Add support for targetPercentile RMF rule parameter

Sources/RemoteMessaging/Mappers/JsonToRemoteMessageModelMapper.swift

@@ -197,21 +197,29 @@ struct JsonToRemoteMessageModelMapper {
         }
     }
 
-    static func maps(jsonRemoteRules: [RemoteMessageResponse.JsonMatchingRule]) -> [Int: [MatchingAttribute]] {
-        var rules: [Int: [MatchingAttribute]] = [:]
-        jsonRemoteRules.forEach { rule in
-            var matchingAttributes: [MatchingAttribute] = []
-            rule.attributes.forEach { attribute in
+    static func maps(jsonRemoteRules: [RemoteMessageResponse.JsonMatchingRule]) -> [RemoteConfigRule] {
+        return jsonRemoteRules.map { jsonRule in
+            let mappedAttributes = jsonRule.attributes.map { attribute in
                 if let key = AttributesKey(rawValue: attribute.key) {
-                    matchingAttributes.append(key.matchingAttribute(jsonMatchingAttribute: attribute.value))
+                    return key.matchingAttribute(jsonMatchingAttribute: attribute.value)
                 } else {
                     os_log("Unknown attribute key %s", log: .remoteMessaging, type: .debug, attribute.key)
-                    matchingAttributes.append(UnknownMatchingAttribute(jsonMatchingAttribute: attribute.value))
+                    return UnknownMatchingAttribute(jsonMatchingAttribute: attribute.value)
                 }
             }
-            rules[rule.id] = matchingAttributes
+
+            var mappedTargetPercentile: RemoteConfigTargetPercentile?
+
+            if let jsonTargetPercentile = jsonRule.targetPercentile {
+                mappedTargetPercentile = .init(before: jsonTargetPercentile.before)
+            }
+
+            return RemoteConfigRule(
+                id: jsonRule.id,
+                targetPercentile: mappedTargetPercentile,
+                attributes: mappedAttributes
+            )
         }
-        return rules
     }
 
     static func getTranslation(from translations: [String: RemoteMessageResponse.JsonContentTranslation]?,

Sources/RemoteMessaging/Model/JsonRemoteMessagingConfig.swift

@@ -64,8 +64,13 @@ public enum RemoteMessageResponse {
         let secondaryActionText: String?
     }
 
+    struct JsonTargetPercentile: Decodable {
+        let before: Float?
+    }
+
     struct JsonMatchingRule: Decodable {
         let id: Int
+        let targetPercentile: JsonTargetPercentile?
         let attributes: [String: AnyDecodable]
     }
 

Sources/RemoteMessaging/Model/RemoteConfigModel.swift

@@ -20,5 +20,15 @@ import Foundation
 
 public struct RemoteConfigModel {
     let messages: [RemoteMessageModel]
-    let rules: [Int: [MatchingAttribute]]
+    let rules: [RemoteConfigRule]
+}
+
+public struct RemoteConfigRule {
+    let id: Int
+    let targetPercentile: RemoteConfigTargetPercentile?
+    let attributes: [MatchingAttribute]
+}
+
+public struct RemoteConfigTargetPercentile {
+    let before: Float?
 }

Sources/RemoteMessaging/RemoteMessagingConfigMatcher.swift

@@ -24,17 +24,20 @@ public struct RemoteMessagingConfigMatcher {
     private let appAttributeMatcher: AppAttributeMatcher
     private let deviceAttributeMatcher: DeviceAttributeMatcher
     private let userAttributeMatcher: UserAttributeMatcher
+    private let percentileStore: RemoteMessagingPercentileStoring
     private let dismissedMessageIds: [String]
 
     private let matchers: [AttributeMatcher]
 
     public init(appAttributeMatcher: AppAttributeMatcher,
                 deviceAttributeMatcher: DeviceAttributeMatcher = DeviceAttributeMatcher(),
                 userAttributeMatcher: UserAttributeMatcher,
+                percentileStore: RemoteMessagingPercentileStoring,
                 dismissedMessageIds: [String]) {
         self.appAttributeMatcher = appAttributeMatcher
         self.deviceAttributeMatcher = deviceAttributeMatcher
         self.userAttributeMatcher = userAttributeMatcher
+        self.percentileStore = percentileStore
         self.dismissedMessageIds = dismissedMessageIds
 
         matchers = [appAttributeMatcher, deviceAttributeMatcher, userAttributeMatcher]
@@ -49,8 +52,8 @@ public struct RemoteMessagingConfigMatcher {
                 return message
             }
 
