using Prism.Events;
using System.Collections.ObjectModel;
using YY.Admin.Core;
using YY.Admin.Core.Events;
using YY.Admin.Core.Extension;
using YY.Admin.Core.Helper;
using YY.Admin.Services.Service;
using YY.Admin.ViewModels.Control;

namespace YY.Admin.ViewModels.SysManage;

public class DataDictionaryManagementViewModel : BaseViewModel
{
    private readonly IJeecgDictSyncService _dictSyncService;
    private SubscriptionToken? _dictChangedToken;

    public ObservableCollection<DictTreeNode> TreeNodes { get; } = [];

    private DictTreeNode? _selectedTreeNode;
    public DictTreeNode? SelectedTreeNode
    {
        get => _selectedTreeNode;
        set => SetProperty(ref _selectedTreeNode, value);
    }

    private PaginationDataGridViewModel<JeecgDictItemOutput> _paginationDataGridViewModel;
    public PaginationDataGridViewModel<JeecgDictItemOutput> PaginationDataGridViewModel
    {
        get => _paginationDataGridViewModel;
        set => SetProperty(ref _paginationDataGridViewModel, value);
    }

    private PageJeecgDictItemInput _input;
    public PageJeecgDictItemInput Input
    {
        get => _input;
        set => SetProperty(ref _input, value);
    }

    public List<KeyValuePair<string, int>> StatusList =>
        Enum.GetValues(typeof(StatusEnum))
            .Cast<StatusEnum>()
            .Select(e => new KeyValuePair<string, int>(e.GetDescription(), (int)e))
            .ToList();

    public DelegateCommand SearchCommand { get; }
    public DelegateCommand ResetCommand { get; }

    public DataDictionaryManagementViewModel(
        IJeecgDictSyncService dictSyncService,
        IContainerExtension container,
        IRegionManager regionManager) : base(container, regionManager)
    {
        _dictSyncService = dictSyncService;
        _paginationDataGridViewModel = new PaginationDataGridViewModel<JeecgDictItemOutput>(FetchAsync);
        _input = new PageJeecgDictItemInput();

        SearchCommand = new DelegateCommand(async () => await SearchAsync());
        ResetCommand = new DelegateCommand(async () => await ResetAsync());

        _dictChangedToken = _eventAggregator
            .GetEvent<DictChangedEvent>()
            .Subscribe(async _ => await OnDictChangedAsync(), ThreadOption.UIThread);

        _ = InitializeAsync();
    }

    private async Task InitializeAsync()
    {
        await LoadDictTreeAsync();
        await UIHelper.WaitForRenderAsync();
        await PaginationDataGridViewModel.LoadDataAsync();
    }

    private async Task<(IEnumerable<JeecgDictItemOutput> data, int totalCount)> FetchAsync()
    {
        Input.Page = PaginationDataGridViewModel.PageIndex;
        Input.PageSize = PaginationDataGridViewModel.DataCountPerPage;
        var result = await _dictSyncService.PageAsync(Input);
        return (result.Items, result.Total);
    }

    private async Task SearchAsync()
    {
        PaginationDataGridViewModel.PageIndex = 1;
        await PaginationDataGridViewModel.LoadDataAsync();
    }

    private async Task ResetAsync()
    {
        Input = new PageJeecgDictItemInput();
        SelectedTreeNode = null;
        await UIHelper.WaitForRenderAsync();
        await SearchAsync();
    }

    public async Task OnDictTreeSelectedAsync(DictTreeNode? node)
    {
        SelectedTreeNode = node;
        Input.DictCode = node?.DictCode;
        await SearchAsync();
    }

    private async Task LoadDictTreeAsync()
    {
        var groups = await _dictSyncService.GetDictGroupsAsync();
        TreeNodes.Clear();
        foreach (var group in groups)
        {
            TreeNodes.Add(new DictTreeNode(group.Key, group.Value));
        }
    }

    private async Task OnDictChangedAsync()
    {
        await LoadDictTreeAsync();
        await PaginationDataGridViewModel.LoadDataAsync();
    }

    protected override void CleanUp()
    {
        base.CleanUp();
        if (_dictChangedToken != null)
        {
            _eventAggregator.GetEvent<DictChangedEvent>().Unsubscribe(_dictChangedToken);
            _dictChangedToken = null;
        }
    }

    public class DictTreeNode
    {
        public string DictCode { get; }
        public string DictName { get; }
        public string DisplayName => $"[{DictCode}] {DictName}";

        public DictTreeNode(string dictCode, string dictName)
        {
            DictCode = dictCode;
            DictName = dictName;
        }
    }
}