feat: file deletion implementation

crates/daemons/crond/src/tasks/prune_dangling_files.rs

@@ -0,0 +1,36 @@
+use std::time::Duration;
+
+use revolt_database::{iso8601_timestamp::Timestamp, Database};
+use revolt_result::Result;
+use tokio::time::sleep;
+
+use log::info;
+
+pub async fn task(db: Database) -> Result<()> {
+    loop {
+        // This could just be a single database query
+        // ... but timestamps are inconsistently serialised
+        // ... sometimes they are dates/numbers, hard to query
+        // ... in the future, we could use Postgres instead! :D
+        // ...
+        // ... on the plus side, it's still only 2 queries
+
+        let files = db.fetch_dangling_files().await?;
+        let file_ids: Vec<String> = files
+            .into_iter()
+            .filter(|file| {
+                file.uploaded_at.is_some_and(|uploaded_at| {
+                    Timestamp::now_utc().duration_since(uploaded_at) > Duration::from_secs(60 * 60)
+                })
+            })
+            .map(|file| file.id)
+            .collect();
+
+        if !file_ids.is_empty() {
+            db.mark_attachments_as_deleted(&file_ids).await?;
+            info!("Marked {} dangling files for deletion", file_ids.len());
+        }
+
+        sleep(Duration::from_secs(60)).await;
+    }
+}