helpers do

  def fetch url, accept = 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'
    p url
    response = `/run/current-system/sw/bin/curl --fail-with-body -sSL -H 'Accept: #{accept}' #{url}`
    halt 400 unless $?.success?
    JSON.parse(response)
  end

  # https://github.com/mastodon/mastodon/blob/main/app/lib/request.rb
  def send_signed object, url

    keypair = OpenSSL::PKey::RSA.new(File.read('private.pem'))
    date = Time.now.utc.httpdate
    sha256 = OpenSSL::Digest::SHA256.new
    body = object.to_json
    digest = "SHA-256=" + sha256.base64digest(body)
    host = URI.parse(url).host
    inbox = fetch(url)["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 + '"'

    #p url
    puts `/run/current-system/sw/bin/curl --fail-with-body -sSL -X POST -H 'Content-Type: application/activity+json' -H 'Host: #{host}' -H 'Date: #{date}' -H 'Digest: #{digest}' -H 'Signature: #{signed_header}' -d '#{body}' #{inbox}`
    #puts `/run/current-system/sw/bin/curl -iL -X POST -H 'Content-Type: application/activity+json' -H 'Host: #{host}' -H 'Date: #{date}' -H 'Digest: #{digest}' -H 'Signature: #{signed_header}' -d '#{body}' #{inbox}`
  end

end