refs #215 Add a function to detect SNS

src/megalodon.ts

@@ -3,9 +3,10 @@ import WebSocket from './web_socket'
 import Response from './response'
 import OAuth from './oauth'
 import Pleroma from './pleroma'
-import { ProxyConfig } from './proxy_config'
+import proxyAgent, { ProxyConfig } from './proxy_config'
 import Mastodon from './mastodon'
 import Entity from './entity'
+import axios, { AxiosRequestConfig, AxiosResponse } from 'axios'
 
 export interface MegalodonInterface {
   /**
@@ -1142,6 +1143,41 @@ export class NoImplementedError extends Error {
   }
 }
 
+type Instance = {
+  title: string
+  uri: string
+  urls: {
+    streaming_api: string
+  }
+  version: string
+}
+
+/**
+ * Detect SNS type.
+ * Now support Mastodon, Pleroma and Pixelfed.
+ *
+ * @param url Base URL of SNS.
+ * @param proxyConfig Proxy setting, or set false if don't use proxy.
+ * @return SNS name.
+ */
+export const detector = async (url: string, proxyConfig: ProxyConfig | false = false): Promise<'mastodon' | 'pleroma' | 'pixelfed'> => {
+  let options: AxiosRequestConfig = {}
+  if (proxyConfig) {
+    options = Object.assign(options, {
+      httpsAgent: proxyAgent(proxyConfig)
+    })
+  }
+  return axios.get<Instance>(url + '/api/v1/instance', options).then((res: AxiosResponse<Instance>) => {
+    if (res.data.version.includes('Pleroma')) {
+      return 'pleroma'
+    } else if (res.data.version.includes('Pixelfed')) {
+      return 'pixelfed'
+    } else {
+      return 'mastodon'
+    }
+  })
+}
+
 /**
  * Get client for each SNS according to megalodon interface.
  *