1 files changed, 106 insertions, 0 deletions
diff --git a/lib/lsg_irc/link_plugin/html.ex b/lib/lsg_irc/link_plugin/html.ex
new file mode 100644
index 0000000..e0e4229
--- /dev/null
+++ b/lib/lsg_irc/link_plugin/html.ex
@@ -0,0 +1,106 @@
+defmodule LSG.IRC.LinkPlugin.HTML do
+  @behaviour LSG.IRC.LinkPlugin
+
+  @impl true
+  def match(_, _), do: false
+
+  @impl true
+  def post_match(_url, "text/html"<>_, _header, _opts) do
+    {:body, nil}
+  end
+  def post_match(_, _, _, _), do: false
+
+  @impl true
+  def post_expand(url, body, _params, _opts) do
+    html = Floki.parse(body)
+    title = collect_title(html)
+    opengraph = collect_open_graph(html)
+    itemprops = collect_itemprops(html)
+    text = if Map.has_key?(opengraph, "title") && Map.has_key?(opengraph, "description") do
+      sitename = if sn = Map.get(opengraph, "site_name") do
+        "#{sn}"
+      else
+        ""
+      end
+      paywall? = if Map.get(opengraph, "article:content_tier", Map.get(itemprops, "article:content_tier", "free")) == "free" do
+        ""
+      else
+        "[paywall] "
+      end
+      section = if section = Map.get(opengraph, "article:section", Map.get(itemprops, "article:section", nil)) do
+        ": #{section}"
+      else
+        ""
+      end
+      date = case DateTime.from_iso8601(Map.get(opengraph, "article:published_time", Map.get(itemprops, "article:published_time", ""))) do
+        {:ok, date, _} ->
+          "#{Timex.format!(date, "%d/%m/%y", :strftime)}. "
+        _ ->
+          ""
+      end
+      uri = URI.parse(url)
+
+      prefix = "#{paywall?}#{Map.get(opengraph, "site_name", uri.host)}#{section}"
+      prefix = unless prefix == "" do
+        "#{prefix} — "
+      else
+          ""
+      end
+      [clean_text("#{prefix}#{Map.get(opengraph, "title")}")] ++ IRC.splitlong(clean_text("#{date}#{Map.get(opengraph, "description")}"))
+    else
+      clean_text(title)
+    end
+    {:ok, text}
+  end
+
+  defp collect_title(html) do
+    case Floki.find(html, "title") do
+    [{"title", [], [title]} | _] ->
+      String.trim(title)
+    _ ->
+      nil
+    end
+  end
+
+  defp collect_open_graph(html) do
+    Enum.reduce(Floki.find(html, "head meta"), %{}, fn(tag, acc) ->
+      case tag do
+        {"meta", values, []} ->
+          name = List.keyfind(values, "property", 0, {nil, nil}) |> elem(1)
+          content = List.keyfind(values, "content", 0, {nil, nil}) |> elem(1)
+          case name do
+           "og:" <> key ->
+              Map.put(acc, key, content)
+            "article:"<>_ ->
+              Map.put(acc, name, content)
+            _other -> acc
+          end
+        _other -> acc
+      end
+    end)
+  end
+
+  defp collect_itemprops(html) do
+    Enum.reduce(Floki.find(html, "[itemprop]"), %{}, fn(tag, acc) ->
+      case tag do
+        {"meta", values, []} ->
+          name = List.keyfind(values, "itemprop", 0, {nil, nil}) |> elem(1)
+          content = List.keyfind(values, "content", 0, {nil, nil}) |> elem(1)
+          case name do
+           "article:" <> key ->
+              Map.put(acc, name, content)
+            _other -> acc
+          end
+        _other -> acc
+      end
+    end)
+  end
+
+  defp clean_text(text) do
+    text
+    |> String.replace("\n", " ")
+    |> HtmlEntities.decode()
+  end
+
+
+end