using System.Diagnostics;

namespace SimpleHttpServer;
public class Logger {
    private readonly string topic;
    private readonly TextWriter outWriter;

    internal Logger(string topic) : this(topic, Console.Out) { }
    internal Logger(string topic, TextWriter? outWriter) {
        this.topic = topic;
        this.outWriter = outWriter ?? Console.Out;
    }

    private readonly object writeLock = new object();
    public void Log(string message, LogOutputLevel level) {
        var fgColor = level switch {
            LogOutputLevel.Debug => ConsoleColor.Gray,
            LogOutputLevel.Information => ConsoleColor.White,
            LogOutputLevel.Warning => ConsoleColor.Yellow,
            LogOutputLevel.Error => ConsoleColor.Red,
            LogOutputLevel.Fatal => ConsoleColor.Magenta,
            _ => throw new NotImplementedException(),
        };

        lock (writeLock) {
            var origColor = Console.ForegroundColor;
            Console.ForegroundColor = fgColor;
            outWriter.WriteLine($"[{topic}] {message}");
            Console.ForegroundColor = origColor;
        }
    }

    [Conditional("DEBUG")]
    public void Debug(string message) => Log(message, LogOutputLevel.Debug);
    public void Information(string message) => Log(message, LogOutputLevel.Information);
    public void Warning(string message) => Log(message, LogOutputLevel.Warning);
    public void Error(string message) => Log(message, LogOutputLevel.Error);
    public void Fatal(string message) => Log(message, LogOutputLevel.Fatal);
}

public enum LogOutputLevel {
    Debug,
    Information,
    Warning,
    Error,
    Fatal
}