added input prompt functionality to bacloud client

tools/bacloud

@@ -92,6 +92,10 @@ class Response:
       dir_prune_empty: If present, all empty dirs under this one should be
         removed.
       open_url: If present, url to display to the user.
+      input_prompt: If present, a line of input is read and placed into
+        endcommand args as 'input'. The first value is the prompt printed
+        before reading and the second is whether it should be read as a
+        password (without echoing to the terminal).
       end_message: If present, a message that should be printed after all other
         response processing is done.
       end_message_end: end arg for end_message print() call.
@@ -110,6 +114,7 @@ class Response:
     deletes: Optional[List[str]] = None
     dir_prune_empty: Optional[str] = None
     open_url: Optional[str] = None
+    input_prompt: Optional[Tuple[str, bool]] = None
     end_message: Optional[str] = None
     end_message_end: str = '\n'
     end_command: Optional[Tuple[str, Dict]] = None
@@ -263,6 +268,7 @@ class App:
                 't': json.dumps(self._state.login_token),
                 'd': json.dumps(data),
                 'z': get_tz_offset_seconds(),
+                'y': int(sys.stdout.isatty()),
             },
             files=files)
         response_raw_2.raise_for_status()  # Except if anything went wrong.
@@ -383,6 +389,15 @@ class App:
         import webbrowser
         webbrowser.open(url)
 
+    def _handle_input_prompt(self, prompt: str, as_password: bool) -> None:
+        if as_password:
+            from getpass import getpass
+            self._end_command_args['input'] = getpass(prompt=prompt)
+        else:
+            if prompt:
+                print(prompt, end='', flush=True)
+            self._end_command_args['input'] = input()
+
     def run_user_command(self, args: List[str]) -> None:
         """Run a single user command to completion."""
         # pylint: disable=too-many-branches
@@ -412,6 +427,9 @@ class App:
                 self._handle_dir_prune_empty(response.dir_prune_empty)
             if response.open_url is not None:
                 self._handle_open_url(response.open_url)
+            if response.input_prompt is not None:
+                self._handle_input_prompt(prompt=response.input_prompt[0],
+                                          as_password=response.input_prompt[1])
             if response.end_message is not None:
                 print(response.end_message,
                       end=response.end_message_end,