1 files changed, 110 insertions, 0 deletions
diff --git a/src/StardewModdingAPI/Framework/LogWriter.cs b/src/StardewModdingAPI/Framework/LogWriter.cs
new file mode 100644
index 00000000..2cabb8d5
--- /dev/null
+++ b/src/StardewModdingAPI/Framework/LogWriter.cs
@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Concurrent;
+using System.IO;
+using System.Linq;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>A log writer which queues messages for output, and periodically flushes them to the console and log file.</summary>
+    internal class LogWriter
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The singleton instance.</summary>
+        private static LogWriter _instance;
+
+        /// <summary>The queued messages to flush.</summary>
+        private static ConcurrentQueue<LogInfo> Queue;
+
+        /// <summary>The underlying file stream.</summary>
+        private static StreamWriter FileStream;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The singleton instance.</summary>
+        internal static LogWriter Instance
+        {
+            get
+            {
+                if (LogWriter._instance == null)
+                {
+                    LogWriter._instance = new LogWriter();
+                    // Field cannot be used by anything else regardless, do not surround with lock { }
+                    // ReSharper disable once InconsistentlySynchronizedField
+                    LogWriter.Queue = new ConcurrentQueue<LogInfo>();
+                    Console.WriteLine(Constants.LogPath);
+
+                    // If the ErrorLogs dir doesn't exist StreamWriter will throw an exception.
+                    if (!Directory.Exists(Constants.LogDir))
+                    {
+                        Directory.CreateDirectory(Constants.LogDir);
+                    }
+
+                    LogWriter.FileStream = new StreamWriter(Constants.LogPath, false);
+                    Console.WriteLine("Created log instance");
+                }
+                return LogWriter._instance;
+            }
+        }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Queue a message for output.</summary>
+        /// <param name="message">The message to log.</param>
+        public void WriteToLog(string message)
+        {
+            lock (LogWriter.Queue)
+            {
+                var logEntry = new LogInfo(message);
+                LogWriter.Queue.Enqueue(logEntry);
+
+                if (LogWriter.Queue.Any())
+                    this.FlushLog();
+            }
+        }
+
+        /// <summary>Queue a message for output.</summary>
+        /// <param name="message">The message to log.</param>
+        public void WriteToLog(LogInfo message)
+        {
+            lock (LogWriter.Queue)
+            {
+                LogWriter.Queue.Enqueue(message);
+                if (LogWriter.Queue.Any())
+                    this.FlushLog();
+            }
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        private LogWriter() { }
+
+        /// <summary>Flush the underlying queue to the console and file.</summary>
+        private void FlushLog()
+        {
+            lock (LogWriter.FileStream)
+            {
+                LogInfo entry;
+                while (LogWriter.Queue.TryDequeue(out entry))
+                {
+                    string m = $"[{entry.LogTime}] {entry.Message}";
+
+                    Console.ForegroundColor = entry.Colour;
+                    Console.WriteLine(m);
+                    Console.ForegroundColor = ConsoleColor.Gray;
+
+                    LogWriter.FileStream.WriteLine(m);
+                }
+                LogWriter.FileStream.Flush();
+            }
+        }
+    }
+}
+\ No newline at end of file