feat: Adds hydronic system pressure calculator.

Sources/ApiController/Extensions/HydronicSystemPressure.swift

@@ -0,0 +1,40 @@
+import Dependencies
+import Logging
+import PsychrometricClient
+import Routes
+
+public extension HydronicSystemPressure.Request {
+
+  func respond(logger: Logger) async throws -> HydronicSystemPressure.Response {
+    @Dependency(\.psychrometricClient) var psychrometricClient
+
+    try validate()
+
+    let waterTemperature = DryBulb.fahrenheit(self.waterTemperature ?? 60)
+
+    let density = try await psychrometricClient.density.water(waterTemperature)
+    let pressure = height * (density.value / 144) + 5
+    var warnings = [String]()
+
+    if self.waterTemperature == nil {
+      warnings.append(
+        """
+        Calculations based on default water temperature of 60°F.
+        """
+      )
+    }
+
+    return .init(pressure: pressure, waterDensity: density, warnings: warnings)
+  }
+
+  private func validate() throws {
+    guard height > 0 else {
+      throw ValidationError(message: "Height should be greater than 0.")
+    }
+    if let waterTemperature {
+      guard waterTemperature > 32 else {
+        throw ValidationError(message: "Water temperature should be above freezing.")
+      }
+    }
+  }
+}

Sources/Routes/Models/HydronicSystemPressure.swift

@@ -0,0 +1,84 @@
+import CasePaths
+import PsychrometricClient
+@preconcurrency import URLRouting
+
+//
+public enum HydronicSystemPressure {
+
+  public static let description = """
+  Calculate the required hydronic system pressure based on height of a building.
+  """
+
+  public struct Request: Codable, Equatable, Hashable, Sendable {
+    public let height: Double
+    public let waterTemperature: Double?
+
+    public init(height: Double, waterTemperature: Double? = nil) {
+      self.height = height
+      self.waterTemperature = waterTemperature
+    }
+
+    public enum FieldKey: String, CaseIterable {
+      case height
+      case waterTemperature
+    }
+  }
+
+  public struct Response: Codable, Equatable, Sendable {
+
+    public let pressure: Double
+    public let waterDensity: DensityOf<Water>
+    public let warnings: [String]
+
+    public init(pressure: Double, waterDensity: DensityOf<Water>, warnings: [String]) {
+      self.pressure = pressure
+      self.waterDensity = waterDensity
+      self.warnings = warnings
+    }
+  }
+}
+
+// MARK: - Router
+
+public extension SiteRoute.View {
+
+  enum HydronicSystemPressure: Equatable, Hashable, Sendable {
+    case index
+    case submit(Routes.HydronicSystemPressure.Request)
+
+    typealias Key = Routes.HydronicSystemPressure.Request.FieldKey
+    static let rootPath = "hydronic-system-pressure"
+
+    public static let router = OneOf {
+      Route(.case(Self.index)) {
+        Path { rootPath }
+        Method.get
+      }
+      Route(.case(Self.submit)) {
+        Path { rootPath }
+        Method.post
+        Body {
+          FormData {
+            Field(Key.height) { Double.parser() }
+            Optionally { Field(Key.waterTemperature) { Double.parser() } }
+          }
+          .map(.memberwise(Routes.HydronicSystemPressure.Request.init))
+        }
+      }
+    }
+  }
+
+}
+
+#if DEBUG
+  public extension HydronicSystemPressure.Response {
+    static let mock = Self(
+      pressure: 15,
+      waterDensity: 62.37,
+      warnings: [
+        "Water density based on 60 water - include water temperature for more accurate result."
+      ]
+    )
+  }
+
+#endif

