post '/outbox' do # TODO
  protected!

  recipients = params[:public] == 'true' ? public : []
  recipients << params[:to]

  tag = []
  params[:content].lines.each do |line|
    tags = line.split(/\s+/).grep(/^#\w+$/)
    tags.each do |name|
      tag_url = File.join(TAGS[:url], name.sub('#', ''))
      tag << {
        'type' => 'Hashtag',
        'href' => tag_url,
        'name' => name
      }
    end

    mentions = line.split(/\s+/).grep(/^@\w+@\S+$/)
    mentions.each do |mention|
      actor = actor(mention)
      tag << {
        'type' => 'Mention',
        'href' => actor,
        'name' => mention
      }
    end
  end

  attachment = []
  extensions = {
    image: %w[jpeg png],
    audio: %w[flac wav mp3 ogg],
    video: %w[mp4 webm]
  }
  if params[:media]
    params[:media].each do |_media|
      ext = File.extname(line).sub('.', '')
      media_type = extensions.select { |_k, v| v.include? ext }.keys[0].to_s + '/' + ext
      attachment << {
        'type' => 'Document',
        'mediaType' => media_type,
        'url' => line
      }
    end
  end

  object = {
    'type' => 'Note',
    'attributedTo' => ACTOR,
    'inReplyTo' => params[:inReplyTo],
    'content' => "<p>\n#{params[:content]}\n</p>",
    'attachment' => attachment,
    'tag' => tag,
    'to' => recipients
  }

  activity = outbox 'Create', object, recipients
  activity['object']['tag'].each do |tag|
    next unless tag['type'] == 'Hashtag'

    tag_path = File.join(TAGS[:dir], tag['name'].sub('#', '')) + '.json'
    next if File.exist? tag_path

    File.open(tag_path, 'w+') do |f|
      tag_collection = {
        '@context' => 'https://www.w3.org/ns/activitystreams',
        'id' => tag['href'],
        'type' => 'OrderedCollection',
        'totalItems' => 0,
        'orderedItems' => []
      }
      f.puts tag_collection.to_json
    end
  end
end