.id,
});
}),
);
}
}
/**
* Custom channel middleware
* @param req
* @param res
* @param next
*/
async middleware(_req: Request, _res: Response, next: NextFunction) {
// Do nothing, override in channel
next();
}
/**
* Generates a signed URL for downloading an attachment.
*
* This function creates a signed URL for a given attachment using a JWT token.
* The signed URL includes the attachment name and a token as query parameters.
*
* @param attachment The attachment ID or object to generate a signed URL for.
* @return A signed URL string for downloading the specified attachment.
*/
public async getPublicUrl(attachment: AttachmentRef | Attachment) {
if ('id' in attachment) {
if (!attachment.id) {
throw new TypeError(
'Attachment ID is empty, unable to generate public URL.',
);
}
const resource = await this.attachmentService.findOne(attachment.id);
if (!resource) {
throw new NotFoundException('Unable to find attachment');
}
const token = this.jwtService.sign({ ...resource }, this.jwtSignOptions);
const [name, _suffix] = this.getName().split('-');
return buildURL(
config.apiBaseUrl,
`/webhook/${name}/download/${resource.name}?t=${encodeURIComponent(token)}`,
);
} else if ('url' in attachment && attachment.url) {
// In case the url is external
return attachment.url;
} else {
throw new TypeError('Unable to resolve the attachment public URL.');
}
}
/**
* Checks if the request is authorized to download a given attachment file.
* Can be overriden by the channel handler to customize, by default it shouldn't
* allow any client to download a subscriber attachment for example.
*
* @param attachment The attachment object
* @param req - The HTTP express request object.
* @return True, if requester is authorized to download the attachment
*/
public async hasDownloadAccess(attachment: Attachment, _req: Request) {
return attachment.access === AttachmentAccess.Public;
}
/**
* Downloads an attachment using a signed token.
*
* This function verifies the provided token and retrieves the corresponding
* attachment as a streamable file. If the verification fails or the attachment
* cannot be located, it throws a NotFoundException.
*
* @param token The signed token used to verify and locate the attachment.
* @param req - The HTTP express request object.
* @return A streamable file of the attachment.
*/
public async download(token: string, req: Request) {
try {
const {
exp: _exp,
iat: _iat,
...result
} = this.jwtService.verify(token, this.jwtSignOptions);
const attachment = plainToClass(Attachment, result);
// Check access
const canDownload = await this.hasDownloadAccess(attachment, req);
if (!canDownload) {
throw new ForbiddenException(
'You are not authorized to download the attachment',
);
}
return await this.attachmentService.download(attachment);
} catch (err) {
this.logger.error('Failed to download attachment', err);
throw new NotFoundException('Unable to locate attachment');
}
}
}