Feature/yaml parser (#7)

* Added Evaluator parser

* Evolution of parser

* Added tuner parser

src/main/scala/io/github/jsarni/CaraStage/CaraStageMapper.scala

@@ -2,8 +2,10 @@ package io.github.jsarni.CaraStage
 
 import io.github.jsarni.CaraStage.DatasetStage.CaraDataset
 import io.github.jsarni.CaraStage.ModelStage._
+import io.github.jsarni.CaraStage.TuningStage.TuningStageDescription
+import org.apache.spark.ml.evaluation._
 
-import scala.util.Try
+import scala.util.{Try, Success, Failure}
 
 trait CaraStageMapper {
 
@@ -13,7 +15,8 @@ trait CaraStageMapper {
 
   def mapModelStage(stageDescription: CaraStageDescription): CaraModel = {
     stageDescription.stageName match {
-      case "LogisticRegression" => LogisticRegression(stageDescription.params)
+      case "LogisticRegression" =>
+        LogisticRegression(stageDescription.params)
       case _ => throw
         new Exception(s"${stageDescription.stageName} is not a valid Cara Stage name. Please verify your Yaml File")
     }
@@ -27,4 +30,39 @@ trait CaraStageMapper {
     }
   }
 
+  def mapEvaluator(evaluatorName: String): Evaluator = {
+    evaluatorName match {
+      case "RegressionEvaluator" => new RegressionEvaluator()
+      case _ =>
+        throw
+          new Exception(s"${evaluatorName} is not a valid SparkML Validator name. Please verify your Yaml File")
+    }
+  }
+
+  def mapTuner(tuningStageDesc: TuningStageDescription): TuningStageDescription = {
+    tuningStageDesc.tuningStage match {
+      case "CrossValidator" =>
+        if (!tuningStageDesc.paramName.equals("NumFolds"))
+          throw new IllegalArgumentException("The only parameter available for CrossValidator is NumFolds")
+        Try(tuningStageDesc.paramValue.toInt) match {
+          case Success(_) =>
+            tuningStageDesc
+          case Failure(_) =>
+            throw new IllegalArgumentException("The NumFolds parameter value must be an Integer")
+        }
+      case "TrainValidationSplit" =>
+        if (!tuningStageDesc.paramName.equals("TrainRatio"))
+          throw new IllegalArgumentException("The only parameter available for TrainValidationSplit is TrainRatio")
+        Try(tuningStageDesc.paramValue.toDouble) match {
+          case Success(value) =>
+            if (value > 1 || value < 0)
+              tuningStageDesc
+            else
+              throw new IllegalArgumentException("The TrainRation parameter value must be a Double between 0 and 1")
+          case Failure(_) =>
+            throw new IllegalArgumentException("The TrainRation parameter value must be a Double between 0 and 1")
+        }
+    }
+  }
+
 }

src/main/scala/io/github/jsarni/CaraStage/TuningStage/TuningStageDescription.scala

@@ -0,0 +1,3 @@
+package io.github.jsarni.CaraStage.TuningStage
+
+case class TuningStageDescription(tuningStage: String, paramName: String, paramValue: String)

src/main/scala/io/github/jsarni/PipelineParser/CaraParser.scala

@@ -1,18 +1,27 @@
 package io.github.jsarni.PipelineParser
 
 import com.fasterxml.jackson.databind.JsonNode
+import io.github.jsarni.CaraStage.TuningStage.TuningStageDescription
 import io.github.jsarni.CaraStage.{CaraStage, CaraStageDescription, CaraStageMapper}
 import io.github.jsarni.CaraYaml.CaraYaml
+import org.apache.spark.ml.evaluation.Evaluator
 import org.apache.spark.ml.{Pipeline, PipelineStage}
 
 import scala.collection.JavaConverters._
-import scala.util.Try
+import scala.util.{Try, Success, Failure}
 
 class CaraParser(caraYaml: CaraYaml) extends ParserUtils with CaraStageMapper{
 
   val contentTry = caraYaml.loadFile()
 
