using System.ComponentModel;
using System.Windows.Controls;
using Microsoft.Web.WebView2.Core;
using SSPCTester.UI.ViewModels;

namespace SSPCTester.UI.Views;

public partial class ReportView : UserControl
{
    private ReportViewModel? _viewModel;

    public ReportView()
    {
        InitializeComponent();
        DataContextChanged += (_, e) =>
        {
            if (_viewModel != null)
                _viewModel.PropertyChanged -= ViewModel_PropertyChanged;

            _viewModel = e.NewValue as ReportViewModel;
            if (_viewModel != null)
            {
                _viewModel.PropertyChanged += ViewModel_PropertyChanged;
                NavigatePreview(_viewModel.PreviewSource);
            }
            else
            {
                NavigateBlank();
            }
        };
        Unloaded += (_, _) =>
        {
            if (_viewModel != null)
                _viewModel.PropertyChanged -= ViewModel_PropertyChanged;
            _viewModel = null;
            NavigateBlank();
        };
    }

    private void ViewModel_PropertyChanged(object? sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName == nameof(ReportViewModel.PreviewSource) && sender is ReportViewModel vm)
            NavigatePreview(vm.PreviewSource);
    }

    private void PdfPreview_CoreWebView2InitializationCompleted(
        object? sender,
        CoreWebView2InitializationCompletedEventArgs e)
    {
        if (e.IsSuccess) return;

        if (DataContext is ReportViewModel vm)
            vm.PreviewUnavailable("PDF 预览初始化失败。请确认已安装 Microsoft Edge WebView2 Runtime，或使用“打开文件夹”查看报告。");
    }

    private void NavigatePreview(Uri? source)
    {
        if (source == null)
        {
            NavigateBlank();
            return;
        }

        try
        {
            PdfPreview.Source = source;
        }
        catch
        {
            NavigateBlank();
            _viewModel?.PreviewUnavailable("PDF 预览加载失败。请使用“打开文件夹”查看报告。");
        }
    }

    private void NavigateBlank()
    {
        try
        {
            PdfPreview.Source = new Uri("about:blank");
        }
        catch
        {
            // WebView2 may not be initialized yet; leave it untouched.
        }
    }
}