using System;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using Panuon.WPF.UI;
using Panuon.WPF.UI.Configurations;

namespace HMI.UI
{
    public class FormGroupHelper
    {
        public static bool GetIsRequired(FormGroup fg)
        {
            return (bool)fg.GetValue(IsRequiredProperty);
        }

        public static void SetIsRequired(FormGroup fg, bool value)
        {
            fg.SetValue(IsRequiredProperty, value);
        }

        public static readonly DependencyProperty IsRequiredProperty =
            DependencyProperty.RegisterAttached("IsRequired", typeof(bool), typeof(FormGroupHelper),
            new PropertyMetadata(false, (d, e) =>
            {
                if (!(d is FormGroup fg)) return;
                if ((bool)e.NewValue)
                {
                    var style = Application.Current.FindResource("RequiredInputFormGroupStyle") as Style;
                    fg.Style = style;
                }
                else
                {
                    var style = Application.Current.FindResource("RequiredInputFormGroupStyle") as Style;
                    fg.Style = style;
                }
            }));


        public delegate bool ValidateMethodDelegate(object value, out string msg);
        public static ValidateMethodDelegate GetValidateMethod(FormGroup fg)
        {
            return (ValidateMethodDelegate)fg.GetValue(ValidateMethodProperty);
        }

        public static void SetValidateMethod(FormGroup fg, ValidateMethodDelegate value)
        {
            fg.SetValue(ValidateMethodProperty, value);
        }

        public static readonly DependencyProperty ValidateMethodProperty =
            DependencyProperty.RegisterAttached("ValidateMethod", typeof(ValidateMethodDelegate), typeof(FormGroupHelper),
            new PropertyMetadata(null));

        public static bool ValidateForm(StackPanel fgPanel)
        {
            if (fgPanel.Children == null) return true;
            bool res = true;
            foreach (var child in fgPanel.Children)
            {
                if (child is FormGroup fg)
                {
                    object content = fg.Content;
                    object value = GetValidateValue(content);
                    if (GetIsRequired(fg) && string.IsNullOrEmpty(value.ToString()))
                    {
                        fg.ValidateResult = ValidateResult.Error;
                        fg.Message = $"{fg.Header}不能为空";
                        res = false;
                    }
                    else
                    {
                        ValidateMethodDelegate method = GetValidateMethod(fg);
                        if (method != null && !method(value, out string err))
                        {
                            fg.ValidateResult = ValidateResult.Error;
                            fg.Message = err;
                            res = false;
                        }
                    }
                }
            }
            return res;
        }

        private static object GetValidateValue(object content)
        {
            if (content == null) return null;
            if (content is UIElementCollection elementCollection)
                return elementCollection.Count > 0 ? GetValidateValue(elementCollection[0]) : null;
            if (content is TextBox tb) return tb.Text;
            if (content is CheckBox cb) return cb.IsChecked;
            if (content is ComboBox cBox) return cBox.Text;

            if (content is Panel panel) return GetValidateValue(panel.Children);
            return null;
        }
    }
}