Add BackgroundEngine to engines.

src/engines/BaseEngine.py

@@ -1,7 +1,11 @@
 import gradio as gr
+import moviepy.editor as mp
+
 from abc import ABC, abstractmethod
+from sqlalchemy.future import select
 
 from ..chore import GenerationContext
+from ..models import SessionLocal, File
 
 
 class BaseEngine(ABC):
@@ -17,3 +21,45 @@ class BaseEngine(ABC):
     @abstractmethod
     def get_options():
         ...
+
+    def get_video_duration(self, path: str) -> float:
+        return mp.VideoFileClip(path).duration
+
+    def get_audio_duration(self, path: str) -> float:
+        return mp.AudioFileClip(path).duration
+
+    @classmethod
+    def get_assets(cls, *, type: str = None) -> list[File]:
+        with SessionLocal() as db:
+            if type:
+                return (
+                    db.execute(
+                        select(File).filter(
+                            File.type == type, File.provider == cls.name
+                        )
+                    )
+                    .scalars()
+                    .all()
+                )
+            else:
+                return (
+                    db.execute(select(File).filter(File.provider == cls.name))
+                    .scalars()
+                    .all()
+                )
+    
+    @classmethod
+    def add_asset(cls, *, path: str, metadata: dict, type: str = None):
+        with SessionLocal() as db:
+            db.add(File(path=path, data=metadata, type=type, provider=cls.name))
+            db.commit()
+
+    @classmethod
+    def remove_asset(cls, *, path: str):
+        with SessionLocal() as db:
+            db.execute(select(File).filter(File.path == path)).delete()
+            db.commit()
+
+    @classmethod
+    def get_settings(cls):
+        ...