From 8630ae659caeefda3c8516d39043da9b11bef519 Mon Sep 17 00:00:00 2001
From: Alex Anderson <alexanderson1993@gmail.com>
Date: Fri, 3 Mar 2023 19:21:40 -0500
Subject: [PATCH] feat: Add a simulation for calculating the power used by a
 ship system.

---
 server/src/systems/PowerDrawSystem.ts | 75 +++++++++++++++++++++++++++
 server/src/systems/index.ts           |  2 +
 2 files changed, 77 insertions(+)
 create mode 100644 server/src/systems/PowerDrawSystem.ts

diff --git a/server/src/systems/PowerDrawSystem.ts b/server/src/systems/PowerDrawSystem.ts
new file mode 100644
index 00000000..6f2cc533
--- /dev/null
+++ b/server/src/systems/PowerDrawSystem.ts
@@ -0,0 +1,75 @@
+import {Entity, System} from "../utils/ecs";
+
+/**
+ * There's a subtle distinction between powerDraw and requestedPower
+ * - powerDraw is how much power the system is currently pulling based
+ *   on it's current workload.
+ * - requestedPower is an artificial limit placed by the crew that keeps
+ *   the power draw at or below that limit.
+ */
+
+export class PowerDrawSystem extends System {
+  test(entity: Entity) {
+    return !!entity.components.power && !!entity.components.isShipSystem;
+  }
+  update(entity: Entity) {
+    const systemType = entity.components.isShipSystem;
+    const power = entity.components.power;
+    const efficiency = entity.components.efficiency?.efficiency || 1;
+    const efficiencyMultiple = 1 / efficiency;
+    if (!systemType?.type || !power) return;
+    const {maxSafePower, requiredPower} = power;
+    let powerDraw = 0;
+    switch (systemType.type) {
+      case "warpEngines": {
+        if (!entity.components.isWarpEngines) return;
+        const {currentWarpFactor, warpFactorCount} =
+          entity.components.isWarpEngines;
+        if (currentWarpFactor === 0) break;
+        const warpEngineUse = currentWarpFactor / warpFactorCount;
+        powerDraw =
+          (maxSafePower - requiredPower) * warpEngineUse + requiredPower;
+        break;
+      }
+      case "impulseEngines": {
+        if (!entity.components.isImpulseEngines) return;
+        const {cruisingSpeed, targetSpeed} = entity.components.isImpulseEngines;
+        if (targetSpeed === 0) break;
+        const impulseEngineUse = targetSpeed / cruisingSpeed;
+        powerDraw =
+          (maxSafePower - requiredPower) * impulseEngineUse + requiredPower;
+        break;
+      }
+      case "thrusters": {
+        if (!entity.components.isThrusters) return;
+        const {direction, rotationDelta, thrusting} =
+          entity.components.isThrusters;
+        if (!thrusting) break;
+        const directionOutput = Math.hypot(
+          direction.x,
+          direction.y,
+          direction.z
+        );
+        const rotationOutput = Math.hypot(
+          rotationDelta.x,
+          rotationDelta.y,
+          rotationDelta.z
+        );
+        const totalOutput = directionOutput + rotationOutput;
+        powerDraw =
+          (maxSafePower - requiredPower) * totalOutput + requiredPower;
+        break;
+      }
+      case "generic":
+        powerDraw = power.requestedPower;
+        break;
+      default:
+        return;
+    }
+
+    // Limit the power draw to the requested power, so we never go over it.
+    entity.updateComponent("power", {
+      powerDraw: Math.min(power.requestedPower, powerDraw * efficiencyMultiple),
+    });
+  }
+}
diff --git a/server/src/systems/index.ts b/server/src/systems/index.ts
index 91ad274d..f3bbdc29 100644
--- a/server/src/systems/index.ts
+++ b/server/src/systems/index.ts
@@ -22,6 +22,7 @@ import {FilterInventorySystem} from "./FilterInventorySystem";
 import {ReactorHeatSystem} from "./ReactorHeatSystem";
 import {HeatToCoolantSystem} from "./HeatToCoolantSystem";
 import {HeatDispersionSystem} from "./HeatDispersionSystem";
+import {PowerDrawSystem} from "./PowerDrawSystem";
 
 const systems = [
   FilterInventorySystem,
@@ -32,6 +33,7 @@ const systems = [
   TimerSystem,
   ReactorFuelSystem,
   ReactorHeatSystem,
+  PowerDrawSystem,
   AutoRotateSystem,
   AutoThrustSystem,
   ThrusterSystem,