Power Rework (#863)

Co-authored-by: py01 <pyronetics01@gmail.com>

Content.Server/GameObjects/Components/Power/PowerNetComponents/BatteryDischargerComponent.cs

@@ -0,0 +1,73 @@
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Server.GameObjects.Components.Power.PowerNetComponents
+{
+    /// <summary>
+    ///     Uses charge from a <see cref="BatteryComponent"/> to supply power via a <see cref="PowerSupplierComponent"/>.
+    /// </summary>
+    [RegisterComponent]
+    public class BatteryDischargerComponent : Component
+    {
+        public override string Name => "BatteryDischarger";
+
+        [ViewVariables]
+        private BatteryComponent _battery;
+
+        [ViewVariables]
+        private PowerSupplierComponent _supplier;
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        public int ActiveSupplyRate { get => _activeSupplyRate; set => SetActiveSupplyRate(value); }
+        private int _activeSupplyRate;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+            serializer.DataField(ref _activeSupplyRate, "activeSupplyRate", 50);
+        }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            _battery = Owner.GetComponent<BatteryComponent>();
+            _supplier = Owner.GetComponent<PowerSupplierComponent>();
+            UpdateSupplyRate();
+        }
+
+        public void Update(float frameTime)
+        {
+            //Simplified implementation - if the battery is empty, and charge is being added to the battery
+            //at a lower rate that this is using it, the charge is used without creating power supply.
+            _battery.CurrentCharge -= ActiveSupplyRate * frameTime;
+            UpdateSupplyRate();
+        }
+
+        private void UpdateSupplyRate()
+        {
+            if (_battery.BatteryState == BatteryState.Empty)
+            {
+                SetSupplierSupplyRate(0);
+            }
+            else
+            {
+                SetSupplierSupplyRate(ActiveSupplyRate);
+            }
+        }
+
+        private void SetSupplierSupplyRate(int newSupplierSupplyRate)
+        {
+            if (_supplier.SupplyRate != newSupplierSupplyRate)
+            {
+                _supplier.SupplyRate = newSupplierSupplyRate;
+            }
+        }
+
+        private void SetActiveSupplyRate(int newEnabledSupplyRate)
+        {
+            _activeSupplyRate = newEnabledSupplyRate;
+            UpdateSupplyRate();
+        }
+    }
+}