add file download

Author: John Doe

CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Changelog
 
+#### tglib v3.0.3
+
+- Added a new high level API `client.tg.download` for downloading files
+
+-----
+
 #### tglib v3.0.2
 
 - Fix WASM verbosity setting for TDLib 1.4.0 (provides official WASM suppor & example)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tglib",
-  "version": "3.0.2",
+  "version": "3.0.3",
   "author": "nodegin",
   "license": "MIT",
   "description": "TDLib (Telegram Database library) bindings for Node.js",

src/ClientBase.js

@@ -35,6 +35,7 @@ class Client {
     this.client = null
     this.tg = new TG(this)
     this.hijackers = {}
+    this.downloading = {}
     this.fetching = {}
     this.callbacks = {
       'td:update': () => {},
@@ -213,6 +214,20 @@ class Client {
       return
     }
     switch (update['@type']) {
+      case 'updateFile': {
+        const fileId = update['file']['id']
+        if (!this.downloading[fileId]) {
+          // default handle
+          this.callbacks['td:update'].call(null, update)
+          return
+        }
+        if (!update['file']['local']['path'].length) {
+          // not yet downloaded
+          return
+        }
+        // resolve downloaded
+        this.downloading[fileId](update)
+      }
       case 'updateOption': {
         if (update['name'] === 'my_id' && update['value']['@type'] === 'optionValueEmpty') {
           // session has been signed out

src/TG.js

@@ -242,6 +242,29 @@ class TG {
     return chat
   }
 
+  /*
+   *  Download a file
+   */
+  async download(remoteFileId) {
+    const { id } = await this.client.fetch({
+      '@type': 'getRemoteFile',
+      'remote_file_id': remoteFileId,
+    })
+    let file = await this.client.fetch({
+      '@type': 'downloadFile',
+      'file_id': id,
+      'priority': 1,
+    })
+    if (!file['local']['path'].length) {
+      const downloadPromise = new Promise((resolve) => {
+        this.client.downloading[id] = resolve
+      })
+      file = await downloadPromise
+    }
+    return file
+  }
+
+
   /*
    *  Call an user
    */