using System.Net;
using System.Net.Http.Json;
using System.Security.Claims;
using System.Text.Encodings.Web;
using FluentAssertions;
using InboxIntel.Application.Abstractions;
using InboxIntel.Domain.Entities;
using InboxIntel.Infrastructure.Persistence;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Xunit;

namespace InboxIntel.IntegrationTests;

// ── Tests proving the Phase-2 audit fixes (see AUDIT_REPORT.md) ────────────────────────────

/// <summary>Pass-through auth scheme so integration tests can exercise authenticated
/// endpoints (model validation, per-user rate limits) without a real Google login.</summary>
public class TestAuthHandler : AuthenticationHandler<AuthenticationSchemeOptions>
{
    public const string Scheme = "Test";
    // Stable across requests so per-user rate-limit partitions accumulate correctly.
    public static readonly string Uid = Guid.NewGuid().ToString();

    public TestAuthHandler(IOptionsMonitor<AuthenticationSchemeOptions> o, ILoggerFactory l, UrlEncoder e)
        : base(o, l, e) { }

    protected override Task<AuthenticateResult> HandleAuthenticateAsync()
    {
        var identity = new ClaimsIdentity(new[]
        {
            new Claim(ClaimTypes.NameIdentifier, "test-sub"),
            new Claim("inboxintel:uid", Uid),
        }, Scheme);
        return Task.FromResult(AuthenticateResult.Success(
            new AuthenticationTicket(new ClaimsPrincipal(identity), Scheme)));
    }
}

/// <summary>Factory with the test auth scheme + tiny rate-limit windows so limits trip fast.</summary>
public class AuditTestAppFactory : WebApplicationFactory<Program>
{
    protected override IHost CreateHost(IHostBuilder builder)
    {
        builder.ConfigureHostConfiguration(cfg => cfg.AddInMemoryCollection(new Dictionary<string, string?>
        {
            ["Database:AutoMigrate"] = "false",
            ["GoogleOAuth:ClientId"] = "test-client-id",
            ["GoogleOAuth:ClientSecret"] = "test-client-secret",
            // H-2: make the auth policy trip on the 3rd request within the window.
            ["RateLimiting:AuthPermitLimit"] = "2",
            ["RateLimiting:WindowSeconds"] = "60",
        }));
        return base.CreateHost(builder);
    }

    protected override void ConfigureWebHost(IWebHostBuilder builder)
    {
        builder.ConfigureServices(services =>
        {
            services.AddAuthentication(TestAuthHandler.Scheme)
                .AddScheme<AuthenticationSchemeOptions, TestAuthHandler>(TestAuthHandler.Scheme, _ => { });
            services.PostConfigure<AuthenticationOptions>(o =>
            {
                o.DefaultAuthenticateScheme = TestAuthHandler.Scheme;
                o.DefaultChallengeScheme = TestAuthHandler.Scheme;
            });
        });
    }
}

public class AuditFixesTests : IClassFixture<AuditTestAppFactory>
{
    private readonly AuditTestAppFactory _factory;
    public AuditFixesTests(AuditTestAppFactory factory) => _factory = factory;

    // H-1: FluentValidation auto-validation now rejects invalid DTOs at the boundary with 400
    // (previously the registered validators never executed).
    [Fact]
    public async Task Invalid_search_request_is_rejected_with_400_by_the_validator()
    {
        var client = _factory.CreateClient();
        var resp = await client.PostAsJsonAsync("/api/v1/search", new { page = 1, pageSize = 0 });
        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
    }

    [Fact]
    public async Task Search_with_from_after_to_is_rejected_with_400()
    {
        var client = _factory.CreateClient();
        var resp = await client.PostAsJsonAsync("/api/v1/search",
            new { page = 1, pageSize = 10, from = "2026-02-01", to = "2026-01-01" });
        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
    }

    // H-2: the "auth" rate-limit policy returns 429 once the per-window permit is exhausted.
    [Fact]
    public async Task Auth_endpoint_rate_limits_with_429_after_the_permit_is_exhausted()
    {
        var client = _factory.CreateClient(new WebApplicationFactoryClientOptions { AllowAutoRedirect = false });
        var s1 = (await client.GetAsync("/api/v1/auth/login")).StatusCode;
        var s2 = (await client.GetAsync("/api/v1/auth/login")).StatusCode;
        var s3 = (await client.GetAsync("/api/v1/auth/login")).StatusCode;

        s1.Should().NotBe(HttpStatusCode.TooManyRequests);
        s2.Should().NotBe(HttpStatusCode.TooManyRequests);
        s3.Should().Be(HttpStatusCode.TooManyRequests);
    }
}

// M-1: absolute session lifetime — a session older than the cap (or missing its issued
// stamp) is expired regardless of sliding renewal.
public class SessionLifetimeTests
{
    private static readonly DateTimeOffset Now = new(2026, 07, 02, 12, 0, 0, TimeSpan.Zero);
    private static readonly TimeSpan Max = TimeSpan.FromDays(30);

    [Fact]
    public void Fresh_session_is_not_expired()
        => SessionLifetime.IsExpired(Now.AddDays(-1).ToString("O"), Now, Max).Should().BeFalse();

    [Fact]
    public void Session_older_than_the_cap_is_expired()
        => SessionLifetime.IsExpired(Now.AddDays(-31).ToString("O"), Now, Max).Should().BeTrue();

    [Fact]
    public void Session_without_a_stamp_is_expired()
        => SessionLifetime.IsExpired(null, Now, Max).Should().BeTrue();
}

// M-6: EmailLabel now carries a matching tenant query filter (via its Email navigation), so
// join rows can never leak across users even without a manual Where.
public class EmailLabelFilterTests
{
    private sealed class FakeCurrentUser : ICurrentUser
    {
        public Guid UserId { get; set; }
        public bool IsAuthenticated => UserId != Guid.Empty;
    }

    [Fact]
    public async Task EmailLabels_are_invisible_across_users()
    {
        var userA = Guid.NewGuid();
        var userB = Guid.NewGuid();
        var opts = new DbContextOptionsBuilder<AppDbContext>()
            .UseInMemoryDatabase(nameof(EmailLabels_are_invisible_across_users)).Options;

        using (var seed = new AppDbContext(opts, new FakeCurrentUser()))
        {
            var emailA = new Email { UserId = userA, GmailMessageId = "a1" };
            var emailB = new Email { UserId = userB, GmailMessageId = "b1" };
            var labelA = new Label { UserId = userA, GmailLabelId = "LA", Name = "A" };
            var labelB = new Label { UserId = userB, GmailLabelId = "LB", Name = "B" };
            seed.AddRange(emailA, emailB, labelA, labelB,
                new EmailLabel { EmailId = emailA.Id, LabelId = labelA.Id },
                new EmailLabel { EmailId = emailB.Id, LabelId = labelB.Id });
            await seed.SaveChangesAsync();
        }

        using var ctx = new AppDbContext(opts, new FakeCurrentUser { UserId = userA });
        var visible = await ctx.Set<EmailLabel>().ToListAsync(); // no manual Where — filter must enforce
        visible.Should().HaveCount(1);
    }
}