using System.Security.Claims;
using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.AspNetCore.Components.Server;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Options;

namespace BuchhaltungBlazor.Areas.Identity;

public class RevalidatingIdentityAuthenticationStateProvider<TUser> : RevalidatingServerAuthenticationStateProvider where TUser : class {
    private readonly IdentityOptions _options;
    private readonly IServiceScopeFactory _scopeFactory;

    public RevalidatingIdentityAuthenticationStateProvider(ILoggerFactory loggerFactory, IServiceScopeFactory scopeFactory, IOptions<IdentityOptions> optionsAccessor) : base(loggerFactory) {
        _scopeFactory = scopeFactory;
        _options = optionsAccessor.Value;
    }

    protected override TimeSpan RevalidationInterval => TimeSpan.FromMinutes(30);

    protected override async Task<bool> ValidateAuthenticationStateAsync(AuthenticationState authenticationState, CancellationToken cancellationToken) {
        // Get the user manager from a new scope to ensure it fetches fresh data
        IServiceScope? scope = _scopeFactory.CreateScope();
        try {
            UserManager<TUser>? userManager = scope.ServiceProvider.GetRequiredService<UserManager<TUser>>();
            return await ValidateSecurityStampAsync(userManager, authenticationState.User);
        }
        finally {
            if (scope is IAsyncDisposable asyncDisposable)
                await asyncDisposable.DisposeAsync();
            else
                scope.Dispose();
        }
    }

    private async Task<bool> ValidateSecurityStampAsync(UserManager<TUser> userManager, ClaimsPrincipal principal) {
        TUser? user = await userManager.GetUserAsync(principal);
        if (user == null) return false;

        if (!userManager.SupportsUserSecurityStamp) return true;

        string? principalStamp = principal.FindFirstValue(_options.ClaimsIdentity.SecurityStampClaimType);
        string? userStamp = await userManager.GetSecurityStampAsync(user);
        return principalStamp == userStamp;
    }
}