-            let matchingResult = evaluateMatchingRules(message.matchingRules, fromRules: rules)
-            let exclusionResult = evaluateExclusionRules(message.exclusionRules, fromRules: rules)
+            let matchingResult = evaluateMatchingRules(message.matchingRules, messageID: message.id, fromRules: rules)
+            let exclusionResult = evaluateExclusionRules(message.exclusionRules, messageID: message.id, fromRules: rules)
 
             if matchingResult == .match && exclusionResult == .fail {
                 return message
@@ -60,16 +63,26 @@ public struct RemoteMessagingConfigMatcher {
         return nil
     }
 
-    func evaluateMatchingRules(_ matchingRules: [Int], fromRules rules: [Int: [MatchingAttribute]]) -> EvaluationResult {
+    func evaluateMatchingRules(_ matchingRules: [Int], messageID: String, fromRules rules: [RemoteConfigRule]) -> EvaluationResult {
         var result: EvaluationResult = .match
 
         for rule in matchingRules {
-            guard let matchingAttributes = rules[rule] else {
+            guard let matchingRule = rules.first(where: { $0.id == rule }) else {
                 return .nextMessage
             }
+
+            if let percentile = matchingRule.targetPercentile, let messagePercentile = percentile.before {
+                let userPercentile = percentileStore.percentile(forMessageId: messageID)
+
+                if userPercentile > messagePercentile {
+                    os_log("Matching rule percentile check failed for message with ID %s", log: .remoteMessaging, type: .debug, messageID)
+                    return .fail
+                }
+            }
+
             result = .match
 
-            for attribute in matchingAttributes {
+            for attribute in matchingRule.attributes {
                 result = evaluateAttribute(matchingAttribute: attribute)
                 if result == .fail || result == .nextMessage {
                     os_log("First failing matching attribute %s", log: .remoteMessaging, type: .debug, String(describing: attribute))
@@ -84,16 +97,26 @@ public struct RemoteMessagingConfigMatcher {
         return result
     }
 
-    func evaluateExclusionRules(_ exclusionRules: [Int], fromRules rules: [Int: [MatchingAttribute]]) -> EvaluationResult {
+    func evaluateExclusionRules(_ exclusionRules: [Int], messageID: String, fromRules rules: [RemoteConfigRule]) -> EvaluationResult {
         var result: EvaluationResult = .fail
 
         for rule in exclusionRules {
-            guard let attributes = rules[rule] else {
+            guard let matchingRule = rules.first(where: { $0.id == rule }) else {
                 return .nextMessage
             }
+
+            if let percentile = matchingRule.targetPercentile, let messagePercentile = percentile.before {
+                let userPercentile = percentileStore.percentile(forMessageId: messageID)
+
+                if userPercentile > messagePercentile {
+                    os_log("Exclusion rule percentile check failed for message with ID %s", log: .remoteMessaging, type: .debug, messageID)
+                    return .fail
+                }
+            }
+
             result = .fail
 
-            for attribute in attributes {
+            for attribute in matchingRule.attributes {
                 result = evaluateAttribute(matchingAttribute: attribute)
                 if result == .fail || result == .nextMessage {
                     os_log("First failing exclusion attribute %s", log: .remoteMessaging, type: .debug, String(describing: attribute))