Sources/Routes/SiteRoutes.swift

@@ -107,6 +107,7 @@ public extension SiteRoute {
     case filterPressureDrop(FilterPressureDrop)
     case heatingBalancePoint(HeatingBalancePoint)
     case hvacSystemPerformance(HVACSystemPerformance)
+    case hydronicSystemPressure(Self.HydronicSystemPressure)
     case moldRisk(MoldRisk)
     case psychrometrics(Self.Psychrometrics)
     case roomPressure(RoomPressure)
@@ -133,6 +134,9 @@ public extension SiteRoute {
       Route(.case(Self.hvacSystemPerformance)) {
         HVACSystemPerformance.router
       }
+      Route(.case(Self.hydronicSystemPressure)) {
+        HydronicSystemPressure.router
+      }
       Route(.case(Self.moldRisk)) {
         MoldRisk.router
       }

Sources/Styleguide/FormElements.swift

@@ -59,6 +59,17 @@ public struct Input: HTML, Sendable {
   }
 }
 
+public extension Input {
+
+  init<Key>(
+    id: Key,
+    name: String? = nil,
+    placeholder: String
+  ) where Key: RawRepresentable, Key.RawValue == String {
+    self.init(id: id.rawValue, name: name, placeholder: placeholder)
+  }
+}
+
 /// A style form input label.
 public struct InputLabel<InputLabel: HTML>: HTML {
 

Sources/Styleguide/ResultBox.swift

@@ -0,0 +1,17 @@
+import Elementary
+
+public struct ResultBox<Body: HTML>: HTML {
+  let body: Body
+
+  public init(@HTMLBuilder body: () -> Body) {
+    self.body = body()
+  }
+
+  public var content: some HTML<HTMLTag.div> {
+    div(.class("w-full rounded-lg shadow-lg bg-blue-100 border border-blue-600 text-blue-600 p-6")) {
+      body
+    }
+  }
+}
+
+extension ResultBox: Sendable where Body: Sendable {}

Sources/Styleguide/RoundedBox.swift

@@ -0,0 +1,18 @@
+import Elementary
+
+// A rounded box, with no color styles. Colors should be added at call site.
+public struct Box<Body: HTML>: HTML {
+  let body: Body
+
+  public init(@HTMLBuilder body: () -> Body) {
+    self.body = body()
+  }
+
+  public var content: some HTML<HTMLTag.div> {
+    div(.class("w-full rounded-lg shadow-lgp-6")) {
+      body
+    }
+  }
+}
+
+extension Box: Sendable where Body: Sendable {}

Sources/Styleguide/SVG.swift

@@ -45,6 +45,7 @@ public struct SVGSize: Sendable {
 public enum SVGType: Sendable, CaseIterable {
   case calculator
   case checkCircle
+  case circleGauge
   case droplets
   case exclamation
   case funnel
@@ -63,6 +64,7 @@ public enum SVGType: Sendable, CaseIterable {
     switch self {
     case .calculator: return calculatorSvg(size: size)
     case .checkCircle: return checkCircleSvg(size: size)
+    case .circleGauge: return circleGaugeSvg(size: size)
     case .droplets: return dropletsSvg(size: size)
     case .exclamation: return exclamationSvg(size: size)
     case .funnel: return funnelSvg(size: size)
@@ -84,6 +86,16 @@ public enum SVGType: Sendable, CaseIterable {
 
 // swiftlint:disable line_length
 
+private func circleGaugeSvg(size: SVGSize) -> HTMLRaw {
+  HTMLRaw("""
+  <svg xmlns="http://www.w3.org/2000/svg" width="\(size.width)" height="\(size.height)" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-circle-gauge">
+  <path d="M15.6 2.7a10 10 0 1 0 5.7 5.7"/>
+  <circle cx="12" cy="12" r="2"/>
+  <path d="M13.4 10.6 19 5"/>
+  </svg>
+  """)
+}
+
 private func scaleSvg(size: SVGSize) -> HTMLRaw {
   HTMLRaw("""
   <svg xmlns="http://www.w3.org/2000/svg" width="\(size.width)" height="\(size.height)" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-scale">

Sources/ViewController/Extensions/String+units.swift

@@ -0,0 +1,3 @@
+public extension String {
+  static let fahrenheit = "°F"
+}

Sources/ViewController/HomePage.swift

@@ -61,6 +61,12 @@ struct HomePage: HTML, Sendable {
         svg: .droplets,
         route: .psychrometrics(.index)
       )
+      group(
+        label: "Hydronic System Pressure",
+        description: HydronicSystemPressure.description,
+        svg: .circleGauge,
+        route: .hydronicSystemPressure(.index)
+      )
     }
   }
 

