Logger C# Exercise - C# Programming Course

using System;
using System.IO;

public class Logger
{
    /// 

    /// Writes a log entry to the specified file.
    /// 
    /// The name of the file where the log entry will be appended.
    /// The message to log.
    public static void Write(string fileName, string message)
    {
        // Validating inputs
        if (string.IsNullOrWhiteSpace(fileName))
        {
            Console.WriteLine("File name cannot be null or empty.");
            return;
        }

        if (string.IsNullOrWhiteSpace(message))
        {
            Console.WriteLine("Message cannot be null or empty.");
            return;
        }

        try
        {
            // Formatting the log message with date and time
            string logEntry = $"{DateTime.Now:yyyy-MM-dd HH:mm:ss} - {message}";

            // Writing the log entry to the file
            using (StreamWriter writer = new StreamWriter(fileName, true))
            {
                writer.WriteLine(logEntry);
            }

            // Confirming the log was written successfully
            Console.WriteLine($"Log entry written: {logEntry}");
        }
        catch (Exception ex)
        {
            // Displaying any errors
            Console.WriteLine($"Error writing log: {ex.Message}");
        }
    }
}

public class Program
{
    public static void Main()
    {
        // Testing the logger
        Logger.Write("myLog.txt", "This is the first log entry.");
        Logger.Write("myLog.txt", "This is another log entry.");
        Logger.Write("myLog.txt", "Logging one more message.");
    }
}