val refererParser = "com.snowplowanalytics" %% "scala-referer-parser" % "1.0.0"

import com.snowplowanalytics.refererparser._
import cats.effect.IO
import cats.data.EitherT
import java.net.URI

val refererUrl = "http://www.google.com/search?q=gateway+oracle+cards+denise+linn&hl=en&client=safari"
val pageUrl    = "http:/www.psychicbazaar.com/shop" // Our current URL

val referersJsonPath = "/opt/referers/referers.json"

// We use EitherT to handle exceptions. The IO routine will short circuit if an exception is returned.
val io: EitherT[IO, Exception, Unit] = for {
  // We can instantiate a new Parser instance with Parser.create
  parser <- EitherT(CreateParser[IO].create(referersJsonPath))

  // Referer is a sealed hierarchy of different referer types
  referer1 <- EitherT.fromOption[IO](parser.parse(refererUrl, pageUrl),
    new Exception("No parseable referer"))
  _ <- EitherT.right(IO { println(referer1) })
    // => SearchReferer(SearchMedium,Google,Some(gateway oracle cards denise linn))

  // You can provide a list of domains which should be considered internal
  referer2 <- EitherT.fromOption[IO](parser.parse(
      new URI("http://www.subdomain1.snowplowanalytics.com"),
      Some("http://www.snowplowanalytics.com"),
      List("www.subdomain1.snowplowanalytics.com", "www.subdomain2.snowplowanalytics.com")
    ), new Exception("No parseable referer"))
  _ <- EitherT.right(IO { println(referer2) })
    // => InternalReferer(InternalMedium)

  // Various overloads are available for common cases, for instance
  maybeReferer1 = parser.parse("https://www.bing.com/search?q=snowplow")
  maybeReferer2 = parser.parse(new URI("https://www.bing.com/search?q=snowplow"), None, Nil)
  _ <- EitherT.right(IO { println( maybeReferer1 == maybeReferer2 ) }) // => true
} yield Unit

io.value.unsafeRunSync()