namespace Common.UI.ViewModels
{
    using Common.Hardware.WaterMeter.eRegister.Features;
    using Common.Hardware.WaterMeter.eRegister.Models;
    using Common.UI.Infrastructure;

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Reflection;

    public class ManualProgrammingVM : VM<ManualProgrammingVM>
    {
        public ManualProgrammingVM()
        {
            var efeatures = new EregisterFeatures();
            var dynamicFeatures = new DynamicTypeVM(efeatures);
            var properties = dynamicFeatures
                .GetAllProperties()
                .ToList();
        }
    }

    public class DynamicPropertyVM : VM<DynamicPropertyVM>
    {
        protected readonly Dictionary<string, DynamicPropertyVM> properties;
        protected readonly PropertyInfo propertyInfo;
        protected readonly object instance;
        protected readonly object value;

        public DynamicPropertyVM(object instance, PropertyInfo propertyInfo)
        {
            this.properties = new Dictionary<string, DynamicPropertyVM>();
            this.propertyInfo = propertyInfo;
            this.instance = instance;

            if (this.propertyInfo != null)
            {
                this.Name = this.propertyInfo.Name;
                this.value = Activator.CreateInstance(this.propertyInfo.PropertyType);

                if (this.value is Pam pam)
                {
                    this.Name = $"{pam.CmdHex} - {this.Name}";
                }
            }
        }

        public event Action PropertyValueChanged;

        public string Name { get; }

        private bool selected;
        public bool Selected
        {
            get => this.selected;
            set => this.SetValue(x =>
            {
                x.selected = value;

                var propertyValue = default(object);

                if (x.selected)
                {
                    propertyValue = this.value;
                }

                this.propertyInfo.SetValue(this.instance, propertyValue);
                this.PropertyValueChanged?.Invoke();
            });
        }

        public virtual IEnumerable<DynamicPropertyVM> GetAllProperties() 
            => this.properties
                   .Values
                   .SelectMany(x => x.GetAllProperties())
                   .Union(this.properties.Values)
                   .OrderBy(x => x.Name);
    }

    public class DynamicTypeVM : DynamicPropertyVM
    {
        private readonly Type type;

        public DynamicTypeVM(object instance) : base(instance, null)
        {
            this.type = this.instance.GetType();

            foreach (var propertyInfo in this.type.GetProperties(BindingFlags.Instance | BindingFlags.Public))
            {
                var pamAttribute = propertyInfo.GetCustomAttribute<PamAttribute>();

                if (pamAttribute is null)
                {
                    continue;
                }

                var dynamicProperty = new DynamicPropertyVM(this.instance, propertyInfo);

                if (propertyInfo.PropertyType == typeof(EregisterDebugFeatures))
                {
                    var propertyInstance = new EregisterDebugFeatures();

                    propertyInfo.SetValue(this.instance, propertyInstance);

                    dynamicProperty = new DynamicTypeVM(propertyInstance);
                }
                
                this.properties[propertyInfo.Name] = dynamicProperty;
            }
        }
    }
}