From 83264de081fd7ad6a50fa23c67344137d33b40e1 Mon Sep 17 00:00:00 2001
From: Chord <chord@tuta.io>
Date: Sun, 14 Aug 2016 16:40:50 -0400
Subject: [PATCH] Packet: QuantityDeltaUpdateMessage (#57)

---
 .../psforever/packet/GamePacketOpcode.scala   |  2 +-
 .../game/QuantityDeltaUpdateMessage.scala     | 29 +++++++++++++++++++
 common/src/test/scala/GamePacketTest.scala    | 21 ++++++++++++++
 3 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 common/src/main/scala/net/psforever/packet/game/QuantityDeltaUpdateMessage.scala

diff --git a/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala b/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
index 461d42a0..a5bb0e2a 100644
--- a/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
+++ b/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
@@ -553,7 +553,7 @@ object GamePacketOpcode extends Enumeration {
       case VanuModuleUpdateMessage => noDecoder(opcode)
       case FacilityBenefitShieldChargeRequestMessage => noDecoder(opcode)
       case ProximityTerminalUseMessage => noDecoder(opcode)
-      case QuantityDeltaUpdateMessage => noDecoder(opcode)
+      case QuantityDeltaUpdateMessage => game.QuantityDeltaUpdateMessage.decode
       case ChainLashMessage => noDecoder(opcode)
       case ZoneInfoMessage => noDecoder(opcode)
       case LongRangeProjectileInfoMessage => noDecoder(opcode)
diff --git a/common/src/main/scala/net/psforever/packet/game/QuantityDeltaUpdateMessage.scala b/common/src/main/scala/net/psforever/packet/game/QuantityDeltaUpdateMessage.scala
new file mode 100644
index 00000000..02572924
--- /dev/null
+++ b/common/src/main/scala/net/psforever/packet/game/QuantityDeltaUpdateMessage.scala
@@ -0,0 +1,29 @@
+// Copyright (c) 2016 PSForever.net to present
+package net.psforever.packet.game
+
+import net.psforever.packet.{GamePacketOpcode, Marshallable, PacketHelpers, PlanetSideGamePacket}
+import scodec.Codec
+import scodec.codecs._
+
+/**
+  * Instructs client to update the quantity of an item based on a delta when sent server to client.
+  *
+  * See also [[QuantityUpdateMessage]]
+  *
+  * @param item_guid the item to update
+  * @param quantity_delta the change in quantity of the item
+  */
+final case class QuantityDeltaUpdateMessage(item_guid : PlanetSideGUID,
+                                            quantity_delta : Int)
+  extends PlanetSideGamePacket {
+  type Packet = QuantityDeltaUpdateMessage
+  def opcode = GamePacketOpcode.QuantityDeltaUpdateMessage
+  def encode = QuantityDeltaUpdateMessage.encode(this)
+}
+
+object QuantityDeltaUpdateMessage extends Marshallable[QuantityDeltaUpdateMessage] {
+  implicit val codec : Codec[QuantityDeltaUpdateMessage] = (
+      ("item_guid" | PlanetSideGUID.codec) ::
+        ("quantity_delta" | int32L)
+    ).as[QuantityDeltaUpdateMessage]
+}
diff --git a/common/src/test/scala/GamePacketTest.scala b/common/src/test/scala/GamePacketTest.scala
index f813c789..1613637f 100644
--- a/common/src/test/scala/GamePacketTest.scala
+++ b/common/src/test/scala/GamePacketTest.scala
@@ -858,6 +858,27 @@ class GamePacketTest extends Specification {
       }
     }
 
+    "QuantityDeltaUpdateMessage" should {
+      val string = hex"C4 5300 FBFFFFFF"
+
+      "decode" in {
+        PacketCoding.DecodePacket(string).require match {
+          case QuantityDeltaUpdateMessage(item_guid, quantity) =>
+            item_guid mustEqual PlanetSideGUID(83)
+            quantity mustEqual -5
+          case default =>
+            ko
+        }
+      }
+
+      "encode" in {
+        val msg = QuantityDeltaUpdateMessage(PlanetSideGUID(83), -5)
+        val pkt = PacketCoding.EncodePacket(msg).require.toByteVector
+
+        pkt mustEqual string
+      }
+    }
+
     "PingMsg" should  {
       val packet = hex"1a 00000000 b0360000"