upstream-rocketchat/ee/packages/media-calls/src/sip/providers/OutgoingSipCall.ts

import type { IMediaCall, MediaCallSignedContact } from '@rocket.chat/core-typings';
import { isBusyState, type ClientMediaSignalBody, type CallHangupReason } from '@rocket.chat/media-signaling';
import { MediaCallNegotiations, MediaCalls } from '@rocket.chat/models';
import type { SrfRequest } from 'drachtio-srf';

import { BaseSipCall } from './BaseSipCall';
import { SIP_CALL_FEATURES } from '../../constants';
import type { InternalCallParams } from '../../definition/common';
import { logger } from '../../logger';
import { BroadcastActorAgent } from '../../server/BroadcastAgent';
import { mediaCallDirector } from '../../server/CallDirector';
import type { SipServerSession } from '../Session';
import { SipError, SipErrorCodes } from '../errorCodes';

export class OutgoingSipCall extends BaseSipCall {
	private sipDialogReq: SrfRequest | null;

	constructor(
		session: SipServerSession,
		call: IMediaCall,
		protected override readonly agent: BroadcastActorAgent,
	) {
		super(session, call, agent);
		this.sipDialogReq = null;
	}

	public static async createCall(session: SipServerSession, params: InternalCallParams): Promise<IMediaCall> {
		logger.debug({ msg: 'OutgoingSipCall.createCall', sessionId: session.sessionId });
		const { callee, features: requestedFeatures, ...extraParams } = params;

		// pre-sign the callee to this session
		const signedCallee: MediaCallSignedContact = {
			...callee,
			contractId: session.sessionId,
		};

		const calleeAgent = await mediaCallDirector.cast.getAgentForActorAndRole(signedCallee, 'callee');
		if (!calleeAgent) {
			throw new SipError(SipErrorCodes.NOT_FOUND, 'Callee agent not found');
		}

		if (!(calleeAgent instanceof BroadcastActorAgent)) {
			throw new SipError(SipErrorCodes.INTERNAL_SERVER_ERROR, 'Caller agent not valid');
		}

		const callerAgent = await mediaCallDirector.cast.getAgentForActorAndRole(params.caller, 'caller');
		if (!callerAgent) {
			throw new SipError(SipErrorCodes.NOT_FOUND, 'Caller agent not found');
		}

		const features = requestedFeatures.filter((feature) => SIP_CALL_FEATURES.includes(feature));
		const call = await mediaCallDirector.createCall({
			...extraParams,
			callee: signedCallee,
			calleeAgent,
			callerAgent,
			features,
		});

		const sipCall = new OutgoingSipCall(session, call, calleeAgent);
		session.registerCall(sipCall);
		calleeAgent.provider = sipCall;

		// report to the caller that the call was created
		await callerAgent.onCallCreated(call);

		return call;
	}

	protected async reflectCall(call: IMediaCall, params: { dtmf?: ClientMediaSignalBody<'dtmf'> }): Promise<void> {
		if (params.dtmf && this.sipDialog) {
			return this.sendDTMF(this.sipDialog, params.dtmf.dtmf, params.dtmf.duration || 2000);
		}

		if (call.transferredTo && call.transferredBy) {
			return this.processTransferredCall(call);
		}

		if (call.state === 'hangup') {
			return this.processEndedCall(call);
		}

		if (this.lastCallState === 'none') {
			return this.createDialog(call);
		}

		if (isBusyState(call.state)) {
			return this.processNegotiations(call);
		}

		logger.debug({ msg: 'no changes detected', method: 'OutgoingSipCall.reflectCall' });
	}

	protected async createDialog(call: IMediaCall): Promise<void> {
		logger.debug({ msg: 'OutgoingSipCall.createDialog', call });
		if (this.lastCallState !== 'none' || this.sipDialog) {
			logger.debug({ msg: 'invalid state to create an outgoing dialog' });
			return;
		}

		const negotiation = await MediaCallNegotiations.findLatestByCallId(call._id);
		if (!negotiation?.offer) {
			return;
		}

		const updateResult = await MediaCalls.startRingingById(call._id, mediaCallDirector.getNewExpirationTime());
		if (!updateResult.modifiedCount) {
			logger.debug({ msg: 'unable to set call state to ringing; skipping dialog creation.' });
			return;
		}

		this.lastCallState = 'ringing';
		const referredBy = call.parentCallId && this.session.geContactUri(call.createdBy);

		let hangupReason: CallHangupReason | null = null;
		try {
			this.sipDialog = await this.session.createSipDialog(
				this.call.callee.id,
				{
					localSdp: negotiation.offer.sdp,
					callingName: call.caller.displayName,
					callingNumber: call.caller.sipExtension,
					...(referredBy && {
						headers: {
							'Referred-By': referredBy,
						},
					}),
				},
				{
					cbProvisional: (provRes) => {
						logger.debug({
							msg: 'OutgoingSipCall.createDialog - got provisional response',
							provRes: provRes && this.session.stripDrachtioServerDetails(provRes),
						});
					},
					cbRequest: (err: unknown, req: SrfRequest) => {
						if (err) {
							logger.error({
								msg: 'OutgoingSipCall.createDialog - request failed',
								err,
							});
							this.hangupCall('signaling-error');
							return;
						}

						if (req) {
							logger.debug({
								msg: 'OutgoingSipCall.createDialog - request initiated',
								req: this.session.stripDrachtioServerDetails(req),
							});

