using CommunityToolkit.Mvvm.ComponentModel;
using MahApps.Metro.Controls;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Windows;
using TwinCAT.Ads.TypeSystem;
using TwinCAT.TypeSystem;
using Heisig.HMI.AdsManager;

namespace UniperHMI
{
    public partial class SettingsEntry : ObservableObject
    {
        [ObservableProperty]
        private string name = "";

        [ObservableProperty]
        private string instancePath = "";

        [ObservableProperty]
        private string? dataType;

        [ObservableProperty]
        private Object? value;

        public ObservableCollection<SettingsEntry> SubEntries { get; set; } = [];

        [ObservableProperty]
        private Visibility visibility = Visibility.Collapsed;

        private readonly IAdsManager _adsManager;

        public SettingsEntry(IAdsManager adsManager)
        {
            _adsManager = adsManager;
        }

        partial void OnValueChanging(object? oldValue, object? newValue)
        {
            if (newValue == null)
            {
                newValue = oldValue;
                return;
            }
                

            try
            {
                _adsManager.WriteValue(InstancePath, newValue);
            }
            catch (Exception)
            {
                newValue = oldValue;
                Debug.WriteLine("Value {0} could not be written to {1}", newValue, InstancePath);
            }
        }
    }

    public partial class SettingsPageVM : ObservableObject, IDisposable
    {
        public ObservableCollection<SettingsEntry> RootItem { get; private set; } = [];

        private readonly IAdsManager _adsManager;

        private readonly string _variableName;

        public SettingsPageVM(IAdsManager adsManager, string variableName)
        {
            _adsManager = adsManager;
            _variableName = variableName;

            _adsManager.Register(_variableName, ConfigChangedEvent);
        }

        private void ConfigChangedEvent(object? sender, ValueChangedEventArgs e)
        {
            App.Current.Invoke(CreateSettingsTree);
        }

        private void CreateSettingsTree()
        {
            ISymbolLoader? symbolLoader = _adsManager.GetSymbolLoader();

            if (symbolLoader == null)
                return;

            Symbol configSymbol = (Symbol)symbolLoader.Symbols[_variableName];
            SettingsEntry entry = GetSymbol(configSymbol);
            RootItem.Add(entry);
        }

        private SettingsEntry GetSymbol(Symbol symbol)
        {
            // Create Symbol
            SettingsEntry entry = new(_adsManager)
            {
                Name = symbol.InstanceName,
                InstancePath = symbol.InstancePath,
                DataType = symbol.DataType?.Name
            };

            // Check if symbol has sub symbols
            if (!symbol.IsPrimitiveType)
            {
                foreach (Symbol subSymbol in symbol.SubSymbols.Cast<Symbol>())
                {
                    entry.SubEntries.Add(GetSymbol(subSymbol));
                }
            }
            else
            {
                entry.Visibility = Visibility.Visible;
                
                entry.Value = symbol.ReadValue();
            }

            return entry;
        }

        public void Dispose()
        {
            _adsManager?.Deregister(_variableName, ConfigChangedEvent);
        }
    }
}