using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Windows.Forms;

namespace Mesnac.Basic.Service
{
    /// <summary>
    /// 操作命令类，用与进行撤销和恢复操作的封装类
    /// </summary>
    public class OperationCommand : ICommand
    {
        #region 字段定义

        private Control _ctrl;
        private object _newValue;
        private object _oldValue;
        private EventHandler _eventHandler;
        private DataGridViewCellEventHandler _dataGridViewCellEventHandler;

        #endregion

        #region 构造方法

        public OperationCommand (Control ctrl, object newValue, object oldValue)
        {
            this._ctrl = ctrl;
            this._newValue = newValue;
            this._oldValue = oldValue;
        }

        public OperationCommand(Control ctrl, object newValue, object oldValue, EventHandler eventHandler)
        {
            this._ctrl = ctrl;
            this._newValue = newValue; 
            this._oldValue = oldValue;
            this._eventHandler = eventHandler;
        }

        public OperationCommand(Control ctrl, object newValue, object oldValue, DataGridViewCellEventHandler dataGridViewCellEventHandler, int rowIndex, int columnIndex)
        {
            this._ctrl = ctrl;
            this._newValue = newValue;
            this._oldValue = oldValue;
            this._dataGridViewCellEventHandler = dataGridViewCellEventHandler;
        }

        #endregion

        #region ICommand接口成员实现

        #region 恢复操作实现

        /// <summary>
        /// 恢复操作实现
        /// </summary>
        public void execute()
        {
            if (this._ctrl is TextBox)
            {
                (this._ctrl as TextBox).TextChanged -= this._eventHandler;
                (this._ctrl as TextBox).Text = this._newValue == null ? String.Empty : this._newValue.ToString();
                (this._ctrl as TextBox).SelectionStart = (this._ctrl as TextBox).Text.Length;
                (this._ctrl as TextBox).TextChanged += this._eventHandler;
            }
            if (this._ctrl is CheckBox)
            {
                (this._ctrl as CheckBox).CheckedChanged -= this._eventHandler;
                bool newValue = false;
                if (this._newValue != null)
                {
                    bool.TryParse(this._newValue.ToString(), out newValue);
                }
                (this._ctrl as CheckBox).Checked = newValue;
                (this._ctrl as CheckBox).CheckedChanged += this._eventHandler;
            }
            if (this._ctrl is ComboBox)
            {
                (this._ctrl as ComboBox).SelectedIndexChanged -= this._eventHandler;
                (this._ctrl as ComboBox).SelectedItem = this._newValue;
                (this._ctrl as ComboBox).SelectedIndexChanged += this._eventHandler;
            }
            if (this._ctrl is DateTimePicker)
            {
                (this._ctrl as DateTimePicker).ValueChanged -= this._eventHandler;
                DateTime newValue = DateTime.Now;
                if (this._newValue != null)
                {
                    DateTime.TryParse(this._newValue.ToString(), out newValue);
                }
                (this._ctrl as DateTimePicker).Value = newValue;
                (this._ctrl as DateTimePicker).ValueChanged += this._eventHandler;
            }
            if (this._ctrl is DataGridView)
            {
                if (this._dataGridViewCellEventHandler != null)
                {
                    (this._ctrl as DataGridView).CellValueChanged -= this._dataGridViewCellEventHandler;
                }
                (this._ctrl as DataGridView).DataSource = this._newValue;
                Mesnac.Basic.DataProcessor.ClearSelectedStatus((this._ctrl as DataGridView));
                if (this._dataGridViewCellEventHandler != null)
                {
                    (this._ctrl as DataGridView).CellValueChanged += this._dataGridViewCellEventHandler;
                }
            }
        }

        #endregion

        #region 撤销操作实现

        /// <summary>
        /// 撤销操作实现
        /// </summary>
        public void undo()
        {
            if (this._ctrl is TextBox)
            {
                (this._ctrl as TextBox).TextChanged -= this._eventHandler;
                (this._ctrl as TextBox).Text = this._oldValue == null ? String.Empty : this._oldValue.ToString();
                (this._ctrl as TextBox).SelectionStart = (this._ctrl as TextBox).Text.Length;
                (this._ctrl as TextBox).TextChanged += this._eventHandler;
            }
            if (this._ctrl is CheckBox)
            {
                (this._ctrl as CheckBox).CheckedChanged -= this._eventHandler;
                bool oldValue = false;
                if (this._oldValue != null)
                {
                    bool.TryParse(this._oldValue.ToString(), out oldValue);
                }
                (this._ctrl as CheckBox).Checked = oldValue;
                (this._ctrl as CheckBox).CheckedChanged += this._eventHandler;
            }
            if (this._ctrl is ComboBox)
            {
                (this._ctrl as ComboBox).SelectedIndexChanged -= this._eventHandler;
                (this._ctrl as ComboBox).SelectedItem = this._oldValue;
                (this._ctrl as ComboBox).SelectedIndexChanged += this._eventHandler;
            }
            if (this._ctrl is DateTimePicker)
            {
                (this._ctrl as DateTimePicker).ValueChanged -= this._eventHandler;
                DateTime oldValue = DateTime.Now;
                if (this._oldValue != null)
                {
                    DateTime.TryParse(this._oldValue.ToString(), out oldValue);
                }
                (this._ctrl as DateTimePicker).Value = oldValue;
                (this._ctrl as DateTimePicker).ValueChanged += this._eventHandler;
            }
            if (this._ctrl is DataGridView)
            {
                if (this._dataGridViewCellEventHandler != null)
                {
                    (this._ctrl as DataGridView).CellValueChanged -= this._dataGridViewCellEventHandler;
                }
                
                (this._ctrl as DataGridView).DataSource = this._oldValue;
                Mesnac.Basic.DataProcessor.ClearSelectedStatus((this._ctrl as DataGridView));
                
                if (this._dataGridViewCellEventHandler != null)
                {
                    (this._ctrl as DataGridView).CellValueChanged += this._dataGridViewCellEventHandler;
                }
            }
        }

        #endregion

        #endregion
    }
}