refactor: get segment offset from segments

lib/hls_playlist.ex

@@ -79,23 +79,9 @@ defmodule HlsPlaylist do
     """
   end
 
-  def get_segment_offset(playlist, target_segment, current_duration \\ 0.0, total_duration \\ 0.0, index \\ 0) do
-    case playlist do
-      [line | rest] ->
-        case String.match?(line, ~r{^#EXTINF:(\d+\.\d+),}) do
-          true ->
-            [_, segment_duration] = Regex.run(~r{^#EXTINF:(\d+\.\d+),}, line, capture: :all)
-            segment_duration = String.to_float(segment_duration)
-
-            if index == target_segment do
-              {segment_duration, total_duration + current_duration}  # Return both the duration of the target segment and total offset duration
-            else
-              get_segment_offset(rest, target_segment, current_duration + segment_duration, total_duration, index + 1)
-            end
-
-          false ->
-            get_segment_offset(rest, target_segment, current_duration, total_duration, index)
-        end
-    end
+  def get_segment_offset(segments, index) when is_list(segments) and is_integer(index) do
+    value = Enum.at(segments, index)
+    sum_previous = Enum.sum(Enum.take(segments, index))
+    {value, sum_previous}
   end
 end

test/hls_playlist_test.exs

@@ -65,33 +65,17 @@ defmodule HlsPlaylistTest do
   end
 
   test "get segment offset" do
-    playlist =
-      """
-      #EXTM3U
-      #EXT-X-VERSION:3
-      #EXT-X-ALLOW-CACHE:NO
-      #EXT-X-TARGETDURATION:4
-      #EXT-X-MEDIA-SEQUENCE:0
-      #EXT-X-PLAYLIST-TYPE:VOD
-      #EXTINF:4.166667,
-      0
-      #EXTINF:4.166666,
-      1
-      #EXTINF:4.166667,
-      2
-      #EXTINF:3.766667,
-      3
-      #EXTINF:3.866666,
-      4
-      #EXTINF:4.166667,
-      5
-      #EXTINF:3.133333,
-      6
-      #EXTINF:2.582667,
-      7
-      #EXT-X-ENDLIST\
-      """
+    segments = [
+      4.166667,
+      4.166666,
+      4.166667,
+      3.766667,
+      3.866666,
+      4.166667,
+      3.133333,
+      2.576667
+    ]
 
-    assert {3.766667, 12.5} = HlsPlaylist.get_segment_offset(String.split(playlist), String.to_integer("3"))
+    assert {3.766667, 12.5} = HlsPlaylist.get_segment_offset(segments, String.to_integer("3"))
   end
 end