using JobTrackerApi.Controllers;
using JobTrackerApi.Models;
using JobTrackerApi.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore.Query;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using Moq;
using System.Collections;
using System.Linq.Expressions;
using Xunit;

namespace JobTrackerApi.Tests;

public sealed class AuthAndSystemControllerTests
{
    [Fact]
    public async Task Update_profile_applies_trimmed_profile_fields()
    {
        var user = new ApplicationUser { Email = "old@example.com", UserName = "olduser" };
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<System.Security.Claims.ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);

        var controller = new AuthController(BuildConfig(), userManager.Object, Mock.Of<ITokenService>(), Mock.Of<IAppEmailSender>(), Mock.Of<IGoogleTokenValidator>(), NullLogger<AuthController>.Instance);

        var result = await controller.UpdateProfile(new AuthController.UpdateProfileRequest(" new@example.com ", " newuser ", " Ada ", " Lovelace ", " Ada L. ", null, null));

        Assert.IsType<NoContentResult>(result);
        Assert.Equal("new@example.com", user.Email);
        Assert.Equal("newuser", user.UserName);
        Assert.Equal("Ada", user.FirstName);
        Assert.Equal("Lovelace", user.LastName);
        Assert.Equal("Ada L.", user.DisplayName);
    }

    [Fact]
    public async Task Request_password_reset_returns_service_unavailable_when_email_send_fails()
    {
        var user = new ApplicationUser { Email = "person@example.com", UserName = "person@example.com" };
        var userManager = CreateUserManager();
        userManager.Setup(x => x.FindByEmailAsync("person@example.com")).ReturnsAsync(user);
        userManager.Setup(x => x.GeneratePasswordResetTokenAsync(user)).ReturnsAsync("reset-token");

        var emailSender = new Mock<IAppEmailSender>();
        emailSender
            .Setup(x => x.SendAsync(user.Email!, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
            .ThrowsAsync(new InvalidOperationException("SMTP unavailable"));

        var controller = new AuthController(BuildConfig(), userManager.Object, Mock.Of<ITokenService>(), emailSender.Object, Mock.Of<IGoogleTokenValidator>(), NullLogger<AuthController>.Instance)
        {
            ControllerContext = new ControllerContext
            {
                HttpContext = new DefaultHttpContext()
            }
        };
        controller.Request.Scheme = "https";
        controller.Request.Host = new HostString("jobtracker.test");

        var result = await controller.RequestPasswordReset(new AuthController.RequestPasswordResetRequest("person@example.com"), CancellationToken.None);

        var problem = Assert.IsType<ObjectResult>(result);
        Assert.Equal(StatusCodes.Status503ServiceUnavailable, problem.StatusCode);
        var details = Assert.IsType<ProblemDetails>(problem.Value);
        Assert.Equal("Email delivery unavailable", details.Title);
    }

    [Fact]
    public async Task Exchange_google_token_auto_links_single_verified_email_match()
    {
        var user = new ApplicationUser
        {
            Id = "user-1",
            Email = "dj@cesnimda.co.uk",
            UserName = "dj@cesnimda.co.uk",
        };

        var userManager = CreateUserManager();
        userManager.Setup(x => x.Users).Returns(new TestAsyncEnumerable<ApplicationUser>(new List<ApplicationUser>()));
        userManager.Setup(x => x.FindByEmailAsync("dj@cesnimda.co.uk")).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);

        var tokenService = new Mock<ITokenService>();
        tokenService.Setup(x => x.CreateAccessTokenAsync(user, It.IsAny<CancellationToken>())).ReturnsAsync("app-token");

        var googleValidator = new Mock<IGoogleTokenValidator>();
        googleValidator
            .Setup(x => x.ValidateAsync("google-token", It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GoogleTokenPrincipal("google-subject", "dj@cesnimda.co.uk", true, "Dan", "Jones", "Dan Jones"));

        var controller = new AuthController(BuildConfig(), userManager.Object, tokenService.Object, Mock.Of<IAppEmailSender>(), googleValidator.Object, NullLogger<AuthController>.Instance);

        var result = await controller.ExchangeGoogleToken(new AuthController.GoogleTokenRequest("google-token"), CancellationToken.None);

        var ok = Assert.IsType<OkObjectResult>(result.Result);
        var payload = Assert.IsType<AuthController.AuthResult>(ok.Value);
        Assert.Equal("app-token", payload.AccessToken);
        Assert.Equal("google-subject", user.GoogleSubject);
        Assert.Equal("dj@cesnimda.co.uk", user.GoogleEmail);
        Assert.NotNull(user.GoogleLinkedAt);
    }

    [Fact]
    public void Me_result_includes_google_link_details_for_local_users()
    {
        var method = typeof(AuthController).GetMethod("ToMeResult", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
        Assert.NotNull(method);

        var user = new ApplicationUser
        {
            Id = "user-1",
            Email = "person@example.com",
            UserName = "person",
            FirstName = "Ada",
            LastName = "Lovelace",
            DisplayName = "Ada Lovelace",
            GoogleSubject = "sub-123",
            GoogleEmail = "person@example.com",
            GoogleLinkedAt = DateTimeOffset.UtcNow,
        };

        var result = (AuthController.MeResult)method!.Invoke(null, new object[] { user, new List<string> { "Admin" } })!;

