refactor: move business logic out of presentation — ReadAssetFile, checksum, auth checks, MetadataValue conversions

crates/application/src/catalog/queries/get_asset.rs

@@ -10,6 +10,7 @@ use std::sync::Arc;
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 pub struct GetAssetQuery {
     pub asset_id: SystemId,
+    pub user_id: SystemId,
 }
 
 pub struct GetAssetHandler {
@@ -38,6 +39,10 @@ impl GetAssetHandler {
             .await?
             .ok_or_else(|| DomainError::NotFound(format!("Asset {} not found", query.asset_id)))?;
 
+        if asset.owner_user_id != query.user_id {
+            return Err(DomainError::Forbidden("Access denied".to_string()));
+        }
+
         let layers = self.metadata_repo.find_by_asset(&asset.asset_id).await?;
         let resolved = resolve_metadata(&layers);
 

crates/application/src/catalog/queries/mod.rs

@@ -1,2 +1,3 @@
 pub mod get_asset;
 pub mod get_timeline;
+pub mod read_asset_file;

crates/application/src/catalog/queries/read_asset_file.rs

@@ -0,0 +1,62 @@
+use bytes::Bytes;
+use domain::{
+    errors::DomainError,
+    ports::{AssetRepository, FileStoragePort},
+    value_objects::SystemId,
+};
+use std::sync::Arc;
+
+#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
+pub struct ReadAssetFileQuery {
+    pub asset_id: SystemId,
+}
+
+pub struct AssetFileResult {
+    pub data: Bytes,
+    pub mime_type: String,
+    pub filename: String,
+}
+
+pub struct ReadAssetFileHandler {
+    asset_repo: Arc<dyn AssetRepository>,
+    file_storage: Arc<dyn FileStoragePort>,
+}
+
+impl ReadAssetFileHandler {
+    pub fn new(
+        asset_repo: Arc<dyn AssetRepository>,
+        file_storage: Arc<dyn FileStoragePort>,
+    ) -> Self {
+        Self {
+            asset_repo,
+            file_storage,
+        }
+    }
+
+    pub async fn execute(&self, query: ReadAssetFileQuery) -> Result<AssetFileResult, DomainError> {
+        let asset = self
+            .asset_repo
+            .find_by_id(&query.asset_id)
+            .await?
+            .ok_or_else(|| DomainError::NotFound(format!("Asset {} not found", query.asset_id)))?;
+
+        let data = self
+            .file_storage
+            .read_file(&asset.source_reference.relative_path)
+            .await?;
+
+        let filename = asset
+            .source_reference
+            .relative_path
+            .rsplit('/')
+            .next()
+            .unwrap_or(&asset.source_reference.relative_path)
+            .to_string();
+
+        Ok(AssetFileResult {
+            data,
+            mime_type: asset.mime_type,
+            filename,
+        })
+    }
+}