From acb4dc23d53f2d85d906ac51cb9591145c10d485 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cihat=20Gu=CC=88ndu=CC=88z?= <commits@cihatguenduez.de>
Date: Thu, 31 Oct 2024 16:32:58 +0100
Subject: [PATCH] Add support for OSLog and default to it on modern systems

---
 .../TelemetryDeck/Helpers/LogHandler.swift    | 30 ++++++++++++++++++-
 Sources/TelemetryDeck/TelemetryClient.swift   |  4 +--
 .../TelemetryDeckTests/LogHandlerTests.swift  |  2 +-
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Sources/TelemetryDeck/Helpers/LogHandler.swift b/Sources/TelemetryDeck/Helpers/LogHandler.swift
index 73695bd..ffb3efe 100644
--- a/Sources/TelemetryDeck/Helpers/LogHandler.swift
+++ b/Sources/TelemetryDeck/Helpers/LogHandler.swift
@@ -1,4 +1,7 @@
 import Foundation
+#if canImport(OSLog)
+import OSLog
+#endif
 
 public struct LogHandler: Sendable {
     public enum LogLevel: Int, CustomStringConvertible, Sendable {
@@ -32,7 +35,32 @@ public struct LogHandler: Sendable {
         }
     }
 
-    public static func stdout(_ logLevel: LogLevel) -> LogHandler {
+    public static func standard(_ logLevel: LogLevel) -> LogHandler {
+        #if canImport(OSLog)
+        if #available(iOS 15, macOS 11, tvOS 15, watchOS 8, *) {
+            return Self.oslog(logLevel)
+        } else {
+            return Self.stdout(logLevel)
+        }
+        #else
+        return Self.stdout(logLevel)
+        #endif
+    }
+
+    @available(iOS 15, macOS 11, tvOS 15, watchOS 8, *)
+    private static func oslog(_ logLevel: LogLevel) -> LogHandler {
+        LogHandler(logLevel: logLevel) { level, message in
+            let logger = Logger(subsystem: "TelemetryDeck", category: "LogHandler")
+
+            switch level {
+            case .debug: logger.debug("\(message)")
+            case .info: logger.info("\(message)")
+            case .error: logger.error("\(message)")
+            }
+        }
+    }
+
+    private static func stdout(_ logLevel: LogLevel) -> LogHandler {
         LogHandler(logLevel: logLevel) { level, message in
             print("[TelemetryDeck: \(level.description)] \(message)")
         }
diff --git a/Sources/TelemetryDeck/TelemetryClient.swift b/Sources/TelemetryDeck/TelemetryClient.swift
index 89a7fe1..af4eb9e 100644
--- a/Sources/TelemetryDeck/TelemetryClient.swift
+++ b/Sources/TelemetryDeck/TelemetryClient.swift
@@ -122,10 +122,10 @@ public struct TelemetryManagerConfiguration: Sendable {
 
     /// A strategy for handling logs.
     ///
-    /// Defaults to `print` with info/errror messages - debug messages are not outputted. Set to `nil` to disable all logging from TelemetryDeck SDK.
+    /// Defaults to `OSLog.Logger` with info/errror messages - debug messages are not outputted. Set to `nil` to disable all logging from TelemetryDeck SDK.
     ///
     /// - NOTE: If ``swiftUIPreviewMode`` is `true` (by default only when running SwiftUI previews), this value is effectively ignored, working like it's set to `nil`.
-    public var logHandler: LogHandler? = LogHandler.stdout(.info)
+    public var logHandler: LogHandler? = LogHandler.standard(.info)
 
     /// An array of signal metadata enrichers: a system for adding dynamic metadata to signals as they are recorded.
     ///
diff --git a/Tests/TelemetryDeckTests/LogHandlerTests.swift b/Tests/TelemetryDeckTests/LogHandlerTests.swift
index 15e21c4..58fdf72 100644
--- a/Tests/TelemetryDeckTests/LogHandlerTests.swift
+++ b/Tests/TelemetryDeckTests/LogHandlerTests.swift
@@ -6,7 +6,7 @@ final class LogHandlerTests: XCTestCase {
     var lastLevel: LogHandler.LogLevel?
 
     func testLogHandler_stdoutLogLevelDefined() {
-        XCTAssertEqual(LogHandler.stdout(.error).logLevel, .error)
+        XCTAssertEqual(LogHandler.standard(.error).logLevel, .error)
     }
     
     func testLogHandler_logLevelRespected() {