using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net.Sockets;

// This file is part of the EonaCat project(s) which is released under the Apache License.
// See the LICENSE file or go to https://EonaCat.com/License for full license details.

namespace EonaCat.Logger.EonaCatCoreLogger
{
    public class TcpLogger : ILogger
    {
        private readonly string _categoryName;
        private readonly TcpLoggerOptions _options;
        private readonly LoggerScopedContext _context = new();
        public bool IncludeCorrelationId { get; set; }
        public event EventHandler<Exception> OnException;

        public TcpLogger(string categoryName, TcpLoggerOptions options)
        {
            _categoryName = categoryName;
            _options = options;
            IncludeCorrelationId = options.IncludeCorrelationId;
        }

        public void SetContext(string key, string value) => _context.Set(key, value);
        public void ClearContext() => _context.Clear();
        public string GetContext(string key) => _context.Get(key);

        public IDisposable BeginScope<TState>(TState state) => null;
        public bool IsEnabled(LogLevel logLevel) => _options.IsEnabled;

        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state,
            Exception exception, Func<TState, Exception, string> formatter)
        {
            if (!IsEnabled(logLevel))
            {
                return;
            }

            try
            {
                string message = formatter(state, exception);
                if (IncludeCorrelationId)
                {
                    var correlationId = _context.Get("CorrelationId") ?? Guid.NewGuid().ToString();
                    _context.Set("CorrelationId", correlationId);
                }

                var logParts = new List<string>
                {
                    $"[{DateTime.UtcNow:u}]",
                    $"[{logLevel}]",
                    $"[{_categoryName}]",
                    $"Message: {message}",
                };

                var contextData = _context.GetAll();
                if (contextData.Count > 0)
                {
                    foreach (var kvp in contextData)
                    {
                        logParts.Add($"{kvp.Key}: {kvp.Value}");
                    }
                }

                if (exception != null)
                {
                    logParts.Add($"Exception: {exception}");
                }

                string fullLog = string.Join(" | ", logParts);

                using var client = new TcpClient();
                client.Connect(_options.Host, _options.Port);
                using var stream = client.GetStream();
                using var writer = new StreamWriter(stream, System.Text.Encoding.UTF8)
                {
                    AutoFlush = true
                };
                writer.WriteLine(fullLog);
            }
            catch (Exception e)
            {
                OnException?.Invoke(this, e);
            }
        }
    }
}
