Drools web based user interactions with a performance diagnostic knowledge base / published by https://github.com/dacr/code-examples-manager #50d2f501-e740-42de-984b-8ad50001137b/c7c1ea2205c96c21b8199ebc6687fb6b7cedf80d

drools-interactions.sc

// summary : Drools web based user interactions with a performance diagnostic knowledge base
// keywords : scala, drools, mvel, scalatest, ai, knowledgebase, interactions, akka-http
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 50d2f501-e740-42de-984b-8ad50001137b
// execution : scala ammonite script (http://ammonite.io/) - run as follow 'amm scriptname.sc'
// created-on : 2018-09-12T21:11:39+02:00
// managed-by : https://github.com/dacr/code-examples-manager

interp.resolutionHooks += { fetch =>
  // -- This is mandatory with drools >= 7.0.46 because drools sources artifacts also brings kie.conf
  // -- (it generates resources conflict at KIE init) and because by default ammonite also load sources artifact...
  // -- WARN : YOU MAY HAVE TO CLEANUP YOUR LOCAL COURSIER CACHE ~/.cache/coursier to remove sources artifact
  // -- WARN :  find ~/.cache/coursier/ -name "*drools*-sources.jar" | xargs rm -f
  import scala.jdk.CollectionConverters._
  fetch.withClassifiers(fetch.getClassifiers.asScala.filter(_ != "sources").asJava)
}

@

import $ivy.`fr.janalyse::drools-scripting:1.0.15`
import fr.janalyse.droolscripting._

import $ivy.`com.typesafe.akka::akka-http:10.2.4`
import $ivy.`com.typesafe.akka::akka-stream:2.6.13`
import scala.collection.immutable.Queue

case class Question(reference:String, message:String) {
  val possibleAnswersRE = """(\[[^]]+\])""".r
  def possibleAnswers():List[String] = {
    possibleAnswersRE.findAllMatchIn(message).map(_.group(1)).toList
  }
}

class DroolsInternalHelper(engine:DroolsEngine) {
  private var questions:Queue[Question] = Queue.empty
  def current:Option[Question] = questions.headOption

  def ask(reference:String, question:String):Unit = {
    questions = questions.enqueue(Question(reference, question))
  }
  def respond(reference:String, answer:String):Unit = {
    if (!questions.isEmpty) {
      questions = questions.tail
      val json = s"""{"reference":"$reference", "answer":"$answer"}"""
      engine.insertJson(json, "interact.UserResponse")
    }
  }
  def reset():Unit = {
    questions = Queue.empty
  }
}

class PerformanceExpertSystem {
  val helperClassName = classOf[DroolsInternalHelper].getCanonicalName
  val drl =
   s"""package interact
      |dialect "mvel"
      |
      |global org.slf4j.Logger logger
      |global $helperClassName helper
      |
      |declare PerformanceIssue
      |  description: String
      |end
      |
      |declare UserResponse
      |  reference: String
      |  answer: String
      |end
      |
      |// -------------------------------------------------------------------------------
      |rule "perf-issue" when then insert("reset"); end
      |
      |rule "perf-issue after reset" when str:String(this == "reset")
      |then
      |  helper.ask("perf-issue", "Do you encounter a performance problem ? [yes] [no]");
      |  delete(str);
      |end
      |// -------------------------------------------------------------------------------
      |rule "perf-context" when
      |  UserResponse(reference == "perf-issue", answer == "yes")
      |then
      |  helper.ask("perf-context", "What is the nature of your performance issue ? [slow response time] [random crash] [high cpu]")
      |end
      |// -------------------------------------------------------------------------------
      |rule "os-context" when
      |  UserResponse(reference == "perf-issue", answer == "yes")
      |then
      |  helper.ask("os-context", "What is your operating system ? [Linux] [Windows] [MacOS]")
      |end
      |// -------------------------------------------------------------------------------
      |rule "app-context" when
      |  UserResponse(reference == "perf-issue", answer == "yes")
      |then
      |  helper.ask("app-context", "What is your technical context ? [java] [php] [javascript]")
      |end
      |// -------------------------------------------------------------------------------
      |//rule "java-context" when
      |//  UserResponse(reference == "app-context", answer == "java")
      |//then
      |//  helper.ask("java-vendor", "What is your java vendor ? [oracle] [openjdk] [ibm]")
      |//  helper.ask("java-release", "What is your java release ? <text>")
      |//end
      |// -------------------------------------------------------------------------------
      |rule "javascript troll rule" when
      |  UserResponse(reference == "app-context", answer=="javascript")
      |then
      |  insert(new PerformanceIssue("Oh NO you're using javascript !! do you know it means java scripting ?"));
      |end
      |// -------------------------------------------------------------------------------
      |rule "php troll rule" when
      |  UserResponse(reference == "app-context", answer=="php")
      |then
      |  insert(new PerformanceIssue("Seriously PHP !?!? A 20th century language..."));
      |end
      |// -------------------------------------------------------------------------------
      |rule "java troll rule" when
      |  UserResponse(reference == "app-context", answer=="java")
      |then
      |  insert(new PerformanceIssue("Java ? And did you consider cobol ?"));
      |end
      |// -------------------------------------------------------------------------------
      |rule "windows/macos troll rule" when
      |  UserResponse(reference == "os-context", answer in ("Windows","MacOS") )
      |then
      |  insert(new PerformanceIssue("What ! Using desktop Operating System to power your backend ?"));
      |end
      |""".stripMargin
  val engineConfig = DroolsEngineConfig(equalsWithIdentity=false, withDroolsLogging=false)
  val engine = DroolsEngine(drl, engineConfig)
  val helper = new DroolsInternalHelper(engine)
  engine.session.setGlobal("helper", helper)
  def session = engine.session
  def run() {
    println("Ctrl-C to stop execution")
    engine.session.fireUntilHalt()
  }
}

