1 files changed, 178 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/restquery/rest/parsers/SearchFilterParser.scala b/src/main/scala/xyz/driver/restquery/rest/parsers/SearchFilterParser.scala
new file mode 100644
index 0000000..ce3009b
--- /dev/null
+++ b/src/main/scala/xyz/driver/restquery/rest/parsers/SearchFilterParser.scala
@@ -0,0 +1,178 @@
+package xyz.driver.restquery.http.parsers
+
+import java.util.UUID
+
+import fastparse.all._
+import fastparse.core.Parsed
+import xyz.driver.restquery.domain.{SearchFilterBinaryOperation, SearchFilterExpr, SearchFilterNAryOperation}
+import xyz.driver.restquery.utils.Utils
+import xyz.driver.restquery.utils.Utils._
+
+import scala.util.Try
+
+@SuppressWarnings(Array("org.wartremover.warts.Product", "org.wartremover.warts.Serializable"))
+object SearchFilterParser {
+
+  private object BinaryAtomFromTuple {
+    def unapply(input: (SearchFilterExpr.Dimension, (String, Any))): Option[SearchFilterExpr.Atom.Binary] = {
+      val (dimensionName, (strOperation, value)) = input
+      val updatedValue                           = trimIfString(value)
+
+      parseOperation(strOperation.toLowerCase).map { op =>
+        SearchFilterExpr.Atom.Binary(dimensionName, op, updatedValue.asInstanceOf[AnyRef])
+      }
+    }
+  }
+
+  private object NAryAtomFromTuple {
+    // Compiler warning: unchecked since it is eliminated by erasure, if we user Seq[String]
+    def unapply(input: (SearchFilterExpr.Dimension, (String, Seq[_]))): Option[SearchFilterExpr.Atom.NAry] = {
+      val (dimensionName, (strOperation, xs)) = input
+      val updatedValues                       = xs.map(trimIfString)
+
+      if (strOperation.toLowerCase == "in") {
+        Some(
+          SearchFilterExpr.Atom
+            .NAry(dimensionName, SearchFilterNAryOperation.In, updatedValues.map(_.asInstanceOf[AnyRef])))
+      } else {
+        None
+      }
+    }
+  }
+
+  private def trimIfString(value: Any) =
+    value match {
+      case s: String => Utils.safeTrim(s)
+      case a         => a
+    }
+
+  private val operationsMapping = {
+    import xyz.driver.restquery.domain.SearchFilterBinaryOperation._
+
+    Map[String, SearchFilterBinaryOperation](
+      "eq"    -> Eq,
+      "noteq" -> NotEq,
+      "like"  -> Like,
+      "gt"    -> Gt,
+      "gteq"  -> GtEq,
+      "lt"    -> Lt,
+      "lteq"  -> LtEq
+    )
+  }
+
+  private def parseOperation(x: String): Option[SearchFilterBinaryOperation] = operationsMapping.get(x)
+
+  private val whitespaceParser = P(CharPred(Utils.isSafeWhitespace))
+
+  val dimensionParser: Parser[SearchFilterExpr.Dimension] = {
+    val identParser = P(
+      CharPred(c => c.isLetterOrDigit)
+        .rep(min = 1)).!.map(s => SearchFilterExpr.Dimension(None, toSnakeCase(s)))
+    val pathParser = P(identParser.! ~ "." ~ identParser.!) map {
+      case (left, right) =>
+        SearchFilterExpr.Dimension(Some(toSnakeCase(left)), toSnakeCase(right))
+    }
+    P(pathParser | identParser)
+  }
+
+  private val commonOperatorParser: Parser[String] = {
+    P(IgnoreCase("eq") | IgnoreCase("like") | IgnoreCase("noteq")).!
+  }
+
+  private val numericOperatorParser: Parser[String] = {
+    P(IgnoreCase("eq") | IgnoreCase("noteq") | ((IgnoreCase("gt") | IgnoreCase("lt")) ~ IgnoreCase("eq").?)).!
+  }
+
+  private val naryOperatorParser: Parser[String] = P(IgnoreCase("in")).!
