fix: batch N+1 queries in import duplicate check and watch event dismiss

apply_mapping: 2 batch queries instead of up to 2N per-row lookups
dismiss: single fetch + single update instead of 2N per-event queries

crates/adapters/postgres/src/lib.rs

@@ -388,6 +388,54 @@ impl MovieRepository for PostgresRepository {
         Ok(())
     }
 
+    async fn existing_external_ids(
+        &self,
+        ids: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        if ids.is_empty() {
+            return Ok(Default::default());
+        }
+        let vals: Vec<String> = ids.iter().map(|id| id.value().to_string()).collect();
+        let rows: Vec<(String,)> = sqlx::query_as(
+            "SELECT external_metadata_id FROM movies WHERE external_metadata_id = ANY($1)",
+        )
+        .bind(&vals)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(Self::map_err)?;
+        Ok(rows.into_iter().map(|(id,)| id).collect())
+    }
+
+    async fn existing_title_year_pairs(
+        &self,
+        pairs: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        if pairs.is_empty() {
+            return Ok(Default::default());
+        }
+        let titles: Vec<&str> = pairs.iter().map(|(t, _)| t.value()).collect();
+        let years: Vec<i64> = pairs.iter().map(|(_, y)| y.value() as i64).collect();
+        use sqlx::Row;
+        let rows = sqlx::query(
+            "SELECT DISTINCT m.title, m.release_year FROM movies m \
+             INNER JOIN unnest($1::text[], $2::bigint[]) AS p(title, release_year) \
+             ON m.title = p.title AND m.release_year = p.release_year",
+        )
+        .bind(&titles)
+        .bind(&years)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(Self::map_err)?;
+        Ok(rows
+            .into_iter()
+            .map(|r| {
+                let t: String = r.get("title");
+                let y: i64 = r.get("release_year");
+                (t, y as u16)
+            })
+            .collect())
+    }
+
     async fn list_movies(
         &self,
         page: &domain::models::collections::PageParams,

crates/adapters/postgres/src/watch_event.rs

@@ -115,6 +115,45 @@ impl WatchEventRepository for PostgresWatchEventRepository {
         row.as_ref().map(row_to_watch_event).transpose()
     }
 
+    async fn get_by_ids(&self, ids: &[WatchEventId]) -> Result<Vec<WatchEvent>, DomainError> {
+        if ids.is_empty() {
+            return Ok(vec![]);
+        }
+        let id_strs: Vec<String> = ids.iter().map(|id| id.value().to_string()).collect();
+        let rows = sqlx::query(
+            "SELECT id, user_id, movie_id, title, year, external_metadata_id, \
+                    source, \
+                    to_char(watched_at AT TIME ZONE 'UTC', 'YYYY-MM-DD HH24:MI:SS') AS watched_at, \
+                    status, \
+                    to_char(created_at AT TIME ZONE 'UTC', 'YYYY-MM-DD HH24:MI:SS') AS created_at \
+             FROM watch_events WHERE id = ANY($1)",
+        )
+        .bind(&id_strs)
+        .fetch_all(&self.pool)
+        .await
+        .map_err(map_err)?;
+        rows.iter().map(row_to_watch_event).collect()
+    }
+
+    async fn update_status_batch(
+        &self,
+        ids: &[WatchEventId],
+        status: WatchEventStatus,
+    ) -> Result<u64, DomainError> {
+        if ids.is_empty() {
+            return Ok(0);
+        }
+        let id_strs: Vec<String> = ids.iter().map(|id| id.value().to_string()).collect();
+        let status_str = status.to_string();
+        let result = sqlx::query("UPDATE watch_events SET status = $1 WHERE id = ANY($2)")
+            .bind(&status_str)
+            .bind(&id_strs)
+            .execute(&self.pool)
+            .await
+            .map_err(map_err)?;
+        Ok(result.rows_affected())
+    }
+
     async fn find_duplicate(
         &self,
         user_id: &UserId,

crates/adapters/sqlite/src/lib.rs

@@ -402,6 +402,57 @@ impl MovieRepository for SqliteMovieRepository {
         Ok(())
     }
 
