using System.Security.Claims;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using Moq;
using PowderCoating.Core.Entities;
using PowderCoating.Infrastructure.Data;
using PowderCoating.Infrastructure.Services;

namespace PowderCoating.UnitTests;

public class TenantContextTests
{
    [Fact]
    public void GetCurrentCompanyId_WhenUnauthenticated_ReturnsNull()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var accessor = CreateHttpContextAccessor(new ClaimsPrincipal(new ClaimsIdentity()));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var companyId = tenantContext.GetCurrentCompanyId();

        Assert.Null(companyId);
    }

    [Fact]
    public void GetCurrentCompanyId_WhenSuperAdminIsImpersonating_ReturnsSessionOverride()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var session = new TestSession();
        session.SetInt32("ImpersonatingCompanyId", 42);
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "admin@example.com", roles: ["SuperAdmin"]),
            session);
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var companyId = tenantContext.GetCurrentCompanyId();

        Assert.Equal(42, companyId);
    }

    [Fact]
    public void GetCurrentCompanyId_PrefersCompanyClaim()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        userManager.Setup(x => x.Users).Returns(Enumerable.Empty<ApplicationUser>().AsQueryable());
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "user@example.com", companyIdClaim: 9));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var companyId = tenantContext.GetCurrentCompanyId();

        Assert.Equal(9, companyId);
    }

    [Fact]
    public async Task GetCurrentCompanyId_WhenClaimMissing_FallsBackToUserLookup()
    {
        await using var context = CreateContext();
        context.Users.Add(new ApplicationUser
        {
            Id = "user-1",
            UserName = "legacy@example.com",
            Email = "legacy@example.com",
            FirstName = "Legacy",
            LastName = "User",
            CompanyId = 17
        });
        await context.SaveChangesAsync();

        var userManager = CreateUserManagerMock();
        userManager.Setup(x => x.Users).Returns(context.Users);
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "legacy@example.com"));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var companyId = tenantContext.GetCurrentCompanyId();

        Assert.Equal(17, companyId);
    }

    [Fact]
    public void IsPlatformAdmin_ReturnsTrue_ForSuperAdminWithoutTenantScope()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        userManager.Setup(x => x.Users).Returns(Enumerable.Empty<ApplicationUser>().AsQueryable());
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, roles: ["SuperAdmin"]));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var isPlatformAdmin = tenantContext.IsPlatformAdmin();

        Assert.True(isPlatformAdmin);
    }

    [Fact]
    public void IsPlatformAdmin_ReturnsFalse_ForSuperAdminImpersonatingCompany()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var session = new TestSession();
        session.SetInt32("ImpersonatingCompanyId", 2);
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "admin@example.com", roles: ["SuperAdmin"]),
            session);
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var isPlatformAdmin = tenantContext.IsPlatformAdmin();

        Assert.False(isPlatformAdmin);
    }

    [Fact]
    public async Task UseMetricSystemAsync_ReturnsStoredPreference()
    {
        await using var context = CreateContext();
        context.CompanyPreferences.Add(new CompanyPreferences
        {
            Id = 1,
            CompanyId = 25,
            UseMetricSystem = true
        });
        await context.SaveChangesAsync();

        var userManager = CreateUserManagerMock();
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "metric@example.com", companyIdClaim: 25));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var useMetric = await tenantContext.UseMetricSystemAsync();

        Assert.True(useMetric);
    }

    [Fact]
    public async Task GetCurrentCompanyAsync_ReturnsCompanyFromUserManager()
    {
        await using var context = CreateContext();
        var company = new Company
        {
            Id = 31,
            CompanyId = 31,
            CompanyName = "Current Co",
            PrimaryContactName = "Owner",
            PrimaryContactEmail = "owner@example.com"
        };
        var principal = CreatePrincipal(isAuthenticated: true, name: "current@example.com", companyIdClaim: 31);
        var user = new ApplicationUser
        {
            Id = "user-31",
            UserName = "current@example.com",
            Email = "current@example.com",
            FirstName = "Current",
            LastName = "User",
            CompanyId = 31,
            Company = company
        };

        var userManager = CreateUserManagerMock();
        userManager.Setup(x => x.GetUserAsync(principal)).ReturnsAsync(user);
        var accessor = CreateHttpContextAccessor(principal);
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var currentCompany = await tenantContext.GetCurrentCompanyAsync();

