using System.Security.Claims;
using AutoMapper;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ViewFeatures;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Moq;
using PowderCoating.Application.DTOs.GiftCertificate;
using PowderCoating.Application.Interfaces;
using PowderCoating.Core.Entities;
using PowderCoating.Core.Enums;
using PowderCoating.Infrastructure.Data;
using PowderCoating.Infrastructure.Repositories;
using PowderCoating.Web.Controllers;

namespace PowderCoating.UnitTests;

public class GiftCertificatesControllerTests
{
    // ── Index — lazy expiration ───────────────────────────────────────────

    [Fact]
    public async Task Index_LazilySetsExpiredStatus_ForActiveCertsPastExpiryDate()
    {
        await using var context = CreateContext();
        context.GiftCertificates.Add(new GiftCertificate
        {
            Id = 1, CompanyId = 1,
            CertificateCode = "GC-2603-0001",
            OriginalAmount = 100m, RedeemedAmount = 0,
            Status = GiftCertificateStatus.Active,
            IssueDate = DateTime.UtcNow.AddMonths(-2),
            ExpiryDate = DateTime.UtcNow.AddDays(-1)    // past expiry
        });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Index(null, null);

        var view = Assert.IsType<ViewResult>(result);
        var dtos = Assert.IsAssignableFrom<List<GiftCertificateListDto>>(view.Model);
        Assert.Single(dtos);
        Assert.Equal(GiftCertificateStatus.Expired, dtos[0].Status);

        var dbCert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Equal(GiftCertificateStatus.Expired, dbCert.Status);
    }

    [Fact]
    public async Task Index_DoesNotExpire_ActiveCertsWithFutureExpiryDate()
    {
        await using var context = CreateContext();
        context.GiftCertificates.Add(new GiftCertificate
        {
            Id = 1, CompanyId = 1,
            CertificateCode = "GC-2604-0001",
            OriginalAmount = 50m, RedeemedAmount = 0,
            Status = GiftCertificateStatus.Active,
            IssueDate = DateTime.UtcNow,
            ExpiryDate = DateTime.UtcNow.AddDays(30)    // future expiry
        });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        await controller.Index(null, null);

        var dbCert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Equal(GiftCertificateStatus.Active, dbCert.Status);
    }

    // ── Index — filtering ─────────────────────────────────────────────────

    [Fact]
    public async Task Index_StatusFilter_ReturnsOnlyMatchingStatus()
    {
        await using var context = CreateContext();
        context.GiftCertificates.AddRange(
            new GiftCertificate { Id = 1, CompanyId = 1, CertificateCode = "GC-2604-0001", OriginalAmount = 100m, Status = GiftCertificateStatus.Active, IssueDate = DateTime.UtcNow },
            new GiftCertificate { Id = 2, CompanyId = 1, CertificateCode = "GC-2604-0002", OriginalAmount = 200m, Status = GiftCertificateStatus.Voided,  IssueDate = DateTime.UtcNow });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Index(null, nameof(GiftCertificateStatus.Active));

        var view = Assert.IsType<ViewResult>(result);
        var dtos = Assert.IsAssignableFrom<List<GiftCertificateListDto>>(view.Model);
        var dto = Assert.Single(dtos);
        Assert.Equal(GiftCertificateStatus.Active, dto.Status);
    }

    [Fact]
    public async Task Index_SearchTerm_FiltersByCertificateCode()
    {
        await using var context = CreateContext();
        context.GiftCertificates.AddRange(
            new GiftCertificate { Id = 1, CompanyId = 1, CertificateCode = "GC-2604-0001", OriginalAmount = 100m, Status = GiftCertificateStatus.Active, IssueDate = DateTime.UtcNow },
            new GiftCertificate { Id = 2, CompanyId = 1, CertificateCode = "GC-2604-0002", OriginalAmount = 100m, Status = GiftCertificateStatus.Active, IssueDate = DateTime.UtcNow });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Index("0001", null);

        var view = Assert.IsType<ViewResult>(result);
        var dtos = Assert.IsAssignableFrom<List<GiftCertificateListDto>>(view.Model);
        var dto = Assert.Single(dtos);
        Assert.Equal("GC-2604-0001", dto.CertificateCode);
    }

    [Fact]
    public async Task Index_ViewBag_TotalValueIncludesOnlyActiveAndPartiallyRedeemed()
    {
        await using var context = CreateContext();
        context.GiftCertificates.AddRange(
            new GiftCertificate { Id = 1, CompanyId = 1, CertificateCode = "GC-A", OriginalAmount = 100m, RedeemedAmount = 0,   Status = GiftCertificateStatus.Active,            IssueDate = DateTime.UtcNow },
            new GiftCertificate { Id = 2, CompanyId = 1, CertificateCode = "GC-P", OriginalAmount = 80m,  RedeemedAmount = 30m,  Status = GiftCertificateStatus.PartiallyRedeemed, IssueDate = DateTime.UtcNow },
            new GiftCertificate { Id = 3, CompanyId = 1, CertificateCode = "GC-V", OriginalAmount = 200m, RedeemedAmount = 200m, Status = GiftCertificateStatus.FullyRedeemed,     IssueDate = DateTime.UtcNow });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        await controller.Index(null, null);

        // Active: RemainingBalance=100, PartiallyRedeemed: 80-30=50, FullyRedeemed: excluded
        Assert.Equal(150m, controller.ViewBag.TotalValue);
        Assert.Equal(2, controller.ViewBag.TotalActive);
    }

