using CommunityToolkit.Mvvm.ComponentModel;
using FluidExplorer.Navigation;
using FluidExplorer.Services;
using FluidExplorer.Services.FileSystem;
using FluidExplorer.Services.ItemVisuals;
using FluidExplorer.Services.Operations;
using FluidExplorer.Services.Search;
using Microsoft.UI.Dispatching;
using PathHelper = FluidExplorer.Services.FileSystem.PathHelper;

namespace FluidExplorer.ViewModels;

/// <summary>一个标签页：包含主窗格，可选第二窗格（双窗格模式，搬文件不用来回切）。</summary>
public sealed partial class ExplorerTabViewModel : ObservableObject
{
    private readonly IFileSystemService _fs;
    private readonly SearchService _search;
    private readonly IFileOperationService _operations;
    private readonly ItemVisualService _visuals;
    private readonly IFileClipboard _clipboard;
    private readonly AppSettings _settings;
    private readonly DispatcherQueue _ui;

    [ObservableProperty] private bool _isDualPane;
    [ObservableProperty] private bool _isActivePaneSecondary;
    [ObservableProperty] private string _header = "新标签页";
    [ObservableProperty] private string _glyph = "\uE8B7";

    public ExplorerTabViewModel(
        IFileSystemService fs,
        SearchService search,
        IFileOperationService operations,
        ItemVisualService visuals,
        IFileClipboard clipboard,
        AppSettings settings,
        DispatcherQueue ui,
        NavigationLocation start)
    {
        _fs = fs;
        _search = search;
        _operations = operations;
        _visuals = visuals;
        _clipboard = clipboard;
        _settings = settings;
        _ui = ui;

        Primary = new ExplorerPaneViewModel(fs, search, operations, visuals, clipboard, settings, ui);
        Primary.PropertyChanged += (_, e) =>
        {
            if (e.PropertyName == nameof(ExplorerPaneViewModel.Title)) UpdateHeader();
        };
        Primary.SettingsChanged += (_, _) => UpdateHeader();
        _ = Primary.NavigateAsync(start);
        UpdateHeader();
    }

    public ExplorerPaneViewModel Primary { get; }

    [ObservableProperty] private ExplorerPaneViewModel? _secondary;

    public ExplorerPaneViewModel ActivePane => IsDualPane && IsActivePaneSecondary && Secondary is not null ? Secondary : Primary;

    public ExplorerPaneViewModel EnsureSecondary()
    {
        if (Secondary is not null) return Secondary;
        var pane = new ExplorerPaneViewModel(_fs, _search, _operations, _visuals, _clipboard, _settings, _ui)
        {
            ShowSidebar = false
        };
        pane.PropertyChanged += (_, e) =>
        {
            if (e.PropertyName == nameof(ExplorerPaneViewModel.Title)) UpdateHeader();
        };
        Secondary = pane;
        return pane;
    }

    public void ToggleDualPane()
    {
        if (IsDualPane)
        {
            IsDualPane = false;
            IsActivePaneSecondary = false;
            return;
        }

        var secondary = EnsureSecondary();
        if (string.IsNullOrEmpty(secondary.CurrentPath) || secondary.CurrentPath.StartsWith("::", StringComparison.Ordinal))
        {
            // 第二个窗格默认停在与主窗格同级的目录，便于对拖
            var parent = PathHelper.GetParent(Primary.CurrentPath);
            _ = secondary.NavigateAsync(NavigationLocation.FromPath(
                Directory.Exists(parent) ? parent : Primary.CurrentPath));
        }
        IsDualPane = true;
    }

    private void UpdateHeader()
    {
        Header = Primary.IsSearchActive && !string.IsNullOrWhiteSpace(Primary.SearchText)
            ? $"搜索：{Primary.SearchText}"
            : Primary.Title;
        Glyph = Primary.Glyph;
    }

    public void Dispose()
    {
        Primary.Dispose();
        Secondary?.Dispose();
    }
}