Code for splitting long messages into chunks giving preference for keeping lines together

chunkerizer.cs

using System;
using System.Collections.Generic;

namespace Chunkerizer
{
    public delegate string ChunkHeaderGenerator(int chunkIndex);

    /// <summary>
    /// 
    ///  _________________.---.______    
    /// (_(______________(_o o_(____()    CHUNKERIZER
    ///              .___.'. .'.___.      Chop a long string into shorter chunks giving preference to 
    ///              \ o    Y    o /      keeping lines together if possible.
    ///               \ \__   __/ /       Supports pushing a prefix on the start of each CHUNK (i.e.
    ///                '.__'-'__.'        "Chunk #")
    ///                    '''
    /// </summary>
    public static class Chunkerizer
    {
        public static List<string> Chunk(string message, int maxChunkLength, ChunkHeaderGenerator chunkHeaderGenerator)
        {
            List<string> chunks = new List<string>();
            List<string> lines = new List<string>(message.Split(new string[] { "\r\n", "\r", "\n" }, StringSplitOptions.None));
            int chunkIndex = 1;
            string currentChunk = chunkHeaderGenerator(chunkIndex);
            foreach (string line in lines)
            {
                if ((2 + line.Length + chunkHeaderGenerator(chunkIndex + 1).Length) > maxChunkLength)
                {
                    // This line will never fit.  Do character split!
                    string tempLine = line;
                    while (!string.IsNullOrEmpty(tempLine))
                    {
                        int availableRoom = Math.Max(0, maxChunkLength - currentChunk.Length - 2);
                        string smallChunk = tempLine.Substring(0, Math.Min(tempLine.Length, availableRoom));
                        if (!string.IsNullOrEmpty(smallChunk)) currentChunk += smallChunk + "\r\n";
                        tempLine = tempLine.Substring(Math.Min(tempLine.Length, availableRoom));
                        chunks.Add(currentChunk);
                        currentChunk = chunkHeaderGenerator(++chunkIndex);
                    }
                }
                else if ((2 + (currentChunk + line).Length) > maxChunkLength)
                {
                    // Line won't find in remainder of chunk.  Skip to next chunk.
                    chunks.Add(currentChunk);
                    currentChunk = chunkHeaderGenerator(++chunkIndex);
                    currentChunk += line + "\r\n";
                }
                else
                {
                    // Line will fit.  Add it.
                    currentChunk += line + "\r\n";
                }
            }
            // Add the last chunk to the list
            if (!string.IsNullOrEmpty(currentChunk))
                chunks.Add(currentChunk);
            return chunks;
        }
    }
}