Sync from development - prepare for v0.5.0

jackify/frontends/cli/ui/indeterminate_status.py

@@ -0,0 +1,70 @@
+"""Single-line CLI pulser for indeterminate background stages."""
+
+from __future__ import annotations
+
+import itertools
+import sys
+import threading
+import time
+from typing import Optional
+
+
+class CliIndeterminateStatus:
+    """Render one in-place pulsing status line for long-running CLI steps."""
+
+    def __init__(self, output=None, interval: float = 0.12):
+        self._output = output or sys.stdout
+        self._interval = interval
+        self._interactive = bool(getattr(self._output, "isatty", lambda: False)())
+        self._message: Optional[str] = None
+        self._printed_message: Optional[str] = None
+        self._stop_event = threading.Event()
+        self._lock = threading.Lock()
+        self._thread: Optional[threading.Thread] = None
+
+    def set(self, message: str) -> None:
+        """Start or update the active pulsing message."""
+        cleaned = (message or "").strip()
+        if not cleaned:
+            self.stop()
+            return
+        if not self._interactive:
+            if cleaned != self._printed_message:
+                print(cleaned, file=self._output, flush=True)
+                self._printed_message = cleaned
+            return
+        with self._lock:
+            self._message = cleaned
+        if self._thread and self._thread.is_alive():
+            return
+        self._stop_event.clear()
+        self._thread = threading.Thread(target=self._run, daemon=True)
+        self._thread.start()
+
+    def stop(self) -> None:
+        """Stop the pulser and clear its terminal line."""
+        if not self._interactive:
+            return
+        self._stop_event.set()
+        if self._thread and self._thread.is_alive():
+            self._thread.join(timeout=0.5)
+        self._thread = None
+        with self._lock:
+            self._message = None
+        self._output.write("\r\033[2K")
+        self._output.flush()
+
+    def close(self) -> None:
+        self.stop()
+
+    def _run(self) -> None:
+        for frame in itertools.cycle("|/-\\"):
+            if self._stop_event.wait(self._interval):
+                return
+            with self._lock:
+                message = self._message
+            if not message:
+                continue
+            self._output.write(f"\r\033[2K{message} {frame}")
+            self._output.flush()
+