Move to hour-resolution adverts

app/migrations.py

@@ -177,6 +177,13 @@ async def run_migrations(conn: aiosqlite.Connection) -> int:
         await set_version(conn, 20)
         applied += 1
 
+    # Migration 21: Enforce minimum 1-hour advert interval
+    if version < 21:
+        logger.info("Applying migration 21: enforce minimum 1-hour advert interval")
+        await _migrate_021_enforce_min_advert_interval(conn)
+        await set_version(conn, 21)
+        applied += 1
+
     if applied > 0:
         logger.info(
             "Applied %d migration(s), schema now at version %d", applied, await get_version(conn)
@@ -1252,3 +1259,27 @@ async def _migrate_020_enable_wal_and_auto_vacuum(conn: aiosqlite.Connection) ->
     logger.info("Journal mode set to %s", mode)
 
     await conn.commit()
+
+
+async def _migrate_021_enforce_min_advert_interval(conn: aiosqlite.Connection) -> None:
+    """
+    Enforce minimum 1-hour advert interval.
+
+    Any advert_interval between 1 and 3599 is clamped up to 3600 (1 hour).
+    Zero (disabled) is left unchanged.
+    """
+    # Guard: app_settings table may not exist if running against a very old schema
+    # (it's created in migration 9). The UPDATE is harmless if the table exists
+    # but has no rows, but will error if the table itself is missing.
+    cursor = await conn.execute(
+        "SELECT name FROM sqlite_master WHERE type='table' AND name='app_settings'"
+    )
+    if await cursor.fetchone() is None:
+        logger.debug("app_settings table does not exist yet, skipping advert_interval clamp")
+        return
+
+    await conn.execute(
+        "UPDATE app_settings SET advert_interval = 3600 WHERE advert_interval > 0 AND advert_interval < 3600"
+    )
+    await conn.commit()
+    logger.debug("Clamped advert_interval to minimum 3600 seconds")

app/radio_sync.py

@@ -41,6 +41,11 @@ _advert_task: asyncio.Task | None = None
 # We still need to periodically check if it's been enabled
 ADVERT_CHECK_INTERVAL = 60
 
+# Minimum allowed advertisement interval (1 hour).
+# Even if the database has a shorter value, we silently refuse to advertise
+# more frequently than this.
+MIN_ADVERT_INTERVAL = 3600
+
 # Counter to pause polling during repeater operations (supports nested pauses)
 _polling_pause_count: int = 0
 
@@ -384,6 +389,9 @@ async def send_advertisement(force: bool = False) -> bool:
             logger.debug("Advertisement skipped: periodic advertising is disabled")
             return False
 
+        # Enforce minimum interval floor
+        interval = max(interval, MIN_ADVERT_INTERVAL)
+
         # Check if enough time has passed
         elapsed = now - last_time
         if elapsed < interval:

app/routers/settings.py

@@ -52,7 +52,7 @@ class AppSettingsUpdate(BaseModel):
     advert_interval: int | None = Field(
         default=None,
         ge=0,
-        description="Periodic advertisement interval in seconds (0 = disabled)",
+        description="Periodic advertisement interval in seconds (0 = disabled, minimum 3600)",
     )
     bots: list[BotConfig] | None = Field(
         default=None,
@@ -111,8 +111,12 @@ async def update_settings(update: AppSettingsUpdate) -> AppSettings:
         kwargs["sidebar_sort_order"] = update.sidebar_sort_order
 
     if update.advert_interval is not None:
-        logger.info("Updating advert_interval to %d", update.advert_interval)
-        kwargs["advert_interval"] = update.advert_interval
+        # Enforce minimum 1-hour interval; 0 means disabled
+        interval = update.advert_interval
+        if 0 < interval < 3600:
+            interval = 3600
+        logger.info("Updating advert_interval to %d", interval)
+        kwargs["advert_interval"] = interval
 
     if update.bots is not None:
         validate_all_bots(update.bots)