Add support for episode NFO files (#84)

* Added nfo builder for 'episodes'

* Added NFO download fields; hooked up NFO generation to downloading pipeline

* Added NFO option to media profile

lib/pinchflat/metadata/nfo_builder.ex

@@ -0,0 +1,44 @@
+defmodule Pinchflat.Metadata.NfoBuilder do
+  @moduledoc """
+  Provides methods for building and storing NFO files for
+  use by Kodi/Jellyfin and other media center software.
+  """
+
+  alias Pinchflat.Metadata.MetadataFileHelpers
+  alias Pinchflat.Filesystem.FilesystemHelpers
+
+  @doc """
+  Builds an NFO file for a media item (read: single "episode") and
+  stores it in the same directory as the media file. Has the same name
+  as the media file, but with a .nfo extension.
+
+  Returns the filepath of the NFO file.
+  """
+  def build_and_store_for_media_item(metadata) do
+    filepath = Path.rootname(metadata["filepath"]) <> ".nfo"
+    nfo = build_for_media_item(metadata)
+
+    FilesystemHelpers.write_p!(filepath, nfo)
+
+    filepath
+  end
+
+  defp build_for_media_item(metadata) do
+    upload_date = MetadataFileHelpers.parse_upload_date(metadata["upload_date"])
+    # Cribbed from a combination of the Kodi wiki, ytdl-nfo, and ytdl-sub.
+    # WHO NEEDS A FANCY XML PARSER ANYWAY?!
+    """
+    <?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
+    <episodedetails>
+      <title>#{metadata["title"]}</title>
+      <showtitle>#{metadata["uploader"]}</showtitle>
+      <uniqueid type="youtube" default="true">#{metadata["id"]}</uniqueid>
+      <plot>#{metadata["description"]}</plot>
+      <premiered>#{upload_date}</premiered>
+      <season>#{upload_date.year}</season>
+      <episode>#{Calendar.strftime(upload_date, "%m%d")}</episode>
+      <genre>YouTube</genre>
+    </episodedetails>
+    """
+  end
+end