wisski-cloud-distillery/utils/wsclient/client/index.ts
2023-11-10 19:37:24 +01:00

71 lines
2.1 KiB
TypeScript

/** @file implements the websocket protocol used by the distillery */
import WebSocket from "ws";
/** A call to the websocket endpoint */
export interface WebSocketCall {
call: string;
params: string[];
}
/** the result of a websocket call */
export interface WebSocketResult {
success: boolean,
message: string,
}
/** optional hooks to call when something happens */
export interface Hooks {
beforeCall: (call: WebSocketCall) => void; // called right before sending the request
afterCall: (call: WebSocketCall, result: WebSocketResult) => void; // called when the socket is closed
onError: (call: WebSocketCall, error: any) => void; // called when an error occurs before rejecting the promise
onLogLine: (call: WebSocketCall, line: string) => void; // called when a log line is received
}
/** specifies a remote endpoint */
export interface Remote {
url: string; // the remote websocket url to talk to
token?: string; // optional token
}
/** run a websocket remote call */
export default async function Call(remote: Remote, call: WebSocketCall, hooks?: Partial<Hooks>): Promise<WebSocketResult> {
return new Promise((resolve, reject) => {
let options = { headers: {} };
if (remote.token) {
options.headers = { 'Authorization': 'Bearer ' + remote.token };
}
const ws = new WebSocket(remote.url, options);
let result = {'success': false, 'message': 'Unknown error'};
ws.on('error', (err) => {
if (hooks && hooks.onError) {
hooks.onError(call, err);
}
reject(err)
});
ws.on('open', () => {
if (hooks && hooks.beforeCall) {
hooks.beforeCall(call);
}
ws.send(Buffer.from(JSON.stringify(call), 'utf8'));
});
ws.on('message', async (msg, isBinary) => {
if (!isBinary) {
if (hooks && hooks.onLogLine) {
hooks.onLogLine(call, msg.toString());
}
return;
}
result = JSON.parse(msg.toString());
});
ws.on('close', () => {
if (hooks && hooks.afterCall) {
hooks.afterCall(call, result);
}
resolve(result);
});
});
}