class SmsSender

# File lib/sms_sender.rb, line 6
def initialize(client_id, client_secret, host='api.smsglobal.com', port='443', request_url='/v1/sms/' )
  @client_id = client_id
  @secret = client_secret
  @host = host
  @port = port
  @request_url = request_url
end

# File lib/sms_sender.rb, line 14
def send(title, msg, mobile)
  @nonce = (0...8).map { (65 + rand(26)).chr }.join
  @ts = Time.now.to_i
  mac = calculate_mac
  header = {'Authorization' => "MAC id=\"#{@client_id}\", ts=\"#{@ts}\", nonce=\"#{@nonce}\", mac=\"#{mac}\"",
            'Content-Type' => 'application/json',
            'Accept' => 'application/json'}

  protocol = @port.to_s == '443' ? 'https' : 'http'
  body = {"origin"=>title, "destination"=>mobile, "message"=>msg }

  response = HTTParty.post("#{protocol}://#{@host}#{@request_url}", headers: header, body: body.to_json)
  response.code
end

# File lib/sms_sender.rb, line 30
def calculate_mac
  body = "#{@ts}\n#{@nonce}\nPOST\n#{@request_url}\n#{@host}\n#{@port}\n\n"
  digest = Digest::HMAC.digest(body, @secret, Digest::SHA256)
  Base64.strict_encode64 digest
end