    // ── Create — success paths ────────────────────────────────────────────

    [Fact]
    public async Task Create_WithSoldReason_SetsPurchasePriceAndGeneratesCode()
    {
        await using var context = CreateContext();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Create(new CreateGiftCertificateDto
        {
            Amount = 100m,
            IssuedReason = GiftCertificateIssuedReason.Sold,
            PurchasePrice = 80m,
            PurchasingCustomerId = null,
            RecipientName = "Jane Doe"
        });

        Assert.IsType<RedirectToActionResult>(result);

        var cert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Equal(80m, cert.PurchasePrice);
        Assert.Equal(GiftCertificateStatus.Active, cert.Status);
        Assert.Matches(@"^GC-\d{4}-\d{4}$", cert.CertificateCode);
        Assert.EndsWith("-0001", cert.CertificateCode);
    }

    [Fact]
    public async Task Create_WithNonSoldReason_NullsPurchasePriceAndPurchasingCustomerId()
    {
        await using var context = CreateContext();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Create(new CreateGiftCertificateDto
        {
            Amount = 50m,
            IssuedReason = GiftCertificateIssuedReason.Promotional,
            PurchasePrice = 50m,            // Provided but should be nulled
            PurchasingCustomerId = 7        // Provided but should be nulled
        });

        Assert.IsType<RedirectToActionResult>(result);

        var cert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Null(cert.PurchasePrice);
        Assert.Null(cert.PurchasingCustomerId);
    }

    // ── Void ─────────────────────────────────────────────────────────────

    [Fact]
    public async Task Void_ActiveCert_ChangesStatusToVoidedAndRedirectsToIndex()
    {
        await using var context = CreateContext();
        context.GiftCertificates.Add(new GiftCertificate
        {
            Id = 1, CompanyId = 1,
            CertificateCode = "GC-2604-0001",
            OriginalAmount = 100m, RedeemedAmount = 0,
            Status = GiftCertificateStatus.Active,
            IssueDate = DateTime.UtcNow
        });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Void(id: 1);

        var redirect = Assert.IsType<RedirectToActionResult>(result);
        Assert.Equal("Index", redirect.ActionName);

        var dbCert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Equal(GiftCertificateStatus.Voided, dbCert.Status);
    }

    [Fact]
    public async Task Void_FullyRedeemedCert_BlocksWithTempDataErrorAndRedirectsToDetails()
    {
        await using var context = CreateContext();
        context.GiftCertificates.Add(new GiftCertificate
        {
            Id = 2, CompanyId = 1,
            CertificateCode = "GC-2604-0002",
            OriginalAmount = 100m, RedeemedAmount = 100m,
            Status = GiftCertificateStatus.FullyRedeemed,
            IssueDate = DateTime.UtcNow
        });
        await context.SaveChangesAsync();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Void(id: 2);

        var redirect = Assert.IsType<RedirectToActionResult>(result);
        Assert.Equal("Details", redirect.ActionName);
        Assert.Contains("fully redeemed", controller.TempData["Error"]?.ToString());

        var dbCert = await context.GiftCertificates.IgnoreQueryFilters().SingleAsync();
        Assert.Equal(GiftCertificateStatus.FullyRedeemed, dbCert.Status);  // unchanged
    }

    [Fact]
    public async Task Void_NonExistentCert_ReturnsNotFound()
    {
        await using var context = CreateContext();
        var controller = CreateController(context, CreateUser(companyId: 1));

        var result = await controller.Void(id: 999);

        Assert.IsType<NotFoundResult>(result);
    }

    // ── Helpers ───────────────────────────────────────────────────────────

    private static GiftCertificatesController CreateController(
        ApplicationDbContext context,
        ApplicationUser? currentUser)
    {
        var uow = new UnitOfWork(context);
        var userManager = CreateUserManagerMock();
        userManager
            .Setup(m => m.GetUserAsync(It.IsAny<ClaimsPrincipal>()))
            .ReturnsAsync(currentUser);

        var httpContext = new DefaultHttpContext();
        var controller = new GiftCertificatesController(
            uow,
            Mock.Of<IMapper>(),
            Mock.Of<ILogger<GiftCertificatesController>>(),
            userManager.Object,
            Mock.Of<IPdfService>());

        controller.ControllerContext = new ControllerContext { HttpContext = httpContext };
        controller.TempData = new TempDataDictionary(httpContext, Mock.Of<ITempDataProvider>());
        return controller;
    }

    private static ApplicationUser CreateUser(int companyId) => new()
    {
        Id = "test-user",
        CompanyId = companyId,
        UserName = "test@example.com",
        Email = "test@example.com",
        FirstName = "Test",
        LastName = "User"
    };

    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;

        // Use a SuperAdmin user (no CompanyId claim) so that IsPlatformAdmin = true and the
        // global query filter evaluates to !IsDeleted only — not !IsDeleted && CompanyId == null,
        // which would filter out every row. DefaultHttpContext.Session throws, so we mock
        // HttpContext itself and stub Session.TryGetValue to return false (no impersonation).
        var identity = new ClaimsIdentity(
            new[] { new Claim(ClaimTypes.Role, "SuperAdmin") }, "Test");
        var principal = new ClaimsPrincipal(identity);

        byte[]? noBytes = null;
        var sessionMock = new Mock<ISession>();
        sessionMock.Setup(s => s.TryGetValue(It.IsAny<string>(), out noBytes)).Returns(false);

        var httpContextMock = new Mock<HttpContext>();
        httpContextMock.SetupGet(c => c.User).Returns(principal);
        httpContextMock.SetupGet(c => c.Session).Returns(sessionMock.Object);

        var accessor = new Mock<IHttpContextAccessor>();
        accessor.SetupGet(a => a.HttpContext).Returns(httpContextMock.Object);

        return new ApplicationDbContext(options, accessor.Object, null!);
    }
}