Uploads WIP

lib/live_beats/id3.ex

@@ -0,0 +1,38 @@
+defmodule LiveBeats.ID3 do
+  alias LiveBeats.ID3
+
+  defstruct title: nil,
+            artist: nil,
+            album: nil,
+            year: nil
+
+  def parse(path) do
+    binary = File.read!(path)
+    size = byte_size(binary) - 128
+    <<_::binary-size(size), id3_tag::binary>> = binary
+
+    case id3_tag do
+      <<
+        "TAG",
+        title::binary-size(30),
+        artist::binary-size(30),
+        album::binary-size(30),
+        year::binary-size(4),
+        _comment::binary-size(30),
+        _rest::binary
+      >> ->
+        {:ok,
+         %ID3{
+           title: strip(title),
+           artist: strip(artist),
+           album: strip(album),
+           year: year
+         }}
+
+      _invalid ->
+        {:error, :invalid}
+    end
+  end
+
+  defp strip(binary), do: String.trim_trailing(binary, <<0>>)
+end