[FSSDK-11454] Swift - Add SDK Multi-Region Support for Data Hosting

Author: esrakartalOpt

Sources/Data Model/DispatchEvents/BatchEvent.swift

@@ -25,6 +25,7 @@ struct BatchEvent: Codable, Equatable {
     let clientName: String
     let anonymizeIP: Bool
     let enrichDecisions: Bool
+    let region: String
 
     enum CodingKeys: String, CodingKey {
         case revision
@@ -35,6 +36,7 @@ struct BatchEvent: Codable, Equatable {
         case clientName = "client_name"
         case anonymizeIP = "anonymize_ip"
         case enrichDecisions = "enrich_decisions"
+        case region
     }
 
     func getEventAttribute(key: String) -> EventAttribute? {

Sources/Data Model/DispatchEvents/EventForDispatch.swift

@@ -18,12 +18,23 @@ import Foundation
 
 @objcMembers public class EventForDispatch: NSObject, Codable {
     public static var eventEndpoint = "https://logx.optimizely.com/v1/events"
+    public static var euEventEndpoint = "https://eu.logx.optimizely.com/v1/events"
+    
+    public static func getEndpoint(for region: Region) -> String {
+        switch region {
+        case .EU:
+            return euEventEndpoint
+        case .US:
+            return eventEndpoint
+        }
+    }
 
     public let url: URL
     public let body: Data
 
-    public init(url: URL? = nil, body: Data) {
-        self.url = url ?? URL(string: EventForDispatch.eventEndpoint)!
+    public init(url: URL? = nil, body: Data, region: Region = .US) {
+        let endpoint = url?.absoluteString ?? EventForDispatch.getEndpoint(for: region)
+        self.url = URL(string: endpoint)!
         self.body = body
     }
 

Sources/Data Model/Project.swift

@@ -16,6 +16,12 @@
 
 import Foundation
 
+/// Optimizely region identifiers
+public enum Region: String, Codable, Equatable {
+    case US
+    case EU
+}
+
 protocol ProjectProtocol {
     func evaluateAudience(audienceId: String, user: OptimizelyUserContext) throws -> Bool
 }
@@ -48,6 +54,8 @@ struct Project: Codable, Equatable {
     var environmentKey: String?
     // Holdouts
     var holdouts: [Holdout]
+    // Region
+    var region: Region?
     let logger = OPTLoggerFactory.getLogger()
 
     // Required since logger is not decodable
@@ -57,7 +65,7 @@ struct Project: Codable, Equatable {
         // V3
         case anonymizeIP
         // V4
-        case rollouts, integrations, typedAudiences, featureFlags, botFiltering, sendFlagDecisions, sdkKey, environmentKey, holdouts
+        case rollouts, integrations, typedAudiences, featureFlags, botFiltering, sendFlagDecisions, sdkKey, environmentKey, holdouts, region
     }
 
     init(from decoder: Decoder) throws {
@@ -88,6 +96,8 @@ struct Project: Codable, Equatable {
         environmentKey = try container.decodeIfPresent(String.self, forKey: .environmentKey)
         // Holdouts - defaults to empty array if key is not present
         holdouts = try container.decodeIfPresent([Holdout].self, forKey: .holdouts) ?? []
+        // Region - defaults to US if not present
+        region = try container.decodeIfPresent(Region.self, forKey: .region)
     }
 
     // Required since logger is not equatable
@@ -97,7 +107,9 @@ struct Project: Codable, Equatable {
             lhs.accountId == rhs.accountId && lhs.events == rhs.events && lhs.revision == rhs.revision &&
             lhs.anonymizeIP == rhs.anonymizeIP && lhs.rollouts == rhs.rollouts &&
             lhs.integrations == rhs.integrations && lhs.typedAudiences == rhs.typedAudiences &&
-            lhs.featureFlags == rhs.featureFlags && lhs.botFiltering == rhs.botFiltering && lhs.sendFlagDecisions == rhs.sendFlagDecisions && lhs.sdkKey == rhs.sdkKey && lhs.environmentKey == rhs.environmentKey
+            lhs.featureFlags == rhs.featureFlags && lhs.botFiltering == rhs.botFiltering && 
+            lhs.sendFlagDecisions == rhs.sendFlagDecisions && lhs.sdkKey == rhs.sdkKey && 
+            lhs.environmentKey == rhs.environmentKey && lhs.region == rhs.region
     }
 }
 

