using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LetterBoxdUnwatchedGenerator
{
    internal static class CommandLineSplitExt
    {

        //public static IEnumerable<string> SplitCommandLine(this string commandLine, char splitChar = ' ')
        //{
        //    bool inQuotes = false;
        //    bool isEscaping = false;

        //    StringBuilder currentArg = new StringBuilder();

        //    foreach (char c in commandLine)
        //    {
        //        if (c == '\\' && !isEscaping) { isEscaping = true; continue; }
        //        if (c == '\"' && !isEscaping) inQuotes = !inQuotes;
        //        isEscaping = false;

        //        if (!inQuotes && (splitChar == ' ' ? Char.IsWhiteSpace(c) : c == splitChar))
        //        {
        //            if (currentArg.Length > 0)
        //            {
        //                yield return currentArg.ToString();
        //                currentArg.Clear();
        //            }
        //        }
        //        else
        //        {
        //            currentArg.Append(c);
        //        }
        //    }

        //    if (currentArg.Length > 0)
        //    {
        //        yield return currentArg.ToString();
        //    }
        //}


        public static IEnumerable<string> SplitCommandLine(this string commandLine, char splitChar = ' ')
        {
            bool inQuotes = false;
            bool isEscaping = false;

            return commandLine.Split(c =>
             {
                 if (c == '\\' && !isEscaping) { isEscaping = true; return false; }
                 if (c == '\"' && !isEscaping) inQuotes = !inQuotes;
                 isEscaping = false;

                 return !inQuotes && (splitChar == ' ' ? Char.IsWhiteSpace(c) : c == splitChar); //Char.IsWhiteSpace(c)/*c == ' '*/;
             }).Select(arg => arg.Trim().TrimMatchingQuotes('\"').Replace("\\\"", "\""));
        }

        public static IEnumerable<string> Split(this string str, Func<char, bool> controller)
        {
            int nextPiece = 0;

            for (int c = 0; c < str.Length; c++)
            {
                if (controller(str[c]))
                {
                    yield return str.Substring(nextPiece, c - nextPiece);
                    nextPiece = c + 1;
                }
            }

            yield return str.Substring(nextPiece);
        }

        public static string TrimMatchingQuotes(this string input, char quote)
        {
            if ((input.Length >= 2) &&
                (input[0] == quote) && (input[input.Length - 1] == quote))
                return input.Substring(1, input.Length - 2);

            return input;
        }

        public static string JoinCommandLine(this IEnumerable<string> arguments, char joinChar = ' ')
        {
            return string.Join(joinChar, arguments.Select(a => a.Contains(joinChar) ? $"\"{a}\"" : a));
        }
    }
}