using FluentAssertions;
using Oms.Application.Dtos.Marketing;
using Oms.Application.Shared;
using Oms.Domain.MarketingAggregate.Entities;
using Oms.Domain.OrdersAggregate.Consts;
using Oms.Domain.OrdersAggregate.Entities;

namespace Oms.Tests;

public class MarketingMemberPointsTests
{
    [Fact]
    public void MemberDiscount_ShouldApplyOnlyToBaseFreight()
    {
        var result = MarketingBillingCalculator.Calculate(
            receivableSubtotal: 1200M,
            baseFreightAmount: 1000M,
            extraDiscountRate: 0.05M,
            memberLevelId: 5,
            memberLevelName: "皇冠会员",
            priceTierKey: null,
            coupon: null);

        result.LevelDiscountAmount.Should().Be(50M);
        result.PayableAmount.Should().Be(1150M);
        result.PaidBaseFreightAmount.Should().Be(950M);
        result.CouponInstanceId.Should().BeNull();
    }

    [Fact]
    public void CouponAndMember_ShouldPickCheaperWithoutStacking()
    {
        var coupon = new CouponDiscountInput
        {
            CouponInstanceId = 9,
            CouponType = MarketingCouponTypeCodes.FixedOff,
            FaceValue = 80M,
            MinOrderAmount = 0M
        };

        var result = MarketingBillingCalculator.Calculate(
            1200M,
            1000M,
            0.05M,
            5,
            "皇冠会员",
            null,
            coupon);

        result.LevelDiscountAmount.Should().Be(0M);
        result.CouponDiscountAmount.Should().Be(80M);
        result.PayableAmount.Should().Be(1120M);
        result.CouponInstanceId.Should().Be(9);
        result.PaidBaseFreightAmount.Should().Be(920M);
    }

    [Fact]
    public void Coupon_ShouldCapAtBaseFreightAndIgnoreSurcharge()
    {
        var coupon = new CouponDiscountInput
        {
            CouponInstanceId = 1,
            CouponType = MarketingCouponTypeCodes.FixedOff,
            FaceValue = 200M,
            MinOrderAmount = 0M
        };

        var result = MarketingBillingCalculator.Calculate(
            150M, 100M, 0M, null, null, null, coupon);

        result.CouponDiscountAmount.Should().Be(100M);
        result.PayableAmount.Should().Be(50M);
        result.PaidBaseFreightAmount.Should().Be(0M);
    }

    [Fact]
    public void CouponThreshold_ShouldUseBaseFreightNotOrderTotal()
    {
        var coupon = new CouponDiscountInput
        {
            CouponInstanceId = 1,
            CouponType = MarketingCouponTypeCodes.FixedOff,
            FaceValue = 15M,
            MinOrderAmount = 150M
        };

        var result = MarketingBillingCalculator.Calculate(
            250M, 140M, 0M, null, null, null, coupon);

        result.CouponDiscountAmount.Should().Be(0M);
        result.CouponInstanceId.Should().BeNull();
        result.PayableAmount.Should().Be(250M);
    }

    [Fact]
    public void CouponScope_ShouldMatchCountryCodes()
    {
        MarketingCouponScope.Matches("""{"countryCodes":["MY","SG"]}""", "MY").Should().BeTrue();
        MarketingCouponScope.Matches("""{"countryCodes":["MY","SG"]}""", "US").Should().BeFalse();
        MarketingCouponScope.Matches(null, "MY").Should().BeTrue();
    }

    [Fact]
    public void EqualOrWorseCoupon_ShouldKeepMemberDiscount()
    {
        var coupon = new CouponDiscountInput
        {
            CouponInstanceId = 9,
            CouponType = MarketingCouponTypeCodes.FixedOff,
            FaceValue = 50M
        };

        var result = MarketingBillingCalculator.Calculate(
            1200M,
            1000M,
            0.05M,
            5,
            "皇冠会员",
            null,
            coupon);

        result.LevelDiscountAmount.Should().Be(50M);
        result.CouponDiscountAmount.Should().Be(0M);
        result.CouponInstanceId.Should().BeNull();
        result.PayableAmount.Should().Be(1150M);
    }

    [Fact]
    public void DiscountRate_ShouldCapAtFivePercent()
    {
        var result = MarketingBillingCalculator.Calculate(
            1000M,
            1000M,
            0.2M,
            1,
            "测试",
            null,
            null);

        result.LevelDiscountAmount.Should().Be(50M);
    }

    [Fact]
    public void FuelSurcharge_ShouldNotCountAsBaseFreight()
    {
        var fees = new[]
        {
            new OrderFee { Type = OrderFeeTypeCodes.Receivable, CostItem = "freight", Amount = 100 },
            new OrderFee { Type = OrderFeeTypeCodes.Receivable, CostItem = "燃油附加费", Amount = 30 },
            new OrderFee { Type = OrderFeeTypeCodes.Receivable, CostItem = "偏远附加费", Amount = 20 }
        };

        MarketingFeeHelper.SumReceivableBaseFreight(fees).Should().Be(100M);
        MarketingFeeHelper.IsBaseFreightCostItem("燃油附加费").Should().BeFalse();
    }

    [Fact]
    public void V5_ShouldStepDownOneLevelOnly()
    {
        var levels = new List<MemberLevel>
        {
            new() { Id = 1, LevelCode = "V0", MinPoints = 0, CanDowngrade = false },
            new() { Id = 2, LevelCode = "V3", MinPoints = 120000, CanDowngrade = false },
            new() { Id = 3, LevelCode = "V4", MinPoints = 240000, CanDowngrade = true },
            new() { Id = 4, LevelCode = "V5", MinPoints = 600000, CanDowngrade = true }
        };
        var v5 = levels[3];
        var v0Target = levels[0];

        var next = MarketingPointsManager.ResolveNextLevel(levels, v5, v0Target, allowDowngrade: true);
        next!.LevelCode.Should().Be("V4");
    }

    [Fact]
    public void V3_ShouldNotDowngrade()
    {
        var levels = new List<MemberLevel>
        {
            new() { Id = 1, LevelCode = "V0", MinPoints = 0, CanDowngrade = false },
            new() { Id = 2, LevelCode = "V3", MinPoints = 120000, CanDowngrade = false }
        };

        var next = MarketingPointsManager.ResolveNextLevel(levels, levels[1], levels[0], allowDowngrade: true);
        next!.LevelCode.Should().Be("V3");
    }

    [Fact]
    public void Upgrade_CanJumpToMatchingLevel()
    {
        var levels = new List<MemberLevel>
        {
            new() { Id = 1, LevelCode = "V0", MinPoints = 0, CanDowngrade = false },
            new() { Id = 2, LevelCode = "V4", MinPoints = 240000, CanDowngrade = true },
            new() { Id = 3, LevelCode = "V5", MinPoints = 600000, CanDowngrade = true }
        };

        var next = MarketingPointsManager.ResolveNextLevel(levels, levels[0], levels[2], allowDowngrade: false);
        next!.LevelCode.Should().Be("V5");
    }
}