1 files changed, 72 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/core/generators.scala b/src/main/scala/xyz/driver/core/generators.scala
new file mode 100644
index 0000000..bb026a9
--- /dev/null
+++ b/src/main/scala/xyz/driver/core/generators.scala
@@ -0,0 +1,72 @@
+package xyz.driver.core
+
+import java.math.MathContext
+
+import xyz.driver.core.revision.Revision
+import xyz.driver.core.time.{Time, TimeRange}
+
+import scala.reflect.ClassTag
+import scala.util.Random
+
+object generators {
+
+  private val random = new Random
+  import random._
+
+  private val DefaultMaxLength = 100
+  private val StringLetters    = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ".toSet
+
+  def nextId[T](): Id[T] = Id[T](scala.math.abs(nextLong()))
+
+  def nextId[T](maxValue: Int): Id[T] = Id[T](scala.math.abs(nextInt(maxValue).toLong))
+
+  def nextName[T](maxLength: Int = DefaultMaxLength): Name[T] = Name[T](nextString(maxLength))
+
+  def nextUuid() = java.util.UUID.randomUUID
+
+  def nextRevision[T]() = Revision[T](nextUuid().toString)
+
+  def nextString(maxLength: Int = DefaultMaxLength): String =
+    (oneOf[Char](StringLetters) +: arrayOf(oneOf[Char](StringLetters), maxLength - 1)).mkString
+
+  def nextOption[T](value: => T): Option[T] = if (nextBoolean) Option(value) else None
+
+  def nextPair[L, R](left: => L, right: => R): (L, R) = (left, right)
+
+  def nextTriad[F, S, T](first: => F, second: => S, third: => T): (F, S, T) = (first, second, third)
+
+  def nextTime(): Time = Time(math.abs(nextLong() % System.currentTimeMillis))
+
+  def nextTimeRange(): TimeRange = {
+    val oneTime     = nextTime()
+    val anotherTime = nextTime()
+
+    TimeRange(Time(scala.math.min(oneTime.millis, anotherTime.millis)),
+              Time(scala.math.max(oneTime.millis, anotherTime.millis)))
+  }
+
+  def nextBigDecimal(multiplier: Double = 1000000.00, precision: Int = 2): BigDecimal =
+    BigDecimal(multiplier * nextDouble, new MathContext(precision))
+
+  def oneOf[T](items: T*): T = oneOf(items.toSet)
+
+  def oneOf[T](items: Set[T]): T = items.toSeq(nextInt(items.size))
+
+  def arrayOf[T: ClassTag](generator: => T, maxLength: Int = DefaultMaxLength): Array[T] =
+    Array.fill(nextInt(maxLength))(generator)
+
+  def seqOf[T](generator: => T, maxLength: Int = DefaultMaxLength): Seq[T] =
+    Seq.fill(nextInt(maxLength))(generator)
+
+  def vectorOf[T](generator: => T, maxLength: Int = DefaultMaxLength): Vector[T] =
+    Vector.fill(nextInt(maxLength))(generator)
+
+  def listOf[T](generator: => T, maxLength: Int = DefaultMaxLength): List[T] =
+    List.fill(nextInt(maxLength))(generator)
+
+  def setOf[T](generator: => T, maxLength: Int = DefaultMaxLength): Set[T] =
+    seqOf(generator, maxLength).toSet
+
+  def mapOf[K, V](maxLength: Int, keyGenerator: => K, valueGenerator: => V): Map[K, V] =
+    seqOf(nextPair(keyGenerator, valueGenerator), maxLength).toMap
+}