        Assert.Equal("local", result.Provider);
        Assert.Equal("Ada", result.FirstName);
        Assert.Equal("Lovelace", result.LastName);
        Assert.Equal("Ada Lovelace", result.DisplayName);
        Assert.NotNull(result.GoogleLink);
        Assert.True(result.GoogleLink!.Linked);
        Assert.Equal("person@example.com", result.GoogleLink.Email);
    }

    [Fact]
    public async Task Admin_system_probe_endpoint_runs_probe_once()
    {
        var summarizer = new Mock<ISummarizerService>();
        summarizer.Setup(x => x.RunProbeAsync(It.IsAny<CancellationToken>())).Returns(Task.CompletedTask);

        var controller = new AdminSystemController(BuildConfig(), new AppPaths(BuildConfig(), new FakeHostEnv()), null!, summarizer.Object, new FakeEnv());

        var result = await controller.RunSummarizerProbe(CancellationToken.None);

        Assert.IsType<NoContentResult>(result);
        summarizer.Verify(x => x.RunProbeAsync(It.IsAny<CancellationToken>()), Times.Once);
    }

    private static IConfiguration BuildConfig()
    {
        return new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>())
            .Build();
    }

    private static Mock<UserManager<ApplicationUser>> CreateUserManager()
    {
        var store = new Mock<IUserStore<ApplicationUser>>();
        return new Mock<UserManager<ApplicationUser>>(
            store.Object,
            Options.Create(new IdentityOptions()),
            new PasswordHasher<ApplicationUser>(),
            Array.Empty<IUserValidator<ApplicationUser>>(),
            Array.Empty<IPasswordValidator<ApplicationUser>>(),
            new UpperInvariantLookupNormalizer(),
            new IdentityErrorDescriber(),
            null!,
            new NullLogger<UserManager<ApplicationUser>>()
        );
    }

    private sealed class TestAsyncQueryProvider<TEntity> : IAsyncQueryProvider
    {
        private readonly IQueryProvider _inner;

        public TestAsyncQueryProvider(IQueryProvider inner)
        {
            _inner = inner;
        }

        public IQueryable CreateQuery(Expression expression) => new TestAsyncEnumerable<TEntity>(expression);
        public IQueryable<TElement> CreateQuery<TElement>(Expression expression) => new TestAsyncEnumerable<TElement>(expression);
        public object? Execute(Expression expression) => _inner.Execute(expression);
        public TResult Execute<TResult>(Expression expression) => _inner.Execute<TResult>(expression);
        public TResult ExecuteAsync<TResult>(Expression expression, CancellationToken cancellationToken = default)
            => (TResult)typeof(Task)
                .GetMethod(nameof(Task.FromResult))!
                .MakeGenericMethod(typeof(TResult).GetGenericArguments()[0])
                .Invoke(null, new[] { Execute(expression) })!;
    }

    private sealed class TestAsyncEnumerable<T> : EnumerableQuery<T>, IAsyncEnumerable<T>, IQueryable<T>
    {
        public TestAsyncEnumerable(IEnumerable<T> enumerable) : base(enumerable) { }
        public TestAsyncEnumerable(Expression expression) : base(expression) { }

        public IAsyncEnumerator<T> GetAsyncEnumerator(CancellationToken cancellationToken = default)
            => new TestAsyncEnumerator<T>(this.AsEnumerable().GetEnumerator());

        IQueryProvider IQueryable.Provider => new TestAsyncQueryProvider<T>(this);
    }

    private sealed class TestAsyncEnumerator<T> : IAsyncEnumerator<T>
    {
        private readonly IEnumerator<T> _inner;

        public TestAsyncEnumerator(IEnumerator<T> inner)
        {
            _inner = inner;
        }

        public T Current => _inner.Current;

        public ValueTask DisposeAsync()
        {
            _inner.Dispose();
            return ValueTask.CompletedTask;
        }

        public ValueTask<bool> MoveNextAsync() => ValueTask.FromResult(_inner.MoveNext());
    }

    private sealed class FakeHostEnv : Microsoft.Extensions.Hosting.IHostEnvironment
    {
        public string EnvironmentName { get; set; } = "Test";
        public string ApplicationName { get; set; } = "JobTrackerApi";
        public string ContentRootPath { get; set; } = AppContext.BaseDirectory;
        public Microsoft.Extensions.FileProviders.IFileProvider ContentRootFileProvider { get; set; } = null!;
    }

    private sealed class FakeEnv : Microsoft.AspNetCore.Hosting.IWebHostEnvironment
    {
        public string ApplicationName { get; set; } = "JobTrackerApi";
        public Microsoft.Extensions.FileProviders.IFileProvider WebRootFileProvider { get; set; } = null!;
        public string WebRootPath { get; set; } = string.Empty;
        public string EnvironmentName { get; set; } = "Test";
        public string ContentRootPath { get; set; } = AppContext.BaseDirectory;
        public Microsoft.Extensions.FileProviders.IFileProvider ContentRootFileProvider { get; set; } = null!;
    }
}