From 2765fd36e36ebcf236fe059d9b1405f0f8cfd07b Mon Sep 17 00:00:00 2001
From: blank X <theblankx@protonmail.com>
Date: Tue, 4 May 2021 19:48:13 +0700
Subject: [PATCH] Fix bugs

---
 streamtg.py | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/streamtg.py b/streamtg.py
index 4075ab1..4ce6a5b 100644
--- a/streamtg.py
+++ b/streamtg.py
@@ -66,17 +66,23 @@ async def handler(request):
         return web.Response(status=400, text='At least one of the messages does not exist')
     if any(True for i in messages if not i.media):
         return web.Response(status=400, text='At least one of the messages do not contain media')
-    http_range = request.http_range
-    offset = http_range.start or 0
-    end = http_range.stop
     max_size = 0
     for i in messages:
         max_size += _get_file_info(i).size
-    if end is None:
-        end = max_size
-    elif end > max_size:
-        return web.Response(status=416, text='Range end size is bigger than file sizes', headers={'Content-Range': f'bytes */{max_size}'})
-    length = end - offset
+    http_range = request.http_range
+    offset = http_range.start or 0
+    if offset < 0:
+        end = offset
+        offset = max_size - offset
+    else:
+        end = http_range.stop
+        if end is None:
+            end = max_size
+        elif end > max_size:
+            return web.Response(status=416, text='Range end size is bigger than file sizes', headers={'Content-Range': f'bytes */{max_size}'})
+        else:
+            end -= 1
+    length = end - offset + 1
 
     async def download():
         tmp_offset = offset
@@ -88,23 +94,18 @@ async def handler(request):
             if tmp_offset > size:
                 tmp_offset -= size
                 continue
-            stream = client._iter_download(i, offset=tmp_offset, request_size=131072, msg_data=(chat_id, i.id))
-            if isinstance(stream, _GenericDownloadIter):
-                __load_next_chunk = stream._load_next_chunk
-                def _load_next_chunk(mask=131071):
-                    return __load_next_chunk(mask=mask)
-                stream._load_next_chunk = _load_next_chunk
-            async for chunk in stream:
+            async for chunk in client._iter_download(i, offset=tmp_offset, msg_data=(chat_id, i.id)):
                 yield chunk[:tmp_length]
                 tmp_length -= len(chunk)
                 if tmp_length < 1:
                     break
+            tmp_offset = 0
 
-    return web.Response(status=206 if (end - offset != max_size) else 200,
+    return web.Response(status=206 if (length != max_size) else 200,
         body=download(),
         headers={
             'Content-Range': f'bytes {offset}-{end}/{max_size}',
-            'Content-Length': str(end - offset),
+            'Content-Length': str(length),
             'Accept-Ranges': 'bytes'
         }
     )