proxy downloads

backend/src/services/documents.rs

@@ -20,10 +20,11 @@ use uuid::Uuid;
 
 use crate::documents::{
     asset::{
-        build_download_path, derive_document_title, filename_with_retained_extension,
-        load_asset_responses_with_conn, load_primary_assets, to_asset_detail_response,
-        to_asset_object_response, to_version_response, DocumentAssetDetailResponse,
-        DocumentAssetResponse, DocumentVersionDetailResponse, DocumentVersionResponse,
+        asset_object_disposition, build_download_path, derive_document_title,
+        filename_with_retained_extension, load_asset_responses_with_conn, load_primary_assets,
+        to_asset_detail_response, to_asset_object_response, to_version_response,
+        DocumentAssetDetailResponse, DocumentAssetResponse, DocumentVersionDetailResponse,
+        DocumentVersionResponse,
     },
     correspondents::{
         insert_document_correspondents, normalize_correspondent_ids, DocumentCorrespondentResponse,
@@ -905,6 +906,7 @@ impl<'a> DocumentsService<'a> {
         &self,
         mut conn: PgPooledConnection,
         tenant_id: Uuid,
+        user_id: Uuid,
         asset_id: Uuid,
         start: i32,
         limit: i32,
@@ -945,25 +947,43 @@ impl<'a> DocumentsService<'a> {
             .checked_add((PRESIGNED_URL_EXPIRY_SECONDS as i64) * 1000)
             .ok_or_else(|| AppError::internal("failed to compute expiry timestamp"))?;
 
-        let storage = self.state.storage_for_tenant(tenant_id)?;
+        let storage = (!self.state.config.proxy_downloads)
+            .then(|| self.state.storage_for_tenant(tenant_id))
+            .transpose()?;
 
         let mut object_responses = Vec::with_capacity(objects.len());
         for object in objects {
-            let response_disposition = presign_disposition_for_asset(&asset, &object);
+            let response_disposition = asset_object_disposition(&asset, &object);
 
-            let url = storage
-                .presign_get_object(
-                    &object.s3_key,
-                    Duration::from_secs(PRESIGNED_URL_EXPIRY_SECONDS),
-                    response_disposition.as_deref(),
-                )
-                .await
-                .storage_context("failed to generate asset URL")?;
+            let (url, object_expires_at) = if self.state.config.proxy_downloads {
+                let token = self
+                    .state
+                    .jwt
+                    .generate_asset_download_token(asset.id, object.id, user_id, tenant_id)
+                    .map_err(|err| {
+                        error!(error = ?err, "failed to issue asset download token");
+                        AppError::internal("failed to issue asset download token")
+                    })?;
+                (format!("/download/{token}"), None)
+            } else {
+                let storage = storage
+                    .as_ref()
+                    .expect("storage preloaded when proxy disabled");
+                let url = storage
+                    .presign_get_object(
+                        &object.s3_key,
+                        Duration::from_secs(PRESIGNED_URL_EXPIRY_SECONDS),
+                        response_disposition.as_deref(),
+                    )
+                    .await
+                    .storage_context("failed to generate asset URL")?;
+                (url, Some(expires_at))
+            };
 
             object_responses.push(to_asset_object_response(
                 object,
                 Some(url),
-                Some(expires_at),
+                object_expires_at,
             ));
         }
 
@@ -1008,7 +1028,7 @@ impl<'a> DocumentsService<'a> {
             .first(conn)?;
 
         let assets = load_asset_responses_with_conn(conn, tenant_id, version.id)?;
-        let download_path = build_download_path(self.state, &document, user_id)?;
+        let download_path = build_download_path(self.state, &document, version.id, user_id)?;
         let version_core = to_version_response(version);
 
         Ok(DocumentVersionDetailResponse {
@@ -1326,11 +1346,14 @@ impl<'a> DocumentsService<'a> {
         current_version: Option<(DocumentVersionResponse, Vec<DocumentAssetResponse>)>,
     ) -> AppResult<DocumentResponse> {
         let current_version = match current_version {
-            Some((version, assets)) => Some(DocumentVersionDetailResponse {
-                version,
-                assets,
-                download_path: build_download_path(self.state, &doc, user_id)?,
-            }),
+            Some((version, assets)) => {
+                let download_path = build_download_path(self.state, &doc, version.id, user_id)?;
+                Some(DocumentVersionDetailResponse {
+                    version,
+                    assets,
+                    download_path,
+                })
+            }
             None => None,
         };
 
@@ -1466,11 +1489,3 @@ impl<'a> DocumentsService<'a> {
         Ok(Some(detail))
     }
 }
-
-fn presign_disposition_for_asset(
-    asset: &DocumentAsset,
-    object: &DocumentAssetObject,
-) -> Option<String> {
-    let filename = format!("{}-{}", asset.asset_type, object.ordinal);
-    inline_content_disposition(&filename)
-}