using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;

namespace WGneu
{
    static class Validator
    {
        public static ValidationResult CheckNumericInput(TextBox input)
        {
            return CheckNumericInput(input, -1);
        }

        private static ValidationResult CheckNumericInput(TextBox input, int maxLen)
        {
            string text = "";
            int pos = input.CaretIndex;
            for (int i = 0; i < input.Text.Length; i++)
            {
                char ch = input.Text[i];
                if (Char.IsDigit(ch))
                    text += ch;
                if (i == input.CaretIndex - 1)
                    pos = text.Length;
            }
            input.Text = text;
            input.CaretIndex = pos;

            if (maxLen >= 0 && input.Text.Length > maxLen)
            {
                input.Text = input.Text.Substring(0, maxLen);
                input.CaretIndex = Math.Min(pos, maxLen);
            }

            return new ValidationResult(true, "");
        }

        public static ValidationResult CheckLfbisNr(TextBox input)
        {
            var res = CheckNumericInput(input, 7);
            if (!res.IsValid)
                return res;
            if (input.Text.Length == 0)
                return new ValidationResult(true, "");
            if (input.Text.Length != 7)
                return new ValidationResult(false, "Betriebsnummer zu kurz");

            // TODO

            return new ValidationResult(true, "Not implemented yet");
        }

        public static ValidationResult CheckUstIdInput(TextBox input)
        {
            return new ValidationResult(false, "Not implemented yet");
        }

        public static void SetInputInvalid(TextBox input)
        {
            input.BorderBrush = System.Windows.Media.Brushes.Red;
        }

        public static void SetInputValid(TextBox input)
        {
            input.ClearValue(TextBox.BorderBrushProperty);
        }
    }
}