Marked Preprocessor for Bear

bear_preprocessor.rb

#!/usr/bin/env ruby
# frozen_string_literal: true

require 'cgi'

input = $stdin.read.force_encoding('utf-8')

# Handle [[links]]
input.gsub!(/\[\[(?<content>.*?)\]\]/) do
  m = Regexp.last_match
  # Test for link|title matchup
  if m['content'] =~ /(?<link>.+)\|(?<title>.+)/
    l = Regexp.last_match
    title = l['title']
    link = l['link']
  else
    title = m['content']
    link = m['content']
  end

  # Test for note/header matchup
  if link =~ %r{(?<page>.+)/(?<header>.+)}
    l = Regexp.last_match
    link = l['page']
    header = l['header']
  else
    header = nil
  end

  header = header.nil? ? '' : "&header=#{CGI.escape(header).gsub(/\+/, '%20')}"

  url = CGI.escape(link).gsub(/\+/, '%20')
  callback = CGI.escape("bear://x-callback-url/create?title=#{url}").gsub(/\+/, '%20')
  "[#{title}](bear://x-callback-url/open-note?title=#{url}#{header}&x-error=#{callback})"
end

# Handle ==highlight==
input.gsub!(/==(.*?)==/, '<mark>\1</mark>')

# Handle ~~deletion~~
input.gsub!(/~~(.*?)~~/, '<del>\1</del>')

# Handle ~underline~
input.gsub!(/~(.*?)~/, '<span class="underline">\1</span>')

# Handle tags, linking to tag pages in Bear
input.gsub!(%r{(?!<#)#(?<tag>[^\s#,?.!]+)}i) do
  m = Regexp.last_match
  tag = CGI.escape(m['tag'])
  %(<span class="mkstyledtag"><a href="bear://x-callback-url/open-tag?name=#{tag}">##{m['tag']}</a></span>)
end

puts input