feat: Initial commit

Sources/ManualS/Internal/BalancePoint.swift

@@ -0,0 +1,39 @@
+import CoreFoundation
+import Models
+import Validations
+
+extension BalancePoint.Request {
+
+  func respond() async throws -> BalancePoint.Response {
+    try await validate()
+    let balancePoint = await thermalBalancePoint(
+      heatLoss: Double(heatLoss),
+      at47: Double(heatPumpCapacity.at47),
+      at17: Double(heatPumpCapacity.at17),
+      designTemperature: Double(winterDesignTemperature)
+    )
+    return .init(balancePointTemperature: balancePoint)
+  }
+}
+
+extension BalancePoint.Request: AsyncValidatable {
+
+  @inlinable
+  public var body: some AsyncValidation<Self> {
+    AsyncValidator.accumulating {
+      AsyncValidator.greaterThan(\.heatLoss, 0)
+      AsyncValidator.validate(\.heatPumpCapacity)
+    }
+  }
+}
+
+private func thermalBalancePoint(
+  heatLoss: Double,
+  at47: Double,
+  at17: Double,
+  designTemperature: Double
+) async -> Double {
+  (30.0 * (((designTemperature - 65.0) * at47) + (65.0 * heatLoss))
+    - ((designTemperature - 65.0) * (at47 - at17) * 47.0))
+    / ((30.0 * heatLoss) - ((designTemperature - 65.0) * (at47 - at17)))
+}