Feature: print files directly from project view (closes #930) (#932)

* feat: print files directly from project view (closes #930)

Show printable files from linked library folders directly in the project
detail page, with Print Now and Add to Queue buttons per file. Removes
the detour through the File Manager for common reprint workflows.

backend/app/api/routes/library.py

@@ -1044,14 +1044,16 @@ async def scan_external_folder(
 async def list_files(
     response: Response,
     folder_id: int | None = None,
+    project_id: int | None = None,
     include_root: bool = True,
     db: AsyncSession = Depends(get_db),
     _: User | None = Depends(require_permission_if_auth_enabled(Permission.LIBRARY_READ)),
 ):
-    """List files, optionally filtered by folder.
+    """List files, optionally filtered by folder or project.
 
     Args:
         folder_id: Filter by folder ID. If None and include_root=True, returns root files.
+        project_id: Return all files across folders linked to this project (bulk fetch, avoids N+1).
         include_root: If True and folder_id is None, returns files at root level.
                      If False and folder_id is None, returns all files.
     """
@@ -1059,6 +1061,10 @@ async def list_files(
 
     if folder_id is not None:
         query = query.where(LibraryFile.folder_id == folder_id)
+    elif project_id is not None:
+        # Single join instead of one query per folder (avoids N+1 pattern)
+        query = query.join(LibraryFolder, LibraryFile.folder_id == LibraryFolder.id)
+        query = query.where(LibraryFolder.project_id == project_id)
     elif include_root:
         query = query.where(LibraryFile.folder_id.is_(None))
 
@@ -2210,6 +2216,12 @@ async def print_library_file(
     if not printer_manager.is_connected(printer_id):
         raise HTTPException(status_code=400, detail="Printer is not connected")
 
+    # Validate project exists before dispatching so a bogus ID yields 404, not a FK-constraint 500
+    if body.project_id is not None:
+        project_result = await db.execute(select(Project).where(Project.id == body.project_id))
+        if not project_result.scalar_one_or_none():
+            raise HTTPException(status_code=404, detail="Project not found")
+
     plate_name = body.plate_name
     if not plate_name and body.plate_id is not None:
         plate_name = f"Plate {body.plate_id}"
@@ -2225,6 +2237,7 @@ async def print_library_file(
             printer_id=printer_id,
             printer_name=printer.name,
             options=body.model_dump(exclude_none=True),
+            project_id=body.project_id,
             requested_by_user_id=None,
             requested_by_username=None,
         )

backend/app/api/routes/print_queue.py

@@ -21,6 +21,7 @@ from backend.app.models.library import LibraryFile
 from backend.app.models.print_batch import PrintBatch
 from backend.app.models.print_queue import PrintQueueItem
 from backend.app.models.printer import Printer
+from backend.app.models.project import Project
 from backend.app.models.user import User
 from backend.app.schemas.print_queue import (
     PrintBatchResponse,
@@ -484,6 +485,12 @@ async def add_to_queue(
                 if plate_time is not None:
                     cached_print_time = plate_time
 
+    # Validate project exists before insert so a bogus ID yields 404, not an FK-constraint 500
+    if data.project_id is not None:
+        project_result = await db.execute(select(Project).where(Project.id == data.project_id))
+        if not project_result.scalar_one_or_none():
+            raise HTTPException(status_code=404, detail="Project not found")
+
     ams_mapping_json = json.dumps(data.ams_mapping) if data.ams_mapping else None
     items = []
     for i in range(quantity):
@@ -508,6 +515,7 @@ async def add_to_queue(
             timelapse=data.timelapse,
             use_ams=data.use_ams,
             gcode_injection=data.gcode_injection,
+            project_id=data.project_id,
             position=max_pos + 1 + i,
             status="pending",
             created_by_id=current_user.id if current_user else None,

backend/app/schemas/library.py

@@ -208,6 +208,8 @@ class FilePrintRequest(BaseModel):
     layer_inspect: bool = False
     timelapse: bool = False
     use_ams: bool = True
+    # Project to associate the resulting archive with
+    project_id: int | None = None
 
 
 class FileUploadResponse(BaseModel):

backend/app/schemas/print_queue.py

@@ -44,6 +44,8 @@ class PrintQueueItemCreate(BaseModel):
     gcode_injection: bool = False
     # Batch: create multiple copies (creates a batch if > 1)
     quantity: int = 1
+    # Project to associate the resulting archive with
+    project_id: int | None = None
 
 
 class PrintQueueItemUpdate(BaseModel):

backend/app/services/archive.py

@@ -854,6 +854,7 @@ class ArchiveService:
         print_data: dict | None = None,
         created_by_id: int | None = None,
         original_filename: str | None = None,
+        project_id: int | None = None,
     ) -> PrintArchive | None:
         """Archive a 3MF file with metadata.
 
@@ -864,6 +865,8 @@ class ArchiveService:
             created_by_id: User ID who created this archive (optional, for user tracking)
             original_filename: Original human-readable filename (optional, for library files
                 stored with UUID names)
+            project_id: Project to associate this archive with (optional, set when triggered
+                from the project view)
         """
         # Verify printer exists if specified
         if printer_id is not None:
@@ -974,6 +977,7 @@ class ArchiveService:
             quantity=quantity,
             extra_data=metadata,
             created_by_id=created_by_id,
+            project_id=project_id,
         )
 
         self.db.add(archive)

backend/app/services/background_dispatch.py

@@ -54,6 +54,7 @@ class PrintDispatchJob:
     options: dict[str, Any] = field(default_factory=dict)
     requested_by_user_id: int | None = None
     requested_by_username: str | None = None
+    project_id: int | None = None
 
 
 @dataclass(slots=True)
@@ -160,6 +161,7 @@ class BackgroundDispatchService:
         options: dict[str, Any],
         requested_by_user_id: int | None,
         requested_by_username: str | None,
+        project_id: int | None = None,
     ) -> dict[str, Any]:
         return await self._dispatch(
             kind="print_library_file",
@@ -170,6 +172,7 @@ class BackgroundDispatchService:
             options=options,
             requested_by_user_id=requested_by_user_id,
             requested_by_username=requested_by_username,
+            project_id=project_id,
         )
 
     async def cancel_job(self, job_id: int) -> dict[str, Any]:
@@ -257,6 +260,7 @@ class BackgroundDispatchService:
         options: dict[str, Any],
         requested_by_user_id: int | None,
         requested_by_username: str | None,
+        project_id: int | None = None,
     ) -> dict[str, Any]:
         async with self._lock:
             has_pending_for_printer = any(job.printer_id == printer_id for job in self._queued_jobs)
@@ -279,6 +283,7 @@ class BackgroundDispatchService:
                 options=options,
                 requested_by_user_id=requested_by_user_id,
                 requested_by_username=requested_by_username,
+                project_id=project_id,
             )
             self._next_job_id += 1
             self._batch_total += 1
@@ -722,6 +727,7 @@ class BackgroundDispatchService:
                 printer_id=job.printer_id,
                 source_file=file_path,
                 original_filename=lib_file.filename,
+                project_id=job.project_id,
             )
             if not archive:
                 raise RuntimeError("Failed to create archive")

backend/app/services/print_scheduler.py

@@ -1641,6 +1641,7 @@ class PrintScheduler:
                     source_file=file_path,
                     original_filename=filename,
                     created_by_id=item.created_by_id,
+                    project_id=item.project_id,
                 )
                 if archive:
                     item.archive_id = archive.id