2.0 Redesign (#11)

README.md

@@ -1,14 +1,24 @@
-# METAR
+# METAR Parser for Swift
 
-This is a simple regular expression based METAR parser.
+SwiftMETAR provides a simple way to parse METARs into Swift types.
 
 ## Usage Example
 
 ``` swift
-let metar = METAR(rawMETAR: "EGLL 290420Z AUTO 05005KT 020V090 7000 R04/1300VP2000U OVC005 09/08 Q1024 TEMPO BKN004")
+import METAR
+
+let metar = METAR("EGLL 290420Z AUTO 05005KT 020V090 7000 R04/1300VP2000U OVC005 09/08 Q1024 TEMPO BKN004")
 print(metar?.visibility?.measurement) // Prints: Optional(7000.0 m)
 print(metar?.temperature?.measurement) // Prints: Optional(9.0 °C)
 print(metar?.qnh?.measurement) // Prints: Optional(1024.0 hPa)
 print(metar?.wind?.speed.measurement) // Prints: Optional(5.0 kn)
 print(metar?.runwayVisualRanges) // Prints: Optional([Runway 04: 1300.0 m – >2000.0 m Increasing])
 ```
+
+## Contribution
+
+If you'd like to contribute, please feel free to create a PR.
+
+## License
+
+SwiftMETAR is available under the MIT license. See the LICENSE file for more info.

Sources/METAR/CloudLayer.swift

@@ -0,0 +1,30 @@
+//
+//  CloudLayer.swift
+//  
+//
+//  Created by Jonathan Downing on 12/4/20.
+//
+
+import Foundation
+
+public struct CloudLayer: Hashable {
+
+    public enum Coverage {
+        case few
+        case scattered
+        case broken
+        case overcast
+        case skyObscured
+        case notReported
+    }
+
+    public enum SignificantCloudType {
+        case cumulonimbus
+        case toweringCumulus
+    }
+
+    public var coverage: Coverage
+    public var height: Measurement<UnitLength>?
+    public var significantCloudType: SignificantCloudType?
+
+}

Sources/METAR/DirectionalVisibility.swift

@@ -0,0 +1,24 @@
+//
+//  DirectionalVisibility.swift
+//  
+//
+//  Created by Jonathan Downing on 12/5/20.
+//
+
+public struct DirectionalVisibility: Hashable {
+
+    public enum Direction {
+        case north
+        case northEast
+        case east
+        case southEast
+        case south
+        case southWest
+        case west
+        case northWest
+    }
+
+    public var visibility: Visibility
+    public var direction: Direction
+
+}

Sources/METAR/FlightRules.swift

@@ -0,0 +1,56 @@
+//
+//  NOAAFlightRules.swift
+//  
+//
+//  Created by Jonathan Downing on 12/4/20.
+//
+
+public enum ICAOFlightRules {
+
+    /// Visual Meteorlogical Conditions
+    ///
+    /// Applicable when either are true:
+    /// - Ceiling is greater than or equal to 1,500 feet.
+    /// - Visibility is greater than or equal to 5,000 meters.
+    case vmc
+
+    /// Instrument Meteorlogical Conditions
+    ///
+    /// Applicable when either are true:
+    /// - Ceiling is less than 1,500 feet.
+    /// - Visibility is less than 5,000 meters.
+    case imc
+
+}
+
+public enum NOAAFlightRules {
+
+    /// Visual Flight Rules
+    ///
+    /// Applicable when both are true:
+    /// - Ceiling is greater than 3,000 feet
+    /// - Visibility is greater than 5 miles
+    case vfr
+
+    /// Marginal Visual Flight Rules
+    ///
+    /// Applicable when either are true:
+    /// - Ceiling is greater than or equal to 1,000 feet and less than or equal to 3,000 feet
+    /// - Visibility is greater than or equal to 3 miles and less than or equal to 5 miles.
+    case mvfr
+
+    /// Instrument Flight Rules
+    ///
+    /// Applicable when either are true:
+    /// - Ceiling is greater than or equal to 500 feet and less than 1,000 feet
+    /// - Visibility is greater than or equal to 1 mile and less than 3 miles.
+    case ifr
+
+    /// Low Instrument Flight Rules
+    ///
+    /// Applicable when either are true:
+    /// - Ceiling is less than 500 feet
+    /// - Visibility is less than 1 mile
+    case lifr
+
+}

