require "rdoc"
require_relative "../core_ext"
require_relative "../utils/string_short_name"

class Blog::Post
  using StringShortname

  def self.get_by(date: nil, topic: nil)
    date ? get_by_date(date) : get_by_topic(topic)
  end

  def self.date_to_filepath(date)
    "blog/posts/dates/#{date}".slug_to_file
  end

  def self.get_by_date(date)
    path = date_to_filepath(date)
    h1 = date.file_to_slug
    body = File.read(path)
    new(type: :date, h1:, body:, path:)
  end

  def self.topic_to_filepath(topic)
    "blog/posts/topics/#{topic}".slug_to_file
  end

  def self.get_by_topic(topic)
    path = topic_to_filepath(topic)
    lines = File.readlines(path)
    if !lines.empty?
      h1 = lines[0][2..]
      body = lines[2..].join("\n")
    end
    new(type: :topic, h1:, body:, path:)
  end

  attr_reader :h1, :body, :path

  def initialize(type:, h1:, body:, path:)
    @type = type
    @h1 = h1
    @body = body
    @path = path
  end

  def body_to_html
    data = body
    formatter = RDoc::Markup::ToHtml.new(RDoc::Options.new, nil)
    RDoc::Markdown.parse(data).accept(formatter)
  end

  def url
    "/#{@type}/#{h1.slugify}"
  end
end