initial commit, add bitget rest api and websockets connector

src/util/websocket-util.ts

@@ -0,0 +1,135 @@
+import { WsKey } from '../types';
+import { signMessage } from './node-support';
+import { BitgetInstType, WsTopicSubscribeEventArgs } from './WsStore';
+
+/**
+ * Some exchanges have two livenet environments, some have test environments, some dont. This allows easy flexibility for different exchanges.
+ * Examples:
+ *  - One livenet and one testnet: NetworkMap<'livenet' | 'testnet'>
+ *  - One livenet, sometimes two, one testnet: NetworkMap<'livenet' | 'testnet', 'livenet2'>
+ *  - Only one livenet, no other networks: NetworkMap<'livenet'>
+ */
+type NetworkMap<
+  TRequiredKeys extends string,
+  TOptionalKeys extends string | undefined = undefined
+> = Record<TRequiredKeys, string> &
+  (TOptionalKeys extends string
+    ? Record<TOptionalKeys, string | undefined>
+    : Record<TRequiredKeys, string>);
+
+export const WS_BASE_URL_MAP: Record<
+  WsKey,
+  Record<'all', NetworkMap<'livenet'>>
+> = {
+  mixv1: {
+    all: {
+      livenet: 'wss://ws.bitget.com/mix/v1/stream',
+    },
+  },
+  spotv1: {
+    all: {
+      livenet: 'wss://ws.bitget.com/spot/v1/stream',
+    },
+  },
+};
+
+/** Should be one WS key per unique URL */
+export const WS_KEY_MAP = {
+  spotv1: 'spotv1',
+  mixv1: 'mixv1',
+} as const;
+
+/** Any WS keys in this list will trigger auth on connect, if credentials are available */
+export const WS_AUTH_ON_CONNECT_KEYS: WsKey[] = [
+  WS_KEY_MAP.spotv1,
+  WS_KEY_MAP.mixv1,
+];
+
+/** Any WS keys in this list will ALWAYS skip the authentication process, even if credentials are available */
+export const PUBLIC_WS_KEYS = [] as WsKey[];
+
+/**
+ * Used to automatically determine if a sub request should be to a public or private ws (when there's two separate connections).
+ * Unnecessary if there's only one connection to handle both public & private topics.
+ */
+export const PRIVATE_TOPICS = ['account', 'orders', 'positions', 'ordersAlgo'];
+
+export function isPrivateChannel<TChannel extends string>(
+  channel: TChannel
+): boolean {
+  return PRIVATE_TOPICS.includes(channel);
+}
+
+export function getWsKeyForTopic(
+  subscribeEvent: WsTopicSubscribeEventArgs,
+  isPrivate?: boolean
+): WsKey {
+  const instType = subscribeEvent.instType.toUpperCase() as BitgetInstType;
+  switch (instType) {
+    case 'SP':
+    case 'SPBL': {
+      return WS_KEY_MAP.spotv1;
+    }
+    case 'MC':
+    case 'UMCBL':
+    case 'DMCBL': {
+      return WS_KEY_MAP.mixv1;
+    }
+    default: {
+      throw neverGuard(
+        instType,
+        `getWsKeyForTopic(): Unhandled market ${'instrumentId'}`
+      );
+    }
+  }
+}
+
+/** Force subscription requests to be sent in smaller batches, if a number is returned */
+export function getMaxTopicsPerSubscribeEvent(wsKey: WsKey): number | null {
+  switch (wsKey) {
+    case 'mixv1':
+    case 'spotv1': {
+      // Technically there doesn't seem to be a documented cap, but there is a size limit per request. Doesn't hurt to batch requests.
+      return 15;
+    }
+    default: {
+      throw neverGuard(wsKey, `getWsKeyForTopic(): Unhandled wsKey`);
+    }
+  }
+}
+
+export const WS_ERROR_ENUM = {
+  INVALID_ACCESS_KEY: 30011,
+};
+
+export function neverGuard(x: never, msg: string): Error {
+  return new Error(`Unhandled value exception "${x}", ${msg}`);
+}
+
+export async function getWsAuthSignature(
+  apiKey: string | undefined,
+  apiSecret: string | undefined,
+  apiPass: string | undefined,
+  recvWindow: number = 0
+): Promise<{
+  expiresAt: number;
+  signature: string;
+}> {
+  if (!apiKey || !apiSecret || !apiPass) {
+    throw new Error(
+      `Cannot auth - missing api key, secret or passcode in config`
+    );
+  }
+  const signatureExpiresAt = ((Date.now() + recvWindow) / 1000).toFixed(0);
+
+  const signature = await signMessage(
+    signatureExpiresAt + 'GET' + '/user/verify',
+    apiSecret,
+    'base64'
+  );
+
+  return {
+    expiresAt: Number(signatureExpiresAt),
+    signature,
+  };
+}