using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Controls;
using System.Windows;

namespace HeuristicLab.OKB.Cockpit {
  public class StringParseValidationRule : ValidationRule {

    private Type type;
    public Type Type {
      get {
        return type;
      }
      set {
        if (type == value)
          return;
        if (type == null)
          return;
        switch (Type.GetTypeCode(value)) {
          // TODO parse nullables
          case TypeCode.Int32: break;
          case TypeCode.Double: break;
          case TypeCode.String: break;
          case TypeCode.DateTime: break;
          default:
            if (value.GetType() == typeof(Guid))
              break;
            //throw new ArgumentException(String.Format(
            //"Parsing validation of type {0} is not supported", value));
            break;
        }
        type = value;
      }
    }

    public override ValidationResult Validate(object value, System.Globalization.CultureInfo cultureInfo) {
      if (type == null)
        return new ValidationResult(true, null);
      try {
        string s = (string)value;
        switch (Type.GetTypeCode(type)) {
          case TypeCode.Int32: int.Parse(s); break;
          case TypeCode.Double: double.Parse(s); break;
          case TypeCode.String: break;
          case TypeCode.DateTime: DateTime.Parse(s); break;
          default:
            if (value.GetType() == typeof(Guid))
              new Guid(s);
            else
              throw new InvalidOperationException();
            break;
        }
        return new ValidationResult(true, null);
      } catch {
        return new ValidationResult(false, String.Format("'{0}' is not a valid '{1}'", value, Type.Name));
      }
    }
  }
}