This is the service responsible for integrate with the TeraVoz's API.
It has a webhook as a REST endpoint,which is suposed to be called by TeraVoz's API, and a websocket for reading the data from the calls.
On this project i used a Clean Architecture approach to create a easy to mantain and readable source code.
The core idea was to build every part as decoupled as possible from the others and make them testable e resusable as well. To achieve this purpose i created interfaces for every part of the API that i want to be easily replaced or modified (eg: ICallRepository can be implemented either in MySql or Mongo,or any other kind of storage). This was one of the reasons i choosed TypeScript as language for this service.
Another important advantage is the segregation between the webserver,database,API clients and other frameworks and drivers from the business logic. This brings a even bigger advantage if is done with functional programming principles in mind, helping to create functions with minimal to zero side effects and predictable results.
Last but not less important, i used a few concepts of event sourcing,which can improve the functional way to think and also brings a entire new view about how to deal with data. Saving every event give us the chance to rebuild our data at any moment in time.
The webhook endpoint was implemented according to TeraVoz's API specification and uses a simple map-based event processor to route the request to the correct function based on the event type sent by TeraVoz.
Currenttly this api accepts the following event types:
call.new, call.standby, call.waiting, actor.entered, call.ongoing, actor.left, call.finished
Instead of using a REST API i decided to use a websocket,thinking about the possibilities this could bring to the frontend application. It allow us to update the frontend in realtime.
The websocket receives the following commands/events:
ListCalls retrieve all the calls for the given params. When params are not defined it retrive all the calls.
Request Payload:
{
"event": "ListCalls",
"data": {
"params": {
"state": "NEW"
}
}
}Example Response:
{
"data": [{
"id": 6,
"aggregate_id": "1463669263.30038",
"state": "NEW",
"created_at": "2019-10-15T00:30:26.000Z",
"updated_at": "2019-10-15T00:30:26.000Z"
}, {
"id": 7,
"aggregate_id": "1463669263.30039",
"state": "NEW",
"created_at": "2019-10-15T00:31:03.000Z",
"updated_at": "2019-10-15T00:31:03.000Z"
}, {
"id": 8,
"aggregate_id": "1463669263.30040",
"state": "NEW",
"created_at": "2019-10-15T00:33:02.000Z",
"updated_at": "2019-10-15T00:33:02.000Z"
}],
"event": "ListCalls",
"status": "Ok"
}ListCallEvents retrive all the events for the informed call.
{
"event": "ListCallEvents",
"data": {
"call_id": "1463669263.30041"
}
}Example Response:
{
"data": [{
"id": 1,
"aggregate_id": "1463669263.30033",
"uuid": "be7d7b70-ec0f-11e9-90fb-0f172d2e84ac",
"event": {
"code": "123456",
"type": "call.new",
"call_id": "1463669263.30033",
"direction": "inbound",
"timestamp": "2017-01-01T00:00:00Z",
"our_number": "0800000000",
"their_number": "11999990000",
"their_number_type": "mobile"
}
}, {
"id": 2,
"aggregate_id": "1463669263.30033",
"uuid": "c40642c0-ec0f-11e9-90fb-0f172d2e84ac",
"event": {
"code": "123456",
"type": "call.standby",
"call_id": "1463669263.30033",
"direction": "inbound",
"timestamp": "2017-01-01T00:00:00Z",
"our_number": "0800000000",
"their_number": "11991910000"
}
}, {
"id": 8,
"aggregate_id": "1463669263.30033",
"uuid": "1259fa70-ed64-11e9-968b-7f3ddd1bb5a9",
"event": {
"code": "123456",
"type": "actor.entered",
"actor": "[email protected]",
"queue": "900",
"number": "200",
"call_id": "1463669263.30033",
"timestamp": "2017-01-01T00:00:00Z"
}
}, {
"id": 13,
"aggregate_id": "1463669263.30033",
"uuid": "81bf4820-ed64-11e9-bf1c-857c9b92792e",
"event": {
"code": "123456",
"type": "actor.left",
"actor": "[email protected]",
"queue": "900",
"number": "200",
"call_id": "1463669263.30033",
"timestamp": "2017-01-01T00:00:00Z"
}
}, {
"id": 14,
"aggregate_id": "1463669263.30033",
"uuid": "a2a44d60-ed64-11e9-b453-7d7f966ecf39",
"event": {
"code": "123456",
"type": "call.finished",
"call_id": "1463669263.30033",
"direction": "inbound",
"timestamp": "2017-01-01T00:00:00Z",
"our_number": "0800000000",
"their_number": "11991910000"
}
}],
"event": "ListCallEvents",
"status": "Ok"
}The project has a Dockerfile for the Node.JS service and a docker-compose with the service,the client,a Redis(used as PubSub system) and a Mysql Database
You can run the project with a docker-compose up -d and access the client UI at localhost