using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace MaterialTraceabilityUI.Common
{
    public class NotifyPropertyBase : INotifyPropertyChanged, IDataErrorInfo
    {
        private Dictionary<String, String> dataErrors = new Dictionary<string, string>();

        public string this[string columnName]
        {
            get
            {
                ValidationContext vc = new ValidationContext(this);
                vc.MemberName = columnName;
                var res = new List<ValidationResult>();
                var result = Validator.TryValidateProperty(this.GetType().GetProperty(columnName).GetValue(this), vc, res);
                if (res.Count > 0)
                {
                    AddDic(dataErrors, vc.MemberName);
                    return string.Join(Environment.NewLine, res.Select(r => r.ErrorMessage).ToArray());
                }
                RemoveDic(dataErrors, vc.MemberName);
                return null;
            }
        }
        #region 附属方法

        /// <summary>
        /// 移除字典
        /// </summary>
        /// <param name="dics"></param>
        /// <param name="dicKey"></param>
        private void RemoveDic(Dictionary<String, String> dics, String dicKey)
        {
            dics.Remove(dicKey);
        }

        /// <summary>
        /// 添加字典
        /// </summary>
        /// <param name="dics"></param>
        /// <param name="dicKey"></param>
        private void AddDic(Dictionary<String, String> dics, String dicKey)
        {
            if (!dics.ContainsKey(dicKey)) dics.Add(dicKey, "");
        }

        #endregion

        public string Error => null;

        public bool IsValided
        {
            get
            {
                return this.dataErrors == null || this.dataErrors.Count == 0;
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        public void Notify([CallerMemberName] string propName = "")
        {
            if (PropertyChanged != null)
                this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
        }
    }
}