# NETLogger

NETLogger is a small logging library for .NET applications targeting .NET Standard 2.0.

## Installation

Add `NETLogger/NETLogger.csproj` as a project reference or install the NuGet package generated during the build.

## Configure the application

Configure the global logger settings once during application startup. The following example stores log files in the current user's application data directory:

```csharp
using NETLogger;

LogConfiguration.MinimumLevel = LogLevel.Info;
LogConfiguration.EnableConsole = true;
LogConfiguration.EnableDebugView = true; // Windows only

string logDirectory = LogConfiguration.CreateAndGetDefaultLoggingPath("MyApplication");
LogConfiguration.GetAndSetNewLogFile(logDirectory);
```

Alternatively, use `LogConfiguration.SetLogFile(path)` to specify a complete file path. Without a configured file path, NETLogger writes only to the enabled console and Windows debug outputs.

## Use a logger directly

For an independent class, create a typed `Logger<T>`. The type name is automatically included in each log entry as its category:

```csharp
public class Service
{
	private readonly ILogger _logger = new Logger<Service>();

	public void Run()
	{
		_logger.Info("Service started.");

		try
		{
			// Application code
		}
		catch (Exception exception)
		{
			_logger.Error("Service failed.", exception);
		}
	}
}
```

A directly created `Logger<T>` can be disabled and enabled independently with `Disable()` and `Enable()`. `ClearOldLogs(logsToKeep)` removes old log files; without an argument, it keeps the 30 most recent files. `ClearLogs()` removes all log files from the configured directory.

## Control multiple loggers centrally

Use a shared `LoggerControlService` when multiple loggers need to be enabled or disabled together. An owning class creates the service and registers its logger:

```csharp
using NETLogger;
using NETLogger.Services;

public sealed class ApplicationController : IDisposable
{
	private readonly ILoggerControlService _loggerControlService;
	private readonly ILogger<ApplicationController> _logger;
	private readonly IDisposable _loggerRegistration;

	public ILoggerControlService LoggerControlService => _loggerControlService;

	public ApplicationController() : this(new LoggerControlService()) { }

	public ApplicationController(ILoggerControlService loggerControlService)
	{
		_loggerControlService = loggerControlService
			?? throw new ArgumentNullException(nameof(loggerControlService));

		_logger = NETLogger.Services.LoggerControlService.CreateAndRegisterNETLogger<ApplicationController>(
			_loggerControlService,
			out _loggerRegistration);

		_logger.Info("Application controller initialized.");
	}

	public void Dispose()
	{
		_loggerRegistration.Dispose();
	}
}
```

Dependent classes receive the same service and register their own typed logger. Dispose the `IDisposable` registration when the owning instance is disposed:

```csharp
public sealed class BackgroundService : IDisposable
{
	private readonly ILogger<BackgroundService> _logger;
	private readonly IDisposable _loggerRegistration;

	public BackgroundService(ILoggerControlService loggerControlService)
	{
		_logger = LoggerControlService.CreateAndRegisterNETLogger<BackgroundService>(
			loggerControlService,
			out _loggerRegistration);

		_logger.Info("Background service initialized.");
	}

	public void Dispose()
	{
		_loggerRegistration.Dispose();
	}
}
```

All registered loggers can be toggled together:

```csharp
loggerControlService.IsEnabled = false; // Disable all registered loggers
loggerControlService.IsEnabled = true;  // Enable all registered loggers
```

## Initialize loggers for static members

Classes with static logging members can use explicit initialization to participate in the shared `LoggerControlService`:

```csharp
public sealed class ConfigurationCache
{
	private static ILogger<ConfigurationCache> _logger;
	private static IDisposable _loggerRegistration;

	private ConfigurationCache() { }

	public static void InitializeLogger(ILoggerControlService loggerControlService)
	{
		if (loggerControlService == null)
			throw new ArgumentNullException(nameof(loggerControlService));

		_loggerRegistration?.Dispose();
		_logger = LoggerControlService.CreateAndRegisterNETLogger<ConfigurationCache>(
			loggerControlService,
			out _loggerRegistration);
	}
}
```

The owning class initializes the logger with its shared service:

```csharp
ConfigurationCache.InitializeLogger(_loggerControlService);
```

## Log levels and outputs

The available levels are `Trace`, `Debug`, `Info`, `Warn`, `Error`, and `Fatal`. Messages below `LogConfiguration.MinimumLevel` are ignored. `Warn`, `Error`, and `Fatal` optionally accept an exception:

```csharp
try
{
	// Application code
}
catch (Exception exception)
{
	_logger.Error("Operation failed.", exception);
}
```

NETLogger can write to the Windows debug output, the console, and a UTF-8 log file at the same time.