From 5dacbdd2a5a1401083dc064195690327d581591f Mon Sep 17 00:00:00 2001
From: Alex Root Junior <jroot.junior@gmail.com>
Date: Sun, 8 Apr 2018 17:22:10 +0300
Subject: [PATCH] Returned back `InputFile.from_url(url)` method.

---
 aiogram/types/input_file.py | 83 +++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/aiogram/types/input_file.py b/aiogram/types/input_file.py
index ff5ab1f0..9b510b09 100644
--- a/aiogram/types/input_file.py
+++ b/aiogram/types/input_file.py
@@ -1,10 +1,15 @@
 import io
 import logging
 import os
+import time
+
+import aiohttp
 
 from . import base
 from ..bot import api
 
+CHUNK_SIZE = 65536
+
 log = logging.getLogger('aiogram')
 
 
@@ -76,6 +81,84 @@ class InputFile(base.TelegramObject):
         """
         return self.file
 
+    @classmethod
+    async def from_url(cls, url, filename=None, chunk_size=65536):
+        """
+        Download file from URL
+
+        Manually is not required action. You can send urls instead!
+
+        :param url: target URL
+        :param filename: optional. set custom file name
+        :param chunk_size:
+
+        :return: InputFile
+        """
+        conf = {
+            'downloaded': True,
+            'url': url
+        }
+
+        # Let's do magic with the filename
+        if filename:
+            filename_prefix, _, ext = filename.rpartition('.')
+            file_suffix = '.' + ext if ext else ''
+        else:
+            filename_prefix, _, ext = url.rpartition('/')[-1].rpartition('.')
+            file_suffix = '.' + ext if ext else ''
+            filename = filename_prefix + file_suffix
+
+        async with aiohttp.ClientSession() as session:
+            start = time.time()
+            async with session.get(url) as response:
+                # Save file in memory
+                file = await cls._process_stream(response, io.BytesIO(), chunk_size=chunk_size)
+
+                log.debug(f"File successful downloaded at {round(time.time() - start, 2)} seconds from '{url}'")
+                return cls(file, filename, conf=conf)
+
+    def save(self, filename, chunk_size=65536):
+        """
+        Write file to disk
+
+        :param filename:
+        :param chunk_size:
+        """
+        with open(filename, 'wb') as fp:
+            while True:
+                # Chunk writer
+                data = self.file.read(chunk_size)
+                if not data:
+                    break
+                fp.write(data)
+            # Flush all data
+            fp.flush()
+
+        # Go to start of file.
+        if self.file.seekable():
+            self.file.seek(0)
+
+    @classmethod
+    async def _process_stream(cls, response, writer, chunk_size=65536):
+        """
+        Transfer data
+
+        :param response:
+        :param writer:
+        :param chunk_size:
+        :return:
+        """
+        while True:
+            chunk = await response.content.read(chunk_size)
+            if not chunk:
+                break
+            writer.write(chunk)
+
+        if writer.seekable():
+            writer.seek(0)
+
+        return writer
+
     def to_python(self):
         raise TypeError('Object of this type is not exportable!')