-  def parse(): Try[Pipeline] = {
+  def build(): Try[CaraPipeline] = {
+    for {
+      pipeline <- parsePipeline()
+      evaluator <- parseEvaluator()
+    } yield CaraPipeline(pipeline, evaluator)
+  }
+
+  private[PipelineParser] def parsePipeline(): Try[Pipeline] = {
     for {
       content <- contentTry
       stagesDescriptions <- extractStages(content)
@@ -22,8 +31,27 @@ class CaraParser(caraYaml: CaraYaml) extends ParserUtils with CaraStageMapper{
     } yield pipeline
   }
 
+  private[PipelineParser] def parseEvaluator(): Try[Evaluator] = {
+    for {
+      content <- contentTry
+      evaluatorName <- extractEvaluator(content)
+      evaluator = mapEvaluator(evaluatorName)
+    } yield evaluator
+  }
+
+  private[PipelineParser] def parseTuner(): Try[TuningStageDescription] = {
+    for {
+      content <- contentTry
+      tunerDesc <- extractTuner(content)
+      validatedTunerDesc = mapTuner(tunerDesc)
+      } yield validatedTunerDesc
+  }
+
+
+
   private[PipelineParser] def extractStages(fileContent: JsonNode): Try[List[CaraStageDescription]] = Try {
-    val stagesList = fileContent.at(s"/CaraPipeline").iterator().asScala.toList
+    val stagesList =
+      fileContent.at(s"/CaraPipeline").iterator().asScala.toList.filter(_.has("stage"))
     val stages = stagesList.map{
       stageDesc =>
         val name = stageDesc.at("/stage").asText()
@@ -50,6 +78,44 @@ class CaraParser(caraYaml: CaraYaml) extends ParserUtils with CaraStageMapper{
     stages
   }
 
+  private[PipelineParser] def extractEvaluator(fileContent: JsonNode): Try[String] = Try {
+
+    val stagesList = fileContent.at(s"/CaraPipeline").iterator().asScala.toList.filter(_.has("evaluator"))
+
+    val evaluatorList = stagesList.map{ stageDesc =>stageDesc.at("/evaluator").asText()}
+
+    evaluatorList.length match {
+      case 1 => evaluatorList.head
+      case _ =>
+        throw new Exception("Error: You must define exactly one SparkML Evaluator")
+    }
+  }
+
+  private[PipelineParser] def extractTuner(fileContent: JsonNode): Try[TuningStageDescription] = {
+
+    val tunersList = fileContent.at(s"/CaraPipeline").iterator().asScala.toList.filter(_.has("tuner"))
+
+    tunersList.length match {
+      case l if l <= 1 =>
+        val tunerJson = tunersList.head
+        val tunerName = tunerJson.at("/tuner").textValue()
+
+        val paramsJson = tunerJson.at("/params")
+          val paramList = paramsJson.iterator().asScala.toList
+          paramList.length match {
+            case 1 =>
+              val paramName = paramList.flatMap { r => r.fieldNames().asScala.toList }.head
+              val paramValue = paramList.head.at(s"/$paramName").asText()
+
+              Success(TuningStageDescription(tunerName, paramName, paramValue))
+            case _ =>
+              Failure(new IllegalArgumentException("Tuners must have exactly one param"))
+          }
+      case _ =>
+        Failure(new IllegalArgumentException("Error: You must define exactly one SparkML Evaluator"))
+    }
+  }
+
   private[PipelineParser] def parseStage(stageDescription: CaraStageDescription): Try[Any] =
     for {
       stageClass <- Try(Class.forName(s"io.github.jsarni.CaraStage.ModelStage.${stageDescription.stageName}"))

