Improve statistics collection (#281)

DemoApp/Sources/Components/Stats/ParticipantStatsViewModel.swift

@@ -47,10 +47,16 @@ final class ParticipantStatsViewModel: ObservableObject {
     private func handleStatsReport(_ report: CallStatsReport?) {
         guard let report,
               let trackId = participant.track?.trackId,
-              let participantStats = report.participantsStats.report[trackId] else {
+              let participantsStatsArray = report.participantsStats.report[trackId],
+              !participantsStatsArray.isEmpty
+        else {
             return
         }
 
+        let participantStats = participantsStatsArray.sorted { lhs, rhs in
+            lhs.frameWidth >= rhs.frameWidth && lhs.frameHeight >= rhs.frameHeight
+        }[0]
+
         let isLocalUser = participant.sessionId == call.state.sessionId
         let datacenter = StatsEntry(
             title: "Region",

Sources/StreamVideo/Models/CallStatsReport.swift

@@ -24,13 +24,20 @@ public struct CallStatsReport: Sendable {
 }
 
 /// A struct representing statistics for participants in the call.
-public struct ParticipantsStats: Sendable {
+public struct ParticipantsStats: Sendable, Equatable {
     /// The report containing statistics for individual participants.
-    public let report: [String: BaseStats]
+    public let report: [String: [BaseStats]]
+
+    public static func + (
+        lhs: ParticipantsStats,
+        rhs: ParticipantsStats
+    ) -> ParticipantsStats {
+        ParticipantsStats(report: lhs.report.merging(rhs.report) { $1 })
+    }
 }
 
 /// A struct representing basic statistics for a participant in the call.
-public struct BaseStats: Sendable {
+public struct BaseStats: Sendable, Equatable {
     /// The total bytes sent by the participant.
     public let bytesSent: Int
     /// The total bytes received by the participant.
@@ -60,23 +67,23 @@ public struct BaseStats: Sendable {
 }
 
 /// A struct representing an aggregated stats report for the call.
-public struct AggregatedStatsReport: Sendable {
+public struct AggregatedStatsReport: Sendable, Equatable {
     /// The total bytes sent by all participants.
-    public let totalBytesSent: Int
+    public internal(set) var totalBytesSent: Int
     /// The total bytes received by all participants.
-    public let totalBytesReceived: Int
+    public internal(set) var totalBytesReceived: Int
     /// The average jitter across all participants in milliseconds.
-    public let averageJitterInMs: Double
+    public internal(set) var averageJitterInMs: Double
     /// The average round-trip time across all participants in milliseconds.
-    public let averageRoundTripTimeInMs: Double
+    public internal(set) var averageRoundTripTimeInMs: Double
     /// The reasons for quality limitations in the call.
-    public let qualityLimitationReasons: String
+    public internal(set) var qualityLimitationReasons: String
     /// The highest frame width among all video streams.
-    public let highestFrameWidth: Int
+    public internal(set) var highestFrameWidth: Int
     /// The highest frame height among all video streams.
-    public let highestFrameHeight: Int
+    public internal(set) var highestFrameHeight: Int
     /// The highest frames per second among all video streams.
-    public let highestFramesPerSecond: Int
+    public internal(set) var highestFramesPerSecond: Int
     /// The timestamp when the aggregated stats report was generated.
-    public let timestamp: Double
+    public internal(set) var timestamp: Double
 }

Sources/StreamVideo/WebRTC/Statistics/Statistics+Convenience.swift

@@ -0,0 +1,88 @@
+//
+// Copyright © 2024 Stream.io Inc. All rights reserved.
+//
+
+import Foundation
+import StreamWebRTC
+
+/// A wrapper around RTCStatistics that can be used to easily access its properties.
+@dynamicMemberLookup
+struct StreamRTCStatistics {
+    /// A structure providing a type-safe way to access values from RTCStatistics' values dictionary.
+    @objcMembers final class CodingKeys: NSObject {
+        var trackIdentifier: String = ""
+        var codecId: String = ""
+        var mimeType: String = ""
+        var bytesSent: Int = 0
+        var bytesReceived: Int = 0
+        var jitter: Double = 0
+        var currentRoundTripTime: Double = 0
+        var qualityLimitationReason: String = ""
+        var frameWidth: Int = 0
+        var frameHeight: Int = 0
+        var framesPerSecond: Int = 0
+        var transportId: String = ""
+        var dtlsState: String = ""
+        var selectedCandidatePairId: String = ""
+        var kind: String = ""
+        var rid: String = ""
+        var ssrc: Int = 0
+    }
+
+    private let source: StreamStatisticsProtocol?
+
+    /// The  of the `source` or empty.
+    var type: String { source?.type ?? "" }
+
+    /// The id of the `source` or empty.
+    var id: String { source?.id ?? "" }
+
+    init?(_ source: StreamStatisticsProtocol?) {
+        guard let source else { return nil }
+        self.source = source
+    }
+
+    /// A handy way to access values from the source's `values` storage.
+    subscript<T>(dynamicMember keyPath: KeyPath<CodingKeys, T>) -> T? {
+        /// Implement logic to dynamically access the members of RTCStatisticsReport
+        let value = NSExpression(forKeyPath: keyPath).keyPath
+        return source?.values[value] as? T
+    }
+}
+
+/// A wrapper around RTCStatisticsReport that can be used to easily access its properties.
+struct StreamRTCStatisticsReport {
+    var statistics: [StreamRTCStatistics]
+    var timestamp: TimeInterval
+    var source: RTCStatisticsReport?
+
+    init(_ source: RTCStatisticsReport?) {
+        self.init(
+            statistics: source?.statistics.compactMap { StreamRTCStatistics($0.value) } ?? [],
+            timestamp: source?.timestamp_us ?? Date().timeIntervalSince1970,
+            source: source
+        )
+    }
+
+    init(
+        statistics: [StreamRTCStatistics],
+        timestamp: TimeInterval,
+        source: RTCStatisticsReport?
+    ) {
+        self.statistics = statistics
+        self.timestamp = timestamp
+        self.source = source
+    }
+}
+
+/// Describes and object that can be queried to get information about a RTCStatistics source.
+protocol StreamStatisticsProtocol {
+
+    var type: String { get }
+
+    var id: String { get }
+
+    var values: [String: NSObject] { get }
+}
+
+extension RTCStatistics: StreamStatisticsProtocol {}