1 files changed, 39 insertions, 0 deletions
diff --git a/lib/lsg_irc/link_plugin/pdf.ex b/lib/lsg_irc/link_plugin/pdf.ex
new file mode 100644
index 0000000..8c4869c
--- /dev/null
+++ b/lib/lsg_irc/link_plugin/pdf.ex
@@ -0,0 +1,39 @@
+defmodule LSG.IRC.LinkPlugin.PDF do
+  require Logger
+  @behaviour LSG.IRC.LinkPlugin
+
+  @impl true
+  def match(_, _), do: false
+
+  @impl true
+  def post_match(_url, "application/pdf"<>_, _header, _opts) do
+    {:file, nil}
+  end
+
+  def post_match(_, _, _, _), do: false
+
+  @impl true
+  def post_expand(url, file, _, _) do
+    case System.cmd("pdftitle", ["-p", file]) do
+      {text, 0} ->
+        text = text
+               |> String.trim()
+
+        if text == "" do
+          :error
+        else
+          basename = Path.basename(url, ".pdf")
+          text = "[#{basename}] " <> text
+               |> String.split("\n")
+          {:ok, text}
+        end
+      {_, 127} ->
+        Logger.error("dependency `pdftitle` is missing, please install it: `pip3 install pdftitle`.")
+        :error
+      {error, code} ->
+        Logger.warn("command `pdftitle` exited with status code #{code}:\n#{inspect error}")
+        :error
+    end
+  end
+
+end