moved postman into separate crate

postman/src/lib.rs

@@ -0,0 +1,33 @@
+mod sender;
+
+use log::info;
+use serenity::client::Context;
+use sqlx::{Executor, MySql};
+use std::env;
+use tokio::time::sleep_until;
+use tokio::time::{Duration, Instant};
+
+type Database = MySql;
+
+pub async fn initialize(ctx: Context, pool: impl Executor<'_, Database = Database> + Copy) {
+    let REMIND_INTERVAL = env::var("REMIND_INTERVAL")
+        .map(|inner| inner.parse::<u64>().ok())
+        .ok()
+        .flatten()
+        .unwrap_or(10);
+
+    loop {
+        let sleep_to = Instant::now() + Duration::from_secs(REMIND_INTERVAL);
+        let reminders = sender::Reminder::fetch_reminders(pool).await;
+
+        if reminders.len() > 0 {
+            info!("Preparing to send {} reminders.", reminders.len());
+
+            for reminder in reminders {
+                reminder.send(pool, ctx.clone()).await;
+            }
+        }
+
+        sleep_until(sleep_to).await;
+    }
+}