try(backend): try hashing approach for progress update

apps/backend/src/miscellaneous/resolver.rs

@@ -28,6 +28,7 @@ use sea_query::{
     PostgresQueryBuilder, Query, SelectStatement, SqliteQueryBuilder, UnionType, Values,
 };
 use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
 use strum::IntoEnumIterator;
 use uuid::Uuid;
 
@@ -1618,8 +1619,25 @@ impl MiscellaneousService {
         input: ProgressUpdateInput,
         user_id: i32,
     ) -> Result<IdObject> {
-        // TODO: Hash `input.{metadata_id,show_season_number,show_episode_number,podcast_episode_number},user_id`
-        // and store it in a database so that implement de-duplication.
+        // Hash `input.{metadata_id,show_season_number,show_episode_number,podcast_episode_number},user_id`
+        // and store it in a memory database to implement de-duplication. Also
+        // set expiry for keys in the DB to the
+        // `config.server.progress_update_threshold` key.
+        let mut hasher = Sha256::new();
+        hasher.update(user_id.to_be_bytes());
+        hasher.update(input.metadata_id.to_be_bytes());
+        if let Some(s) = input.show_season_number {
+            hasher.update(s.to_be_bytes());
+        }
+        if let Some(s) = input.show_episode_number {
+            hasher.update(s.to_be_bytes());
+        }
+        if let Some(s) = input.podcast_episode_number {
+            hasher.update(s.to_be_bytes());
+        }
+        let result = hasher.finalize();
+        println!("{:?}", &result);
+
         let prev_seen = Seen::find()
             .filter(seen::Column::Progress.lt(100))
             .filter(seen::Column::UserId.eq(user_id))