From 8e5bd41a477db743beca6bf43d31c9f7e745bd28 Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Fri, 1 Dec 2023 13:17:46 +0100
Subject: [PATCH] allow using ANSI escape sequences for the console sink

---
 ExtremelySimpleLogger/ConsoleSink.cs | 16 +++++++---
 ExtremelySimpleLogger/Extensions.cs  | 45 ++++++++++++++++++++++++++++
 Sample/Program.cs                    |  2 +-
 3 files changed, 58 insertions(+), 5 deletions(-)
 create mode 100644 ExtremelySimpleLogger/Extensions.cs

diff --git a/ExtremelySimpleLogger/ConsoleSink.cs b/ExtremelySimpleLogger/ConsoleSink.cs
index 8abe01e..880d29c 100644
--- a/ExtremelySimpleLogger/ConsoleSink.cs
+++ b/ExtremelySimpleLogger/ConsoleSink.cs
@@ -19,13 +19,16 @@ namespace ExtremelySimpleLogger {
             {LogLevel.Fatal, ConsoleColor.DarkRed}
         };
         private readonly TextWriter console;
+        private readonly bool useAnsiCodes;
 
         /// <summary>
         /// Creates a new console sink with the given settings.
         /// </summary>
         /// <param name="error">Whether to log to <see cref="Console.Error"/> instead of <see cref="Console.Out"/>.</param>
-        public ConsoleSink(bool error = false) {
+        /// <param name="useAnsiCodes">Whether to wrap log output text in ANSI escape codes using <see cref="Extensions.WrapAnsiCode"/> instead of using the <see cref="Console.ForegroundColor"/> and <see cref="Console.ResetColor"/>. This may work better on some terminals.</param>
+        public ConsoleSink(bool error = false, bool useAnsiCodes = false) {
             this.console = error ? Console.Error : Console.Out;
+            this.useAnsiCodes = useAnsiCodes;
         }
 
         /// <summary>
@@ -65,10 +68,15 @@ namespace ExtremelySimpleLogger {
         protected override void Log(Logger logger, LogLevel level, string s) {
             lock (this.console) {
                 var color = this.GetColor(level);
-                if (color.HasValue)
-                    Console.ForegroundColor = color.Value;
+                if (color.HasValue) {
+                    if (this.useAnsiCodes) {
+                        s = s.WrapAnsiCode(color.Value);
+                    } else {
+                        Console.ForegroundColor = color.Value;
+                    }
+                }
                 this.console.WriteLine(s);
-                if (color.HasValue)
+                if (color.HasValue && !this.useAnsiCodes)
                     Console.ResetColor();
             }
         }
diff --git a/ExtremelySimpleLogger/Extensions.cs b/ExtremelySimpleLogger/Extensions.cs
new file mode 100644
index 0000000..7364d17
--- /dev/null
+++ b/ExtremelySimpleLogger/Extensions.cs
@@ -0,0 +1,45 @@
+using System;
+using System.Linq;
+
+namespace ExtremelySimpleLogger {
+    /// <summary>
+    /// A set of extension methods for logging-related activities, like converting <see cref="ConsoleColor"/> to ANSI color codes.
+    /// </summary>
+    public static class Extensions {
+
+        private static readonly int[] AnsiCodes = new[] {
+            ConsoleColor.Black, ConsoleColor.DarkRed, ConsoleColor.DarkGreen, ConsoleColor.DarkYellow,
+            ConsoleColor.DarkBlue, ConsoleColor.DarkMagenta, ConsoleColor.DarkCyan, ConsoleColor.Gray,
+            ConsoleColor.DarkGray, ConsoleColor.Red, ConsoleColor.Green, ConsoleColor.Yellow,
+            ConsoleColor.Blue, ConsoleColor.Magenta, ConsoleColor.Cyan, ConsoleColor.White
+        }.Select((s, i) => (int) s).ToArray();
+
+        /// <summary>
+        /// Converts the given <see cref="ConsoleColor"/> to its ANSI escape sequence representation. If the supplied <paramref name="color"/> is <see langword="null"/>, the reset escape sequence for the given color type will be returned.
+        /// </summary>
+        /// <param name="color">The color. If <see langword="null"/>, the reset escape sequence for the given color type will be returned.</param>
+        /// <param name="background">Whether to return a background color. If this is <see langword="false"/>, a foreground color is returned instead.</param>
+        /// <returns>The ANSI escape sequence representation of the given <paramref name="color"/>.</returns>
+        /// <exception cref="ArgumentOutOfRangeException">If the <paramref name="color"/> is not in defined range.</exception>
+        public static string ToAnsiCode(this ConsoleColor? color, bool background = false) {
+            if (color.HasValue) {
+                if (color < 0 || (int) color >= Extensions.AnsiCodes.Length)
+                    throw new ArgumentOutOfRangeException(nameof(color), color, null);
+                return $"\x1B[{(background ? 48 : 38)};5;{Extensions.AnsiCodes[(int) color]}m";
+            }
+            return $"\x1B[{(background ? 49 : 39)}m";
+        }
+
+        /// <summary>
+        /// Wraps the given string in the ANSI escape sequence representation of the given <paramref name="color"/> and the appropriate reset escape sequence using <see cref="ToAnsiCode"/>.
+        /// </summary>
+        /// <param name="s">The string to wrap.</param>
+        /// <param name="color">The color.</param>
+        /// <param name="background">Whether to use <paramref name="color"/> as a background color. If this is <see langword="false"/>, a foreground color is used instead.</param>
+        /// <returns>The given string, wrapped in ANSI color codes.</returns>
+        public static string WrapAnsiCode(this string s, ConsoleColor color, bool background = false) {
+            return Extensions.ToAnsiCode(color, background) + s + Extensions.ToAnsiCode(null, background);
+        }
+
+    }
+}
diff --git a/Sample/Program.cs b/Sample/Program.cs
index 2620791..6f4b43a 100644
--- a/Sample/Program.cs
+++ b/Sample/Program.cs
@@ -12,7 +12,7 @@ namespace Sample {
             var sinks = new List<Sink> {
                 new FileSink("Log.txt", true),
                 // We only want to log messages with a higher importance in the console
-                new ConsoleSink {MinimumLevel = LogLevel.Info},
+                new ConsoleSink() {MinimumLevel = LogLevel.Info},
                 // we allow a total of 5 files in our directory sink before old ones start being deleted
                 new DirectorySink("AllLogs", 5)
             };