using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace PCMonitor {

    /// <summary>
    /// Main Agent Entry Point
    /// Windows Service untuk monitoring PC
    /// </summary>
    public class Program {
        private static readonly ILog logger = new FileLogger();
        private static AgentService agentService;
        private static ServiceWrapper serviceWrapper;

        [STAThread]
        static void Main(string[] args) {
            try {
                AppDomain.CurrentDomain.UnhandledException += (sender, e) => {
                    logger.Error($"Unhandled exception: {e.ExceptionObject}");
                };

                if (Environment.UserInteractive && args.Length > 0 && args[0].ToLower() == "debug") {
                    // Run in debug mode
                    RunDebugMode();
                } else {
                    // Run as Windows Service
                    RunAsService();
                }
            } catch (Exception ex) {
                logger.Error($"Fatal error: {ex.Message}");
                if (Environment.UserInteractive) {
                    Console.WriteLine($"ERROR: {ex.Message}");
                    Console.ReadKey();
                }
            }
        }

        private static void RunDebugMode() {
            Console.WriteLine("=== PC Monitor Agent (Debug Mode) ===");
            Console.WriteLine($"Version: {GetVersion()}");
            Console.WriteLine($"PC Name: {Environment.MachineName}");
            Console.WriteLine();

            agentService = new AgentService();
            
            Console.WriteLine("Starting agent service...");
            agentService.Start();

            Console.WriteLine("Agent running. Press 'q' to quit...");
            while (Console.ReadLine()?.ToLower() != "q") {
                Console.WriteLine("Still running...");
            }

            Console.WriteLine("Stopping agent...");
            agentService.Stop();
            Console.WriteLine("Done.");
        }

        private static void RunAsService() {
            agentService = new AgentService();
            serviceWrapper = new ServiceWrapper(agentService);

            System.ServiceProcess.ServiceBase.Run(serviceWrapper);
        }

        private static string GetVersion() {
            var version = Assembly.GetExecutingAssembly().GetName().Version;
            return $"{version.Major}.{version.Minor}.{version.Build}";
        }
    }

    /// <summary>
    /// Logging Interface
    /// </summary>
    public interface ILog {
        void Info(string message);
        void Warning(string message);
        void Error(string message);
        void Debug(string message);
    }

    /// <summary>
    /// File-based Logger
    /// </summary>
    public class FileLogger : ILog {
        private readonly string _logPath;
        private readonly object _lockObj = new object();

        public FileLogger() {
            _logPath = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData),
                "PCMonitor", "Logs"
            );
            Directory.CreateDirectory(_logPath);
        }

        private void WriteLog(string level, string message) {
            lock (_lockObj) {
                try {
                    string fileName = Path.Combine(_logPath, $"Agent_{DateTime.Now:yyyy-MM-dd}.log");
                    string logEntry = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] [{level}] {message}";
                    File.AppendAllText(fileName, logEntry + Environment.NewLine);
                } catch {
                    // Silent fail if logging fails
                }
            }
        }

        public void Info(string message) => WriteLog("INFO", message);
        public void Warning(string message) => WriteLog("WARN", message);
        public void Error(string message) => WriteLog("ERROR", message);
        public void Debug(string message) => WriteLog("DEBUG", message);
    }
}