feat(telegram): allow receiving file/audio/video/image (#543)

* feat(telegram): allow receiving file/audio/video/image

* Pr changes

Author: davidvitora

packages/channels/src/telegram/README.md

@@ -24,8 +24,8 @@
 | Postback      |    ✅    |         |
 | Say Something |    ✅    |         |
 | Voice         |    ❌    |         |
-| Image         |    ❌    |         |
-| File          |    ❌    |         |
-| Audio         |    ❌    |         |
-| Video         |    ❌    |         |
+| Image         |    ✅    |         |
+| File          |    ✅    |         |
+| Audio         |    ✅    |         |
+| Video         |    ✅    |         |
 | Location      |    ❌    |         |

packages/channels/src/telegram/api.ts

@@ -1,6 +1,7 @@
 import { Response } from 'express'
+import _ from 'lodash'
 import { Context, NarrowedContext } from 'telegraf'
-import { Update } from 'telegraf/typings/core/types/typegram'
+import { Update, Document, Video, Audio, Message } from 'telegraf/typings/core/types/typegram'
 import yn from 'yn'
 import { ChannelApi, ChannelApiManager, ChannelApiRequest } from '../base/api'
 import { ChannelInitializeEvent, ChannelStartEvent, ChannelStopEvent } from '../base/service'
@@ -58,6 +59,36 @@ export class TelegramApi extends ChannelApi<TelegramService> {
   private async handleTelegrafMessage(scope: string, ctx: NarrowedContext<Context<Update>, Update.MessageUpdate>) {
     if ('text' in ctx.message) {
       await this.service.receive(scope, this.extractEndpoint(ctx), { type: 'text', text: ctx.message.text })
+    } else if ('photo' in ctx.message) {
+      // Same photo in different sizes, get the last one since it
+      // has the best quality
+      const item = ctx.message.photo.pop()
+
+      if (!item) {
+        return
+      }
+
+      await this.service.receive(scope, this.extractEndpoint(ctx), {
+        type: this.mapTypeToStandardType('photo'),
+        url: await ctx.telegram.getFileLink(item.file_id),
+        title: ctx.message.caption
+      })
+    } else {
+      const message = ctx.message as Message.CaptionableMessage
+      const type = Object.keys(message).find((i) => ['document', 'video', 'audio'].includes(i))
+
+      if (!type) {
+        // Type not supported, swallow
+        return
+      }
+
+      const item = _.get(message, type) as Document | Video | Audio
+
+      await this.service.receive(scope, this.extractEndpoint(ctx), {
+        type: this.mapTypeToStandardType(type),
+        url: await ctx.telegram.getFileLink(item.file_id),
+        title: message.caption
+      })
     }
   }
 
@@ -103,4 +134,15 @@ export class TelegramApi extends ChannelApi<TelegramService> {
     // TODO: remove this dependency on server env vars
     return !yn(process.env.SPINNED) || yn(process.env.CLUSTER_ENABLED)
   }
+
+  private mapTypeToStandardType(type: string) {
+    switch (type) {
+      case 'document':
+        return 'file'
+      case 'photo':
+        return 'image'
+      default:
+        return type
+    }
+  }
 }