From 915be5f136ee61bfb8f7ff06d2f206f9a7290856 Mon Sep 17 00:00:00 2001
From: Shantanu Jamble <shantanu@argus.gg>
Date: Mon, 11 Nov 2024 16:35:57 -0800
Subject: [PATCH] sjamble/feature-query-msg

---
 cardinal/component/movement.go     |  6 ++--
 cardinal/msg/movement_player.go    |  1 +
 cardinal/system/MovementSystem.go  | 30 ------------------
 cardinal/system/movement_system.go | 49 ++++++++++++++++++++++++++++++
 4 files changed, 53 insertions(+), 33 deletions(-)
 create mode 100644 cardinal/msg/movement_player.go
 delete mode 100644 cardinal/system/MovementSystem.go
 create mode 100644 cardinal/system/movement_system.go

diff --git a/cardinal/component/movement.go b/cardinal/component/movement.go
index 28205a2..2a62415 100644
--- a/cardinal/component/movement.go
+++ b/cardinal/component/movement.go
@@ -18,9 +18,9 @@ type Location struct {
 }
 
 type Movement struct {
-	Direction Direction
-	Velocity  float32
-	Location  Location
+	CurrentDirection Direction
+	Velocity         float32
+	CurrentLocation  Location
 }
 
 func (Movement) Name() string {
diff --git a/cardinal/msg/movement_player.go b/cardinal/msg/movement_player.go
new file mode 100644
index 0000000..6cb5870
--- /dev/null
+++ b/cardinal/msg/movement_player.go
@@ -0,0 +1 @@
+package msg
diff --git a/cardinal/system/MovementSystem.go b/cardinal/system/MovementSystem.go
deleted file mode 100644
index 51d0a87..0000000
--- a/cardinal/system/MovementSystem.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package system
-
-import (
-	"pkg.world.dev/world-engine/cardinal"
-	"pkg.world.dev/world-engine/cardinal/search/filter"
-	"pkg.world.dev/world-engine/cardinal/types"
-	comp "shantanu-starter-game/component"
-)
-
-// RegenSystem replenishes the player's HP at every tick.
-// This provides an example of a system that doesn't rely on a transaction to update a component.
-func MovementSystem(world cardinal.WorldContext) error {
-	return cardinal.NewSearch().Entity(
-		filter.Exact(filter.Component[comp.Player](), filter.Component[comp.Movement]())).
-		Each(world, func(id types.EntityID) bool {
-			movement, err := cardinal.GetComponent[comp.Movement](world, id)
-			if err != nil {
-				return true
-			}
-
-			// TODO: How to get delta time?
-			movement.Location.X += movement.Velocity * float32(movement.Direction.X)
-			movement.Location.Y += movement.Velocity * float32(movement.Direction.Y)
-
-			if err := cardinal.SetComponent[comp.Movement](world, id, movement); err != nil {
-				return true
-			}
-			return true
-		})
-}
diff --git a/cardinal/system/movement_system.go b/cardinal/system/movement_system.go
new file mode 100644
index 0000000..a1d6e6a
--- /dev/null
+++ b/cardinal/system/movement_system.go
@@ -0,0 +1,49 @@
+package system
+
+import (
+	"fmt"
+	"pkg.world.dev/world-engine/cardinal"
+	"pkg.world.dev/world-engine/cardinal/search/filter"
+	"pkg.world.dev/world-engine/cardinal/types"
+	comp "shantanu-starter-game/component"
+	"shantanu-starter-game/msg"
+)
+
+// MovementSystem updates the player's location based on its velocity and direction.
+func MovementSystem(world cardinal.WorldContext) error {
+	return cardinal.NewSearch().Entity(
+		filter.Exact(filter.Component[comp.Player](), filter.Component[comp.Movement]())).
+		Each(world, func(id types.EntityID) bool {
+			movement, err := cardinal.GetComponent[comp.Movement](world, id)
+			if err != nil {
+				return true
+			}
+
+			// TODO: How to get delta time?
+			movement.CurrentLocation.X += movement.Velocity * float32(movement.CurrentDirection.X)
+			movement.CurrentLocation.Y += movement.Velocity * float32(movement.CurrentDirection.Y)
+
+			if err := cardinal.SetComponent[comp.Movement](world, id, movement); err != nil {
+				return true
+			}
+			return true
+		})
+}
+
+func MovementValidationSystem(world cardinal.WorldContext) error {
+	return cardinal.EachMessage[msg.AttackPlayerMsg, msg.AttackPlayerMsgReply](
+		world,
+		func(attack cardinal.TxData[msg.AttackPlayerMsg]) (msg.AttackPlayerMsgReply, error) {
+			playerID, playerHealth, err := queryTargetPlayer(world, attack.Msg.TargetNickname)
+			if err != nil {
+				return msg.AttackPlayerMsgReply{}, fmt.Errorf("failed to inflict damage: %w", err)
+			}
+
+			playerHealth.HP -= AttackDamage
+			if err := cardinal.SetComponent[comp.Health](world, playerID, playerHealth); err != nil {
+				return msg.AttackPlayerMsgReply{}, fmt.Errorf("failed to inflict damage: %w", err)
+			}
+
+			return msg.AttackPlayerMsgReply{Damage: AttackDamage}, nil
+		})
+}