+    async fn existing_external_ids(
+        &self,
+        ids: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        if ids.is_empty() {
+            return Ok(Default::default());
+        }
+        let placeholders: Vec<&str> = ids.iter().map(|_| "?").collect();
+        let sql = format!(
+            "SELECT external_metadata_id FROM movies WHERE external_metadata_id IN ({})",
+            placeholders.join(",")
+        );
+        let mut q = sqlx::query_scalar::<_, String>(&sql);
+        for id in ids {
+            q = q.bind(id.value().to_string());
+        }
+        let rows = q.fetch_all(&self.pool).await.map_err(Self::map_err)?;
+        Ok(rows.into_iter().collect())
+    }
+
+    async fn existing_title_year_pairs(
+        &self,
+        pairs: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        if pairs.is_empty() {
+            return Ok(Default::default());
+        }
+        let conditions: Vec<String> = pairs
+            .iter()
+            .map(|_| "(title = ? AND release_year = ?)".to_string())
+            .collect();
+        let sql = format!(
+            "SELECT DISTINCT title, release_year FROM movies WHERE {}",
+            conditions.join(" OR ")
+        );
+        use sqlx::Row;
+        let mut q = sqlx::query(&sql);
+        for (t, y) in pairs {
+            q = q.bind(t.value().to_string()).bind(y.value() as i64);
+        }
+        let rows = q.fetch_all(&self.pool).await.map_err(Self::map_err)?;
+        Ok(rows
+            .into_iter()
+            .map(|r| {
+                let t: String = r.get("title");
+                let y: i64 = r.get("release_year");
+                (t, y as u16)
+            })
+            .collect())
+    }
+
     async fn list_movies(
         &self,
         page: &domain::models::collections::PageParams,

crates/adapters/sqlite/src/watch_event.rs

@@ -122,6 +122,46 @@ impl WatchEventRepository for SqliteWatchEventRepository {
         row.as_ref().map(row_to_watch_event).transpose()
     }
 
+    async fn get_by_ids(&self, ids: &[WatchEventId]) -> Result<Vec<WatchEvent>, DomainError> {
+        if ids.is_empty() {
+            return Ok(vec![]);
+        }
+        let placeholders: Vec<&str> = ids.iter().map(|_| "?").collect();
+        let sql = format!(
+            "SELECT id, user_id, movie_id, title, year, external_metadata_id, \
+                    source, watched_at, status, created_at \
+             FROM watch_events WHERE id IN ({})",
+            placeholders.join(",")
+        );
+        let mut q = sqlx::query(&sql);
+        for id in ids {
+            q = q.bind(id.value().to_string());
+        }
+        let rows = q.fetch_all(&self.pool).await.map_err(map_err)?;
+        rows.iter().map(row_to_watch_event).collect()
+    }
+
+    async fn update_status_batch(
+        &self,
+        ids: &[WatchEventId],
+        status: WatchEventStatus,
+    ) -> Result<u64, DomainError> {
+        if ids.is_empty() {
+            return Ok(0);
+        }
+        let placeholders: Vec<&str> = ids.iter().map(|_| "?").collect();
+        let sql = format!(
+            "UPDATE watch_events SET status = ? WHERE id IN ({})",
+            placeholders.join(",")
+        );
+        let mut q = sqlx::query(&sql).bind(status.to_string());
+        for id in ids {
+            q = q.bind(id.value().to_string());
+        }
+        let result = q.execute(&self.pool).await.map_err(map_err)?;
+        Ok(result.rows_affected())
+    }
+
     async fn find_duplicate(
         &self,
         user_id: &UserId,

