feat: Begins room pressure calculations

Sources/ApiController/Extensions/RoomPressure.swift

@@ -0,0 +1,76 @@
+import Foundation
+import Logging
+import OrderedCollections
+import Routes
+
+public extension RoomPressure.Request {
+
+  static let pascalToIWCMultiplier = 0.004014
+  static let targetVelocity = 400.0
+  static let maxVelocity = 600.0
+  static let minGrilleFreeArea = 0.7
+  static let standardDuctSizes = OrderedSet([4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20])
+  static let standardGrilleHeights = OrderedSet([4, 6, 8, 10, 12, 14, 20])
+  static let standardGrilleSizes = [
+    4: OrderedSet([8, 10, 12, 14]),
+    6: OrderedSet([8, 10, 12, 14]),
+    8: OrderedSet([10, 12, 14]),
+    10: OrderedSet([10]),
+    12: OrderedSet([12]),
+    14: OrderedSet([14])
+  ]
+
+  // OrderedSet([
+  //   (width: 8, height: 4),
+  //   (width: 10, height: 4),
+  //   (width: 12, height: 4),
+  //   (width: 14, height: 4),
+  //   (width: 8, height: 6),
+  //   (width: 10, height: 6),
+  //   (width: 12, height: 6),
+  //   (width: 14, height: 6),
+  //   (width: 10, height: 8),
+  //   (width: 12, height: 8),
+  //   (width: 14, height: 8),
+  //   (width: 10, height: 10),
+  //   (width: 12, height: 12),
+  //   (width: 14, height: 14)
+  // ])
+
+  func respond(logger: Logger) async throws -> RoomPressure.Response {
+    fatalError()
+  }
+
+  private func getStandardDuctSize(for calculatedSize: Int) -> Int {
+    Self.standardDuctSizes.sorted()
+      .first { $0 >= calculatedSize }
+      ?? 20
+  }
+
+  private func getStandardGrilleSize(requiredArea: Double, selectedHeight: Int) throws -> (width: Int, height: Int) {
+    guard let availableSizes = Self.standardGrilleSizes[selectedHeight] else {
+      throw RoomPressureError.invalidPreferredHeight
+    }
+
+    if let width = availableSizes.first(where: {
+      Double($0) * Double(selectedHeight) * Self.minGrilleFreeArea >= (requiredArea / Self.minGrilleFreeArea)
+    }) {
+      return (width, selectedHeight)
+    }
+
+    // If no width matches return largest for the selectedHeight.
+    if let largestSize = availableSizes.last { return (largestSize, selectedHeight) }
+    return (14, selectedHeight)
+  }
+
+  // Calculate door leakage area in sq. ft.
+  private func calculateDoorLeakageArea(doorWidth: Double, doorHeight: Double, doorUndercut: Double) -> Double {
+    let doorLeakageArea = (doorWidth * doorUndercut) / 144.0
+    let doorPerimiterLeakage = ((2 * doorHeight + doorWidth) * 0.125) / 144.0
+    return doorLeakageArea + doorPerimiterLeakage
+  }
+
+  enum RoomPressureError: Error {
+    case invalidPreferredHeight
+  }
+}