1 files changed, 109 insertions, 0 deletions
diff --git a/core-types/src/main/scala/xyz/driver/core/date.scala b/core-types/src/main/scala/xyz/driver/core/date.scala
new file mode 100644
index 0000000..5454093
--- /dev/null
+++ b/core-types/src/main/scala/xyz/driver/core/date.scala
@@ -0,0 +1,109 @@
+package xyz.driver.core
+
+import java.util.Calendar
+
+import enumeratum._
+import scalaz.std.anyVal._
+import scalaz.syntax.equal._
+
+import scala.collection.immutable.IndexedSeq
+import scala.util.Try
+
+/**
+  * Driver Date type and related validators/extractors.
+  * Day, Month, and Year extractors are from ISO 8601 strings => driver...Date integers.
+  * TODO: Decouple extractors from ISO 8601, as we might want to parse other formats.
+  */
+object date {
+
+  sealed trait DayOfWeek extends EnumEntry
+  object DayOfWeek extends Enum[DayOfWeek] {
+    case object Monday    extends DayOfWeek
+    case object Tuesday   extends DayOfWeek
+    case object Wednesday extends DayOfWeek
+    case object Thursday  extends DayOfWeek
+    case object Friday    extends DayOfWeek
+    case object Saturday  extends DayOfWeek
+    case object Sunday    extends DayOfWeek
+
+    val values: IndexedSeq[DayOfWeek] = findValues
+
+    val All: Set[DayOfWeek] = values.toSet
+
+    def fromString(day: String): Option[DayOfWeek] = withNameInsensitiveOption(day)
+  }
+
+  type Day = Int @@ Day.type
+
+  object Day {
+    def apply(value: Int): Day = {
+      require(1 to 31 contains value, "Day must be in range 1 <= value <= 31")
+      value.asInstanceOf[Day]
+    }
+
+    def unapply(dayString: String): Option[Int] = {
+      require(dayString.length === 2, s"ISO 8601 day string, DD, must have length 2: $dayString")
+      Try(dayString.toInt).toOption.map(apply)
+    }
+  }
+
+  type Month = Int @@ Month.type
+
+  object Month {
+    def apply(value: Int): Month = {
+      require(0 to 11 contains value, "Month is zero-indexed: 0 <= value <= 11")
+      value.asInstanceOf[Month]
+    }
+    val JANUARY   = Month(Calendar.JANUARY)
+    val FEBRUARY  = Month(Calendar.FEBRUARY)
+    val MARCH     = Month(Calendar.MARCH)
+    val APRIL     = Month(Calendar.APRIL)
+    val MAY       = Month(Calendar.MAY)
+    val JUNE      = Month(Calendar.JUNE)
+    val JULY      = Month(Calendar.JULY)
+    val AUGUST    = Month(Calendar.AUGUST)
+    val SEPTEMBER = Month(Calendar.SEPTEMBER)
+    val OCTOBER   = Month(Calendar.OCTOBER)
+    val NOVEMBER  = Month(Calendar.NOVEMBER)
+    val DECEMBER  = Month(Calendar.DECEMBER)
+
+    def unapply(monthString: String): Option[Month] = {
+      require(monthString.length === 2, s"ISO 8601 month string, MM, must have length 2: $monthString")
+      Try(monthString.toInt).toOption.map(isoM => apply(isoM - 1))
+    }
+  }
+
+  type Year = Int @@ Year.type
+
+  object Year {
+    def apply(value: Int): Year = value.asInstanceOf[Year]
+
+    def unapply(yearString: String): Option[Int] = {
+      require(yearString.length === 4, s"ISO 8601 year string, YYYY, must have length 4: $yearString")
+      Try(yearString.toInt).toOption.map(apply)
+    }
+  }
+
+  final case class Date(year: Int, month: Month, day: Int) {
+    override def toString = f"$year%04d-${month + 1}%02d-$day%02d"
+  }
+
+  object Date {
+    implicit def dateOrdering: Ordering[Date] = Ordering.fromLessThan { (date1, date2) =>
+      if (date1.year != date2.year) {
+        date1.year < date2.year
+      } else if (date1.month != date2.month) {
+        date1.month < date2.month
+      } else {
+        date1.day < date2.day
+      }
+    }
+
+    def fromString(dateString: String): Option[Date] = {
+      dateString.split('-') match {
+        case Array(Year(year), Month(month), Day(day)) => Some(Date(year, month, day))
+        case _                                         => None
+      }
+    }
+  }
+}