open-pod/lib/podcast_feed/provider/archive/parser.ex

defmodule PodcastFeed.Provider.Archive.Parser do
  def feed(url) do
    url
    |> fetch_xml()
    |> parse()
    |> IO.inspect()
    |> filter_mp3()
    |> compose()
  end

  defp fetch_xml(url) do
    {:ok, {_, _, xml}} = :httpc.request(:get, {url, []}, [], [body_format: :binary])
    xml
  end

  defp parse(xml) do
    xml |> XmlToMap.naive_map() |> Map.get("files") |> Map.get("file") |> Enum.map(fn f -> Map.get(f, "#content") |> Map.put("filename", Map.get(f, "-name")) end)
  end

  defp filter_mp3(files) do
    files |> Enum.filter(fn f -> Map.get(f, "format") =~ ~r/MP3/i end)
  end

  defp compose(files) do
    files
    |> Enum.map(&to_feed_item/1)
  end

    # <item>
    #     <title>Episode Name 2</title>
    #     <link>
    #         http://podcast.example.com/episode2.mp4
    #     </link>
    #     <pubDate>Sat, 02 Jan 2016 16:00:00 PDT</pubDate>
    #     <description>
    #         The full length episode 2 description
    #     </description>
    #     <enclosure url="http://podcasts.example.com/episode.mp4" length="36715125" type="audio/mpeg"/>
    #     <guid>
    #         http://podcast.example.com/episode2.mp4
    #     </guid>
    #     <itunes:duration>19:07</itunes:duration>
    #     <itunes:summary>
    #         The full length episode 2 description
    #     </itunes:summary>
    #     <itunes:image href="http://www.example.com/image3000x3000.png"/>
    #     <itunes:keywords>
    #         comma,separated,key,words
    #     </itunes:keywords>
    #     <itunes:explicit>no</itunes:explicit>
    # </item>
# %{
#     "album" => "Incontri al Piano Terra",
#     "artist" => "APE Milano",
#     "crc32" => "f1820595",
#     "creator" => "APE Milano",
#     "format" => "VBR MP3",
#     "genre" => "podcast",
#     "height" => "0",
#     "length" => "3943.31",
#     "md5" => "9ca26043a3e82e6f86c3a9309b88f4f5",
#     "mtime" => "1590154757",
#     "sha1" => "dcacfa46fcad1d656312784ad06886b5614c6420",
#     "size" => "47148690",
#     "title" => "Presentazione di Montagna femminile plurale con N1DM",
#     "track" => "03",
#     "width" => "0"
#   }

  defp to_feed_item(file) do
    %{
      title: file |> Map.get("title"),
      link: "http://archive.org/download/incontri-a-piano-terra/" <> (file |> Map.get("filename")) |> URI.encode(), #FIXME:! identifier should by dynamic
      pubDate: file |> Map.get("mtime") |> Integer.parse() |> elem(0) |> DateTime.from_unix!(:second),
      description: "",
      length: (file |> Map.get("length") |> Float.parse() |> elem(0)) * 100,
      guid: "",
      duration: "",
      summary: "",
      image: "",
      keywords: file |> Map.take(["album", "artist", "genre"]) |> Map.values(),
      explicit: "no",
    }
  end
end

# <?xml version="1.0" encoding="utf-8"?>
# <rss xmlns:atom="http://www.w3.org/2005/Atom" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" xmlns:itunesu="http://www.itunesu.com/feed" version="2.0">
# <channel>
# <link>http://www.YourSite.com</link>
# <language>en-us</language>
# <copyright>&#xA9;2013</copyright>
# <webMaster>your@email.com (Your Name)</webMaster>
# <managingEditor>your@email.com (Your Name)</managingEditor>
# <image>
# <url>http://www.YourSite.com/ImageSize300X300.jpg</url>
# <title>Title or description of your logo</title>
# <link>http://www.YourSite.com</link>
# </image>
# <itunes:owner>
# <itunes:name>Your Name</itunes:name>
# <itunes:email>your@email.com</itunes:email>
# </itunes:owner>
# <itunes:category text="Education">
# <itunes:category text="Higher Education" />
# </itunes:category>
# <itunes:keywords>separate, by, comma, and, space</itunes:keywords>
# <itunes:explicit>no</itunes:explicit>
# <itunes:image href="http://www.YourSite.com/ImageSize300X300.jpg" />
# <atom:link href="http://www.YourSite.com/feed.xml" rel="self" type="application/rss+xml" />
# <pubDate>Sun, 01 Jan 2012 00:00:00 EST</pubDate>
# <title>Verbose title of the podcast</title>
# <itunes:author>College, school, or department owning the podcast</itunes:author>
# <description>Verbose description of the podcast.</description>
# <itunes:summary>Duplicate of above verbose description.</itunes:summary>
# <itunes:subtitle>Short description of the podcast - 255 character max.</itunes:subtitle>
# <lastBuildDate>Thu, 02 Feb 2012 00:00:00 EST</lastBuildDate>
# <item>
# <title>Verbose title of the episode</title>
# <description>Verbose description of the episode.</description>
# <itunes:summary>Duplicate of above verbose description.</itunes:summary>
# <itunes:subtitle>Short description of the episode - 255 character max.</itunes:subtitle>
# <itunesu:category itunesu:code="112" />
# <enclosure url="http://www.YourSite.com/FILE.EXT" type="audio/mpeg" length="1" />
# <guid>http://www.YourSite.com/FILE.EXT</guid>
# <itunes:duration>H:MM:SS</itunes:duration>
# <pubDate>Thu, 02 Feb 2012 00:00:00 EST</pubDate>
# </item>
# </channel>
# </rss>