From c907e8146a77a7e04fa74d230def9c162fb83008 Mon Sep 17 00:00:00 2001
From: Dan <14043624+delivrance@users.noreply.github.com>
Date: Fri, 28 Dec 2018 14:34:47 +0100
Subject: [PATCH] Allow get_chat to work with chat invite links

---
 pyrogram/client/methods/chats/get_chat.py  | 23 ++++++++++++++++++++++
 pyrogram/client/methods/chats/join_chat.py |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/pyrogram/client/methods/chats/get_chat.py b/pyrogram/client/methods/chats/get_chat.py
index f5bf19a9..03bf2a08 100644
--- a/pyrogram/client/methods/chats/get_chat.py
+++ b/pyrogram/client/methods/chats/get_chat.py
@@ -32,13 +32,36 @@ class GetChat(BaseClient):
         Args:
             chat_id (``int`` | ``str``):
                 Unique identifier (int) or username (str) of the target chat.
+                Unique identifier for the target chat in form of a *t.me/joinchat/* link, identifier (int) or username
+                of the target channel/supergroup (in the format @username).
 
         Returns:
             On success, a :obj:`Chat <pyrogram.Chat>` object is returned.
 
         Raises:
             :class:`Error <pyrogram.Error>` in case of a Telegram RPC error.
+            ``ValueError`` in case the chat invite link refers to a chat you haven't joined yet.
         """
+        match = self.INVITE_LINK_RE.match(str(chat_id))
+
+        if match:
+            h = match.group(1)
+
+            r = self.send(
+                functions.messages.CheckChatInvite(
+                    hash=h
+                )
+            )
+
+            if isinstance(r, types.ChatInvite):
+                raise ValueError("You haven't joined \"t.me/joinchat/{}\" yet".format(h))
+
+            if isinstance(r.chat, types.Chat):
+                chat_id = -r.chat.id
+
+            if isinstance(r.chat, types.Channel):
+                chat_id = int("-100" + str(r.chat.id))
+
         peer = self.resolve_peer(chat_id)
 
         if isinstance(peer, types.InputPeerChannel):
diff --git a/pyrogram/client/methods/chats/join_chat.py b/pyrogram/client/methods/chats/join_chat.py
index 2f14c617..2c70a52f 100644
--- a/pyrogram/client/methods/chats/join_chat.py
+++ b/pyrogram/client/methods/chats/join_chat.py
@@ -27,7 +27,7 @@ class JoinChat(BaseClient):
 
         Args:
             chat_id (``str``):
-                Unique identifier for the target chat in form of *t.me/joinchat/* links or username of the target
+                Unique identifier for the target chat in form of a *t.me/joinchat/* link or username of the target
                 channel/supergroup (in the format @username).
 
         Raises: