using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.UI;
using System.Web;
using System.IO;

namespace StringLib
{
    public static class JonFormatter
    {
        public static string JonFormat(this string format, object source)
        {
            if (format == null)
            {
                throw new ArgumentNullException("format");
            }

            StringBuilder sb = new StringBuilder(format.Length * 2);
          
            char[] a = format.ToCharArray();

            int last = a.Length - 1;

            for (int i = 0; i <= last; i++)
            {
                switch(a[i])
                {
                    case '{':
                        if (i < last && a[i + 1] != '{')
                        {
                            i++;
                            int j = i;
                            int b = -1;
                            while (i < last && a[i] != '}')
                            {
                                i++;
                                if (a[i] == ':')
                                {
                                    b = i;
                                }
                            }

                            if (i == last && a[i] != '}')
                            {
                                throw new FormatException();
                            }

                            try
                            {
                                if (b < 0)
                                {
                                    sb.Append(DataBinder.Eval(source, format.Substring(j, i - j)));
                                }
                                else
                                {
                                    sb.Append(String.Format("{0" + format.Substring(b, i - (b - 1)), DataBinder.Eval(source, format.Substring(j, b - j))));
                                }
                                
                            }
                            catch (HttpException)
                            {
                                throw new FormatException();
                            }
                        }
                        else
                        {
                            if (i == last)
                            {
                                throw new FormatException();
                            }

                            sb.Append('{');
                            i++;
                        }
                        break;
                    case '}':
                        if (i == last || a[i + 1] != '}')
                        {
                            throw new FormatException();
                        }
                        else
                        {
                            sb.Append('}');
                            i++;
                        }
                        break;
                    default:
                        sb.Append(a[i]);
                        break;
                }
            }

            return sb.ToString();
        }
    }
}