class AIService(expertSystem:PerformanceExpertSystem) {
  import akka.http.scaladsl._
  import akka.http.scaladsl.server.Directives._
  import akka.http.scaladsl.model._
  import scala.concurrent.Await
  import scala.concurrent.duration.Duration
  import akka.http.scaladsl.model.ContentTypes._

  implicit val system = akka.actor.ActorSystem("MySystem")
  implicit val materializer = akka.stream.ActorMaterializer()
  implicit val executionContext = system.dispatcher

  def render(question:Question): HttpResponse = {
    val renderedQuestion =
      question.possibleAnswers().foldLeft(question.message) { case (nquest,answer) =>
        val cleanedAnswer = answer.tail.init // remove []
        val lnk = s"/response/${question.reference}/$cleanedAnswer"
        nquest.replace(answer, s"""<a href="$lnk">$answer</a> """)
      }
    val content =
      s"""<html>
         |  <body>
         |    <h1>$renderedQuestion</h1>
         |  </body>
         |</html>""".stripMargin
    HttpResponse(entity = HttpEntity(`text/html(UTF-8)`, content))
  }

  def renderDiagnostic():HttpResponse = {
    val issues = expertSystem.engine.getModelInstances("interact.PerformanceIssue")
    val renderedIssues =
      if (issues.isEmpty) {
        "No issue found"
      } else {
        issues.map(issue => s"<p>$issue</p>").mkString("\n")
      }
    val content =
      s"""<html>
         |  <body>
         |    <h1>Performance diagnostics results</h1>
         |    $renderedIssues
         |    <br/>
         |    <a href="/reset">Reset</a>
         |  </body>
         |</html>""".stripMargin
    HttpResponse(entity = HttpEntity(`text/html(UTF-8)`, content))
  }

  def stopRoute = path("shutdown") {
    get { complete { expertSystem.engine.session.halt(); shutdown() ; "OK" } }
  }

  def homeRoute= path("") {
    get {
      complete {
        expertSystem.helper.current match {
          case Some(question) => render(question)
          case None => renderDiagnostic()
        }
      }
    }
  }

  def responseRoute = path("response" / Segment / Segment) {
    case (reference, answer) => get {
      expertSystem.helper.respond(reference, answer)
      redirect("/", StatusCodes.TemporaryRedirect)
    }
  }

  def resetRoute = path("reset") {
    get {
      for { ob <- expertSystem.engine.getObjects } {
        val handle = expertSystem.engine.getFactHandle(ob)
        expertSystem.session.delete(handle)
      }
      expertSystem.engine.insert("reset")
      expertSystem.helper.reset()
      redirect("/", StatusCodes.TemporaryRedirect)
    }
  }

  val chosenPort = 6080
  val chosenInterface = "0.0.0.0"
  val routes = stopRoute ~ resetRoute ~ homeRoute ~ responseRoute
  val bindingFuture = Http().bindAndHandle(routes, chosenInterface, chosenPort)
  println(s"***** Local web server is running on $chosenInterface:$chosenPort *****")

  def shutdown():Unit = bindingFuture.flatMap(_.unbind()).onComplete { _ => system.terminate() }
  def waitForShutdown(): Unit = Await.ready(system.whenTerminated, Duration.Inf)
}

val expertSystem = new PerformanceExpertSystem
val aiService = new AIService(expertSystem)
expertSystem.run()
aiService.waitForShutdown()