Sources/ViewController/Live.swift

@@ -133,6 +133,15 @@ extension ViewController: DependencyKey {
           return HVACSystemPerformanceResult(response: response)
         }
 
+      case let .hydronicSystemPressure(route):
+        switch route {
+        case .index:
+          return request.respond(HydronicSystemPressureForm(response: nil))
+        case let .submit(request):
+          let response = try await request.respond(logger: logger)
+          return HydronicSystemPressureResponse(response: response)
+        }
+
       case let .moldRisk(route):
         switch route {
         case .index:

Sources/ViewController/Views/HydronicSystemPressure.swift

@@ -0,0 +1,74 @@
+import Elementary
+import ElementaryHTMX
+import PsychrometricClient
+import Routes
+import Styleguide
+
+struct HydronicSystemPressureForm: HTML, Sendable {
+  let response: HydronicSystemPressure.Response?
+
+  typealias Key = HydronicSystemPressure.Request.FieldKey
+
+  var content: some HTML {
+    FormHeader(label: "Hydronic System Pressure", svg: .circleGauge)
+
+    form(
+      .hx.post(route: .hydronicSystemPressure(.index)),
+      .hx.target("#result")
+    ) {
+      div(.class("space-y-6")) {
+        div(.class("grid grid-cols-2 gap-4")) {
+          LabeledContent(label: "Height (ft.)") {
+            Input(id: Key.height, placeholder: "Building height")
+              .attributes(.type(.number), .min("0.1"), .step("0.1"), .autofocus, .required)
+          }
+
+          LabeledContent(label: "Water Temperature (\(String.fahrenheit))") {
+            Input(id: Key.waterTemperature, placeholder: "Temperature (optional)")
+              .attributes(.type(.number), .min("32.0"), .step("0.1"))
+          }
+        }
+
+        Note {
+          """
+          Water temperature should be the coldest water temperature the system sees, which for boilers will be
+          when the system is filled with water.
+          """
+        }
+
+        div {
+          SubmitButton(label: "Calculate System Pressure")
+        }
+      }
+    }
+
+    div(.id("result")) {
+      if let response {
+        HydronicSystemPressureResponse(response: response)
+      }
+    }
+  }
+}
+
+struct HydronicSystemPressureResponse: HTML, Sendable {
+  let response: HydronicSystemPressure.Response
+
+  var content: some HTML {
+    ResultContainer(reset: .hydronicSystemPressure(.index)) {
+      ResultBox {
+        div(.class("grid grid-cols-2")) {
+          VerticalGroup(label: "Pressure", value: "\(double: response.pressure)", valueLabel: "psi")
+          VerticalGroup(
+            label: "Water Density",
+            value: "\(double: response.waterDensity.value)",
+            valueLabel: response.waterDensity.units.rawValue
+          )
+        }
+      }
+      WarningBox(warnings: response.warnings)
+      Note {
+        "Expansion tank pressure should match system fill pressure."
+      }
+    }
+  }
+}

Tests/ViewControllerTests/ViewControllerTests.swift

@@ -124,7 +124,11 @@ struct ViewControllerTests {
             doorHeight: 86,
             doorUndercut: 1,
             preferredGrilleHeight: .fourteen
-          ))))
+          )))),
+
+          // Hydronic system pressure
+          .hydronicSystemPressure(.index),
+          .hydronicSystemPressure(.submit(.init(height: 12, waterTemperature: 60)))
 
         ])
 

Tests/ViewControllerTests/__Snapshots__/ViewControllerTests/snapShotTests.30.html

