Added mofule with functions for managing and parsing markdown files to be used for page content or blogposts on website

lib/sukaato_web/marker.ex

@@ -0,0 +1,81 @@
+defmodule SukaatoWeb.Marker do
+  @moduledoc """
+  Manages markdown files or strings and their conversion to HTML pages or posts.
+  """
+  @rel_proj_root "."
+  @markdown_root Path.expand(@rel_proj_root <> "/controllers/page_md", __DIR__)
+  @markdown_pages Path.wildcard(@markdown_root <> "/*.md")
+  @markdown_posts @markdown_root <> "/users"
+  @site_config_file Path.expand("../../site.toml", __DIR__)
+  @site_config Toml.decode_file(@site_config_file)
+  @admin_username elem(@site_config, 1)["site"]["username"]
+
+  @doc """
+  Converts markdown and YAML frontmatter from files for pages or posts to HTML5.
+  """
+  def render_mark(filename, category \\ :markdown_page, username \\ @admin_username) do
+    filename = if is_atom(filename), do: Atom.to_string(filename), else: filename
+    filename = if !String.contains?(filename, ".md"), do: filename <> ".md", else: filename
+
+    markdown_paths = case category, do: (:markdown_page -> @markdown_pages; :markdown_post -> Path.wildcard(@markdown_posts <> "/" <> username <> "/posts/*.md"))
+    markdown_files = Enum.map(markdown_paths, fn p -> Path.basename(p) end)
+
+    if Enum.member?(markdown_files, filename) do
+      markdown_filepath = @markdown_root <> "/" <> filename
+
+      if category == :markdown_post do
+        markdown_filepath = if username != "" and username != nil, do: @markdown_root <> "/users/" <> username <> "/posts/" <> filename, else: Path.wildcard(@markdown_root <> "/users/*/posts/" <> filename)
+        post_data = if is_list(markdown_filepath), do: Enum.map(markdown_filepath, fn m -> YamlFrontMatter.parse_file(m) end), else: YamlFrontMatter.parse_file(markdown_filepath)
+
+        if is_list(post_data) do
+          post_content = Enum.filter(post_data, fn m -> elem(m, 0) == :ok end)
+          post_content = if length(post_content) > 0, do: Enum.map(post_content, fn m -> Panpipe.to_html5(elem(m, 2)) end), else: []
+          post_content = Enum.filter(post_content, fn m -> elem(m, 0) == :ok end)
+          frontmatter = if length(post_content) > 0, do: Enum.map(post_data, fn p -> elem(p, 1) end), else: []
+
+          if length(frontmatter) > 0 and length(post_content) > 0 do
+            {:ok, frontmatter, post_content}
+          else
+            {:error, frontmatter, post_content}
+          end
+        else
+          if elem(post_data, 0) == :ok do
+            post_content = Panpipe.to_html5(elem(post_data, 2))
+
+            if elem(post_content, 0) == :ok do
+              frontmatter = elem(post_data, 1)
+              {:ok, frontmatter, post_content}
+            end
+          else
+            frontmatter = elem(post_data, 1)
+            markdown = elem(post_data, 2)
+            {:error, frontmatter, markdown}
+          end
+        end
+      end
+
+      if category == :markdown_page do
+        post_content = Panpipe.pandoc(input: markdown_filepath, to: :html5)
+
+        if elem(post_content, 0) == :ok do
+          markup = elem(post_content, 1)
+          {:ok, markup}
+        # else
+        #   {:error, "something's up"}
+        end
+      end
+    else
+      {:error, "no such markdown file '" <> filename <> "'"}
+    end
+  end
+
+  def backup_marks(), do: nil
+
+  # defp create_page(), do: nil
+
+  # @NOTE following two functions should integrate markdown file creation and db insertion
+
+  # defp create_post(), do: nil
+
+  def create_mark(), do: nil
+end