using System;
using System.Globalization;
using System.Windows.Forms;

namespace KryukovLib
{
    public partial class DateBoxWithNull : UserControl
    {
        public event EventHandler? CombinedEvent;

        public Exception? Error;

        public DateBoxWithNull()
        {
            InitializeComponent();
        }

        public DateTime? Value
        {
            get
            {
                if (!checkBoxNull.Checked)
                {
                    if (string.IsNullOrEmpty(textBoxDate.Text))
                    {
                        throw new NotFilledException("Text box can't be empty, click checkbox if value must be empty!");
                    }
                    if (DateTime.TryParseExact(textBoxDate.Text, "dd.MM.yyyy", null, DateTimeStyles.None, out DateTime parsedDate))
                    {
                        return parsedDate;
                    }
                    else
                    {
                        throw new ParseException($"Wrong format <{textBoxDate.Text}>!");
                    }
                }
                return null;
            }
            set
            {
                bool isNull = value is null;
                checkBoxNull.Checked = isNull;
                textBoxDate.Text = isNull ? string.Empty : value?.ToString("dd.MM.yyyy");
            }
        }

        private void TextBoxDate_TextChanged(object sender, EventArgs e)
        {
            CombinedEvent?.Invoke(sender, e);
        }

        private void CheckBoxNull_CheckedChanged(object sender, EventArgs e)
        {
            textBoxDate.Enabled = !checkBoxNull.Checked;
            CombinedEvent?.Invoke(sender, e);
        }
    }
}