From 234bbdb76bacb1373b83418121aae6beb68d70d9 Mon Sep 17 00:00:00 2001
From: perama-v <83961755+perama-v@users.noreply.github.com>
Date: Fri, 10 Mar 2023 16:04:25 +1100
Subject: [PATCH] implement failed strategy

---
 glados-audit/src/selection.rs | 84 ++++++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 2 deletions(-)

diff --git a/glados-audit/src/selection.rs b/glados-audit/src/selection.rs
index aea5954e..c471d84e 100644
--- a/glados-audit/src/selection.rs
+++ b/glados-audit/src/selection.rs
@@ -14,7 +14,7 @@ use tracing::{debug, error, warn};
 
 use entity::{
     content::{self, Model},
-    content_audit,
+    content_audit::{self, AuditResult},
 };
 
 /// Interval between audit selections for a particular strategy.
@@ -55,7 +55,7 @@ impl SelectionStrategy {
         match self {
             SelectionStrategy::Latest => select_latest_content_for_audit(tx, conn).await,
             SelectionStrategy::Random => select_random_content_for_audit(tx, conn).await,
-            SelectionStrategy::Failed => warn!("Need to implement SelectionStrategy::Failed"),
+            SelectionStrategy::Failed => select_failed_content_for_audit(tx, conn).await,
             SelectionStrategy::OldestMissing => {
                 warn!("Need to implement SelectionStrategy::OldestMissing")
             }
@@ -105,6 +105,55 @@ async fn select_latest_content_for_audit(
     }
 }
 
+/// Finds and sends audit tasks for [SelectionStrategy::Failed].
+///
+/// Strategy achieved by:
+/// 1. Look in audit table, filter for Failures, then sort oldest-first
+/// 2. Left join with the content table using find_with_related().
+async fn select_failed_content_for_audit(
+    tx: mpsc::Sender<HistoryContentKey>,
+    conn: DatabaseConnection,
+) -> ! {
+    debug!("initializing audit process for 'failed' strategy");
+
+    let mut interval = interval(Duration::from_secs(AUDIT_SELECTION_PERIOD_SECONDS));
+    loop {
+        interval.tick().await;
+        if tx.is_closed() {
+            error!("Channel is closed.");
+            panic!();
+        }
+        let search_result: Vec<(content_audit::Model, Vec<content::Model>)> =
+            match content_audit::Entity::find()
+                .filter(content_audit::Column::Result.eq(AuditResult::Failure))
+                .order_by_asc(content_audit::Column::CreatedAt)
+                .find_with_related(content::Entity)
+                .limit(KEYS_PER_PERIOD)
+                .all(&conn)
+                .await
+            {
+                Ok(result) => result,
+                Err(err) => {
+                    error!(audit.strategy="failed", err=?err, "Could not make audit query");
+                    continue;
+                }
+            };
+        // The search returns multiple possible content for each audit.
+        // Yet, we know there will be one content because audits only have one one content foreign key.
+        let content_key_db_entries: Vec<content::Model> = search_result
+            .into_iter()
+            .filter_map(|(_audit, contents)| contents.into_iter().next())
+            .collect();
+
+        let item_count = content_key_db_entries.len();
+        debug!(
+            strategy = "failed",
+            item_count, "Adding content keys to the audit queue."
+        );
+        add_to_queue(tx.clone(), content_key_db_entries).await;
+    }
+}
+
 /// Adds Glados database History sub-protocol search results
 /// to a channel for auditing against a Portal Node.
 async fn add_to_queue(tx: mpsc::Sender<HistoryContentKey>, items: Vec<Model>) {
@@ -324,4 +373,35 @@ mod tests {
         // Make sure no key was audited twice by pushing to a hashmap and checking it's length.
         assert_eq!(checked_ids.len(), KEYS_PER_PERIOD as usize);
     }
+
+    /// Tests that the `SelectionStrategy::Failed` selects the correct values
+    /// from the test database.
+    #[tokio::test]
+    async fn test_failed_strategy() {
+        // Orchestration
+        let conn = get_populated_test_audit_db().await.unwrap();
+        let (tx, mut rx) = channel::<HistoryContentKey>(100);
+        // Start strategy
+        tokio::spawn(select_failed_content_for_audit(tx.clone(), conn.clone()));
+        let mut checked_ids: HashSet<i32> = HashSet::new();
+        // There are 7 correct values: [17, 19, ..., 27, 29]
+        let expected_key_ids: Vec<i32> = vec![17, 19, 21, 23, 25, 27, 29];
+        // Await strategy results
+        while let Some(key) = rx.recv().await {
+            let key_model = content::Entity::find()
+                .filter(content::Column::ContentKey.eq(key.to_bytes()))
+                .one(&conn)
+                .await
+                .unwrap()
+                .unwrap();
+            // Check that strategy only yields expected keys.
+            assert!(expected_key_ids.contains(&key_model.id));
+            checked_ids.insert(key_model.id);
+            if checked_ids.len() == expected_key_ids.len() as usize {
+                break;
+            }
+        }
+        // Make sure no key was audited twice by pushing to a hashmap and checking it's length.
+        assert_eq!(checked_ids.len(), expected_key_ids.len() as usize);
+    }
 }