Sources/METAR/METAR+Ceiling.swift

@@ -0,0 +1,28 @@
+//
+//  METAR+Ceiling.swift
+//
+//
+//  Created by Jonathan Downing on 07/01/2017.
+//
+
+import Foundation
+
+extension METAR {
+
+    var ceiling: Measurement<UnitLength> {
+        var ceiling: Double = .greatestFiniteMagnitude
+        for layer in cloudLayers {
+            guard layer.coverage == .overcast || layer.coverage == .skyObscured || layer.coverage == .broken else {
+                continue
+            }
+            guard let height = layer.height?.converted(to: .feet).value else {
+                continue
+            }
+            if ceiling > height {
+                ceiling = height
+            }
+        }
+        return .init(value: ceiling, unit: .feet)
+    }
+
+}

Sources/METAR/METAR+Date.swift

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+//
+//  METAR+Date.swift
+//  
+//
+//  Created by Jonathan Downing on 12/6/20.
+//
+
+import Foundation
+
+extension METAR {
+
+    /// The date the report was issued.
+    ///
+    /// Since METARs only encode day, hour, and minute information—the date from this property is the
+    /// most recent date in the past matching those date components. If the METAR is recent, this should
+    /// not be a problem.
+    public var date: Date {
+        date(relativeTo: Date())
+    }
+
+    func date(relativeTo referenceDate: Date) -> Date {
+        let calendar = Calendar(identifier: .gregorian)
+
+        var dateComponents = self.dateComponents
+        dateComponents.year = calendar.component(.year, from: referenceDate)
+        dateComponents.month = calendar.component(.month, from: referenceDate)
+
+        guard var date = calendar.date(from: dateComponents) else { return .distantPast }
+
+        if date > referenceDate {
+            dateComponents.month! -= 1
+            date = calendar.date(from: dateComponents) ?? .distantPast
+        }
+
+        return date
+    }
+
+}

Sources/METAR/METAR+FlightRules.swift

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+//
+//  File.swift
+//  
+//
+//  Created by Jonathan Downing on 12/6/20.
+//
+
+import Foundation
+
+extension METAR {
+
+    public var icaoFlightRules: ICAOFlightRules? {
+        if ceiling.converted(to: .feet).value < 1500 {
+            return .imc
+        }
+        if let visibility = visibility?.measurement.converted(to: .meters).value {
+            return visibility < 5000 ? .imc : .vmc
+        }
+        return .vmc
+    }
+
+    public var noaaFlightRules: NOAAFlightRules? {
+        if ceiling.converted(to: .feet).value < 500 {
+            return .lifr
+        }
+        if let visibility = visibility?.measurement.converted(to: .miles).value, visibility < 1 {
+            return .lifr
+        }
+        if ceiling.converted(to: .feet).value < 1000 {
+            return .ifr
+        }
+        if let visibility = visibility?.measurement.converted(to: .miles).value, visibility < 3 {
+            return .ifr
+        }
+        if ceiling.converted(to: .feet).value <= 3000 {
+            return .mvfr
+        }
+        if let visibility = visibility?.measurement.converted(to: .miles).value, visibility <= 5 {
+            return .mvfr
+        }
+        if let visibility = visibility?.measurement.converted(to: .miles).value, visibility > 5, ceiling.converted(to: .feet).value > 3000 {
+            return .vfr
+        }
+        if isCeilingAndVisibilityOK {
+            return .vfr
+        }
+        return nil
+    }
+
+}