Migration to a ServiceWorker for most tasks.

Implementation of basic PatchComplianceTask. First real iteration, basic/raw asf.

LD-SysInfo/Services/OsqueryTaskScheduler.cs

@@ -0,0 +1,152 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using System.IO;
+using Newtonsoft.Json;
+
+namespace LD_SysInfo.Services
+{
+    /// <summary>
+    /// Manages scheduled osquery-based tasks
+    /// Designed to be portable to Windows Service (OversightService) later
+    /// </summary>
+    public class OsqueryTaskScheduler
+    {
+        private readonly List<IScheduledTask> _tasks = new();
+        private readonly Timer _timer;
+        private readonly string _stateFilePath;
+        private bool _isRunning;
+
+        public OsqueryTaskScheduler()
+        {
+            // Store task state in AppData to persist last run times
+            var appDataDir = Path.Combine(
+                Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+                "PSG-Oversight"
+            );
+            Directory.CreateDirectory(appDataDir);
+            _stateFilePath = Path.Combine(appDataDir, "task_scheduler_state.json");
+
+            // Check every minute for tasks that need to run
+            _timer = new Timer(CheckAndRunTasks, null, TimeSpan.Zero, TimeSpan.FromMinutes(1));
+        }
+
+        /// <summary>
+        /// Register a task with the scheduler
+        /// </summary>
+        public void RegisterTask(IScheduledTask task)
+        {
+            _tasks.Add(task);
+            LoadTaskState(task);
+        }
+
+        /// <summary>
+        /// Start the scheduler
+        /// </summary>
+        public void Start()
+        {
+            _isRunning = true;
+        }
+
+        /// <summary>
+        /// Stop the scheduler
+        /// </summary>
+        public void Stop()
+        {
+            _isRunning = false;
+            _timer?.Change(Timeout.Infinite, Timeout.Infinite);
+        }
+
+        private async void CheckAndRunTasks(object? state)
+        {
+            if (!_isRunning) return;
+
+            foreach (var task in _tasks.Where(t => t.ShouldRun()))
+            {
+                try
+                {
+                    await task.ExecuteAsync();
+                    task.LastRun = DateTime.Now;
+                    SaveTaskState(task);
+                }
+                catch (Exception ex)
+                {
+                    LogError($"Task '{task.TaskName}' failed: {ex.Message}");
+                }
+            }
+        }
+
+        private void LoadTaskState(IScheduledTask task)
+        {
+            try
+            {
+                if (!File.Exists(_stateFilePath)) return;
+
+                var json = File.ReadAllText(_stateFilePath);
+                var states = JsonConvert.DeserializeObject<Dictionary<string, DateTime>>(json);
+
+                if (states != null && states.TryGetValue(task.TaskName, out var lastRun))
+                {
+                    task.LastRun = lastRun;
+                }
+            }
+            catch (Exception ex)
+            {
+                LogError($"Failed to load task state: {ex.Message}");
+            }
+        }
+
+        private void SaveTaskState(IScheduledTask task)
+        {
+            try
+            {
+                Dictionary<string, DateTime> states;
+
+                if (File.Exists(_stateFilePath))
+                {
+                    var json = File.ReadAllText(_stateFilePath);
+                    states = JsonConvert.DeserializeObject<Dictionary<string, DateTime>>(json)
+                             ?? new Dictionary<string, DateTime>();
+                }
+                else
+                {
+                    states = new Dictionary<string, DateTime>();
+                }
+
+                states[task.TaskName] = task.LastRun ?? DateTime.Now;
+
+                var updatedJson = JsonConvert.SerializeObject(states, Formatting.Indented);
+                File.WriteAllText(_stateFilePath, updatedJson);
+            }
+            catch (Exception ex)
+            {
+                LogError($"Failed to save task state: {ex.Message}");
+            }
+        }
+
+        private void LogError(string message)
+        {
+            try
+            {
+                var logDir = Path.Combine(
+                    Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+                    "PSG-Oversight"
+                );
+                var logPath = Path.Combine(logDir, "scheduler_error.log");
+                File.AppendAllText(logPath, $"[{DateTime.Now}] {message}\n");
+            }
+            catch
+            {
+                // Silently fail if we can't write logs
+            }
+        }
+
+        public void Dispose()
+        {
+            Stop();
+            _timer?.Dispose();
+        }
+    }
+}