Temporarily use atoms as text-id

lib/vyasa/adapters/og_adapter.ex

@@ -10,10 +10,12 @@ defmodule Vyasa.Adapters.OgAdapter do
   Retrieves the actual content from the gita that is alluded to by an opengraph file name.
   """
   def get_content(:gita, filename) do
-    [chapter_num, verse_num] = Regex.scan(~r/\d+/, filename) |> List.flatten()
-    %{text: text} = Gita.verse(chapter_num, verse_num)
-
-    %{"src"=> :gita , "text"=> text}
+    case Regex.scan(~r/\d+/, filename) |> List.flatten() do
+      [chapter_num, verse_num] -> # TODO: this could use better guards. e.g. gita-1-000.png will break it
+        %{text: text} = Gita.verse(chapter_num, verse_num)
+        %{"src"=> :gita , "text"=> text}
+      _ -> {:error, "Malformed / unsupported filename #{filename}"}
+    end
   end
 
 
@@ -28,11 +30,10 @@ defmodule Vyasa.Adapters.OgAdapter do
   @doc """
   Returns a string representing the filename for a particular verse from a particular chapter of
   the gita. Currently just supports gita.
-
-  TODO: use text-id of some sort to generify the text part.
   """
   def encode_filename(src, [chapter_num, verse_num]) when src == :gita do
-    Integer.to_string(chapter_num) <> "-" <> Integer.to_string(verse_num) <> ".png"
+    gita_uuid = "gita" # TODO: consider better unique ids based on what we want to support for our corpus.
+    gita_uuid <> "-" <> Integer.to_string(chapter_num) <> "-" <> Integer.to_string(verse_num) <> ".png"
   end
 
 
@@ -44,5 +45,16 @@ defmodule Vyasa.Adapters.OgAdapter do
     %{chapter_num => chapter_num, verse_num => verse_num}
   end
 
+  @supported_src_ids ["gita"]
+  @doc """
+  Resolves src id from filename. Currently merely converts it to an existing atom.
+  """
+  def resolve_src_id(filename) do
+    src_id = List.first(String.split(filename, "-"))
+    case Enum.member?(@supported_src_ids, src_id) do
+      true -> {:ok, String.to_existing_atom(src_id)}
+      _ -> {:error, "Unsupported source"}
+    end
+  end
 
- end
+end

lib/vyasa_web/controllers/og_image_controller.ex

@@ -22,7 +22,7 @@ defmodule VyasaWeb.OgImageController do
     if File.exists?(target_url) do
       {:ok, target_url}
     else
-      case get_content_for_file(filename) do
+      case get_og_content(filename) do
         %{"src" => :gita, "text" => text} ->
           ImageGenerator.generate_opengraph_image!(filename, text)
           {:ok, target_url}
@@ -32,15 +32,16 @@ defmodule VyasaWeb.OgImageController do
     end
   end
 
-  # TODO file name needs to have an identifier for the title of the text for a text based lookup currently defaults just to gita
-  # TODO also needs unique title id -- perhaps we can just use url params for this for now.
   @doc """
   Fetches the actual content, by parsing the filename.
 
   For now, this shall only fetch gita-related content. Subsequently, this function may be
   updated to support other texts and media formats.
   """
-  def get_content_for_file(filename) do
-    OgAdapter.get_content(:gita, filename)
+  def get_og_content(filename) do
+    case OgAdapter.resolve_src_id(filename) do
+      {:ok, :gita} -> OgAdapter.get_content(:gita, filename)
+      _ -> {:error}
+    end
   end
 end