feat: stream provider responses

src/javis/interface/cli.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 
 import argparse
 import getpass
+import re
 import sys
 from collections.abc import Callable, Sequence
 from pathlib import Path
@@ -27,6 +28,7 @@ from javis.security.secrets import SecretProvider, SecretStoreError
 
 InputFunction = Callable[[str], str]
 OutputFunction = Callable[[str], None]
+StreamOutputFunction = Callable[[str], None]
 StatusFunction = Callable[[], list[str]]
 
 HELP_TEXT = """Befehle:
@@ -144,12 +146,48 @@ def _show_sessions(sessions: list[ChatSession], output: OutputFunction) -> None:
         )
 
 
+class TerminalMarkdownRenderer:
+    """Turn common Markdown markers into readable incremental terminal text."""
+
+    _tail_size = 3
+
+    def __init__(self) -> None:
+        self._pending = ""
+
+    @staticmethod
+    def _clean(text: str) -> str:
+        text = re.sub(r"(?m)^[ \t]{0,3}#{1,6}[ \t]+", "", text)
+        for marker in ("```", "**", "__", "~~", "`"):
+            text = text.replace(marker, "")
+        return text
+
+    def feed(self, chunk: str) -> str:
+        combined = self._pending + chunk
+        if len(combined) <= self._tail_size:
+            self._pending = combined
+            return ""
+        visible = combined[: -self._tail_size]
+        self._pending = combined[-self._tail_size :]
+        return self._clean(visible)
+
+    def finish(self) -> str:
+        visible = self._clean(self._pending)
+        self._pending = ""
+        return visible
+
+
+def _terminal_write(text: str) -> None:
+    sys.stdout.write(text)
+    sys.stdout.flush()
+
+
 def run_chat(
     service: ChatService,
     *,
     session_id: str | None = None,
     input_fn: InputFunction = input,
     output: OutputFunction = print,
+    stream_output: StreamOutputFunction | None = None,
     status_fn: StatusFunction | None = None,
 ) -> int:
     try:
@@ -262,12 +300,41 @@ def run_chat(
             output("Unbekannter Befehl. /help zeigt die verfügbaren Befehle.")
             continue
 
+        stream = service.stream_send(active_id, entered)
+        writer = stream_output or (_terminal_write if output is print else output)
+        renderer = TerminalMarkdownRenderer()
+        started = False
         try:
-            response = service.send(active_id, entered)
-            output(f"Javis: {response}")
+            for chunk in stream:
+                visible = renderer.feed(chunk)
+                if not visible:
+                    continue
+                if not started:
+                    writer("Javis: ")
+                    started = True
+                writer(visible)
+            remaining = renderer.finish()
+            if remaining:
+                if not started:
+                    writer("Javis: ")
+                    started = True
+                writer(remaining)
+            if started:
+                writer("\n")
+        except KeyboardInterrupt:
+            close = getattr(stream, "close", None)
+            if callable(close):
+                close()
+            if started:
+                writer("\n")
+            output("Generierung abgebrochen. Die unvollständige Antwort wurde nicht gespeichert.")
         except (ProviderError, SessionStoreError, SessionProviderMismatchError) as exc:
+            if started:
+                writer("\n")
             output(f"Fehler: {exc}")
         except ValueError as exc:
+            if started:
+                writer("\n")
             output(f"Fehler: {exc}")