Download cutoff date for sources (#69)

* Added new uploaded_at column to media items

* Updated indexer to pull upload date

* Updates media item creation to update on conflict

* Added download cutoff date to sources

* Applies cutoff date logic to pending media logic

* Updated docs

lib/pinchflat/media.ex

@@ -64,6 +64,7 @@ defmodule Pinchflat.Media do
     MediaItem
     |> where([mi], mi.source_id == ^source.id and is_nil(mi.media_filepath))
     |> where(^build_format_clauses(media_profile))
+    |> where(^maybe_apply_cutoff_date(source))
     |> Repo.maybe_limit(limit)
     |> Repo.all()
   end
@@ -92,11 +93,12 @@ defmodule Pinchflat.Media do
   Returns boolean()
   """
   def pending_download?(%MediaItem{} = media_item) do
-    media_profile = Repo.preload(media_item, source: :media_profile).source.media_profile
+    media_item = Repo.preload(media_item, source: :media_profile)
 
     MediaItem
     |> where([mi], mi.id == ^media_item.id and is_nil(mi.media_filepath))
-    |> where(^build_format_clauses(media_profile))
+    |> where(^build_format_clauses(media_item.source.media_profile))
+    |> where(^maybe_apply_cutoff_date(media_item.source))
     |> Repo.exists?()
   end
 
@@ -184,14 +186,25 @@ defmodule Pinchflat.Media do
 
   @doc """
   Creates a media item from the attributes returned by the video backend
-  (read: yt-dlp)
+  (read: yt-dlp).
+
+  Unlike `create_media_item`, this will attempt an update if the media_item
+  already exists. This is so that future indexing can pick up attributes that
+  we may not have asked for in the past (eg: upload_date)
 
   Returns {:ok, %MediaItem{}} | {:error, %Ecto.Changeset{}}
   """
   def create_media_item_from_backend_attrs(source, media_attrs_struct) do
-    %{source_id: source.id}
-    |> Map.merge(Map.from_struct(media_attrs_struct))
-    |> create_media_item()
+    attrs = Map.merge(%{source_id: source.id}, Map.from_struct(media_attrs_struct))
+
+    %MediaItem{}
+    |> MediaItem.changeset(attrs)
+    |> Repo.insert(
+      on_conflict: [
+        set: Map.to_list(attrs)
+      ],
+      conflict_target: [:source_id, :media_id]
+    )
   end
 
   @doc """
@@ -249,6 +262,14 @@ defmodule Pinchflat.Media do
     {:ok, media_item}
   end
 
+  defp maybe_apply_cutoff_date(source) do
+    if source.download_cutoff_date do
+      dynamic([mi], mi.upload_date >= ^source.download_cutoff_date)
+    else
+      dynamic(true)
+    end
+  end
+
   defp build_format_clauses(media_profile) do
     mapped_struct = Map.from_struct(media_profile)