Sources/Data Model/ProjectConfig.swift

@@ -215,6 +215,13 @@ extension ProjectConfig {
 
 extension ProjectConfig {
 
+    /**
+     * Get the region value. Defaults to US if not specified in the project.
+     */
+    public var region: Region {
+        return project.region ?? .US
+    }
+    
     /**
      * Get sendFlagDecisions value.
      */

Sources/Extensions/ArrayEventForDispatch+Extension.swift

@@ -45,6 +45,7 @@ extension Array where Element == EventForDispatch {
         var url: URL?
         var projectId: String?
         var revision: String?
+        var region: String?
 
         let checkUrl = { (event: EventForDispatch) -> Bool in
             if url == nil {
@@ -69,10 +70,18 @@ extension Array where Element == EventForDispatch {
             }
             return revision == batchEvent.revision
         }
+        
+        let checkRegion = { (batchEvent: BatchEvent) -> Bool in
+            if region == nil {
+                region = batchEvent.region
+                return region != nil
+            }
+            return region == batchEvent.region
+        }
 
         for event in self {
             if let batchEvent = try? JSONDecoder().decode(BatchEvent.self, from: event.body) {
-                if !checkUrl(event) || !checkProjectId(batchEvent) || !checkRevision(batchEvent) {
+                if !checkUrl(event) || !checkProjectId(batchEvent) || !checkRevision(batchEvent) || !checkRegion(batchEvent) {
                     break
                 }
 
@@ -101,12 +110,14 @@ extension Array where Element == EventForDispatch {
                                     projectID: base.projectID,
                                     clientName: base.clientName,
                                     anonymizeIP: base.anonymizeIP,
-                                    enrichDecisions: true)
+                                    enrichDecisions: true,
+                                    region: base.region)
 
         guard let data = try? JSONEncoder().encode(batchEvent) else {
             return nil
         }
-        
-        return EventForDispatch(url: url, body: data)
+
+        let regionValue = base.region == Region.EU.rawValue ? Region.EU : Region.US
+        return EventForDispatch(url: url, body: data, region: regionValue)
     }
 }

Sources/Implementation/Events/BatchEventBuilder.swift

@@ -47,7 +47,8 @@ class BatchEventBuilder {
                                 userId: userId,
                                 attributes: attributes,
                                 decisions: [decision],
-                                dispatchEvents: [dispatchEvent])
+                                dispatchEvents: [dispatchEvent],
+                                region: config.region)
     }
 
     // MARK: - Converison Event
@@ -77,7 +78,8 @@ class BatchEventBuilder {
                                 userId: userId,
                                 attributes: attributes,
                                 decisions: nil,
-                                dispatchEvents: [dispatchEvent])
+                                dispatchEvents: [dispatchEvent],
+                                region: config.region)
     }
 
     // MARK: - Create Event
@@ -86,7 +88,9 @@ class BatchEventBuilder {
                                  userId: String,
                                  attributes: OptimizelyAttributes?,
                                  decisions: [Decision]?,
-                                 dispatchEvents: [DispatchEvent]) -> Data? {
+                                 dispatchEvents: [DispatchEvent],
+                                 region: Region? = nil) -> Data? {
+        let eventRegion = region ?? config.region
         let snapShot = Snapshot(decisions: decisions, events: dispatchEvents)
 
         let eventAttributes = getEventAttributes(config: config, attributes: attributes)
@@ -100,9 +104,13 @@ class BatchEventBuilder {
                                     projectID: config.project.projectId,
                                     clientName: Utils.swiftSdkClientName,
                                     anonymizeIP: config.project.anonymizeIP,
-                                    enrichDecisions: true)
+                                    enrichDecisions: true,
+                                    region: eventRegion.rawValue)
+
+        let data = try? JSONEncoder().encode(batchEvent)
+        let eventForDispatch = EventForDispatch(url: nil, body: data ?? Data(), region: eventRegion)
 
-        return try? JSONEncoder().encode(batchEvent)
+        return eventForDispatch.body
     }
 
     // MARK: - Event Tags