using System.Text.Json;
using System.Text.Json.Serialization;

namespace PainoBar_Helper
{
    /// <summary>
    /// Monitors Pianobar event output file for song changes and metadata updates
    /// </summary>
    public class PianobarEventMonitor : IDisposable
    {
        private FileSystemWatcher? _watcher;
        private string? _eventFilePath;
        private bool _disposed;

        public event EventHandler<PianobarEventData>? EventReceived;

        public void StartMonitoring(string eventFilePath)
        {
            if (string.IsNullOrEmpty(eventFilePath))
                throw new ArgumentException("Event file path cannot be empty", nameof(eventFilePath));

            StopMonitoring();

            _eventFilePath = eventFilePath;

            // Ensure the directory exists
            var directory = Path.GetDirectoryName(eventFilePath);
            if (!string.IsNullOrEmpty(directory))
                Directory.CreateDirectory(directory);

            // Create initial file if it doesn't exist
            if (!File.Exists(eventFilePath))
                File.WriteAllText(eventFilePath, "{}");

            // Set up file watcher
            _watcher = new FileSystemWatcher
            {
                Path = directory!,
                Filter = Path.GetFileName(eventFilePath),
                NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.Size
            };

            _watcher.Changed += OnFileChanged;
            _watcher.EnableRaisingEvents = true;
        }

        public void StopMonitoring()
        {
            if (_watcher != null)
            {
                _watcher.EnableRaisingEvents = false;
                _watcher.Changed -= OnFileChanged;
                _watcher.Dispose();
                _watcher = null;
            }
        }

        private void OnFileChanged(object sender, FileSystemEventArgs e)
        {
            try
            {
                // Give the file a moment to finish writing
                Thread.Sleep(50);

                if (string.IsNullOrEmpty(_eventFilePath) || !File.Exists(_eventFilePath))
                    return;

                string json = File.ReadAllText(_eventFilePath);
                if (string.IsNullOrWhiteSpace(json))
                    return;

                var eventData = JsonSerializer.Deserialize<PianobarEventData>(json);
                if (eventData != null)
                {
                    EventReceived?.Invoke(this, eventData);
                }
            }
            catch
            {
                // Ignore file read errors (file might be locked, etc.)
            }
        }

        public void Dispose()
        {
            if (_disposed)
                return;

            StopMonitoring();
            _disposed = true;
        }
    }

    /// <summary>
    /// Represents event data from Pianobar
    /// </summary>
    public class PianobarEventData
    {
        [JsonPropertyName("event")]
        public string Event { get; set; } = string.Empty;

        [JsonPropertyName("timestamp")]
        public string Timestamp { get; set; } = string.Empty;

        [JsonPropertyName("artist")]
        public string Artist { get; set; } = string.Empty;

        [JsonPropertyName("title")]
        public string Title { get; set; } = string.Empty;

        [JsonPropertyName("album")]
        public string Album { get; set; } = string.Empty;

        [JsonPropertyName("coverArt")]
        public string CoverArt { get; set; } = string.Empty;

        [JsonPropertyName("stationName")]
        public string StationName { get; set; } = string.Empty;

        [JsonPropertyName("songDuration")]
        public string SongDuration { get; set; } = string.Empty;

        [JsonPropertyName("songPlayed")]
        public string SongPlayed { get; set; } = string.Empty;

        [JsonPropertyName("rating")]
        public string Rating { get; set; } = string.Empty;

        [JsonPropertyName("detailUrl")]
        public string DetailUrl { get; set; } = string.Empty;
    }
}