# encoding: UTF-8

module Vines
  # A module for utility methods with no better home.
  module Kit
    # Create a hex-encoded, SHA-512 HMAC of the data, using the secret key.
    def self.hmac(key, data)
      digest = OpenSSL::Digest::Digest.new("sha512")
      OpenSSL::HMAC.hexdigest(digest, key, data)
    end

    # Generates a random uuid per rfc 4122 that's useful for including in
    # stream, iq, and other xmpp stanzas.
    def self.uuid
      SecureRandom.uuid
    end

    # Generates a random 128 character authentication token.
    def self.auth_token
      SecureRandom.hex(64)
    end

    def self.local_ip
      orig = Socket.do_not_reverse_lookup
      Socket.do_not_reverse_lookup = true
      UDPSocket.open do |s|
        s.connect '64.223.187.99', 1
        s.addr.last
      end

      ensure
        Socket.do_not_reverse_lookup = orig
    end

    # Generates dialback key as described in XEP-0185
    def self.dialback_key(receiving_server, originating_server, stream_id)
      sha = Digest::SHA2.new(256)
      sha.update("#{receiving_server} #{originating_server} #{stream_id}")
      sha.to_s
    end
  end
end