EonaCat.Logger/EonaCat.Logger/EonaCatCoreLogger/DatabaseLogger.cs

using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Text;

namespace EonaCat.Logger.EonaCatCoreLogger
{
    public class DatabaseLogger : ILogger
    {
        private readonly string _categoryName;
        private readonly DatabaseLoggerOptions _options;
        private readonly LoggerScopedContext _context = new();

        public bool IncludeCorrelationId { get; set; }
        public event EventHandler<Exception> OnException;

        public DatabaseLogger(string categoryName, DatabaseLoggerOptions options)
        {
            _categoryName = categoryName;
            _options = options;
            IncludeCorrelationId = options.IncludeCorrelationId;
        }

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

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

            var message = formatter(state, exception);

            if (IncludeCorrelationId)
            {
                var correlationId = _context.Get("CorrelationId") ?? Guid.NewGuid().ToString();
                _context.Set("CorrelationId", correlationId);
            }

            try
            {
                using var connection = _options.DbProviderFactory.CreateConnection();
                if (connection == null)
                {
                    throw new InvalidOperationException("Failed to create database connection.");
                }

                connection.ConnectionString = _options.ConnectionString;
                connection.Open();

                using var command = connection.CreateCommand();
                command.CommandText = _options.InsertCommand;
                command.Parameters.Clear();

                command.Parameters.Add(CreateParameter(command, "Timestamp", DateTime.UtcNow));
                command.Parameters.Add(CreateParameter(command, "LogLevel", logLevel.ToString()));
                command.Parameters.Add(CreateParameter(command, "Category", _categoryName));
                command.Parameters.Add(CreateParameter(command, "Message", message));
                command.Parameters.Add(CreateParameter(command, "Exception", exception?.ToString()));
                command.Parameters.Add(CreateParameter(command, "CorrelationId", _context.Get("CorrelationId")));

                command.ExecuteNonQuery();
            }
            catch (Exception e)
            {
                OnException?.Invoke(this, e);
            }
        }

        private DbParameter CreateParameter(DbCommand command, string name, object value)
        {
            var param = command.CreateParameter();
            param.ParameterName = $"@{name}";
            param.Value = value ?? DBNull.Value;
            return param;
        }
    }
}