@@ -0,0 +1,45 @@
+<div class="flex items-center gap-3 mb-6">
+  <div class="block text-blue-500">
+    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-circle-gauge">
+    <path d="M15.6 2.7a10 10 0 1 0 5.7 5.7"/>
+    <circle cx="12" cy="12" r="2"/>
+    <path d="M13.4 10.6 19 5"/>
+    </svg>
+  </div>
+  <h2 class="text-2xl font-extrabold">Hydronic System Pressure</h2>
+</div>
+<form hx-post="/hydronic-system-pressure" hx-target="#result">
+  <div class="space-y-6">
+    <div class="grid grid-cols-2 gap-4">
+      <div>
+        <label for="height" class="block text-sm font-medium mb-2">Height (ft.)</label>
+        <input id="height" placeholder="Building height" name="height" class="  w-full px-4 py-2 border rounded-md min-h-11
+  focus:ring-2 focus:ring-yellow-800 focus:border-yellow-800
+  placeholder-shown:!border-gray-400
+  invalid:border-red-500 out-of-range:border-red-500" type="number" min="0.1" step="0.1" autofocus required>
+      </div>
+      <div>
+        <label for="waterTemperature" class="block text-sm font-medium mb-2">Water Temperature (°F)</label>
+        <input id="waterTemperature" placeholder="Temperature (optional)" name="waterTemperature" class="  w-full px-4 py-2 border rounded-md min-h-11
+  focus:ring-2 focus:ring-yellow-800 focus:border-yellow-800
+  placeholder-shown:!border-gray-400
+  invalid:border-red-500 out-of-range:border-red-500" type="number" min="32.0" step="0.1">
+      </div>
+    </div>
+    <div class="mt-8 p-4 bg-gray-100 dark:bg-gray-700 rounded-md shadow-md
+border border-blue-500 text-blue-500 text-sm">
+      <p class="font-extrabold mb-3">Note:</p>
+      <p class="px-6">
+        Water temperature should be the coldest water temperature the system sees, which for boilers will be
+        when the system is filled with water.
+      </p>
+    </div>
+    <div>
+      <button type="submit" class="  w-full font-bold py-3 rounded-md transition-colors
+  bg-yellow-300 dark:bg-blue-500
+  hover:bg-yellow-400 hover:dark:bg-blue-600
+  text-blue-500 dark:text-yellow-300">Calculate System Pressure</button>
+    </div>
+  </div>
+</form>
+<div id="result"></div>

Tests/ViewControllerTests/__Snapshots__/ViewControllerTests/snapShotTests.31.html

@@ -0,0 +1,29 @@
+<div class="  mt-6 p-6 rounded-lg border border-blue-500
+  bg-blue-50 dark:bg-slate-600
+  text-blue-500 dark:text-slate-200">
+  <div class="relative">
+    <h3 class="text-xl font-semibold mb-4">Results</h3>
+    <button class="  font-bold px-4 py-2 rounded-md transition-colors
+  bg-blue-500 dark:bg-yellow-300
+  hover:bg-blue-600 hover:dark:bg-yellow-400
+  text-yellow-300 dark:text-blue-500 absolute bottom-0 right-0" hx-get="/hydronic-system-pressure" hx-target="#content">Reset</button>
+  </div>
+  <div class="w-full rounded-lg shadow-lg bg-blue-100 border border-blue-600 text-blue-600 p-6">
+    <div class="grid grid-cols-2">
+      <div class="grid grid-cols-1 justify-items-center">
+        <p class="font-medium">Pressure</p>
+        <h3 class="text-3xl font-extrabold">10.22<span class="text-lg ms-2">psi</span></h3>
+      </div>
+      <div class="grid grid-cols-1 justify-items-center">
+        <p class="font-medium">Water Density</p>
+        <h3 class="text-3xl font-extrabold">62.58<span class="text-lg ms-2">lb/ft³</span></h3>
+      </div>
+    </div>
+  </div>
+  <div id="warnings"></div>
+  <div class="mt-8 p-4 bg-gray-100 dark:bg-gray-700 rounded-md shadow-md
+border border-blue-500 text-blue-500 text-sm">
+    <p class="font-extrabold mb-3">Note:</p>
+    <p class="px-6">Expansion tank pressure should match system fill pressure.</p>
+  </div>
+</div>