1 files changed, 81 insertions, 11 deletions
diff --git a/IrcTokens/StatefulDecoder.cs b/IrcTokens/StatefulDecoder.cs
index 65dd3de..e094760 100644
--- a/IrcTokens/StatefulDecoder.cs
+++ b/IrcTokens/StatefulDecoder.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
@@ -6,26 +7,95 @@ namespace IrcTokens
 {
     public class StatefulDecoder
     {
-        private string _buffer;
-        public EncodingInfo Encoding { get; set; }
-        public EncodingInfo Fallback { get; set; }
+        private byte[] _buffer;
+        private Encoding _encoding;
+        private Encoding _fallback;
 
-        public string Pending => _buffer;
+        public Encoding Encoding
+        {
+            get => _encoding ?? Encoding.UTF8;
+            set => _encoding = value;
+        }
+
+        public Encoding Fallback
+        {
+            get => _fallback ?? Encoding.GetEncoding("iso-8859-1");
+            set => _fallback = value;
+        }
+
+        public string Pending => Encoding.GetString(_buffer);
+
+        public StatefulDecoder()
+        {
+            Clear();
+        }
 
         public void Clear()
         {
-            _buffer = "";
+            _buffer = Array.Empty<byte>();
         }
 
         public List<Line> Push(string data)
         {
-            if (string.IsNullOrEmpty(data))
+            return Push(Encoding.GetBytes(data));
+        }
+
+        public List<Line> Push(byte[] data)
+        {
+            if (data == null || data.Length == 0)
                 return null;
 
-            _buffer += data;
-            return _buffer
-                .Split('\n')
-                .Select(l => l.TrimEnd('\r'))
+            _buffer = _buffer.Concat(data).ToArray();
+
+            // simulate string.Split('\n') before decoding
+            var newLineIndices = _buffer.Select((b, i) => b == '\n' ? i : -1).Where(i => i != -1).ToArray();
+            var lines = new List<byte[]>();
+
+            for (int i = 0, currentIndex = 0; i < newLineIndices.Length; ++i)
+            {
+                var n = new byte[newLineIndices[i] - currentIndex];
+                Array.Copy(_buffer, currentIndex, n, 0, newLineIndices[i] - currentIndex);
+                currentIndex = newLineIndices[i] + 1;
+                lines.Add(n);
+            }
+
+            var listLines = lines.Select(l => l.ToList()).ToList();
+
+            // simulate string.Trim('\r') before decoding
+            foreach (var line in listLines)
+            {
+                var i = 0;
+                while (line[i] == '\r')
+                {
+                    line.RemoveAt(i);
+                    i++;
+                }
+
+                i = line.Count - 1;
+                while (line[i] == '\r')
+                {
+                    line.RemoveAt(i);
+                    i--;
+                }
+            }
+
+            //_buffer = listLines.Last().ToArray();
+            //listLines.RemoveAt(listLines.Count - 1);
+
+            var decodeLines = new List<string>();
+            foreach (var line in listLines.Select(l => l.ToArray()))
+            {
+                try
+                {
+                    decodeLines.Add(Encoding.GetString(line));
+                }
+                catch (DecoderFallbackException)
+                {
+                    decodeLines.Add(Fallback.GetString(line));
+                }
+            }
+
+            return decodeLines
                 .Select(l => new Line(l))
                 .ToList();
         }