Pow3r: stage 1 (#4208)

Co-authored-by: 20kdc <asdd2808@gmail.com>

Content.Server/Power/Components/BatteryComponent.cs

@@ -0,0 +1,101 @@
+#nullable enable
+using System;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Maths;
+using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Server.Power.Components
+{
+    /// <summary>
+    ///     Battery node on the pow3r network. Needs other components to connect to actual networks.
+    /// </summary>
+    [RegisterComponent]
+    public class BatteryComponent : Component
+    {
+        public override string Name => "Battery";
+
+        /// <summary>
+        /// Maximum charge of the battery in joules (ie. watt seconds)
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)] public float MaxCharge { get => _maxCharge; set => SetMaxCharge(value); }
+        [DataField("maxCharge")]
+        private float _maxCharge;
+
+        /// <summary>
+        /// Current charge of the battery in joules (ie. watt seconds)
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        public float CurrentCharge { get => _currentCharge; set => SetCurrentCharge(value); }
+        [DataField("startingCharge")]
+        private float _currentCharge;
+
+        /// <summary>
+        /// True if the battery is fully charged.
+        /// </summary>
+        [ViewVariables] public bool IsFullyCharged => MathHelper.CloseTo(CurrentCharge, MaxCharge);
+
+        [ViewVariables(VVAccess.ReadWrite)] [DataField("autoRecharge")] public bool AutoRecharge { get; set; }
+
+        [ViewVariables(VVAccess.ReadWrite)] [DataField("autoRechargeRate")] public float AutoRechargeRate { get; set; }
+
+        /// <summary>
+        ///     If sufficient charge is avaiable on the battery, use it. Otherwise, don't.
+        /// </summary>
+        public virtual bool TryUseCharge(float chargeToUse)
+        {
+            if (chargeToUse >= CurrentCharge)
+            {
+                return false;
+            }
+            else
+            {
+                CurrentCharge -= chargeToUse;
+                return true;
+            }
+        }
+
+        public virtual float UseCharge(float toDeduct)
+        {
+            var chargeChangedBy = Math.Min(CurrentCharge, toDeduct);
+            CurrentCharge -= chargeChangedBy;
+            return chargeChangedBy;
+        }
+
+        public void FillFrom(BatteryComponent battery)
+        {
+            var powerDeficit = MaxCharge - CurrentCharge;
+            if (battery.TryUseCharge(powerDeficit))
+            {
+                CurrentCharge += powerDeficit;
+            }
+            else
+            {
+                CurrentCharge += battery.CurrentCharge;
+                battery.CurrentCharge = 0;
+            }
+        }
+
+        protected virtual void OnChargeChanged() { }
+
+        private void SetMaxCharge(float newMax)
+        {
+            _maxCharge = Math.Max(newMax, 0);
+            _currentCharge = Math.Min(_currentCharge, MaxCharge);
+            OnChargeChanged();
+        }
+
+        private void SetCurrentCharge(float newChargeAmount)
+        {
+            _currentCharge = MathHelper.Clamp(newChargeAmount, 0, MaxCharge);
+            OnChargeChanged();
+        }
+
+        public void OnUpdate(float frameTime)
+        {
+            if (!AutoRecharge) return;
+            if (IsFullyCharged) return;
+            CurrentCharge += AutoRechargeRate * frameTime;
+        }
+    }
+}