1 files changed, 64 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/restquery/rest/parsers/SortingParser.scala b/src/main/scala/xyz/driver/restquery/rest/parsers/SortingParser.scala
new file mode 100644
index 0000000..f2a3c04
--- /dev/null
+++ b/src/main/scala/xyz/driver/restquery/rest/parsers/SortingParser.scala
@@ -0,0 +1,64 @@
+package xyz.driver.restquery.http.parsers
+
+import fastparse.all._
+import fastparse.core.Parsed
+import xyz.driver.restquery.domain.{Sorting, SortingOrder}
+import xyz.driver.restquery.utils.Utils._
+
+import scala.util.Try
+
+object SortingParser {
+
+  private val sortingOrderParser: Parser[SortingOrder] = P("-".!.?).map {
+    case Some(_) => SortingOrder.Descending
+    case None    => SortingOrder.Ascending
+  }
+
+  private def dimensionSortingParser(validDimensions: Seq[String]): Parser[Sorting.Dimension] = {
+    P(sortingOrderParser ~ StringIn(validDimensions: _*).!).map {
+      case (sortingOrder, field) =>
+        val prefixedFields = field.split("\\.", 2)
+        prefixedFields.size match {
+          case 1 => Sorting.Dimension(None, toSnakeCase(field), sortingOrder)
+          case 2 =>
+            Sorting.Dimension(Some(prefixedFields.head).map(toSnakeCase),
+                              toSnakeCase(prefixedFields.last),
+                              sortingOrder)
+        }
+    }
+  }
+
+  private def sequentialSortingParser(validDimensions: Seq[String]): Parser[Sorting.Sequential] = {
+    P(dimensionSortingParser(validDimensions).rep(min = 1, sep = ",") ~ End).map { dimensions =>
+      Sorting.Sequential(dimensions)
+    }
+  }
+
+  @deprecated("play-akka transition", "0")
+  def parse(validDimensions: Set[String], query: Map[String, Seq[String]]): Try[Sorting] =
+    parse(validDimensions, query.toSeq.flatMap {
+      case (key, values) =>
+        values.map(value => key -> value)
+    })
+
+  def parse(validDimensions: Set[String], query: Seq[(String, String)]): Try[Sorting] = Try {
+    query.toList.collect { case ("sort", value) => value } match {
+      case Nil => Sorting.Sequential(Seq.empty)
+
+      case rawSorting :: Nil =>
+        val parser = sequentialSortingParser(validDimensions.toSeq)
+        parser.parse(rawSorting) match {
+          case Parsed.Success(x, _) => x
+          case e: Parsed.Failure[_, _] =>
+            throw new ParseQueryArgException("sort" -> formatFailure(e))
+        }
+
+      case _ => throw new ParseQueryArgException("sort" -> "multiple sections are not allowed")
+    }
+  }
+
+  private def formatFailure(e: Parsed.Failure[_, _]): String = {
+    fastparse.core.ParseError.msg(e.extra.input, e.extra.traced.expected, e.index)
+  }
+
+}