asciidoctor

defmodule Asciidoctor do
  @moduledoc """
    Asciidoctor utilities 

    Work In Progress!
	
    :toc: right|left
    :imagesdir: ./images
    :iconsdir: ./icons
    :stylesdir: ./styles

    :doctitle: = :title:
    :description:
    :keywords:

	"""

	def compile(file) do
			file
			|> File.read!()
			|> parse_document
			#|> extract(post)
	end

	def parse_document(data) do
			[meta, asciidoc] = String.split(data, ~r/\n{2,}\n/, parts: 2)
			parse_asciidoc(parse_meta(meta), asciidoc)
	end

	#Parsing 
	def parse_asciidoc(metadata, asciidoc) do
			String.split(asciidoc, "\n")
			|> parse_block(metadata)
	
	end

	def parse_block(block, metadata) do
			block 
			#|> substitute_variables(metadata)
			#|> parse_individual_block(metadata)
	end

	def parse_meta(meta) do
			split_metadata = String.split(meta,"\n")
			{title_split, remaining_meta} = split_metadata |> Enum.split(1)
			title_data = parse_meta_title(title_split)
			metadata = if(title_data, do: remaining_meta , else: split_metadata )
			metadata
			# |> Enum.map(&(parse_meta_item(&1)))
			|> Enum.reduce(%{}, &(reduce_meta_attribute(&1, &2)))
			|> Map.merge(%{"doctitle" => title_data, "title" => title_data})
	end

	def reduce_meta_attribute(%{"attribute" => attribute, "value" => ""}, acc ) do
			Map.put(acc, attribute, true)
	end
	def reduce_meta_attribute(%{"attribute" => attribute, "value" => value}, acc ) do
			Map.put(acc, attribute, value)
	end
	def reduce_meta_attribute(nil, acc) do
			acc
	end

	
	def parse_meta_title(meta) do
			Regex.named_captures(~r/^=\s*(?<title>[^\n:]+)(:[ \t](?<subtitle>[^\n]+))?/, meta)
	end

	#TODO unset attributes :!fba:
	def parse_meta_attribute(meta) do
			Regex.named_captures(~r/^:(?<attribute>[A-Za-z0-9_]{1}[A-Za-z0-9_\s-]*):([ \t]*(?<value>[^\n]+))?/, meta)
	end
	
	@doc """
			Author extraction is not complete refer to using :author: instead
			TODO
	"""
	def parse_meta_author(meta) do
			#firstname middlename lastname email author_initials
			# split second author by ;
			Regex.named_captures(~r/^(?<author>[\w ]+) ?(<(?<email>[^\s]+)>)?/, meta)

			Regex.named_captures(~r/^(?<author>[^\n]+) (<(?<url>[^\s]+)>)?/, meta)
			Regex.named_captures(~r/^(?<firstname>[^\s]+)(?<middlename>[^\s]* )?(?<lastname>[^\s]* )? ?(<(?<url>[^\s]+)>)?/, meta)
	end

	@doc """
		Revisions
				v1.0, October 2, 2013: First incarnation 
		:revnumber:
		:revdate:
		:revmark:
		TODO
	"""
	def parse_meta_revisions(meta) do
	end
	#replace {varname} with varname attribute!

	def parse_block_section(meta) do
			section = Regex.named_captures(~r/^(?<section_type>=+|#+)\s*(?<section>[^\n:]+)?/, meta)
			level = if String.contains(section["section_type"], "=") do
					String.count(section["section_type"]) -1
			else
					String.count(section["section_type"]) 
			end
			# %{"type" => "header",  "header" => header, "level" => level }
			%{"type" => "header", "data" => %{ "text" => section, "level" =>  level}}
  end

  @doc """
  Hello world.

  ## Examples

      iex> Asciidoctor.hello()
      :world

  """
  def hello do
    :world
  end
end