        Assert.NotNull(currentCompany);
        Assert.Equal("Current Co", currentCompany!.CompanyName);
    }

    [Fact]
    public void IsPlatformAdmin_ReturnsTrue_ForSuperAdminOnCompanyOne()
    {
        using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var accessor = CreateHttpContextAccessor(
            CreatePrincipal(isAuthenticated: true, name: "platform@example.com", companyIdClaim: 1, roles: ["SuperAdmin"]));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var isPlatformAdmin = tenantContext.IsPlatformAdmin();

        Assert.True(isPlatformAdmin);
    }

    [Fact]
    public async Task UseMetricSystemAsync_WhenNoCompanyContext_ReturnsFalse()
    {
        await using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var accessor = CreateHttpContextAccessor(CreatePrincipal(isAuthenticated: true, name: "nocompany@example.com"));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var useMetric = await tenantContext.UseMetricSystemAsync();

        Assert.False(useMetric);
    }

    [Fact]
    public async Task GetCurrentCompanyAsync_WhenUnauthenticated_ReturnsNull()
    {
        await using var context = CreateContext();
        var userManager = CreateUserManagerMock();
        var accessor = CreateHttpContextAccessor(new ClaimsPrincipal(new ClaimsIdentity()));
        var tenantContext = new TenantContext(accessor.Object, userManager.Object, context);

        var currentCompany = await tenantContext.GetCurrentCompanyAsync();

        Assert.Null(currentCompany);
    }

    private static Mock<IHttpContextAccessor> CreateHttpContextAccessor(ClaimsPrincipal principal, ISession? session = null)
    {
        var httpContext = new Mock<HttpContext>();
        httpContext.SetupGet(x => x.User).Returns(principal);
        httpContext.SetupGet(x => x.Session).Returns(session ?? new TestSession());

        var accessor = new Mock<IHttpContextAccessor>();
        accessor.SetupGet(x => x.HttpContext).Returns(httpContext.Object);
        return accessor;
    }

    private static ClaimsPrincipal CreatePrincipal(
        bool isAuthenticated,
        string? name = null,
        int? companyIdClaim = null,
        string[]? roles = null)
    {
        if (!isAuthenticated)
        {
            return new ClaimsPrincipal(new ClaimsIdentity());
        }

        var claims = new List<Claim>();
        if (!string.IsNullOrWhiteSpace(name))
        {
            claims.Add(new Claim(ClaimTypes.Name, name));
        }

        if (companyIdClaim.HasValue)
        {
            claims.Add(new Claim("CompanyId", companyIdClaim.Value.ToString()));
        }

        foreach (var role in roles ?? [])
        {
            claims.Add(new Claim(ClaimTypes.Role, role));
        }

        var identity = new ClaimsIdentity(claims, "TestAuth", ClaimTypes.Name, ClaimTypes.Role);
        return new ClaimsPrincipal(identity);
    }

    private static Mock<UserManager<ApplicationUser>> CreateUserManagerMock()
    {
        var store = new Mock<IUserStore<ApplicationUser>>();
        return new Mock<UserManager<ApplicationUser>>(
            store.Object,
            null!,
            null!,
            null!,
            null!,
            null!,
            null!,
            null!,
            null!);
    }

    private static ApplicationDbContext CreateContext()
    {
        var options = new DbContextOptionsBuilder<ApplicationDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;

        return new ApplicationDbContext(options);
    }

    private sealed class TestSession : ISession
    {
        private readonly Dictionary<string, byte[]> _values = new();

        public IEnumerable<string> Keys => _values.Keys;
        public string Id => "test-session";
        public bool IsAvailable => true;

        public void Clear() => _values.Clear();

        public Task CommitAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;

        public Task LoadAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;

        public void Remove(string key) => _values.Remove(key);

        public void Set(string key, byte[] value) => _values[key] = value;

        public bool TryGetValue(string key, out byte[] value) => _values.TryGetValue(key, out value!);
    }
}