using Fake.DependencyInjection;
using Oms.Application.Dtos.Marketing;
using Oms.Domain.CustomersAggregate.Repositories;
using Oms.Domain.MarketingAggregate.Entities;
using Oms.Domain.MarketingAggregate.Repositories;
using Oms.Domain.OrdersAggregate.Entities;

namespace Oms.Application.Shared;

/// <summary>
/// 订单营销快照写入与查价叠加。
/// </summary>
public class MarketingOrderHelper : IScopedDependency
{
    private readonly ICustomerRepository _customerRepository;
    private readonly IMemberLevelRepository _memberLevelRepository;
    private readonly MarketingCouponManager _couponManager;

    public MarketingOrderHelper(
        ICustomerRepository customerRepository,
        IMemberLevelRepository memberLevelRepository,
        MarketingCouponManager couponManager)
    {
        _customerRepository = customerRepository;
        _memberLevelRepository = memberLevelRepository;
        _couponManager = couponManager;
    }

    public async Task<MarketingPriceBreakdown> BuildBreakdownAsync(
        int? customerId,
        decimal receivableSubtotal,
        int? couponInstanceId,
        CancellationToken cancellationToken = default)
    {
        return await BuildBreakdownAsync(
            customerId,
            receivableSubtotal,
            receivableSubtotal,
            couponInstanceId,
            cancellationToken);
    }

    public async Task<MarketingPriceBreakdown> BuildBreakdownAsync(
        int? customerId,
        decimal receivableSubtotal,
        decimal baseFreightAmount,
        int? couponInstanceId,
        CancellationToken cancellationToken = default)
    {
        return await BuildBreakdownAsync(
            customerId,
            receivableSubtotal,
            baseFreightAmount,
            couponInstanceId,
            null,
            cancellationToken: cancellationToken);
    }

    /// <summary>
    /// 计算会员折/券互斥后的应付拆解；<paramref name="ownerOrderId"/> 为当前订单时允许使用被该订单锁定的券。
    /// </summary>
    public async Task<MarketingPriceBreakdown> BuildBreakdownAsync(
        int? customerId,
        decimal receivableSubtotal,
        decimal baseFreightAmount,
        int? couponInstanceId,
        string? destinationCountry,
        int? ownerOrderId = null,
        CancellationToken cancellationToken = default)
    {
        if (!customerId.HasValue || customerId.Value <= 0)
        {
            return MarketingBillingCalculator.Calculate(
                receivableSubtotal, baseFreightAmount, 0M, null, null, null, null);
        }

        var sessionCustomer = await _customerRepository.FirstOrDefaultAsync(x => x.Id == customerId.Value, cancellationToken);
        if (sessionCustomer == null)
        {
            return MarketingBillingCalculator.Calculate(
                receivableSubtotal, baseFreightAmount, 0M, null, null, null, null);
        }

        var mainCustomer = await MarketingCustomerHelper.ResolveMarketingMainCustomerAsync(_customerRepository, sessionCustomer, cancellationToken);
        var mainCustomerId = mainCustomer.Id;
        MemberLevel? level = null;
        if (mainCustomer.MemberLevelId.HasValue)
        {
            level = await _memberLevelRepository.FirstOrDefaultAsync(x => x.Id == mainCustomer.MemberLevelId.Value, cancellationToken);
        }

        var priceTierKey = MarketingCustomerHelper.NormalizePriceTierKeyOrDefault(mainCustomer.PriceTierKey);
        var couponInput = await _couponManager.ResolveCouponDiscountInputAsync(
            couponInstanceId, mainCustomerId, destinationCountry, ownerOrderId, cancellationToken);

        return MarketingBillingCalculator.Calculate(
            receivableSubtotal,
            baseFreightAmount,
            level?.ExtraDiscountRate ?? 0M,
            level?.Id,
            level?.LevelName,
            priceTierKey,
            couponInput);
    }

    public void ApplySnapshotToOrder(Order order, MarketingPriceBreakdown breakdown, int? couponInstanceId)
    {
        order.MemberLevelId = breakdown.MemberLevelId;
        order.PriceTierKey = breakdown.PriceTierKey;
        order.ReceivableSubtotal = breakdown.ReceivableSubtotal;
        order.LevelDiscountAmount = breakdown.LevelDiscountAmount;
        order.CouponInstanceId = couponInstanceId ?? breakdown.CouponInstanceId;
        order.CouponDiscountAmount = breakdown.CouponDiscountAmount;
        order.PayableAmount = breakdown.PayableAmount;
    }

    public async Task<List<CouponAvailableOutput>> BuildAvailableCouponsAsync(
        int? customerId,
        decimal? baseFreightAmount,
        string? destinationCountry = null,
        int? ownerOrderId = null,
        CancellationToken cancellationToken = default)
    {
        if (!customerId.HasValue || customerId.Value <= 0)
        {
            return [];
        }

        var sessionCustomer = await _customerRepository.FirstOrDefaultAsync(x => x.Id == customerId.Value, cancellationToken);
        if (sessionCustomer == null)
        {
            return [];
        }

        var mainCustomer = await MarketingCustomerHelper.ResolveMarketingMainCustomerAsync(
            _customerRepository,
            sessionCustomer,
            cancellationToken);
        return await _couponManager.BuildAvailableCouponsAsync(
            mainCustomer.Id, baseFreightAmount, destinationCountry, ownerOrderId, cancellationToken);
    }
}