1 files changed, 57 insertions, 0 deletions
diff --git a/Sources/WireGuardApp/UI/LogViewHelper.swift b/Sources/WireGuardApp/UI/LogViewHelper.swift
new file mode 100644
index 0000000..eb5c9da
--- /dev/null
+++ b/Sources/WireGuardApp/UI/LogViewHelper.swift
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2023 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+
+public class LogViewHelper {
+    var log: OpaquePointer
+    var cursor: UInt32 = UINT32_MAX
+    static let formatOptions: ISO8601DateFormatter.Options = [
+        .withYear, .withMonth, .withDay, .withTime,
+        .withDashSeparatorInDate, .withColonSeparatorInTime, .withSpaceBetweenDateAndTime,
+        .withFractionalSeconds
+    ]
+
+    struct LogEntry {
+        let timestamp: String
+        let message: String
+
+        func text() -> String {
+            return timestamp + " " + message
+        }
+    }
+
+    class LogEntries {
+        var entries: [LogEntry] = []
+    }
+
+    init?(logFilePath: String?) {
+        guard let logFilePath = logFilePath else { return nil }
+        guard let log = open_log(logFilePath) else { return nil }
+        self.log = log
+    }
+
+    deinit {
+        close_log(self.log)
+    }
+
+    func fetchLogEntriesSinceLastFetch(completion: @escaping ([LogViewHelper.LogEntry]) -> Void) {
+        var logEntries = LogEntries()
+        DispatchQueue.global(qos: .userInitiated).async { [weak self] in
+            guard let self = self else { return }
+            let newCursor = view_lines_from_cursor(self.log, self.cursor, &logEntries) { cStr, timestamp, ctx in
+                let message = cStr != nil ? String(cString: cStr!) : ""
+                let date = Date(timeIntervalSince1970: Double(timestamp) / 1000000000)
+                let dateString = ISO8601DateFormatter.string(from: date, timeZone: TimeZone.current, formatOptions: LogViewHelper.formatOptions)
+                if let logEntries = ctx?.bindMemory(to: LogEntries.self, capacity: 1) {
+                    logEntries.pointee.entries.append(LogEntry(timestamp: dateString, message: message))
+                }
+            }
+            DispatchQueue.main.async { [weak self] in
+                guard let self = self else { return }
+                self.cursor = newCursor
+                completion(logEntries.entries)
+            }
+        }
+    }
+}