omni_embed_sdk.rb

require 'securerandom'

module OmniEmbedSdk

  def self.dashboard_url(content_id:, external_id:, domain: 'embed-omniapp.co', name:, nonce:nil, org_name:, port: nil, secret:, user_attributes:nil)
    login_url = "https://#{org_name}.#{domain}#{port ? ":#{port}" : ''}/embed/login"
    content_path = "/embed/dashboards/#{content_id}"
    nonce ||= SecureRandom.alphanumeric(32)
    signature = sign(login_url: login_url, content_path: content_path, external_id: external_id, name: name, nonce: nonce, secret: secret, user_attributes: user_attributes)

    query_params = { 
      :contentPath => content_path,
      :externalId => external_id, 
      :name => name,
      :nonce => nonce,
      :signature => signature
    }
    query_params[:userAttributes] = JSON.generate(user_attributes) if user_attributes

    URI::HTTPS.build(
      :host => "#{org_name}.#{domain}",
      :port => port,
      :path => "/embed/login",
      :query => query_params.to_query
      )
  end

  def self.sign(login_url:, content_path:, external_id:, name:, nonce:, secret:, user_attributes:nil)
    user_attributes = user_attributes ? JSON.generate(user_attributes) : ''
    signing_str = <<~HEREDOC
      #{login_url}
      #{content_path}
      #{external_id}
      #{name}
      #{nonce}
      #{user_attributes}
    HEREDOC
    signing_str = signing_str.strip
    p signing_str
    digest = OpenSSL::Digest.new('sha256')
    hmac = OpenSSL::HMAC.digest(digest, secret, signing_str)
    Base64.urlsafe_encode64(hmac, padding: false)
  end
end