From 419a58a48e1ae961de236274180d8b495abba9ff Mon Sep 17 00:00:00 2001
From: Inhji <johnnie@posteo.de>
Date: Sun, 9 Jul 2023 19:59:47 +0200
Subject: [PATCH] initial outline code

---
 lib/chiya_web/outline.ex        | 21 +++++++++++++++++++++
 test/chiya_web/outline_test.exs | 20 ++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 lib/chiya_web/outline.ex
 create mode 100644 test/chiya_web/outline_test.exs

diff --git a/lib/chiya_web/outline.ex b/lib/chiya_web/outline.ex
new file mode 100644
index 0000000..0d88e14
--- /dev/null
+++ b/lib/chiya_web/outline.ex
@@ -0,0 +1,21 @@
+defmodule ChiyaWeb.Outline do
+  @outline_regex ~r/\#{1,6}\s.+/
+  @heading_regex ~r/^(#+)\s(.+)$/
+
+  def get(markdown) do
+    headings =
+      @outline_regex
+      |> Regex.scan(markdown, capture: :all)
+
+    Enum.chunk_by(headings, fn h -> nil end)
+  end
+
+  def level(heading) do
+    Regex.scan(@heading_regex, heading)
+    |> Enum.map(fn [_, level, heading] ->
+      [level_from_string(level), heading]
+    end)
+  end
+
+  defp level_from_string(string), do: String.length(string)
+end
diff --git a/test/chiya_web/outline_test.exs b/test/chiya_web/outline_test.exs
new file mode 100644
index 0000000..8722b0b
--- /dev/null
+++ b/test/chiya_web/outline_test.exs
@@ -0,0 +1,20 @@
+defmodule ChiyaWeb.OutlineTest do
+  use Chiya.SimpleCase
+
+  alias ChiyaWeb.Outline
+
+  describe "extract_outline/1" do
+    test "extracts headlines from markdown" do
+      markdown = "# Heading\nsome paragraph\n## Sub Heading\n# Second Heading"
+
+      assert [{1, "Heading", [{2, "Sub Heading", []}]}, {1, "Second Heading", []}] =
+               Outline.get(markdown)
+    end
+  end
+
+  describe "outline_level/1" do
+    test "extracts outline level" do
+      assert {1, "Heading"} = Outline.level("# Heading")
+    end
+  end
+end