							this.sipDialogReq = req;
							req.on('response', (res, ack) => {
								logger.debug({
									msg: 'OutgoingSipCall - request got a response',
									req: this.session.stripDrachtioServerDetails(req),
									res: res && this.session.stripDrachtioServerDetails(res),
									ack,
								});
							});
						}
					},
				},
			);

			if (!this.sipDialog) {
				logger.debug({ msg: 'OutgoingSipCall.createDialog - no dialog' });
			}
		} catch (error) {
			this.sipDialog = null;
			const errorCode = this.getSipErrorCode(error);
			hangupReason = this.getHangupReasonForSipErrorCode(errorCode);

			if (!hangupReason || hangupReason.includes('error')) {
				logger.error({ msg: 'OutgoingSipCall.createDialog - failed to create sip dialog', err: error, callId: call._id });
			} else {
				logger.info({ msg: 'SIP call failed with a natural reason', hangupReason, callId: call._id, err: error });
			}
		}

		if (!this.sipDialog) {
			this.cancelAnyPendingRequest();
			this.hangupCall(hangupReason || 'signaling-error');
			return;
		}

		logger.debug({ msg: 'OutgoingSipCall.createDialog - dialog created', callId: this.sipDialog.sip?.callId });
		this.sipDialog.on('destroy', () => this.onDialogDestroyed());

		this.sipDialog.on('modify', (req, res) => {
			void this.handleDialogModify(req, res);
		});

		logger.debug({ msg: 'OutgoingSipCall.createDialog - remote data', data: this.sipDialog.remote });

		// This will not do anything if the call is no longer waiting to be accepted.
		await mediaCallDirector.acceptCall(call, this.agent, {
			calleeContractId: this.session.sessionId,
			webrtcAnswer: { type: 'answer', sdp: this.sipDialog.remote.sdp },
			supportedFeatures: SIP_CALL_FEATURES,
			sipCallId: this.sipDialog.sip?.callId,
		});
	}

	protected async processNegotiations(call: IMediaCall): Promise<void> {
		const negotiation = await MediaCallNegotiations.findLatestByCallId(call._id);
		if (negotiation?.offerer !== 'caller' || !negotiation.offer?.sdp || negotiation.answer) {
			return this.processCalleeNegotiations();
		}

		if (!this.sipDialog) {
			return;
		}

		logger.debug('OutgoingSipCall.processNegotiations');
		let answer: string | void = undefined;
		try {
			answer = await this.sipDialog.modify(negotiation.offer.sdp).catch(() => {
				logger.debug('modify failed');
			});
		} catch (err) {
			logger.error({ msg: 'Error on OutgoingSipCall.processNegotiations', err });
		}

		if (!answer) {
			logger.error({ msg: 'No answer from callee initiated negotiation' });
			// If a caller initiated negotiation fails, we need to hangup
			void mediaCallDirector.hangupDetachedCall(call, { reason: 'renegotiation-failed', endedBy: call.caller });
			return;
		}

		await mediaCallDirector.saveWebrtcSession(
			call,
			this.agent,
			{ sdp: { sdp: answer, type: 'answer' }, negotiationId: negotiation._id },
			this.session.sessionId,
		);
	}

	protected async processCalleeNegotiations(): Promise<void> {
		const localNegotiation = await this.getPendingInboundNegotiation();
		// If we don't have an sdp, we can't respond to it yet
		if (!localNegotiation?.answer?.sdp) {
			return;
		}

		logger.debug('OutgoingSipCall.processCalleeNegotiations');
		localNegotiation.res.send(200, {
			body: localNegotiation.answer.sdp,
		});
	}

	protected async processEndedCall(_call: IMediaCall): Promise<void> {
		if (this.lastCallState === 'hangup') {
			return;
		}

		logger.debug({ msg: 'OutgoingSipCall.processEndedCall', lastCallState: this.lastCallState });

		this.cancelAnyPendingRequest();

		const { sipDialog } = this;
		this.sipDialog = null;
		this.lastCallState = 'hangup';

		if (sipDialog) {
			try {
				await sipDialog.destroy();
			} catch (err) {
				logger.error({ msg: 'Failed to destroy SIP dialog', err, method: 'OutgoingSipCall.processEndedCall' });
			}
		}
	}

	private getSipErrorCode(error: unknown): number | null {
		if (!error || typeof error !== 'object') {
			return null;
		}

		if (!('name' in error) || error.name !== 'SipError') {
			return null;
		}

		if (!('status' in error) || typeof error.status !== 'number') {
			return null;
		}

		return error.status;
	}

	private getHangupReasonForSipErrorCode(errorCode: number | null): CallHangupReason | null {
		if (!errorCode) {
			return null;
		}

		switch (errorCode) {
			case SipErrorCodes.DECLINED:
				return 'rejected';
			case SipErrorCodes.UNWANTED:
				return 'rejected';
			case SipErrorCodes.NOT_ACCEPTABLE_HERE:
				return 'service-error';
		}

		return null;
	}

	private cancelAnyPendingRequest(): void {
		if (!this.sipDialogReq) {
			return;
		}

		const req = this.sipDialogReq;
		this.sipDialogReq = null;

		try {
			req.cancel(() => null);
		} catch {
			// ignore errors on cancel
		}
	}
}