Add session, client and server with the promise result API

src/sms.ts

@@ -0,0 +1,129 @@
+import type { ErrorName } from './defs/errors.ts';
+import type { MessageState } from './defs/constants.ts';
+import type { PduObject } from './pdu.ts';
+import type { Result, VoidResult } from './result.ts';
+import type { Session } from './session.ts';
+import { consts } from './defs/constants.ts';
+import { receiptCodes } from './dlr.ts';
+import { smppDate } from './message.ts';
+import { uuidv7 } from './uuid.ts';
+
+/**
+ * A received SMS, and the handle for answering it. Multipart messages arrive as one Sms carrying
+ * every segment's PDU.
+ */
+export type Sms = {
+	dlr: boolean;
+	flash: boolean;
+	from: string;
+	message: string;
+	pduObjs: PduObject[];
+	/** Sends a delivery report back to the sender. Defaults to DELIVERED. */
+	sendDlr: (status?: MessageState) => Promise<Result<{ pduObjs: PduObject[] }>>;
+	/** Answers every segment. Part of the protocol, not optional. Defaults to ESME_ROK. */
+	sendResp: (status?: ErrorName) => Promise<VoidResult>;
+	session: Session;
+	/** Generated as a UUID v7 unless the application sets its own before answering. */
+	smsId: string;
+	submitTime: Date;
+	to: string;
+};
+
+export type SmsInput = {
+	from: string;
+	message: string;
+	pduObjs: PduObject[];
+	session: Session;
+	to: string;
+};
+
+/** Each segment of a multipart message gets its own message_id, as a separate submit_sm must. */
+function segmentId(smsId: string, index: number, total: number): string {
+	return total === 1 ? smsId : `${smsId}-${String(index + 1)}`;
+}
+
+export function createSms(input: SmsInput): Sms {
+	const first = input.pduObjs[0];
+	const registered = first?.params.registered_delivery;
+	const dataCoding = first?.params.data_coding;
+
+	const sms: Sms = {
+		dlr: typeof registered === 'number' && registered !== 0,
+		flash: typeof dataCoding === 'number' && (dataCoding & 0xF0) === 0x10,
+		from: input.from,
+		message: input.message,
+		pduObjs: input.pduObjs,
+		sendDlr: status => sendDlr(sms, status),
+		sendResp: status => sendResp(sms, status),
+		session: input.session,
+		smsId: uuidv7(),
+		submitTime: new Date(),
+		to: input.to,
+	};
+
+	return sms;
+}
+
+async function sendResp(sms: Sms, status: ErrorName = 'ESME_ROK'): Promise<VoidResult> {
+	const total = sms.pduObjs.length;
+
+	if (total === 0) {
+		return { err: new Error('No PDUs to answer') };
+	}
+
+	const results = await Promise.all(sms.pduObjs.map((pduObj, index) => sms.session.sendReturn(
+		pduObj,
+		status,
+		{ message_id: segmentId(sms.smsId, index, total) },
+	)));
+
+	return results.find(result => result.err) ?? {};
+}
+
+async function sendDlr(
+	sms: Sms,
+	status: MessageState = 'DELIVERED',
+): Promise<Result<{ pduObjs: PduObject[] }>> {
+	const statusId = consts.MESSAGE_STATE[status];
+	const total = sms.pduObjs.length;
+	const pduObjs: PduObject[] = [];
+
+	for (let index = 0; index < total; index++) {
+		const smsId = segmentId(sms.smsId, index, total);
+		const delivered = status === 'DELIVERED';
+		const message = [
+			`id:${smsId}`,
+			'sub:001',
+			`dlvrd:${delivered ? '001' : '000'}`,
+			`submit date:${smppDate(sms.submitTime)}`,
+			`done date:${smppDate(new Date())}`,
+			`stat:${receiptCodes[status]}`,
+			`err:${delivered ? '000' : '001'}`,
+			'text:',
+		].join(' ');
+
+		const sent = await sms.session.send({
+			cmdName: 'deliver_sm',
+			params: {
+				destination_addr: sms.from,
+				esm_class: consts.ESM_CLASS.MC_DELIVERY_RECEIPT,
+				short_message: message,
+				source_addr: sms.to,
+			},
+			tlvs: {
+				message_state: { tagId: 0x0427, tagName: 'message_state', tagValue: statusId },
+				receipted_message_id: {
+					tagId: 0x001E,
+					tagName: 'receipted_message_id',
+					tagValue: smsId,
+				},
+			},
+		});
+
+		if (sent.err) return { err: sent.err };
+
+		pduObjs.push(sent.pduObj);
+	}
+
+	return { pduObjs };
+}