Sources/RemoteMessaging/RemoteMessagingPercentileStoring.swift

@@ -0,0 +1,37 @@
+//
+//  RemoteMessagingPercentileStoring.swift
+//
+//  Copyright © 2024 DuckDuckGo. All rights reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+import Foundation
+
+public protocol RemoteMessagingPercentileStoring {
+    func percentile(forMessageId: String) -> Float
+}
+
+public class RemoteMessagingPercentileUserDefaultsStore: RemoteMessagingPercentileStoring {
+
+    private let userDefaults: UserDefaults
+
+    init(userDefaults: UserDefaults) {
+        self.userDefaults = userDefaults
+    }
+
+    public func percentile(forMessageId: String) -> Float {
+        return 0.95
+    }
+
+}

Tests/BrowserServicesKitTests/RemoteMessaging/Mappers/JsonToRemoteConfigModelMapperTests.swift

@@ -102,39 +102,49 @@ class JsonToRemoteConfigModelMapperTests: XCTestCase {
 
     func testWhenValidJsonParsedThenRulesMappedIntoRemoteConfig() throws {
         let config = try decodeAndMapJson(fileName: "Resources/remote-messaging-config.json")
-        XCTAssertTrue(config.rules.count == 4)
+        XCTAssertTrue(config.rules.count == 5)
 
-        let rule5 = config.rules.filter { $0.key == 5 }.first
+        let rule5 = config.rules.filter { $0.id == 5 }.first
         XCTAssertNotNil(rule5)
-        XCTAssertTrue(rule5?.value.count == 16)
-        var attribs = rule5?.value.filter { $0 is LocaleMatchingAttribute }
+        XCTAssertNil(rule5?.targetPercentile)
+        XCTAssertTrue(rule5?.attributes.count == 16)
+        var attribs = rule5?.attributes.filter { $0 is LocaleMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? LocaleMatchingAttribute, LocaleMatchingAttribute(value: ["en-US", "en-GB"], fallback: true))
 
-        let rule6 = config.rules.filter { $0.key == 6 }.first
+        let rule6 = config.rules.filter { $0.id == 6 }.first
         XCTAssertNotNil(rule6)
-        XCTAssertTrue(rule6?.value.count == 1)
-        attribs = rule6?.value.filter { $0 is LocaleMatchingAttribute }
+        XCTAssertNil(rule6?.targetPercentile)
+        XCTAssertTrue(rule6?.attributes.count == 1)
+        attribs = rule6?.attributes.filter { $0 is LocaleMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? LocaleMatchingAttribute, LocaleMatchingAttribute(value: ["en-GB"], fallback: nil))
 
-        let rule7 = config.rules.filter { $0.key == 7 }.first
+        let rule7 = config.rules.filter { $0.id == 7 }.first
         XCTAssertNotNil(rule7)
-        XCTAssertTrue(rule7?.value.count == 1)
-        attribs = rule7?.value.filter { $0 is WidgetAddedMatchingAttribute }
+        XCTAssertNil(rule7?.targetPercentile)
+        XCTAssertTrue(rule7?.attributes.count == 1)
+        attribs = rule7?.attributes.filter { $0 is WidgetAddedMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? WidgetAddedMatchingAttribute, WidgetAddedMatchingAttribute(value: false, fallback: nil))
 
-        let rule8 = config.rules.filter { $0.key == 8 }.first
+        let rule8 = config.rules.filter { $0.id == 8 }.first
         XCTAssertNotNil(rule8)
-        XCTAssertTrue(rule8?.value.count == 2)
-        attribs = rule8?.value.filter { $0 is DaysSinceNetPEnabledMatchingAttribute }
+        XCTAssertNil(rule8?.targetPercentile)
+        XCTAssertTrue(rule8?.attributes.count == 2)
+        attribs = rule8?.attributes.filter { $0 is DaysSinceNetPEnabledMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? DaysSinceNetPEnabledMatchingAttribute, DaysSinceNetPEnabledMatchingAttribute(min: 5, fallback: nil))
 