+
+  private val isPositiveParser: Parser[Boolean] = P(CharIn("-+").!.?).map {
+    case Some("-") => false
+    case _         => true
+  }
+
+  private val digitsParser: Parser[String] = P(CharIn('0' to '9').rep(min = 1).!) // Exclude Unicode "digits"
+
+  private val numberParser: Parser[String] = P(isPositiveParser ~ digitsParser.! ~ ("." ~ digitsParser).!.?).map {
+    case (false, intPart, Some(fracPart)) => s"-$intPart.${fracPart.tail}"
+    case (false, intPart, None)           => s"-$intPart"
+    case (_, intPart, Some(fracPart))     => s"$intPart.${fracPart.tail}"
+    case (_, intPart, None)               => s"$intPart"
+  }
+
+  private val nAryValueParser: Parser[String] = P(CharPred(_ != ',').rep(min = 1).!)
+
+  private val longParser: Parser[Long] = P(CharIn('0' to '9').rep(min = 1).!.map(_.toLong))
+
+  private val booleanParser: Parser[Boolean] =
+    P((IgnoreCase("true") | IgnoreCase("false")).!.map(_.toBoolean))
+
+  private val hexDigit: Parser[String] = P((CharIn('a' to 'f') | CharIn('A' to 'F') | CharIn('0' to '9')).!)
+
+  private val uuidParser: Parser[UUID] =
+    P(
+      hexDigit.rep(8).! ~ "-" ~ hexDigit.rep(4).! ~ "-" ~ hexDigit.rep(4).! ~ "-" ~ hexDigit.rep(4).! ~ "-" ~ hexDigit
+        .rep(12)
+        .!).map {
+      case (group1, group2, group3, group4, group5) => UUID.fromString(s"$group1-$group2-$group3-$group4-$group5")
+    }
+
+  private val binaryAtomParser: Parser[SearchFilterExpr.Atom.Binary] = P(
+    dimensionParser ~ whitespaceParser ~
+      ((numericOperatorParser.! ~ whitespaceParser ~ (longParser | numberParser.!) ~ End) |
+        (commonOperatorParser.! ~ whitespaceParser ~ (uuidParser | booleanParser | AnyChar.rep(min = 1).!) ~ End))
+  ).map {
+    case BinaryAtomFromTuple(atom) => atom
+  }
+
+  private val nAryAtomParser: Parser[SearchFilterExpr.Atom.NAry] = P(
+    dimensionParser ~ whitespaceParser ~ (
+      naryOperatorParser ~ whitespaceParser ~
+        ((longParser.rep(min = 1, sep = ",") ~ End) | (booleanParser.rep(min = 1, sep = ",") ~ End) |
+          (nAryValueParser.!.rep(min = 1, sep = ",") ~ End))
+    )
+  ).map {
+    case NAryAtomFromTuple(atom) => atom
+  }
+
+  private val atomParser: Parser[SearchFilterExpr.Atom] = P(binaryAtomParser | nAryAtomParser)
+
+  @deprecated("play-akka transition", "0")
+  def parse(query: Map[String, Seq[String]]): Try[SearchFilterExpr] =
+    parse(query.toSeq.flatMap {
+      case (key, values) =>
+        values.map(value => key -> value)
+    })
+
+  def parse(query: Seq[(String, String)]): Try[SearchFilterExpr] = Try {
+    query.toList.collect { case ("filters", value) => value } match {
+      case Nil => SearchFilterExpr.Empty
+
+      case head :: Nil =>
+        atomParser.parse(head) match {
+          case Parsed.Success(x, _)    => x
+          case e: Parsed.Failure[_, _] => throw new ParseQueryArgException("filters" -> formatFailure(1, e))
+        }
+
+      case xs =>
+        val parsed = xs.map(x => atomParser.parse(x))
+        val failures: Seq[String] = parsed.zipWithIndex.collect {
+          case (e: Parsed.Failure[_, _], index) => formatFailure(index, e)
+        }
+
+        if (failures.isEmpty) {
+          val filters = parsed.collect {
+            case Parsed.Success(x, _) => x
+          }
+
+          SearchFilterExpr.Intersection.create(filters: _*)
+        } else {
+          throw new ParseQueryArgException("filters" -> failures.mkString("; "))
+        }
+    }
+  }
+
+  private def formatFailure(sectionIndex: Int, e: Parsed.Failure[_, _]): String = {
+    s"section $sectionIndex: ${fastparse.core.ParseError.msg(e.extra.input, e.extra.traced.expected, e.index)}"
+  }
+
+}