Fetch content from most recent posts on reddit

scraper.ex

defmodule Scraper do
  def scrape(subreddit) do
    %{body: body} = HTTPoison.get!("https://www.reddit.com/r/#{subreddit}/.rss")
    {:ok, feed, ""} = FeederEx.parse(body)
    fetch_content(get_links(feed))
  end

  defp get_links(%FeederEx.Feed{entries: entries}) do
    Enum.map(entries, fn (%FeederEx.Entry{link: link}) ->
      link
    end)
  end

  defp fetch_content(links) when is_list(links) do
    links
    |> Enum.reduce("", fn (link, acc) ->
      id = get_id_from_link(link)
      case acc do
        "" -> id
        _ -> "#{acc},#{id}"
      end
    end)
    |> fetch_content
  end
  defp fetch_content(ids) do
    HTTPoison.get!(
      "http://www.reddit.com/by_id/#{ids}.json",
      [{"User-Agent", "haikubot 0.1"}])
    |> Map.get(:body)
    |> parse_content
  end

  defp parse_content(content) do
    %{"data" => %{"children" => children}} = Poison.decode!(content)
    Enum.map(children, fn %{"data" => %{"selftext_html" => text}} ->
      Floki.parse(text) |> Floki.text
    end)
  end

  defp get_id_from_link(link) do
    "t3_" <> Enum.at(String.split(link, "/", trim: true), 5)
  end
end