components/LiteCharms.Features/ShoppingCarts/Queries/Handlers/GetCustomerShoppingCartsQueryHandler.cs

using LiteCharms.Extensions;
using LiteCharms.Features.ShoppingCarts.Queries;
using LiteCharms.Infrastructure.Database;
using LiteCharms.Models;

namespace LiteCharms.Features.ShoppingCarts.Queries.Handlers;

public class GetCustomerShoppingCartsQueryHandler(IDbContextFactory<LeadGeneratorDbContext> contextFactory) : IRequestHandler<GetCustomerShoppingCartsQuery, Result<ShoppingCart[]>>
{
    public async ValueTask<Result<ShoppingCart[]>> Handle(GetCustomerShoppingCartsQuery request, CancellationToken cancellationToken)
    {
		try
		{
            using var context = await contextFactory.CreateDbContextAsync(cancellationToken);

            if (!await context.Customers.AnyAsync(c => c.Id == request.CustomerId, cancellationToken))
                return Result.Fail<ShoppingCart[]>(new Error($"Customer with Id {request.CustomerId} does not exist."));

            var shoppingCarts = await context.ShoppingCarts.Where(sc => sc.CustomerId == request.CustomerId).ToArrayAsync(cancellationToken);

            return shoppingCarts?.Length > 0
                ? Result.Ok(shoppingCarts.Select(c => c.ToModel()).ToArray())
                : Result.Fail<ShoppingCart[]>(new Error($"No shopping carts found for customer with Id {request.CustomerId}."));
        }
		catch (Exception ex)
		{
            return Result.Fail<ShoppingCart[]>(new Error(ex.Message).CausedBy(ex));
        }
    }
}