Add a sleep loop based on next action times clamping to a min/max range.

src/db/init.rs

@@ -68,9 +68,21 @@ impl DbHandle {
     pub(crate) fn get_time_until_next_action(
         &mut self,
     ) -> Result<Duration, Box<dyn std::error::Error>> {
-        let now = SystemTime::now()
-            .duration_since(SystemTime::UNIX_EPOCH)?
-            .as_secs();
-        todo!()
+        let now = SystemTime::now();
+        let mut stmt = self.conn.prepare(
+            "WITH next_runs AS (SELECT next_run FROM global_action UNION SELECT next_run FROM local_action) SELECT next_run FROM next_runs ORDER BY next_run ASC",
+        )?;
+        let rows = stmt
+            .query_map(params![], |row| Ok(row.get(0)?))?
+            .collect::<Result<Vec<u64>, _>>()?;
+        if let Some(r) = rows.into_iter().next() {
+            let next_run = SystemTime::UNIX_EPOCH + Duration::from_secs(r);
+            if next_run <= now {
+                return Ok(Duration::from_secs(0));
+            } else {
+                return Ok(next_run.duration_since(now)?);
+            }
+        }
+        return Ok(Duration::from_secs(0));
     }
 }

src/main.rs

@@ -9,6 +9,12 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut db_conn: db::DbHandle = db::DbHandle::new(db_path)?;
 
     loop {
-        thread::sleep(time::Duration::from_secs(300));
+        let time_until_next_action = db_conn.get_time_until_next_action()?;
+        let sleep_duration = std::cmp::min(
+            time::Duration::from_secs(60),
+            std::cmp::max(time_until_next_action, time::Duration::from_secs(300)),
+        );
+        println!("Sleeping for {} seconds.", sleep_duration.as_secs());
+        thread::sleep(sleep_duration);
     }
 }