using System.IO.MemoryMappedFiles;
using System.Text;

namespace SharedComponents
{
    public class LiveLogCache
    {
        /*// Staticka instancia pre singleton
        private static readonly LiveLogCache _instance = new LiveLogCache();

        // Uzamykaci objekt pre bezpecny pristup z viacerych vlakien
        private static readonly object _lock = new object();

        // Zoznam na ukladanie logov
        private readonly List<string> _logs = new List<string>();

        // Udalost pre notifikaciu pri zmene logov
        public event Action<string> LogAdded;

        // Sukromny konstruktor (singleton pattern)
        private LiveLogCache() { }

        // Metoda na ziskanie poctu logov
        public int GetCount()
        {
            return _logs.Count;
        }

        // Staticka metoda na ziskanie instancie
        public static LiveLogCache Instance
        {
            get
            {
                lock (_lock)
                {
                    return _instance;
                }
            }
        }

        // Verejna vlastnost na ziskanie logov
        public IReadOnlyList<string> Logs
        {
            get
            {
                lock (_lock)
                {
                    return _logs.AsReadOnly();
                }
            }
        }

        // Metoda na pridanie logu
        public void AddLog(string log)
        {
            // Ziskanie aktualneho casu v pozadovanom formate
            string timeStamp = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:");

            // Vytvorenie noveho logu s casovou peciatkou na zaciatku
            string logWithTimeStamp = $"{timeStamp} {log}";

            // Pridanie logu do zoznamu
            lock (_lock)
            {
                _logs.Add(logWithTimeStamp);
            }

            // Spustenie udalosti pre notifikaciu
            LogAdded?.Invoke(logWithTimeStamp);
        }

        // Metoda na vycistenie logov
        public void ClearLogs()
        {
            lock (_lock)
            {
                _logs.Clear();
            }

            // Volitelne: Spusti udalost, ak by sme chceli notifikovat aj o vymazani logov
            LogAdded?.Invoke("Logs were cleared.");
        }

        // Ziskanie vsetkych logov
        public List<string> GetAllLogs()
        {
            return new List<string>(_logs);  // Vratime kopiu logov
        }

        // Ziskanie logov medzi urcitou poziciou (s upravenym indexovanim)
        public List<string> GetLogs(int startIndex, int count)
        {
            // Zabezpeci, ze indexy nebudu mimo rozsahu
            return _logs.Skip(startIndex).Take(count).ToList();
        }*/

        // Zlepseny kod, ktory umoznuje pracu s MemoryMappedFile, namiesto len priestoru vo virtualnej pamati, navyse je tento subor velkostne obmedzeny na 1MB

        // Staticka instancia pre singleton
        private static readonly LiveLogCache _instance = new LiveLogCache(true);

        // Uzamykaci objekt pre bezpecny pristup z viacerych vlakien
        private static readonly object _lock = new object();

        // Zoznam na ukladanie logov
        private readonly List<string> _logs = new List<string>();

        // Udalost pre notifikaciu pri zmene logov
        public event Action<string> LogAdded;

        // Memory-mapped file
        private MemoryMappedFile _mmf;
        private MemoryMappedViewAccessor _accessor;
        private const int MaxLogSize = 1024 * 1024; // 1MB

        // Sukromny konstruktor (singleton pattern)
        private LiveLogCache(bool itsLogsCreator)
        {
            if (itsLogsCreator == true)
            {
                _mmf = MemoryMappedFile.CreateOrOpen("LiveLogCacheMMF", MaxLogSize);
            }
            else
            {
                _mmf = MemoryMappedFile.OpenExisting("LiveLogCacheMMF");
            }

            _accessor = _mmf.CreateViewAccessor();
        }

        // Metoda na ziskanie poctu logov
        public int GetCount()
        {
            return _logs.Count;
        }

        // Staticka metoda na ziskanie instancie
        public static LiveLogCache Instance
        {
            get
            {
                lock (_lock)
                {
                    return _instance;
                }
            }
        }

        // Verejna vlastnost na ziskanie logov
        public IReadOnlyList<string> Logs
        {
            get
            {
                lock (_lock)
                {
                    return _logs.AsReadOnly();
                }
            }
        }

        // Metoda na pridanie logu
        public void AddLog(string log)
        {
            // Ziskanie aktualneho casu v pozadovanom formate
            string timeStamp = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:");

            // Vytvorenie noveho logu s casovou peciatkou na zaciatku
            string logWithTimeStamp = $"{timeStamp} {log}";

            // Pridanie logu do zoznamu
            lock (_lock)
            {
                _logs.Add(logWithTimeStamp);
                WriteLogToMemoryMappedFile(logWithTimeStamp);
            }

            // Spustenie udalosti pre notifikaciu
            LogAdded?.Invoke(logWithTimeStamp);
        }

        // Metoda na vycistenie logov
        public void ClearLogs()
        {
            lock (_lock)
            {
                _logs.Clear();
                ClearMemoryMappedFile();
            }

            // Volitelne: Spusti udalost, ak by sme chceli notifikovat aj o vymazani logov
            LogAdded?.Invoke("Logs were cleared.");
        }

        // Ziskanie vsetkych logov
        public List<string> GetAllLogs()
        {
            return new List<string>(_logs);  // Vratime kopiu logov
        }

        // Ziskanie logov medzi urcitou poziciou (s upravenym indexovanim)
        public List<string> GetLogs(int startIndex, int count)
        {
            // Zabezpeci, ze indexy nebudu mimo rozsahu
            return _logs.Skip(startIndex).Take(count).ToList();
        }

        // Metoda na naplnenie ListView
        /*public void PopulateListView(ListView listView)
        {
            listView.Items.Clear();
            lock (_lock)
            {
                foreach (var log in _logs)
                {
                    listView.Items.Add(new ListView Item(log));
                }
            }
        }*/

        // Write log to memory-mapped file
        private void WriteLogToMemoryMappedFile(string log)
        {
            byte[] logBytes = Encoding.UTF8.GetBytes(log + Environment.NewLine);
            _accessor.WriteArray(0, logBytes, 0, logBytes.Length);
        }

        // Clear memory-mapped file
        private void ClearMemoryMappedFile()
        {
            byte[] emptyBytes = new byte[MaxLogSize];
            _accessor.WriteArray(0, emptyBytes, 0, emptyBytes.Length);
        }
    }
}