crates/application/src/diary/tests/movie_resolver.rs

@@ -55,6 +55,18 @@ impl MovieRepository for RepoWithExternalMovie {
     async fn delete_movie(&self, _: &MovieId) -> Result<(), DomainError> {
         panic!("unexpected")
     }
+    async fn existing_external_ids(
+        &self,
+        _: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        panic!("unexpected")
+    }
+    async fn existing_title_year_pairs(
+        &self,
+        _: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        panic!("unexpected")
+    }
     async fn list_movies(
         &self,
         _: &domain::models::collections::PageParams,
@@ -89,6 +101,18 @@ impl MovieRepository for RepoEmpty {
     async fn delete_movie(&self, _: &MovieId) -> Result<(), DomainError> {
         panic!("unexpected")
     }
+    async fn existing_external_ids(
+        &self,
+        _: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        panic!("unexpected")
+    }
+    async fn existing_title_year_pairs(
+        &self,
+        _: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        panic!("unexpected")
+    }
     async fn list_movies(
         &self,
         _: &domain::models::collections::PageParams,
@@ -123,6 +147,18 @@ impl MovieRepository for RepoWithTitleMatch {
     async fn delete_movie(&self, _: &MovieId) -> Result<(), DomainError> {
         panic!("unexpected")
     }
+    async fn existing_external_ids(
+        &self,
+        _: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        panic!("unexpected")
+    }
+    async fn existing_title_year_pairs(
+        &self,
+        _: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        panic!("unexpected")
+    }
     async fn list_movies(
         &self,
         _: &domain::models::collections::PageParams,

crates/application/src/import/apply_mapping.rs

@@ -20,7 +20,6 @@ pub async fn execute(
         .await?
         .ok_or_else(|| DomainError::NotFound("import session".into()))?;
 
-    // clone to avoid borrow conflict when mutating session fields below
     let parsed = session
         .parsed_file
         .clone()
@@ -31,11 +30,7 @@ pub async fn execute(
         .document_parser
         .apply_mapping(&parsed, &mappings);
 
-    for row in annotated.iter_mut() {
-        if let RowResult::Valid(ref import_row) = row.result {
-            row.is_duplicate = check_duplicate(ctx, import_row).await?;
-        }
-    }
+    mark_duplicates(ctx, &mut annotated).await?;
 
     session.field_mappings = Some(mappings);
     session.row_results = Some(annotated.clone());
@@ -45,33 +40,52 @@ pub async fn execute(
     Ok(annotated)
 }
 
-async fn check_duplicate(
-    ctx: &AppContext,
-    row: &domain::models::ImportRow,
-) -> Result<bool, DomainError> {
-    if let Some(ext_id) = &row.external_metadata_id
-        && let Ok(eid) = ExternalMetadataId::new(ext_id.clone())
-        && ctx
-            .repos
-            .movie
-            .get_movie_by_external_id(&eid)
-            .await?
-            .is_some()
-    {
-        return Ok(true);
-    }
-    if let (Some(title), Some(year_str)) = (&row.title, &row.release_year) {
-        let title_vo = MovieTitle::new(title.clone());
-        let year_vo = year_str
-            .parse::<u16>()
-            .ok()
-            .and_then(|y| ReleaseYear::new(y).ok());
-        if let (Ok(t), Some(y)) = (title_vo, year_vo) {
-            let matches = ctx.repos.movie.get_movies_by_title_and_year(&t, &y).await?;
-            if !matches.is_empty() {
-                return Ok(true);
+async fn mark_duplicates(ctx: &AppContext, rows: &mut [AnnotatedRow]) -> Result<(), DomainError> {
+    let mut ext_ids = Vec::new();
+    let mut title_year_pairs = Vec::new();
+
+    for row in rows.iter() {
+        if let RowResult::Valid(ref r) = row.result {
+            if let Some(ext_id) = &r.external_metadata_id
+                && let Ok(eid) = ExternalMetadataId::new(ext_id.clone())
+            {
+                ext_ids.push(eid);
+            }
+            if let (Some(title), Some(year_str)) = (&r.title, &r.release_year)
+                && let Ok(t) = MovieTitle::new(title.clone())
+                && let Some(y) = year_str
+                    .parse::<u16>()
+                    .ok()
+                    .and_then(|y| ReleaseYear::new(y).ok())
+            {
+                title_year_pairs.push((t, y));
             }
         }
     }
-    Ok(false)
+
+    let known_ext = ctx.repos.movie.existing_external_ids(&ext_ids).await?;
+    let known_ty = ctx
+        .repos
+        .movie
+        .existing_title_year_pairs(&title_year_pairs)
+        .await?;
+
+    for row in rows.iter_mut() {
+        if let RowResult::Valid(ref r) = row.result {
+            if let Some(ext_id) = &r.external_metadata_id
+                && known_ext.contains(ext_id)
+            {
+                row.is_duplicate = true;
+                continue;
+            }
+            if let (Some(title), Some(year_str)) = (&r.title, &r.release_year)
+                && let Ok(y) = year_str.parse::<u16>()
+                && known_ty.contains(&(title.clone(), y))
+            {
+                row.is_duplicate = true;
+            }
+        }
+    }
+
+    Ok(())
 }

