Finish most of skeleton

src/media.py

@@ -0,0 +1,32 @@
+from abc import ABC, abstractmethod
+
+
+class Media(ABC):
+    async def rip(self):
+        await self.preprocess()
+        await self.download()
+        await self.postprocess()
+
+    @abstractmethod
+    async def preprocess(self):
+        """Create directories, download cover art, etc."""
+        raise NotImplemented
+
+    @abstractmethod
+    async def download(self):
+        """Download and tag the actual audio files in the correct directories."""
+        raise NotImplemented
+
+    @abstractmethod
+    async def postprocess(self):
+        """Update database, run conversion, delete garbage files etc."""
+        raise NotImplemented
+
+
+class Pending(ABC):
+    """A request to download a `Media` whose metadata has not been fetched."""
+
+    @abstractmethod
+    async def resolve(self) -> Media:
+        """Fetch metadata and resolve into a downloadable `Media` object."""
+        raise NotImplemented