Tau.Acuvim/portal/tests/Tau.Acuvim.Portal.Tests/CustomerTokenGraceTests.cs

using Microsoft.EntityFrameworkCore;
using Tau.Acuvim.Portal.Data;
using Tau.Acuvim.Portal.DTOs;
using Tau.Acuvim.Portal.Services;

namespace Tau.Acuvim.Portal.Tests;

public class CustomerTokenGraceTests
{
    private static AdminDbContext NewDb()
    {
        var opts = new DbContextOptionsBuilder<AdminDbContext>()
            .UseInMemoryDatabase(databaseName: "grace-" + Guid.NewGuid())
            .Options;
        return new AdminDbContext(opts);
    }

    private static async Task<(CustomerService svc, Guid id, string originalToken)> SeedAsync()
    {
        var db = NewDb();
        var svc = new CustomerService(db);
        var created = await svc.CreateAsync(new CreateCustomerRequest("ABC0001", "Test"));
        return (svc, created.Customer.Id, created.Token);
    }

    [Fact]
    public async Task Create_DoesNotSetPreviousToken()
    {
        var (svc, id, _) = await SeedAsync();
        var list = await svc.ListAsync();
        var c = list.Single(x => x.Id == id);
        Assert.Null(c.PreviousTokenExpiresAt);
    }

    [Fact]
    public async Task Rotate_MovesCurrentTokenIntoPreviousSlot()
    {
        var (svc, id, originalToken) = await SeedAsync();

        var rotated = await svc.RotateTokenAsync(id);
        Assert.NotNull(rotated);

        // Original token still accepted within grace window.
        var found = await svc.FindByTokenAsync(originalToken);
        Assert.NotNull(found);

        // New token also accepted.
        var newToken = rotated!.Token;
        Assert.NotEqual(originalToken, newToken);
        var foundNew = await svc.FindByTokenAsync(newToken);
        Assert.NotNull(foundNew);

        // PreviousTokenExpiresAt populated and in the near future.
        var listed = (await svc.ListAsync()).Single(x => x.Id == id);
        Assert.NotNull(listed.PreviousTokenExpiresAt);
        Assert.True(listed.PreviousTokenExpiresAt > DateTime.UtcNow);
        Assert.True(listed.PreviousTokenExpiresAt <= DateTime.UtcNow + CustomerService.DefaultTokenGracePeriod + TimeSpan.FromMinutes(1));
    }

    [Fact]
    public async Task Rotate_WithZeroGrace_RejectsOriginalImmediately()
    {
        var (svc, id, originalToken) = await SeedAsync();

        await svc.RotateTokenAsync(id, graceWindow: TimeSpan.Zero);

        // PreviousExpiresAt is now-ish; the strict-greater-than check in FindByTokenAsync
        // rejects it. So the original is dead.
        var found = await svc.FindByTokenAsync(originalToken);
        Assert.Null(found);
    }

    [Fact]
    public async Task SecondRotation_OverwritesPreviousSlot_OriginalDies()
    {
        var (svc, id, originalToken) = await SeedAsync();

        var firstRotation = await svc.RotateTokenAsync(id);
        var secondRotation = await svc.RotateTokenAsync(id);

        Assert.NotNull(firstRotation);
        Assert.NotNull(secondRotation);

        // Original is gone — the previous slot now holds the first-rotation token.
        Assert.Null(await svc.FindByTokenAsync(originalToken));

        // First-rotation token is still accepted (it's the new previous).
        Assert.NotNull(await svc.FindByTokenAsync(firstRotation!.Token));

        // Second-rotation token is accepted (current).
        Assert.NotNull(await svc.FindByTokenAsync(secondRotation!.Token));
    }

    [Fact]
    public async Task InactiveCustomer_RejectsBothCurrentAndPrevious()
    {
        var (svc, id, originalToken) = await SeedAsync();
        var rotated = await svc.RotateTokenAsync(id);
        await svc.UpdateAsync(id, new UpdateCustomerRequest("Test", IsActive: false));

        Assert.Null(await svc.FindByTokenAsync(originalToken));
        Assert.Null(await svc.FindByTokenAsync(rotated!.Token));
    }
}