using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core;
using Tango.Core.Commands;

namespace Tango.MachineStudio.MachineDesigner.Models
{
    /// <summary>
    /// The HardwareParameter class.
    /// Contains default/editable/actual value and data type of each hardware parameter reflected in .
    /// </summary>
    /// <remarks>
    /// This class provides data state changes.
    /// </remarks>
    public class HardwareParameter : ExtendedObject, IHasDifference
    {
        #region properties
        public HardwareComponent Component { get; set; }

        public String PropertyName { get; set; }

        /// <summary>
        /// The default value contains data from database
        /// </summary>
        private Object _defaultValue;
        public Object DefaultValue
        {
            get { return _defaultValue; }
            set
            {
                _defaultValue = value;
            }
        }
        /// <summary>
        /// The type of hardware parameter is used for display correct ui element.
        /// Can be boolean, int32, or Double
        /// </summary>
        public Type Type
        {
            get { return DefaultValue.GetType(); }
        }

        /// <summary>
        /// The value contains modified data, saved in database or immediately after editing in this session
        /// </summary>
        private Object _actualValue = null;
        public Object ActualValue
        {
            get { return _actualValue; }
            set
            {
                _actualValue = value;
                RaisePropertyChangedAuto();
                RaisePropertyChanged(nameof(HasDifferences));
                RaisePropertyChanged(nameof(IsValuesMatched));
            }
        }

        /// <summary>
        /// The editable value contains value displayed in edit box in UI. 
        /// Initialization the value occurs by clicking in UI and the value will be equal actual value if it exists or default value. 
        /// </summary>
        private Object _editableValue = null;
        public Object EditableValue
        {
            get { return _editableValue; }
            set
            {
                _editableValue = value;
                RaisePropertyChangedAuto();
            }
        }

        private bool _isSelected;
        public bool IsSelected
        {
            get { return _isSelected; }
            set
            {
                _isSelected = value;

                OnIsSelectedChanged();

                RaisePropertyChangedAuto();
                if (_isSelected)
                {
                    Selected?.Invoke(this, new EventArgs());
                }
            }
        }
        /// <summary>
        /// Used in UI to display modified value 
        /// </summary>
        public bool HasDifferences
        {
            get
            {
                return (ActualValue != null);
            }
        }
        /// <summary>
        /// Used to display warning explanation icon in case actual value equals default value
       /// </summary>
        public bool IsValuesMatched
        {
            get
            {
                return ActualValue != null && ActualValue.ToString() == DefaultValue.ToString();
            }
        }
        #endregion properties

        #region events        
        /// <summary>
        /// Occurs when start select mode.
        /// Used to set in all others Parameter IsSelected to false except this.
        /// </summary>
        public event EventHandler Selected;
        private void OnIsSelectedChanged()
        {
            if (IsSelected)
            {
                EditableValue = ActualValue != null ? ActualValue : DefaultValue;
            }
            else
            {
                if (EditableValue != null)
                {
                    ActualValue = EditableValue;
                }
            }
        }
        #endregion
        #region constructors
        public HardwareParameter()
        {
            DeleteCommand = new RelayCommand(DeleteValue);
        }
        #endregion
        #region commands
        public RelayCommand DeleteCommand { get; set; }
        public void DeleteValue()
        {
            ActualValue = null;
            EditableValue = null;
        }
        #endregion
    }
}