39 lines
1.1 KiB
Swift
39 lines
1.1 KiB
Swift
import Dependencies
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import Logging
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import PsychrometricClient
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import Routes
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public extension FeetOfHead.Request {
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private static let specificGravity = 1.02
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func respond(logger: Logger) async throws -> FeetOfHead.Response {
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@Dependency(\.psychrometricClient) var psychrometricClient
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try validate()
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let waterTemperature = DryBulb.fahrenheit(self.waterTemperature ?? 60)
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let density = try await psychrometricClient.density.water(waterTemperature)
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let feetOfHead = pressure / ((density.value / 144) * Self.specificGravity)
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var warnings = [String]()
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if self.waterTemperature == nil {
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warnings.append(
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"Calculations are based on 60°F water temperature."
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)
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}
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return .init(feetOfHead: feetOfHead, density: density, warnings: warnings)
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}
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private func validate() throws {
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guard pressure > 0 else {
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throw ValidationError(message: "Pressure should be greater than 0.")
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}
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if let waterTemperature {
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guard waterTemperature > 32 else {
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throw ValidationError(message: "Water temperature should be above freezing.")
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}
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}
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}
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}
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