using NSubstitute;
using PnvPanel.Application.Billing;
using PnvPanel.Application.Billing.CreatePaymentRequest;
using PnvPanel.Application.Common.Interfaces;
using PnvPanel.Application.Common.Models;
using PnvPanel.Application.Tests.TestSupport;
using PnvPanel.Domain.Billing;
using PnvPanel.Domain.Pricing;
using Xunit;

namespace PnvPanel.Application.Tests.Billing.CreatePaymentRequest;

public class CreatePaymentRequestCommandHandlerTests
{
    private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();

    private static CurrentUserProfile Profile(
        Guid userId,
        bool billingEnabled = true,
        int maxConfigs = 5,
        DateTimeOffset? paidUntil = null
    ) =>
        new(
            userId,
            "alice",
            Guid.NewGuid(),
            "premium",
            IsActivated: true,
            IsBlocked: false,
            MaxConfigs: maxConfigs,
            MaxIpLimit: 3,
            SubscriptionToken: "sub-token",
            BillingEnabled: billingEnabled,
            BillingPaidUntil: paidUntil,
            BillingSuspended: false
        );

    [Fact]
    public async Task Handle_WithConfiguredPricing_ComputesAmountAndCreatesRequest()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        var pricing = PricingSettings.CreateDefault();
        pricing.Update(500, 450, 400);
        dbContext.PricingSettings.Add(pricing);
        await dbContext.SaveChangesAsync(CancellationToken.None);

        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId, maxConfigs: 5));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.True(result.IsSuccess);
        Assert.Equal(500 * 5 * 3, result.Value.AmountSnapshot);
        Assert.Equal(PaymentRequestStatus.AwaitingPayment, result.Value.Status);
    }

    [Fact]
    public async Task Handle_WithApplicableDiscountTier_AppliesDiscountToAmount()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        var pricing = PricingSettings.CreateDefault();
        pricing.Update(500, 450, 400);
        dbContext.PricingSettings.Add(pricing);
        dbContext.PricingDiscountTiers.Add(PricingDiscountTier.Create(pricing.Id, minConfigs: 3, discountPercent: 10));
        dbContext.PricingDiscountTiers.Add(PricingDiscountTier.Create(pricing.Id, minConfigs: 6, discountPercent: 20));
        await dbContext.SaveChangesAsync(CancellationToken.None);

        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId, maxConfigs: 5));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.True(result.IsSuccess);
        // 500 * 5 * 3 = 7500, скидка 10% (порог 6 не достигнут при 5 конфигах) → 6750.
        Assert.Equal(6750, result.Value.AmountSnapshot);
    }

    [Fact]
    public async Task Handle_WhenBillingNotEnabled_ReturnsNotEnabled()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId, billingEnabled: false));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(BillingErrors.NotEnabled, result.Error);
    }

    [Fact]
    public async Task Handle_WhenRoleHasUnlimitedConfigs_ReturnsUnlimitedRoleNotSupported()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId, maxConfigs: RoleQuota.Unlimited));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(BillingErrors.UnlimitedRoleNotSupported, result.Error);
    }

    [Fact]
    public async Task Handle_WhenActiveRequestExists_ReturnsActiveRequestExists()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        dbContext.PaymentRequests.Add(PaymentRequest.Create(userId, PaymentPeriod.Quarter, 1000));
        await dbContext.SaveChangesAsync(CancellationToken.None);

        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(BillingErrors.ActiveRequestExists, result.Error);
    }

    [Fact]
    public async Task Handle_WhenPricingNotConfigured_ReturnsPricingNotConfigured()
    {
        using var dbContext = InMemoryDbContextFactory.Create();
        var userId = Guid.NewGuid();
        _identityService
            .GetProfileAsync(userId, Arg.Any<CancellationToken>())
            .Returns(Profile(userId));

        var handler = new CreatePaymentRequestCommandHandler(
            dbContext,
            _identityService,
            FakeCurrentUser.Authenticated(userId)
        );

        var result = await handler.Handle(
            new CreatePaymentRequestCommand(PaymentPeriod.Quarter),
            CancellationToken.None
        );

        Assert.False(result.IsSuccess);
        Assert.Equal(BillingErrors.PricingNotConfigured, result.Error);
    }
}