feat: Introduce ntfy.sh message polling, content fetching with caching, and microphone input monitoring.

engine/ntfy.py

@@ -0,0 +1,75 @@
+"""
+ntfy.sh message poller — standalone, zero internal dependencies.
+Reusable by any visualizer:
+
+    from engine.ntfy import NtfyPoller
+    poller = NtfyPoller("https://ntfy.sh/my_topic/json?since=20s&poll=1")
+    poller.start()
+    # in render loop:
+    msg = poller.get_active_message()
+    if msg:
+        title, body, ts = msg
+        render_my_message(title, body)
+"""
+
+import json
+import time
+import threading
+import urllib.request
+
+
+class NtfyPoller:
+    """Background poller for ntfy.sh topics."""
+
+    def __init__(self, topic_url, poll_interval=15, display_secs=30):
+        self.topic_url = topic_url
+        self.poll_interval = poll_interval
+        self.display_secs = display_secs
+        self._message = None   # (title, body, monotonic_timestamp) or None
+        self._lock = threading.Lock()
+
+    def start(self):
+        """Start background polling thread. Returns True."""
+        t = threading.Thread(target=self._poll_loop, daemon=True)
+        t.start()
+        return True
+
+    def get_active_message(self):
+        """Return (title, body, timestamp) if a message is active and not expired, else None."""
+        with self._lock:
+            if self._message is None:
+                return None
+            title, body, ts = self._message
+            if time.monotonic() - ts < self.display_secs:
+                return self._message
+            self._message = None
+            return None
+
+    def dismiss(self):
+        """Manually dismiss the current message."""
+        with self._lock:
+            self._message = None
+
+    def _poll_loop(self):
+        while True:
+            try:
+                req = urllib.request.Request(
+                    self.topic_url, headers={"User-Agent": "mainline/0.1"})
+                resp = urllib.request.urlopen(req, timeout=10)
+                for line in resp.read().decode('utf-8', errors='replace').strip().split('\n'):
+                    if not line.strip():
+                        continue
+                    try:
+                        data = json.loads(line)
+                    except json.JSONDecodeError:
+                        continue
+                    if data.get("event") == "message":
+                        with self._lock:
+                            self._message = (
+                                data.get("title", ""),
+                                data.get("message", ""),
+                                time.monotonic(),
+                            )
+            except Exception:
+                pass
+            time.sleep(self.poll_interval)