Add configuration to send requests with user ID to a Focal Meter endp…

…oint (close #745)

Sources/Snowplow/Configurations/FocalMeterConfiguration.swift

@@ -1,8 +1,97 @@
 //
-//  File.swift
-//  
+//  FocalMeterConfiguration.swift
+//  Snowplow
 //
-//  Created by Matus Tomlein on 30/12/2022.
+//  Copyright (c) 2013-2022 Snowplow Analytics Ltd. All rights reserved.
+//
+//  This program is licensed to you under the Apache License Version 2.0,
+//  and you may not use this file except in compliance with the Apache License
+//  Version 2.0. You may obtain a copy of the Apache License Version 2.0 at
+//  http://www.apache.org/licenses/LICENSE-2.0.
+//
+//  Unless required by applicable law or agreed to in writing,
+//  software distributed under the Apache License Version 2.0 is distributed on
+//  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+//  express or implied. See the Apache License Version 2.0 for the specific
+//  language governing permissions and limitations there under.
+//
+//  License: Apache License Version 2.0
 //
 
 import Foundation
+
+/// This configuration tells the tracker to send requests with the user ID in session context entity
+/// to a Kantar endpoint used with FocalMeter.
+/// The request is made when the first event with a new user ID is tracked.
+/// The requests are only made if session context is enabled (default).
+@objc(SPFocalMeterConfiguration)
+public class FocalMeterConfiguration: NSObject, PluginConfigurationProtocol, ConfigurationProtocol {
+    public private(set) var identifier = "KantarFocalMeter"
+    public private(set) var entitiesConfiguration: PluginEntitiesConfiguration? = nil
+    public private(set) var afterTrackConfiguration: PluginAfterTrackConfiguration?
+    /// URL of the Kantar endpoint to send the requests to
+    public private(set) var kantarEndpoint: String
+    private var lastUserId: String?
+
+    /// Creates a configuration for the Kantar FocalMeter.
+    /// - Parameters:
+    ///    - endpoint: URL of the Kantar endpoint to send the requests to
+    @objc
+    public init(kantarEndpoint: String) {
+        self.kantarEndpoint = kantarEndpoint
+        super.init()
+
+        self.afterTrackConfiguration = PluginAfterTrackConfiguration { event in
+            let session = event.entities.first { entity in
+                entity.schema == kSPSessionContextSchema
+            }
+            if let userId = session?.data[kSPSessionUserId] as? String {
+                if self.shouldUpdate(userId) {
+                    self.makeRequest(userId: userId)
+                }
+            }
+        }
+    }
+
+    private func shouldUpdate(_ newUserId: String) -> Bool {
+        objc_sync_enter(self)
+        defer { objc_sync_exit(self) }
+
+        if lastUserId == nil || newUserId != lastUserId {
+            lastUserId = newUserId
+            return true
+        }
+        return false
+    }
+
+    private func makeRequest(userId: String) {
+        var components = URLComponents(string: kantarEndpoint)
+        components?.queryItems = [
+            URLQueryItem(name: "vendor", value: "snowplow"),
+            URLQueryItem(name: "cs_fpid", value: userId),
+            URLQueryItem(name: "c12", value: "not_set"),
+        ]
+
+        guard let url = components?.url else {
+            logError(message: "Failed to build URL to request Kantar endpoint")
+            return
+        }
+
+        var request = URLRequest(url: url)
+        request.httpMethod = "GET"
+        let task = URLSession.shared.dataTask(with: request) { data, response, error in
+            if let error = error {
+                logError(message: "Request to Kantar endpoint failed: \(error)")
+            }
+            else if let httpResponse = response as? HTTPURLResponse {
+                if httpResponse.statusCode >= 200 && httpResponse.statusCode < 300 {
+                    logDebug(message: "Request to Kantar endpoint sent with user ID: \(userId)")
+                    return
+                } else {
+                    logError(message: "Request to Kantar endpoint was not successful")
+                }
+            }
+        }
+        task.resume()
+    }
+}

