using System;
using Artemis.Core;
using Artemis.Core.Modules;
using Artemis.UI.Shared.Services;
using ReactiveUI;

namespace Artemis.UI.Shared.DataModelVisualization.Shared
{
    /// <summary>
    ///     Represents a view model that visualizes a single data model property contained in a
    ///     <see cref="DataModelPropertiesViewModel" />
    /// </summary>
    public class DataModelPropertyViewModel : DataModelVisualizationViewModel
    {
        private object? _displayValue;
        private Type? _displayValueType;
        private DataModelDisplayViewModel? _displayViewModel;

        internal DataModelPropertyViewModel(DataModel? dataModel, DataModelVisualizationViewModel? parent, DataModelPath? dataModelPath)
            : base(dataModel, parent, dataModelPath)
        {
        }

        /// <summary>
        ///     Gets the value of the property that is being visualized
        /// </summary>
        public object? DisplayValue
        {
            get => _displayValue;
            internal set => this.RaiseAndSetIfChanged(ref _displayValue, value);
        }

        /// <summary>
        ///     Gets the type of the property that is being visualized
        /// </summary>
        public Type? DisplayValueType
        {
            get => _displayValueType;
            protected set => this.RaiseAndSetIfChanged(ref _displayValueType, value);
        }

        /// <summary>
        /// Gets the view model used to display the display value
        /// </summary>
        public DataModelDisplayViewModel? DisplayViewModel
        {
            get => _displayViewModel;
            internal set => this.RaiseAndSetIfChanged(ref _displayViewModel, value);
        }

        /// <inheritdoc />
        public override void Update(IDataModelUIService dataModelUIService, DataModelUpdateConfiguration? configuration)
        {
            if (Parent != null && !Parent.IsVisualizationExpanded && !Parent.IsRootViewModel)
                return;

            if (DisplayViewModel == null)
            {
                Type? propertyType = DataModelPath?.GetPropertyType();
                if (propertyType != null)
                {
                    DisplayViewModel = dataModelUIService.GetDataModelDisplayViewModel(propertyType, PropertyDescription, true);
                    if (DisplayViewModel != null) 
                        DisplayViewModel.PropertyDescription = DataModelPath?.GetPropertyDescription();
                }
            }

            DisplayValue = GetCurrentValue();
            DisplayValueType = DisplayValue != null ? DisplayValue.GetType() : DataModelPath?.GetPropertyType();

            DisplayViewModel?.UpdateValue(DisplayValue);
        }

        /// <inheritdoc />
        public override string ToString()
        {
            if (DisplayValueType != null)
                return $"[{DisplayValueType.Name}] {DisplayPath ?? Path} - {DisplayValue}";
            return $"{DisplayPath ?? Path} - {DisplayValue}";
        }
    }
}