Narrows to stream/user and opens images

Narrows to stream/user successfuly. Opens selected image in default viewer.
Gives 401 error while trying to open gifs or videos.

zulipterminal/helper.py

@@ -7,7 +7,7 @@
 )
 from mypy_extensions import TypedDict
 
-import os
+import os, sys, requests, subprocess, tempfile
 
 Message = Dict[str, Any]
 
@@ -359,3 +359,23 @@ def match_user(user: Any, text: str) -> bool:
         if keyword.startswith(text.lower()):
             return True
     return False
+
+def open_media(url: str):
+    img_name = url.split("/")[-1]
+    img_dir_path = os.path.join(tempfile.gettempdir(), "ZulipTerminal_media")
+    img_path = os.path.join(img_dir_path, img_name)
+    try:
+        os.mkdir(img_dir_path)
+    except FileExistsError:
+        pass
+    with requests.get(url, stream=True) as r:
+        if r.status_code == 200:
+            with open(img_path, 'wb') as f:
+                for chunk in r.iter_content(chunk_size=1024):
+                    if chunk:  # filter out keep-alive new chunks
+                        f.write(chunk)
+    r.close()
+    imageViewerFromCommandLine = {'linux': 'xdg-open',
+                                    'win32': 'explorer',
+                                    'darwin': 'open'}[sys.platform]
+    subprocess.run([imageViewerFromCommandLine, img_path])

zulipterminal/ui_tools/views.py

@@ -5,7 +5,7 @@
 import urwid
 
 from zulipterminal.config.keys import KEY_BINDINGS, is_command_key
-from zulipterminal.helper import asynch, match_user
+from zulipterminal.helper import asynch, match_user, open_media
 from zulipterminal.ui_tools.buttons import (
     TopicButton,
     UnreadPMButton,
@@ -681,6 +681,7 @@ def __init__(self, controller: Any, msg: Any):
     def perform_action(self, button):
         # If stream
         if self.msg['links'][button.caption].startswith('/#narrow'):
+            found_stream = False
             for stream_details in self.controller.model.stream_dict.values():
                 # Check mentioned stream with all subscribed streams
                 if stream_details['name'] == button.caption[1:]:
@@ -693,9 +694,14 @@ def perform_action(self, button):
                                        width=self.width,
                                        count=0)
                     self.controller.narrow_to_stream(btn)
+                    found_stream = True
                     break
+            if not found_stream:
+                self.controller.view.set_footer_text("You are not subscribed to this stream.", 3)
+
         # If user
         elif self.msg['links'][button.caption].startswith('@'):
+            found_user = False
             for user in self.controller.model.users:
                 if user['full_name'] == button.caption[1:]:
                     btn = UserButton(user,
@@ -705,12 +711,13 @@ def perform_action(self, button):
                                      color=user['status'],
                                      count=0)
                     self.controller.narrow_to_user(btn)
+                    btn._narrow_with_compose(btn)
+                    found_user = True
                     break
-
+            if not found_user:
+                self.controller.view.set_footer_text("User not found in realm. Their account may be deactivated.", 3)
         else:
-            # Will open images and links in default image viewer and browser
-            pass
-
+            open_media(self.msg['links'][button.caption])
 
     def keypress(self, size: Tuple[int, int], key: str) -> str:
         if is_command_key('GO_BACK', key) or is_command_key('MSG_LINKS', key):