deepdrft/DeepDrftPublic.Client/Pages/ReleaseDetailBase.cs

using DeepDrftModels.DTOs;
using DeepDrftPublic.Client.ViewModels;
using Microsoft.AspNetCore.Components;

namespace DeepDrftPublic.Client.Pages;

/// <summary>
/// Shared load + prerender-bridge logic for the single-release detail pages (Session, Mix).
/// Subclasses supply only their markup; this base loads the release through
/// <see cref="ReleaseDetailViewModel"/> and bridges the prerendered release across the prerender ->
/// WASM seam so the WASM pass does not re-fetch (see the TracksView seam). The playable track is
/// re-resolved on a restore miss only.
/// </summary>
public abstract class ReleaseDetailBase : ComponentBase, IDisposable
{
    [Parameter] public long Id { get; set; }
    [Inject] public required ReleaseDetailViewModel ViewModel { get; set; }
    [Inject] public required PersistentComponentState PersistentState { get; set; }

    private PersistingComponentStateSubscription _persistingSubscription;

    // Distinct keys per medium so a Session restore never lands on a Mix page.
    protected abstract string PersistKey { get; }

    protected override async Task OnInitializedAsync()
    {
        _persistingSubscription = PersistentState.RegisterOnPersisting(Persist);

        // The bridged payload carries both the release and its resolved track so the interactive
        // pass renders identically without a second round-trip.
        if (PersistentState.TryTakeFromJson<BridgedDetail>(PersistKey, out var restored) && restored?.Release is not null)
        {
            ViewModel.Restore(restored.Release, restored.Track);
        }
        else
        {
            await ViewModel.Load(Id);
        }
    }

    private Task Persist()
    {
        if (ViewModel.Release is not null)
            PersistentState.PersistAsJson(PersistKey, new BridgedDetail(ViewModel.Release, ViewModel.Track));
        return Task.CompletedTask;
    }

    public void Dispose() => _persistingSubscription.Dispose();

    // JSON-serializable bridge payload. Round-trips through PersistentComponentState's serializer.
    protected sealed record BridgedDetail(ReleaseDto Release, TrackDto? Track);
}