# frozen_string_literal: true

require 'English'
helpers do
  def curl(ext, url)
    p url
    response = `/run/current-system/sw/bin/curl --fail-with-body -sSL #{ext} #{url}`
    $CHILD_STATUS.success? ? response : nil
  end

  # def fetch(url, accept = 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"')
  def fetch(url, accept = 'application/activity+json')
    response = curl("-H 'Accept: #{accept}'", url)
    response ? JSON.parse(response) : nil
  end

  # https://github.com/mastodon/mastodon/blob/main/app/lib/request.rb
  # , url
  def send_signed(object)
    keypair = OpenSSL::PKey::RSA.new(File.read('private.pem'))
    date = Time.now.utc.httpdate
    body = object.to_json
    sha256 = OpenSSL::Digest.new('SHA256')
    digest = "SHA-256=#{sha256.base64digest(body)}"
    recipients = [object['to'], object['cc'], object['bto'], object['bcc'], object['audience']].flatten.compact.uniq
    recipients.each do |url|
      next if url == 'https://www.w3.org/ns/activitystreams#Public'

      host = URI.parse(url).host
      inbox = fetch(url)['inbox']
      if inbox
        request_uri = URI(inbox).request_uri

        signed_string = "(request-target): post #{request_uri}\nhost: #{host}\ndate: #{date}\ndigest: #{digest}\ncontent-type: application/activity+json"
        signature = Base64.strict_encode64(keypair.sign(OpenSSL::Digest.new('SHA256'), signed_string))
        signed_header = "keyId=\"#{ACTOR}#main-key\",algorithm=\"rsa-sha256\",headers=\"(request-target) host date digest content-type\",signature=\"#{signature}\""

        curl(
          "-X POST -H 'Content-Type: application/activity+json' -H 'Host: #{host}' -H 'Date: #{date}' -H 'Digest: #{digest}' -H 'Signature: #{signed_header}' -d '#{body}'", inbox
        )
      else
        p "No inbox for #{url}"
      end
    end
  end

  def people
    File.read('cache/people.tsv').split("\n").collect { |l| l.chomp.split("\t") }
  end

  def mention(actor)
    person = people.select { |p| p[1] == actor }
    if person.empty?
      a = fetch(actor)
      return nil unless a

      mention = "#{a['preferredUsername']}@#{URI(actor).host}"
      File.open('cache/people.tsv', 'a') { |f| f.puts "#{mention}\t#{actor}" }
      mention
    else
      person[0][0]
    end
  end

  def actor(mention)
    mention = mention.sub(/^@/, '').chomp
    actors = people.select { |p| p[0] == mention }
    if actors.empty?
      _, server = mention.split('@')
      a = fetch("https://#{server}/.well-known/webfinger?resource=acct:#{mention}", 'application/jrd+json')
      return nil unless a

      actor = a['links'].select do |l|
        l['rel'] == 'self'
      end[0]['href']
      File.open('cache/people.tsv', 'a') { |f| f.puts "#{mention}\t#{actor}" }
      actor
    else
      actors[0][1]
    end
  end
end