using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using YY.Admin.ViewModels.RawMaterialEntry;

namespace YY.Admin.Views.RawMaterialEntry;

public partial class RawMaterialEntryOperationView : UserControl
{
    private RawMaterialEntryOperationViewModel? _vm;
    private bool _initialized;

    public RawMaterialEntryOperationView()
    {
        InitializeComponent();
        Loaded += OnLoaded;
        DataContextChanged += OnDataContextChanged;
        Unloaded += (_, _) => DetachVm();
    }

    private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
    {
        DetachVm();
        if (DataContext is RawMaterialEntryOperationViewModel vm)
        {
            _vm = vm;
            vm.PropertyChanged += OnVmPropertyChanged;
        }

        ApplySplitLayout();
    }

    private void DetachVm()
    {
        if (_vm != null)
        {
            _vm.PropertyChanged -= OnVmPropertyChanged;
            _vm = null;
        }
    }

    private void OnVmPropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        // null/空 表示“所有属性”通知（Prism/BindableBase 批量刷新时），需同步分割布局
        if (!string.IsNullOrEmpty(e.PropertyName)
            && e.PropertyName is not nameof(RawMaterialEntryOperationViewModel.IsRightPanelExpanded)
            && e.PropertyName is not nameof(RawMaterialEntryOperationViewModel.ExpandedRightPanelWidth))
            return;

        _ = Dispatcher.InvokeAsync(ApplySplitLayout);
    }

    /// <summary>按钮 Click 在 Command 之后执行，用于兜底刷新列宽（不重复切换状态）。</summary>
    private void ToggleTodayPanelButton_OnClick(object sender, RoutedEventArgs e) => ApplySplitLayout();

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        // 兜底：XAML 解析 prism:AutoWireViewModel 时设置 DataContext 早于构造函数订阅 DataContextChanged，
        // 首次进入页面 OnDataContextChanged 会错过回调，导致 _vm 为 null、PropertyChanged 未挂接，
        // 表现为「首次点击展开/收起按钮不生效」。这里在 Loaded 时补一次订阅。
        EnsureVmAttached();

        ApplySplitLayout();

        if (DataContext is RawMaterialEntryOperationViewModel vm && !_initialized)
        {
            vm.InitializeForAdd();
            _initialized = true;
            _ = vm.LoadTodayEntriesOnFirstShowAsync();
        }
    }

    private void EnsureVmAttached()
    {
        if (_vm != null) return;
        if (DataContext is RawMaterialEntryOperationViewModel vm)
        {
            _vm = vm;
            vm.PropertyChanged += OnVmPropertyChanged;
        }
    }

    /// <summary>
    /// 根据 ViewModel 同步右侧栏与分割条：展开时使用持久化宽度；折叠时右栏与分割条占宽均为 0（完全隐藏）。
    /// </summary>
    private void ApplySplitLayout()
    {
        var vm = _vm ?? DataContext as RawMaterialEntryOperationViewModel;
        if (vm == null) return;

        if (vm.IsRightPanelExpanded)
        {
            RightPaneSplitter.Visibility = Visibility.Visible;
            SplitterCol.Width = new GridLength(4);
            RightPaneCol.Width = new GridLength(vm.ExpandedRightPanelWidth);
        }
        else
        {
            RightPaneSplitter.Visibility = Visibility.Collapsed;
            SplitterCol.Width = new GridLength(0);
            RightPaneCol.Width = new GridLength(0);
        }

        MainSplitRoot.InvalidateMeasure();
        MainSplitRoot.UpdateLayout();
    }

    private void RightPaneSplitter_OnDragCompleted(object sender, DragCompletedEventArgs e)
    {
        var vm = _vm ?? DataContext as RawMaterialEntryOperationViewModel;
        if (vm == null || !vm.IsRightPanelExpanded || e.Canceled) return;

        var w = RightPaneCol.ActualWidth;
        if (w >= 120)
            vm.CommitRightPanelWidthFromView(w);
    }
}