@using RackPeek.Domain.Persistence
@using RackPeek.Domain.Resources
@typeparam TResource where TResource : Resource

@inject IResourceCollection Repo

<PageTitle>@Title</PageTitle>

<h1 class="text-lg text-zinc-100" data-testid="@($"{TestId}-page-title")">
    @Title
</h1>

<div class="min-h-screen bg-zinc-950 text-zinc-200 font-mono p-6 space-y-6"
     data-testid="@($"{TestId}-page-root")">

    <div data-testid="@($"{TestId}-add-section")">
        <AddResourceComponent TResource="TResource"
                              Placeholder=@($"{ResourceKind} name")
                              OnCreated="OnCreated"/>
    </div>

    @if (ResourcesToRender is null)
    {
        <div class="text-zinc-500" data-testid="@($"{TestId}-loading")">
            loading @ResourceKind.ToLower()…
        </div>
    }
    else if (!ResourcesToRender.Any())
    {
        <div class="text-zinc-500" data-testid="@($"{TestId}-empty")">
            no @ResourceKind.ToLower() found
        </div>
    }
    else
    {
        <div class="space-y-4" data-testid="@($"{TestId}-list")">
            @foreach (var group in GroupResources(ResourcesToRender))
            {
                var groupKey = FormatGroupKey(group.Key);

                <div data-testid="@($"{TestId}-group-{groupKey}")">
                    @if (ShouldGroup)
                    {
                        <div class="text-xs text-zinc-500 uppercase tracking-wider mb-2"
                             data-testid="@($"{TestId}-group-title-{groupKey}")">
                            @DisplayGroupKey(group.Key)
                        </div>
                    }

                    <div class="space-y-4" data-testid="@($"{TestId}-group-list-{groupKey}")">
                        @foreach (var item in group)
                        {
                            @ItemTemplate(item)
                        }
                    </div>
                </div>
            }
        </div>
    }
</div>

@code {
    [Parameter] public string Title { get; set; } = default!;
    [Parameter] public string TestId { get; set; } = default!;

    [Parameter] public IReadOnlyList<TResource>? Resources { get; set; }

    [Parameter] public RenderFragment AddSection { get; set; } = default!;
    [Parameter] public RenderFragment<TResource> ItemTemplate { get; set; } = default!;

    [Parameter] public bool ShouldGroup { get; set; }
    [Parameter] public Func<TResource, string?> GroupBy { get; set; } = _ => null;

    [Parameter] public EventCallback<string> OnCreated { get; set; }

    private IReadOnlyList<TResource>? _loadedResources;

    private IReadOnlyList<TResource>? ResourcesToRender => Resources ?? _loadedResources;

    public string ResourceKind { get; set; } = Resource.GetKind<TResource>();

    protected override async Task OnParametersSetAsync()
    {
        if (Resources is not null)
            return;

        if (_loadedResources is null)
            _loadedResources = await Repo.GetAllOfTypeAsync<TResource>();
    }

    private IEnumerable<IGrouping<string?, TResource>> GroupResources(IEnumerable<TResource> resources)
    {
        return resources.GroupBy(GroupBy).OrderByDescending(g => g.Count());
    }

    private static string FormatGroupKey(string? key)
    {
        return string.IsNullOrWhiteSpace(key) ? "unassigned" : key.Replace(" ", "-");
    }

    private static string DisplayGroupKey(string? key)
    {
        return string.IsNullOrWhiteSpace(key) ? "Unassigned" : key;
    }

}