// add appId and appKey from https://developer.nutritionix.com/admin/access_details
def appId = ""
def appKey = ""

def apiEndpoint = "https://trackapi.nutritionix.com/v2/natural/nutrients"

try {
    // do post request with appropriate keys
    URL url = new URL(apiEndpoint)
    HttpURLConnection connection = (HttpURLConnection)url.openConnection()

    // use input param 'query' to construct query details
    def data = "{\"query\":\"" + query + "\"}"

    connection.setDoOutput(true)
    connection.setDoInput(true)
    connection.setRequestMethod("POST")

    connection.setRequestProperty("Content-Length", "" + Integer.toString(data.getBytes().length))
    connection.setRequestProperty("x-app-id", appId)
    connection.setRequestProperty("x-app-key", appKey)
    connection.addRequestProperty("Content-Type", "application/json")

    connection.connect();

    DataOutputStream wr = new DataOutputStream (connection.getOutputStream())
    wr.writeBytes (data)
    wr.flush()
    wr.close()

    InputStream response = connection.getInputStream()
    String content = new java.util.Scanner(response).useDelimiter("\\A").next()

    // parse json response
    def slurper = new groovy.json.JsonSlurper()
    def result = slurper.parseText(content)
 
    // set output param calories
    calories = result.foods[0].nf_calories
    
    // calculate walking duration
    def durationMinutes = (int)Math.ceil((calories/4))

    // set output param walkingDuration
    walkingDuration = (durationMinutes == 1 ? durationMinutes + " minute" : durationMinutes + " minutes")

} catch (Exception e) {
    println "Error retrieving calories: " + e.getMessage()
}