From 65bf0c0c8a5543a235b3969dbbc09872c69a515c Mon Sep 17 00:00:00 2001
From: Chris McCord <chris@chrismccord.com>
Date: Sun, 31 Oct 2021 21:20:04 -0400
Subject: [PATCH] Uploads WIP

---
 lib/live_beats/id3.ex | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 lib/live_beats/id3.ex

diff --git a/lib/live_beats/id3.ex b/lib/live_beats/id3.ex
new file mode 100644
index 0000000..d78f99b
--- /dev/null
+++ b/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