using System.Collections.ObjectModel;
using System.Windows;
using Prism.Commands;
using Prism.Events;
using YY.Admin.Core;
using YY.Admin.Core.Entity;
using YY.Admin.Core.Events;
using YY.Admin.Core.Services;
using YY.Admin.Views.Print;

namespace YY.Admin.ViewModels.Print;

/// <summary>业务打印绑定列表（只读，本地缓存 + 同步）</summary>
public class PrintBizTemplateBindListViewModel : BaseViewModel
{
    private readonly IPrintBizTemplateBindService _bindService;
    private SubscriptionToken? _changeToken;

    private List<PrintBizTemplateBind> _all = new();

    public ObservableCollection<PrintBizTemplateBind> Items { get; } = new();

    private string _statusMessage = string.Empty;
    public string StatusMessage
    {
        get => _statusMessage;
        set => SetProperty(ref _statusMessage, value);
    }

    private string? _filterBizCode;
    public string? FilterBizCode
    {
        get => _filterBizCode;
        set => SetProperty(ref _filterBizCode, value);
    }

    private string? _filterBizName;
    public string? FilterBizName
    {
        get => _filterBizName;
        set => SetProperty(ref _filterBizName, value);
    }

    private string? _filterTemplateCode;
    public string? FilterTemplateCode
    {
        get => _filterTemplateCode;
        set => SetProperty(ref _filterTemplateCode, value);
    }

    public DelegateCommand SearchCommand { get; }
    public DelegateCommand ResetCommand { get; }
    public DelegateCommand<PrintBizTemplateBind> DetailCommand { get; }

    public PrintBizTemplateBindListViewModel(
        IPrintBizTemplateBindService bindService,
        IContainerExtension container,
        IRegionManager regionManager) : base(container, regionManager)
    {
        _bindService = bindService;

        SearchCommand = new DelegateCommand(ApplyFilter);
        ResetCommand = new DelegateCommand(() =>
        {
            FilterBizCode = null;
            FilterBizName = null;
            FilterTemplateCode = null;
            ApplyFilter();
        });
        DetailCommand = new DelegateCommand<PrintBizTemplateBind>(OpenDetail);

        _changeToken = _eventAggregator
            .GetEvent<PrintBizTemplateBindChangedEvent>()
            .Subscribe(_ => { RefreshSilentlyAsync().ConfigureAwait(false); }, ThreadOption.UIThread);

        ShowCached();
        _ = RefreshSilentlyAsync();
    }

    private void ShowCached()
    {
        var cached = _bindService.GetCached();
        if (cached.Count == 0) return;
        _all = cached.ToList();
        ApplyFilter();
        UpdateStatus();
    }

    private async Task RefreshSilentlyAsync()
    {
        try
        {
            var list = await _bindService.RefreshCacheAsync().ConfigureAwait(false);
            await Application.Current.Dispatcher.InvokeAsync(() =>
            {
                _all = list.ToList();
                ApplyFilter();
                UpdateStatus();
            });
        }
        catch
        {
            var cached = _bindService.GetCached();
            if (cached.Count > 0 && _all.Count == 0)
            {
                await Application.Current.Dispatcher.InvokeAsync(() =>
                {
                    _all = cached.ToList();
                    ApplyFilter();
                    UpdateStatus();
                });
            }
        }
    }

    private void ApplyFilter()
    {
        IEnumerable<PrintBizTemplateBind> result = _all;

        if (!string.IsNullOrWhiteSpace(FilterBizCode))
            result = result.Where(x => (x.BizCode ?? string.Empty)
                .Contains(FilterBizCode, StringComparison.OrdinalIgnoreCase));

        if (!string.IsNullOrWhiteSpace(FilterBizName))
            result = result.Where(x => (x.BizName ?? string.Empty)
                .Contains(FilterBizName, StringComparison.OrdinalIgnoreCase));

        if (!string.IsNullOrWhiteSpace(FilterTemplateCode))
            result = result.Where(x => (x.TemplateCode ?? string.Empty)
                .Contains(FilterTemplateCode, StringComparison.OrdinalIgnoreCase));

        var filtered = result.ToList();

        for (int i = Items.Count - 1; i >= 0; i--)
        {
            if (!filtered.Any(t => t.Id == Items[i].Id))
                Items.RemoveAt(i);
        }
        for (int i = 0; i < filtered.Count; i++)
        {
            var item = filtered[i];
            var existingIdx = -1;
            for (int j = 0; j < Items.Count; j++)
            {
                if (Items[j].Id == item.Id) { existingIdx = j; break; }
            }
            if (existingIdx < 0)
                Items.Insert(i, item);
            else
            {
                if (existingIdx != i) Items.Move(existingIdx, i);
                Items[i] = item;
            }
        }
    }

    private void UpdateStatus()
    {
        var hasFilter = !string.IsNullOrWhiteSpace(FilterBizCode)
                     || !string.IsNullOrWhiteSpace(FilterBizName)
                     || !string.IsNullOrWhiteSpace(FilterTemplateCode);
        StatusMessage = hasFilter
            ? $"筛选结果 {Items.Count} / {_all.Count} 条"
            : _all.Count > 0
                ? $"共 {_all.Count} 条绑定（缓存于本地，可离线查看）"
                : "暂无数据（联网后将自动同步）";
    }

    private async void OpenDetail(PrintBizTemplateBind? row)
    {
        if (row == null) return;
        PrintBizTemplateBind model = row;
        try
        {
            var fresh = await _bindService.GetByIdAsync(row.Id ?? "").ConfigureAwait(false);
            if (fresh != null) model = fresh;
        }
        catch { /* 使用列表行数据 */ }

        // 网络请求 continuation 可能在非 STA 线程，Window 必须在 UI 线程创建
        var app = Application.Current;
        if (app?.Dispatcher == null) return;
        await app.Dispatcher.InvokeAsync(() =>
        {
            var win = new PrintBizTemplateBindDetailWindow(model)
            {
                Owner = app.MainWindow
            };
            win.ShowDialog();
        });
    }
}