crates/application/src/integrations/dismiss.rs

@@ -8,28 +8,34 @@ use crate::{context::AppContext, integrations::commands::DismissWatchEventsComma
 
 pub async fn execute(ctx: &AppContext, cmd: DismissWatchEventsCommand) -> Result<u32, DomainError> {
     let user_id = UserId::from_uuid(cmd.user_id);
-    let mut dismissed = 0u32;
+    if cmd.event_ids.is_empty() {
+        return Ok(0);
+    }
 
-    for id in cmd.event_ids {
-        let event_id = WatchEventId::from_uuid(id);
-        let event = ctx
-            .repos
-            .watch_event
-            .get_by_id(&event_id)
-            .await?
-            .ok_or_else(|| DomainError::NotFound(format!("WatchEvent {id}")))?;
+    let ids: Vec<WatchEventId> = cmd
+        .event_ids
+        .iter()
+        .map(|id| WatchEventId::from_uuid(*id))
+        .collect();
 
+    let events = ctx.repos.watch_event.get_by_ids(&ids).await?;
+
+    if events.len() != ids.len() {
+        return Err(DomainError::NotFound(
+            "one or more WatchEvents not found".into(),
+        ));
+    }
+    for event in &events {
         if event.user_id() != &user_id {
             return Err(DomainError::Unauthorized("not your watch event".into()));
         }
-
-        ctx.repos
-            .watch_event
-            .update_status(&event_id, WatchEventStatus::Dismissed)
-            .await?;
-
-        dismissed += 1;
     }
 
-    Ok(dismissed)
+    let count = ctx
+        .repos
+        .watch_event
+        .update_status_batch(&ids, WatchEventStatus::Dismissed)
+        .await?;
+
+    Ok(count as u32)
 }

crates/domain/src/ports.rs

@@ -100,6 +100,14 @@ pub trait MovieRepository: Send + Sync {
     ) -> Result<Vec<Movie>, DomainError>;
     async fn upsert_movie(&self, movie: &Movie) -> Result<(), DomainError>;
     async fn delete_movie(&self, movie_id: &MovieId) -> Result<(), DomainError>;
+    async fn existing_external_ids(
+        &self,
+        ids: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError>;
+    async fn existing_title_year_pairs(
+        &self,
+        pairs: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError>;
     async fn list_movies(
         &self,
         page: &collections::PageParams,
@@ -434,6 +442,12 @@ pub trait WatchEventRepository: Send + Sync {
     ) -> Result<(), DomainError>;
     async fn list_pending(&self, user_id: &UserId) -> Result<Vec<WatchEvent>, DomainError>;
     async fn get_by_id(&self, id: &WatchEventId) -> Result<Option<WatchEvent>, DomainError>;
+    async fn get_by_ids(&self, ids: &[WatchEventId]) -> Result<Vec<WatchEvent>, DomainError>;
+    async fn update_status_batch(
+        &self,
+        ids: &[WatchEventId],
+        status: WatchEventStatus,
+    ) -> Result<u64, DomainError>;
     async fn find_duplicate(
         &self,
         user_id: &UserId,