src/main/scala/io/github/jsarni/PipelineParser/CaraPipeline.scala

@@ -0,0 +1,6 @@
+package io.github.jsarni.PipelineParser
+
+import org.apache.spark.ml.Pipeline
+import org.apache.spark.ml.evaluation.Evaluator
+
+case class CaraPipeline(pipeline: Pipeline, evaluator: Evaluator)

src/test/resources/cara_for_build.yaml

@@ -4,3 +4,7 @@ CaraPipeline:
     - MaxIter: 10
     - RegParam: 0.3
     - ElasticNetParam: 0.1
+- evaluator: RegressionEvaluator
+- tuner: CrossValidator
+  params:
+    - NumFolds: 3

src/test/resources/cara_two_evaluator.yaml

@@ -0,0 +1,8 @@
+CaraPipeline:
+- stage: LogisticRegression
+  params:
+    - MaxIter: 10
+    - RegParam: 0.3
+    - ElasticNetParam: 0.1
+- tuner: Tuner 1
+- tuner: Tuner 2

src/test/resources/cara_zero_evaluator.yaml

@@ -0,0 +1,8 @@
+CaraPipeline:
+- stage: LogisticRegression
+  params:
+    - MaxIter: 10
+    - RegParam: 0.3
+    - ElasticNetParam: 0.1
+- evaluator: RegressionEvaluator
+- evaluator: OtherEvaluator

src/test/scala/io/github/jsarni/PipelineParser/CaraParserTest.scala

@@ -2,15 +2,19 @@ package io.github.jsarni.PipelineParser
 
 import io.github.jsarni.CaraStage.{CaraStage, CaraStageDescription}
 import io.github.jsarni.CaraStage.ModelStage.LogisticRegression
+import io.github.jsarni.CaraStage.TuningStage.TuningStageDescription
 import io.github.jsarni.CaraYaml.CaraYaml
 import io.github.jsarni.TestBase
 import org.apache.spark.ml.{Pipeline, PipelineStage}
 import org.apache.spark.ml.classification.{LogisticRegression => SparkLR}
+import org.apache.spark.ml.evaluation.RegressionEvaluator
+import org.apache.spark.ml.evaluation.Evaluator
+
 import scala.util.Try
 
 class CaraParserTest extends TestBase {
 
-  "extractStages" should "return parse the yaml description file to a json object" in {
+  "extractTuner" should "return parse the yaml description file to a json object" in {
     val caraPath = getClass.getResource("/cara.yaml").getPath
     val caraYaml = CaraYaml(caraPath)
     val caraParser = new CaraParser(caraYaml)
@@ -30,21 +34,6 @@ class CaraParserTest extends TestBase {
     result.get should contain theSameElementsAs expectedResult
   }
 
-
-//  "parseStage" should "return parse the yaml description file to a json object" in {
-//    val caraPath = getClass.getResource("/cara.yaml").getPath
-//    val caraYaml = CaraYaml(caraPath)
-//    val caraParser = new CaraParser(caraYaml)
-//
-//
-//    val stageDesc =
-//      CaraStageDescription("TestStage", Map("MaxIter" -> "10", "RegParam" -> "0.3", "ElasticNetParam" -> "0.1"))
-//
-//    val res = caraParser.parseStage(stageDesc)
-//    print(res.get)
-//
-//  }
-
   "parseSingleStageMap" should "parse a CaraStageDescription to a CaraStage " in {
     val caraPath = getClass.getResource("/cara.yaml").getPath
     val caraParser = new CaraParser(CaraYaml(caraPath))
@@ -126,16 +115,127 @@ class CaraParserTest extends TestBase {
     res.get.getStages shouldBe new Pipeline().setStages(stagesList.toArray).getStages
   }
 
-  "parse" should "build the described Pipeline of the Yaml File" in {
+  "parsePipeline" should "build the described Pipeline of the Yaml File" in {
     val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
     val caraYaml = CaraYaml(caraPath)
     val caraParser = new CaraParser(caraYaml)
 
