Add parsers to common

1 files changed, 60 insertions, 0 deletions

diff --git a/src/main/scala/xyz/driver/pdsuicommon/parsers/PaginationParser.scala b/src/main/scala/xyz/driver/pdsuicommon/parsers/PaginationParser.scala
new file mode 100644
index 0000000..a6a7fae
--- /dev/null
+++ b/src/main/scala/xyz/driver/pdsuicommon/parsers/PaginationParser.scala
@@ -0,0 +1,60 @@
+package xyz.driver.server.parsers
+
+import xyz.driver.pdsuicommon.db.Pagination
+import xyz.driver.server.parsers.errors.ParseQueryArgException
+import play.api.data.validation._
+import play.api.routing.sird.QueryString
+import xyz.driver.pdsuicommon.validation.AdditionalConstraints
+
+import scala.util.Try
+
+object PaginationParser {
+
+  private val oneQueryArgConstraint: Constraint[Seq[String]] = {
+    Constraint("query.oneArg") {
+      case Nil      => Valid
+      case x +: Nil => Valid
+      case xs =>
+        Invalid(new ValidationError(Seq(s"must be one argument, but there are multiple: '${xs.mkString(", ")}'")))
+    }
+  }
+
+  private val pageSizeCheckConstraint: Constraint[Seq[String]] = {
+    Constraint("pagination.pageSize") { args =>
+      oneQueryArgConstraint(args) match {
+        case x: Invalid => x
+        case Valid      => AdditionalConstraints.positivePrintedNumber(args.head)
+      }
+    }
+  }
+
+  private val pageNumberCheckConstraint: Constraint[Seq[String]] = {
+    Constraint("pagination.pageNumber") { args =>
+      oneQueryArgConstraint(args) match {
+        case x: Invalid => x
+        case Valid      => AdditionalConstraints.positivePrintedNumber(args.head)
+      }
+    }
+  }
+
+  def parse(queryString: QueryString): Try[Pagination] = Try {
+    val rawPageSizes   = queryString.getOrElse("pageSize", Seq(Pagination.Default.pageSize.toString))
+    val rawPageNumbers = queryString.getOrElse("pageNumber", Seq(Pagination.Default.pageNumber.toString))
+
+    val validation = Seq(
+      "pageSize"   -> pageSizeCheckConstraint(rawPageSizes),
+      "pageNumber" -> pageNumberCheckConstraint(rawPageNumbers)
+    )
+
+    val validationErrors = validation.collect {
+      case (fieldName, e: Invalid) => (fieldName, e.errors.mkString("; "))
+    }
+
+    if (validationErrors.isEmpty) {
+      Pagination(Integer.parseInt(rawPageSizes.head), Integer.parseInt(rawPageNumbers.head))
+    } else {
+      throw new ParseQueryArgException(validationErrors: _*)
+    }
+  }
+
+}