crates/domain/src/testing.rs

@@ -97,6 +97,38 @@ impl MovieRepository for InMemoryMovieRepository {
         Ok(())
     }
 
+    async fn existing_external_ids(
+        &self,
+        ids: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        let store = self.store.lock().unwrap();
+        let known: std::collections::HashSet<String> = store
+            .values()
+            .filter_map(|m| m.external_metadata_id().map(|e| e.value().to_string()))
+            .collect();
+        Ok(ids
+            .iter()
+            .map(|id| id.value().to_string())
+            .filter(|v| known.contains(v))
+            .collect())
+    }
+
+    async fn existing_title_year_pairs(
+        &self,
+        pairs: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        let store = self.store.lock().unwrap();
+        let known: std::collections::HashSet<(String, u16)> = store
+            .values()
+            .map(|m| (m.title().value().to_string(), m.release_year().value()))
+            .collect();
+        Ok(pairs
+            .iter()
+            .map(|(t, y)| (t.value().to_string(), y.value()))
+            .filter(|p| known.contains(p))
+            .collect())
+    }
+
     async fn list_movies(
         &self,
         _page: &crate::models::collections::PageParams,
@@ -868,6 +900,19 @@ impl crate::ports::WatchEventRepository for PanicWatchEventRepository {
     ) -> Result<Option<crate::models::WatchEvent>, DomainError> {
         panic!("PanicWatchEventRepository called")
     }
+    async fn get_by_ids(
+        &self,
+        _: &[crate::value_objects::WatchEventId],
+    ) -> Result<Vec<crate::models::WatchEvent>, DomainError> {
+        panic!("PanicWatchEventRepository called")
+    }
+    async fn update_status_batch(
+        &self,
+        _: &[crate::value_objects::WatchEventId],
+        _: crate::models::WatchEventStatus,
+    ) -> Result<u64, DomainError> {
+        panic!("PanicWatchEventRepository called")
+    }
     async fn find_duplicate(
         &self,
         _: &UserId,

crates/presentation/src/tests/extractors.rs

@@ -60,6 +60,18 @@ impl MovieRepository for Panic {
     async fn delete_movie(&self, _: &MovieId) -> Result<(), DomainError> {
         panic!()
     }
+    async fn existing_external_ids(
+        &self,
+        _: &[ExternalMetadataId],
+    ) -> Result<std::collections::HashSet<String>, DomainError> {
+        panic!()
+    }
+    async fn existing_title_year_pairs(
+        &self,
+        _: &[(MovieTitle, ReleaseYear)],
+    ) -> Result<std::collections::HashSet<(String, u16)>, DomainError> {
+        panic!()
+    }
     async fn list_movies(
         &self,
         _: &domain::models::collections::PageParams,
@@ -496,6 +508,19 @@ impl domain::ports::WatchEventRepository for Panic {
     ) -> Result<Option<domain::models::WatchEvent>, DomainError> {
         panic!()
     }
+    async fn get_by_ids(
+        &self,
+        _: &[domain::value_objects::WatchEventId],
+    ) -> Result<Vec<domain::models::WatchEvent>, DomainError> {
+        panic!()
+    }
+    async fn update_status_batch(
+        &self,
+        _: &[domain::value_objects::WatchEventId],
+        _: domain::models::WatchEventStatus,
+    ) -> Result<u64, DomainError> {
+        panic!()
+    }
     async fn find_duplicate(
         &self,
         _: &domain::value_objects::UserId,