-    val res = caraParser.parse()
+
+    val parsePipeline = PrivateMethod[Try[Pipeline]]('parsePipeline)
+    val res = caraParser.invokePrivate(parsePipeline())
     val exprectedRes = new Pipeline().setStages(Array(new SparkLR().setMaxIter(10).setRegParam(0.3).setElasticNetParam(0.1)))
 
     res.isSuccess shouldBe true
     res.get.getStages.map(_.extractParamMap().toSeq.map(_.value)).head should contain theSameElementsAs
       exprectedRes.getStages.map(_.extractParamMap().toSeq.map(_.value)).head
   }
+
+  "extractTuner" should "get the correct Evaluator Name from the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractEvaluator = PrivateMethod[Try[String]]('extractEvaluator)
+    val result = caraParser.invokePrivate(extractEvaluator(myJson.get))
+
+    result.isSuccess shouldBe true
+    result.get shouldBe "RegressionEvaluator"
+  }
+
+  it should "Raise an exception if there is no evaluator specified" in {
+    val caraPath = getClass.getResource("/cara_zero_evaluator.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractEvaluator = PrivateMethod[Try[String]]('extractEvaluator)
+    val result = caraParser.invokePrivate(extractEvaluator(myJson.get))
+
+    result.isFailure shouldBe true
+  }
+
+  it should "Raise an exception if there is more than one evaluator specified" in {
+    val caraPath = getClass.getResource("/cara_two_evaluator.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractEvaluator = PrivateMethod[Try[String]]('extractEvaluator)
+    val result = caraParser.invokePrivate(extractEvaluator(myJson.get))
+
+    result.isFailure shouldBe true
+  }
+
+  "parseEvaluator" should "build the described evaluator of the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val parseEvaluator = PrivateMethod[Try[Evaluator]]('parseEvaluator)
+    val res = caraParser.invokePrivate(parseEvaluator())
+
+    res.isSuccess shouldBe true
+    res.get.isInstanceOf[RegressionEvaluator] shouldBe true
+  }
+
+  "extractTuner" should "get the correct Tuner Description from the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractTuner = PrivateMethod[Try[TuningStageDescription]]('extractTuner)
+    val result = caraParser.invokePrivate(extractTuner(myJson.get))
+
+    result.isSuccess shouldBe true
+    result.get shouldBe TuningStageDescription("CrossValidator", "NumFolds", "3")
+  }
+
+  it should "raise an exception ilf there is more than one tuner in the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_two_evaluator.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractTuner = PrivateMethod[Try[TuningStageDescription]]('extractTuner)
+    val result = caraParser.invokePrivate(extractTuner(myJson.get))
+
+    result.isFailure shouldBe true
+    an [IllegalArgumentException] should be thrownBy result.get
+  }
+
+  "parseTuner" should "build the described Tuner of the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val myJson = caraYaml.loadFile()
+
+    val extractTuner = PrivateMethod[Try[TuningStageDescription]]('extractTuner)
+    val result = caraParser.invokePrivate(extractTuner(myJson.get))
+
+    result.isSuccess shouldBe true
+    result.get shouldBe TuningStageDescription("CrossValidator", "NumFolds", "3")
+  }
+
+  "build" should "build the described Pipeline of the Yaml File" in {
+    val caraPath = getClass.getResource("/cara_for_build.yaml").getPath
+    val caraYaml = CaraYaml(caraPath)
+    val caraParser = new CaraParser(caraYaml)
+
+    val res = caraParser.build()
+
+    val exprectedRes = new Pipeline().setStages(Array(new SparkLR().setMaxIter(10).setRegParam(0.3).setElasticNetParam(0.1)))
+
+    res.isSuccess shouldBe true
+    res.get.evaluator.isInstanceOf[RegressionEvaluator] shouldBe true
+    res.get.pipeline.getStages.map(_.extractParamMap().toSeq.map(_.value)).head should contain theSameElementsAs
+      exprectedRes.getStages.map(_.extractParamMap().toSeq.map(_.value)).head
+  }
 }