Tests/Configurations/TestFocalMeterConfiguration.swift

@@ -0,0 +1,114 @@
+//
+//  TestFocalMeterConfiguration.swift
+//  Snowplow-iOSTests
+//
+//  Copyright (c) 2013-2022 Snowplow Analytics Ltd. All rights reserved.
+//
+//  This program is licensed to you under the Apache License Version 2.0,
+//  and you may not use this file except in compliance with the Apache License
+//  Version 2.0. You may obtain a copy of the Apache License Version 2.0 at
+//  http://www.apache.org/licenses/LICENSE-2.0.
+//
+//  Unless required by applicable law or agreed to in writing,
+//  software distributed under the Apache License Version 2.0 is distributed on
+//  an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+//  express or implied. See the Apache License Version 2.0 for the specific
+//  language governing permissions and limitations there under.
+//
+//  Authors: Alex Benini, Matus Tomlein
+//  License: Apache License Version 2.0
+//
+
+import XCTest
+import Mocker
+@testable import SnowplowTracker
+
+class TestFocalMeterConfiguration: XCTestCase {
+    let endpoint = "https://fake-snowplow.io"
+
+#if !os(watchOS) // Mocker seems not to currently work on watchOS
+
+    override class func tearDown() {
+        Mocker.removeAll()
+        Snowplow.removeAllTrackers()
+        super.tearDown()
+    }
+
+    func testMakesRequestToKantarEndpointWithUserId() {
+        let tracker = createTracker()
+
+        let requestExpectation = expectation(description: "Request made")
+        mockRequest { query in
+            let userId = tracker.session!.userId!
+            XCTAssertTrue(query!.contains(userId))
+            requestExpectation.fulfill()
+        }
+
+        _ = tracker.track(Structured(category: "cat", action: "act"))
+        wait(for: [requestExpectation], timeout: 1)
+    }
+
+    func testMakesRequestToKantarEndpointWhenUserIdChanges() {
+        // log queries of requests
+        var kantarRequestQueries: [String] = []
+        let tracker = createTracker()
+        var requestExpectation: XCTestExpectation? = expectation(description: "Anonymous request made")
+        mockRequest { query in
+            kantarRequestQueries.append(query!)
+            requestExpectation?.fulfill()
+        }
+
+        // enable user anonymisation, should trigger request with anonymous user id
+        tracker.userAnonymisation = true
+        _ = tracker.track(Structured(category: "cat", action: "act"))
+        wait(for: [requestExpectation!], timeout: 1)
+        XCTAssertEqual(1, kantarRequestQueries.count)
+        XCTAssertTrue(kantarRequestQueries.first!.contains("00000000-0000-0000-0000-000000000000"))
+        kantarRequestQueries.removeAll()
+
+        // disable user anonymisation, should trigger new request
+        requestExpectation = expectation(description: "Second request made")
+        tracker.userAnonymisation = false
+        _ = tracker.track(ScreenView(name: "sv"))
+        wait(for: [requestExpectation!], timeout: 1)
+        XCTAssertEqual(1, kantarRequestQueries.count)
+        let userId = tracker.session!.userId!
+        XCTAssertTrue(kantarRequestQueries.first!.contains(userId))
+        kantarRequestQueries.removeAll()
+
+        // tracking another should not trigger a request as user ID did not change
+        requestExpectation = nil
+        _ = tracker.track(Structured(category: "cat", action: "act"))
+        let sleep = expectation(description: "Wait for events to be tracked")
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { () -> Void in
+            sleep.fulfill()
+        }
+        wait(for: [sleep], timeout: 1)
+        XCTAssertEqual(0, kantarRequestQueries.count)
+    }
+
+    private func mockRequest(callback: @escaping (String?) -> Void) {
+        var mock = Mock(url: URL(string: endpoint)!, ignoreQuery: true, dataType: .json, statusCode: 200, data: [
+            .get: Data()
+        ])
+        mock.onRequest = { (request, body) in
+            callback(request.url?.query)
+        }
+        mock.register()
+    }
+
+    private func createTracker() -> TrackerController {
+        let connection = MockNetworkConnection(requestOption: .post, statusCode: 200)
+        let networkConfig = NetworkConfiguration(networkConnection: connection)
+        let trackerConfig = TrackerConfiguration()
+        trackerConfig.installAutotracking = false
+        trackerConfig.diagnosticAutotracking = false
+        let focalMeterConfig = FocalMeterConfiguration(kantarEndpoint: endpoint)
+        let namespace = "testFocalMeter" + String(describing: Int.random(in: 0..<100))
+        return Snowplow.createTracker(namespace: namespace,
+                                      network: networkConfig,
+                                      configurations: [trackerConfig, focalMeterConfig])!
+    }
+
+#endif
+}