@page "/admin/areas"
@using ScadaLink.Security
@using ScadaLink.Commons.Entities.Instances
@using ScadaLink.Commons.Entities.Sites
@using ScadaLink.Commons.Interfaces.Repositories
@attribute [Authorize(Policy = AuthorizationPolicies.RequireDesign)]
@inject ISiteRepository SiteRepository
@inject ITemplateEngineRepository TemplateEngineRepository
@inject NavigationManager NavigationManager

<div class="container-fluid mt-3">
    <h4 class="mb-3">Area Management</h4>

    <ToastNotification @ref="_toast" />

    @if (_loading)
    {
        <LoadingSpinner IsLoading="true" />
    }
    else if (_errorMessage != null)
    {
        <div class="alert alert-danger">@_errorMessage</div>
    }
    else
    {
        <TreeView TItem="AreaTreeNode" Items="_treeRoots"
                  ChildrenSelector="n => n.Children"
                  HasChildrenSelector="n => n.Children.Count > 0"
                  KeySelector="n => n.Key"
                  StorageKey="areas-tree">
            <NodeContent Context="node">
                @if (node.Kind == AreaNodeKind.Site)
                {
                    <span class="fw-semibold">@node.Label</span>
                    <span class="badge bg-secondary ms-1">@node.AreaCount</span>
                }
                else
                {
                    <span>@node.Label</span>
                }
            </NodeContent>
            <ContextMenu Context="node">
                @if (node.Kind == AreaNodeKind.Site)
                {
                    <button class="dropdown-item"
                            @onclick='() => NavigationManager.NavigateTo($"/admin/areas/add?siteId={node.SiteId}")'>
                        Add Area
                    </button>
                }
                else
                {
                    <button class="dropdown-item"
                            @onclick='() => NavigationManager.NavigateTo($"/admin/areas/add?siteId={node.SiteId}&parentAreaId={node.Area!.Id}")'>
                        Add Child Area
                    </button>
                    <button class="dropdown-item"
                            @onclick='() => NavigationManager.NavigateTo($"/admin/areas/{node.Area!.Id}/edit")'>
                        Edit Area
                    </button>
                    <div class="dropdown-divider"></div>
                    <button class="dropdown-item text-danger"
                            @onclick='() => NavigationManager.NavigateTo($"/admin/areas/{node.Area!.Id}/delete")'>
                        Delete Area
                    </button>
                }
            </ContextMenu>
            <EmptyContent>
                <span class="text-muted fst-italic">No sites configured.</span>
            </EmptyContent>
        </TreeView>
    }
</div>

@code {
    record AreaTreeNode(string Key, string Label, AreaNodeKind Kind, List<AreaTreeNode> Children,
        int SiteId, Area? Area = null, int AreaCount = 0);
    enum AreaNodeKind { Site, Area }

    private List<Site> _sites = new();
    private List<AreaTreeNode> _treeRoots = new();
    private bool _loading = true;
    private string? _errorMessage;

    private ToastNotification _toast = default!;

    protected override async Task OnInitializedAsync()
    {
        await LoadDataAsync();
    }

    private async Task LoadDataAsync()
    {
        _loading = true;
        try
        {
            _sites = (await SiteRepository.GetAllSitesAsync()).ToList();
            _treeRoots = new();
            foreach (var site in _sites)
            {
                var areas = (await TemplateEngineRepository.GetAreasBySiteIdAsync(site.Id)).ToList();
                var rootAreas = areas.Where(a => a.ParentAreaId == null).OrderBy(a => a.Name);
                var children = rootAreas.Select(a => BuildAreaNode(a, site.Id)).ToList();
                _treeRoots.Add(new AreaTreeNode(
                    Key: $"site-{site.Id}",
                    Label: site.Name,
                    Kind: AreaNodeKind.Site,
                    Children: children,
                    SiteId: site.Id,
                    AreaCount: areas.Count));
            }
        }
        catch (Exception ex)
        {
            _errorMessage = $"Failed to load data: {ex.Message}";
        }
        _loading = false;
    }

    private AreaTreeNode BuildAreaNode(Area area, int siteId)
    {
        var children = area.Children
            .OrderBy(c => c.Name)
            .Select(c => BuildAreaNode(c, siteId))
            .ToList();
        return new AreaTreeNode(
            Key: $"area-{area.Id}",
            Label: area.Name,
            Kind: AreaNodeKind.Area,
            Children: children,
            SiteId: siteId,
            Area: area);
    }
}