From 232ec6ee42615cb58f0a7dff4aed277a3947bdae Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Thu, 22 Feb 2018 19:21:29 +0200
Subject: [PATCH] Add room pill bridging. Fixes #62

---
 mautrix_appservice/intent_api.py          |  2 +-
 mautrix_telegram/formatter/from_matrix.py | 16 ++++++++---
 mautrix_telegram/portal.py                | 34 +++++++++++++++++++++--
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/mautrix_appservice/intent_api.py b/mautrix_appservice/intent_api.py
index f011f3c0..fa148b2e 100644
--- a/mautrix_appservice/intent_api.py
+++ b/mautrix_appservice/intent_api.py
@@ -168,7 +168,7 @@ class IntentAPI:
         self.mxid = mxid
         self.log = log
 
-        results = self.mxid_regex.search(mxid)
+        results = self.mxid_regex.match(mxid)
         if not results:
             raise ValueError("invalid MXID")
         self.localpart = results.group(1)
diff --git a/mautrix_telegram/formatter/from_matrix.py b/mautrix_telegram/formatter/from_matrix.py
index dfbe490b..ab543523 100644
--- a/mautrix_telegram/formatter/from_matrix.py
+++ b/mautrix_telegram/formatter/from_matrix.py
@@ -22,7 +22,7 @@ import logging
 
 from telethon.tl.types import *
 
-from .. import user as u, puppet as p
+from .. import user as u, puppet as pu, portal as po
 from ..db import Message as DBMessage
 from .util import add_surrogates, remove_surrogates
 
@@ -30,7 +30,8 @@ log = logging.getLogger("mau.fmt.mx")
 
 
 class MatrixParser(HTMLParser):
-    mention_regex = re.compile("https://matrix.to/#/(@.+)")
+    mention_regex = re.compile("https://matrix.to/#/(@.+:.+)")
+    room_regex = re.compile("https://matrix.to/#/(#.+:.+)")
 
     def __init__(self):
         super().__init__()
@@ -69,10 +70,11 @@ class MatrixParser(HTMLParser):
                 url = attrs["href"]
             except KeyError:
                 return
-            mention = self.mention_regex.search(url)
+            mention = self.mention_regex.match(url)
+            room = self.room_regex.match(url)
             if mention:
                 mxid = mention.group(1)
-                user = p.Puppet.get_by_mxid(mxid, create=False)
+                user = pu.Puppet.get_by_mxid(mxid, create=False)
                 if not user:
                     user = u.User.get_by_mxid(mxid, create=False)
                     if not user:
@@ -83,6 +85,12 @@ class MatrixParser(HTMLParser):
                 else:
                     entity_type = MessageEntityMentionName
                     args["user_id"] = user.tgid
+            elif room:
+                username = po.Portal.get_username_from_mx_alias(room.group(1))
+                portal = po.Portal.find_by_username(username)
+                if portal and portal.username:
+                    url = f"@{portal.username}"
+                    entity_type = MessageEntityMention
             elif url.startswith("mailto:"):
                 url = url[len("mailto:"):]
                 entity_type = MessageEntityEmail
diff --git a/mautrix_telegram/portal.py b/mautrix_telegram/portal.py
index ed14c20a..949b929a 100644
--- a/mautrix_telegram/portal.py
+++ b/mautrix_telegram/portal.py
@@ -21,6 +21,7 @@ import random
 import mimetypes
 import hashlib
 import logging
+import re
 
 import magic
 
@@ -44,6 +45,9 @@ class Portal:
     az = None
     bot = None
     bridge_notices = False
+    mx_alias_regex = None
+    hs_domain = None
+    mxid_regex = None
     by_mxid = {}
     by_tgid = {}
 
@@ -278,9 +282,7 @@ class Portal:
         return levels
 
     def _get_room_alias(self, username=None):
-        username = username or self.username
-        return config.get("bridge.alias_template", "telegram_{groupname}").format(
-            groupname=username)
+        return self.alias_template.format(groupname=username or self.username)
 
     async def sync_telegram_users(self, source, users):
         allowed_tgids = set()
@@ -1110,6 +1112,28 @@ class Portal:
 
         return None
 
+    @classmethod
+    def get_username_from_mx_alias(cls, alias):
+        match = cls.mx_alias_regex.match(alias)
+        if match:
+            return match.group(1)
+        return None
+
+    @classmethod
+    def find_by_username(cls, username):
+        if not username:
+            return None
+
+        for _, portal in cls.by_tgid.items():
+            if portal.username == username:
+                return portal
+
+        portal = DBPortal.query.filter(DBPortal.username == username).one_or_none()
+        if portal:
+            return cls.from_db(portal)
+
+        return None
+
     @classmethod
     def get_by_tgid(cls, tgid, tg_receiver=None, peer_type=None):
         tg_receiver = tg_receiver or tgid
@@ -1163,3 +1187,7 @@ def init(context):
     global config
     Portal.az, Portal.db, config, _, Portal.bot = context
     Portal.bridge_notices = config["bridge.bridge_notices"]
+    Portal.alias_template = config.get("bridge.alias_template", "telegram_{groupname}")
+    Portal.hs_domain = config["homeserver"]["domain"]
+    localpart = Portal.alias_template.format(groupname="(.+)")
+    Portal.mx_alias_regex = re.compile(f"#{localpart}:{Portal.hs_domain}")