Network: working with HealthCenter.

1Weather/Network/Health/BlendHealthSource.swift

@@ -8,7 +8,7 @@
 import Foundation
 
 
-public enum BlendHealthError: Error {
+public enum BlendHealthSourceError: Error {
     case insufficientLocationInfo
     case badUrl
     case networkError(Error?)
@@ -17,6 +17,88 @@ public enum BlendHealthError: Error {
     case alreadyBeingUpdated
 }
 
-public class BlendHealthSource {
+public class BlendHealthSource: HealthSource {
+    private let log = Logger(componentName: "BlendHealthSource")
+    #warning("Not implemented: staging / prod switching!")
+    //TODO: Not implemented: staging / prod switching!
+    private static let healthCenterUrl = "http://sta-1w-dataaggregator.onelouder.com/1weather/api/v1/weather/current"
     
+    public var healthUpdateInterval: TimeInterval = TimeInterval(15 * 60) // 15 minutes
+    /// This queue is needed to synchronize access to locationsBeingUpdated. Also, to make logging more clear.
+    private let internalQueue: OperationQueue = {
+        let queue = OperationQueue()
+        queue.name = "BlendHealthSource Queue"
+        queue.maxConcurrentOperationCount = 1
+        return queue
+    }()
+    
+    private var locationsBeingUpdated = Set<Location>()
+    
+    public func updateHelath(for location: Location, completion: @escaping HealthSourceCompletion) {
+        internalQueue.addOperation { [weak self] in
+            let extendedCompletion: HealthSourceCompletion = { [weak self] (health, error) in
+                self?.internalQueue.addOperation {
+                    completion(health, error)
+                    self?.locationsBeingUpdated.remove(location)
+                }
+            }
+            self?.updateHelathInternal(for: location, completion: extendedCompletion)
+        }
+    }
+    
+    private func updateHelathInternal(for location: Location, completion: @escaping HealthSourceCompletion) {
+        guard !locationsBeingUpdated.contains(location) else {
+            completion(nil, BlendHealthSourceError.alreadyBeingUpdated)
+            return
+        }
+        locationsBeingUpdated.insert(location)
+        guard var urlComponents = URLComponents(string: BlendHealthSource.healthCenterUrl) else {
+            assertionFailure("Should never happen. The URL should be correct.")
+            return
+        }
+        
+        var queryParameters = [String: String]()
+        
+        if let coordinates = location.coordinates {
+            queryParameters["LAT"] = String(format: "%.5f", coordinates.latitude)
+            queryParameters["LON"] = String(format: "%.5f", coordinates.longitude)
+        }
+        queryParameters["ZIP"] = location.zip
+        queryParameters["CITY"] = location.cityName
+        queryParameters["STATE"] = location.region
+        queryParameters["COUNTRY"] = location.countryName
+        
+        guard !queryParameters.isEmpty else {
+            completion(nil, BlendHealthSourceError.insufficientLocationInfo)
+            log.error("Not enough information about location.")
+            return
+        }
+        guard let url = urlComponents.url else {
+            completion(nil, BlendHealthSourceError.badUrl)
+            return
+        }
+        log.debug("query params: \(queryParameters)")
+        
+        let urlSession = URLSession.shared
+        let dataTask = urlSession.dataTask(with: url) { [weak self] (data, reponse, error) in
+            guard let self = self else { return }
+            guard let data = data else {
+                completion(nil, BlendHealthSourceError.networkError(error))
+                return
+            }
+            let decoder = JSONDecoder()
+            let dateFormatter = DateFormatter()
+            dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
+            decoder.dateDecodingStrategy = .formatted(dateFormatter)
+            do {
+                let updatedHealth = try decoder.decode(BlendHealthCenter.self, from: data)
+                let appHealth = updatedHealth.toAppModel()
+                completion(appHealth, nil)
+            }
+            catch {
+                completion(nil, BlendHealthSourceError.badServerResponse(error))
+            }
+        }
+        dataTask.resume()
+    }
 }

1Weather/Network/Health/Model/BlendHealthModels.swift

@@ -12,9 +12,9 @@ import UIKit
 struct BlendHealthCenter: Codable {
     public let s2CellID: String
     public let updatedOn: Date
-    public let airQuality: BlendAirQuality
+    public let airQuality: BlendAirQuality?
     public let fire: BlendFire
-    public let pollutants, pollen: [BlendPoll]
+    public let pollutants, pollen: [BlendPoll]?
 
     enum CodingKeys: String, CodingKey {
         case s2CellID = "s2_cell_id"
@@ -22,6 +22,20 @@ struct BlendHealthCenter: Codable {
         case airQuality = "air_quality"
         case fire, pollutants, pollen
     }
+    
+    func toAppModel() -> Health {
+        let airQuality = self.airQuality?.toAppModel()
+        let pollutants = self.pollutants?.reduce([String: Pollutant]()) { (dict, blendPoll) in
+            var dict = dict
+            if let pollutant = blendPoll.toAppModel() {
+                dict[pollutant.name] = pollutant
+            }
+            return dict
+        }
+        
+        let result = Health(lastUpdateTime: updatedOn, airQuality: airQuality, pollutants: pollutants ?? [:])
+        return result
+    }
 }
 
 // MARK: - AirQuality
@@ -39,6 +53,13 @@ struct BlendAirQuality: Codable {
         case color = "color_code"
         case imageURL = "image_url"
     }
+    
+    func toAppModel() -> AirQuality {
+        #warning("Not implemented!")
+        //TODO: implement health advice groups support (general / sensitive / active)
+        let result = AirQuality(index: aqi, advice: healthAdvice.general)
+        return result
+    }
 }
 
 // MARK: - HealthAdvice
@@ -72,6 +93,17 @@ struct BlendPoll: Codable {
         case status
         case colorCode = "color_code"
     }
+    
+    // Note: the same model in Blend is also used for pollen, which, in my opinion, should be
+    // a different app-level model object.
+    func toAppModel() -> Pollutant? {
+        //  Note: pollutants always seem to have a value. Pollen doesn't.
+        guard let value = value else {
+            return nil
+        }
+        let result = Pollutant(name: name, value: value)
+        return result
+    }
 }
 
 struct BlendColor: Codable {
@@ -85,7 +117,7 @@ struct BlendColor: Codable {
     
     func encode(to encoder: Encoder) throws {
         guard let hexRepresentation = uiColor.toHex() else {
-            throw BlendHealthError.dataEncodingError("BlendColor to HEX conversion failed for color \(uiColor)")
+            throw BlendHealthSourceError.dataEncodingError("BlendColor to HEX conversion failed for color \(uiColor)")
         }
         var container = encoder.singleValueContainer()
         try container.encode("#\(hexRepresentation)")

1Weather/Network/Weather/WdtWeatherSource.swift

@@ -31,7 +31,6 @@ public class WdtWeatherSource: WeatherSource {
         return queue
     }()
     
-    /// This is used
     private var locationsBeingUpdated = Set<Location>()
     
     public let weatherUpdateInterval = TimeInterval(15 * 60) // 15 minutes