-        attribs = rule8?.value.filter { $0 is IsNetPWaitlistUserMatchingAttribute }
+        attribs = rule8?.attributes.filter { $0 is IsNetPWaitlistUserMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? IsNetPWaitlistUserMatchingAttribute, IsNetPWaitlistUserMatchingAttribute(value: true, fallback: nil))
+
+        let rule9 = config.rules.filter { $0.id == 9 }.first
+        XCTAssertNotNil(rule9)
+        XCTAssertNotNil(rule9?.targetPercentile)
+        XCTAssertTrue(rule9?.attributes.count == 1)
+        XCTAssertEqual(rule9?.targetPercentile?.before, 0.9)
     }
 
     func testWhenJsonMessagesHaveUnknownTypesThenMessagesNotMappedIntoConfig() throws {
@@ -147,15 +157,15 @@ class JsonToRemoteConfigModelMapperTests: XCTestCase {
         let config = try decodeAndMapJson(fileName: "Resources/remote-messaging-config-unsupported-items.json")
         XCTAssertTrue(config.rules.count == 2)
 
-        let rule6 = config.rules.filter { $0.key == 6 }.first
+        let rule6 = config.rules.filter { $0.id == 6 }.first
         XCTAssertNotNil(rule6)
-        var attribs = rule6?.value.filter { $0 is UnknownMatchingAttribute }
+        var attribs = rule6?.attributes.filter { $0 is UnknownMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? UnknownMatchingAttribute, UnknownMatchingAttribute(fallback: true))
 
-        let rule7 = config.rules.filter { $0.key == 7 }.first
+        let rule7 = config.rules.filter { $0.id == 7 }.first
         XCTAssertNotNil(rule7)
-        attribs = rule7?.value.filter { $0 is WidgetAddedMatchingAttribute }
+        attribs = rule7?.attributes.filter { $0 is WidgetAddedMatchingAttribute }
         XCTAssertEqual(attribs?.count, 1)
         XCTAssertEqual(attribs?.first as? WidgetAddedMatchingAttribute, WidgetAddedMatchingAttribute(value: true, fallback: nil))
     }
@@ -167,11 +177,11 @@ class JsonToRemoteConfigModelMapperTests: XCTestCase {
         let config = JsonToRemoteConfigModelMapper.mapJson(remoteMessagingConfig: remoteMessagingConfig)
         XCTAssertTrue(config.rules.count == 2)
 
-        let rule6 = config.rules.filter { $0.key == 6 }.first
+        let rule6 = config.rules.filter { $0.id == 6 }.first
         XCTAssertNotNil(rule6)
-        XCTAssertEqual(rule6?.value.filter { $0 is LocaleMatchingAttribute }.count, 1)
-        XCTAssertEqual(rule6?.value.filter { $0 is OSMatchingAttribute }.count, 1)
-        XCTAssertEqual(rule6?.value.filter { $0 is UnknownMatchingAttribute }.count, 1)
+        XCTAssertEqual(rule6?.attributes.filter { $0 is LocaleMatchingAttribute }.count, 1)
+        XCTAssertEqual(rule6?.attributes.filter { $0 is OSMatchingAttribute }.count, 1)
+        XCTAssertEqual(rule6?.attributes.filter { $0 is UnknownMatchingAttribute }.count, 1)
     }
 
     func decodeAndMapJson(fileName: String) throws -> RemoteConfigModel {

Tests/BrowserServicesKitTests/RemoteMessaging/Mocks/MockRemoteMessagePercentileStore.swift

@@ -0,0 +1,37 @@
+//
+//  MockRemoteMessagePercentileStore.swift
+//  DuckDuckGo
+//
+//  Copyright © 2024 DuckDuckGo. All rights reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+import Foundation
+import RemoteMessaging
+
+class MockRemoteMessagePercentileStore: RemoteMessagingPercentileStoring {
+
+    var percentileStorage: [String: Float] = [:]
+    var defaultPercentage: Float = 0
+
+    func percentile(forMessageId messageID: String) -> Float {
+        if let percentile = percentileStorage[messageID] {
+            return percentile
+        }
+
+        percentileStorage[messageID] = defaultPercentage
+        return defaultPercentage
+    }
+
+}