From 1d32f70f50ad3e31db0313eff9b4ce0ecc316193 Mon Sep 17 00:00:00 2001
From: Alan Souza Fagundes <alan.souza.fagundes@gmail.com>
Date: Sun, 30 Oct 2022 00:06:23 -0300
Subject: [PATCH] Adding Flywheight Pattern in scala

---
 Structural/Flyweight/scala/Flywheight.scala | 58 +++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 Structural/Flyweight/scala/Flywheight.scala

diff --git a/Structural/Flyweight/scala/Flywheight.scala b/Structural/Flyweight/scala/Flywheight.scala
new file mode 100644
index 0000000..c6c2489
--- /dev/null
+++ b/Structural/Flyweight/scala/Flywheight.scala
@@ -0,0 +1,58 @@
+import scala.collection.mutable.ListBuffer
+
+case class Flyweight(sharedState: String)
+
+case class Context(uniqueState: Int, flyweight: Flyweight)
+
+class FlyweightFactory {
+
+  var flyweights = ListBuffer.empty[Flyweight]
+
+  def getFlyweight(sharedState: String): Flyweight = {
+    val selectedFlyweights = flyweights.filter(flyweight => flyweight.sharedState.equals(sharedState))
+
+    if (selectedFlyweights.size > 0) {
+      selectedFlyweights(0)
+    } else {
+      val newFlyweight = Flyweight(sharedState)
+      flyweights.addOne(newFlyweight)
+      newFlyweight
+    }
+  }
+
+  def total = flyweights.size
+}
+
+
+class Client(flyweightFactory: FlyweightFactory) {
+
+  val contexts = ListBuffer.empty[Context]
+
+  def getContext(uniqueState: Int, sharedState: String): Context = {
+    val flyweight = flyweightFactory.getFlyweight(sharedState)
+    val context = Context(uniqueState, flyweight)
+    contexts.addOne(context)
+
+    context
+  }
+
+}
+
+object FlyweightPattern {
+
+  def main(args: Array[String]): Unit = {
+    val flyweightFactory = new FlyweightFactory()
+    val client = new Client(flyweightFactory)
+
+
+    val uniqueStates = Range(0, 10).toSeq
+    val sharedStates = Seq("Alpha", "Beta", "Gamma")
+
+    val contexts = uniqueStates.flatMap(uniqueState => {
+      sharedStates.map(sharedState => client.getContext(uniqueState, sharedState))
+    })
+
+    println(f"Contexts: ${contexts.size}")
+    println(f"Flyweights: ${flyweightFactory.total}")
+  }
+}