components/LiteCharms.Features/Shop/CartPackages/Commands/Handlers/AddPackageItemCommandHandler.cs

using LiteCharms.Features.Shop.Postgres;

namespace LiteCharms.Features.CartPackages.Commands.Handlers;

public class AddPackageItemCommandHandler(IDbContextFactory<ShopDbContext> contextFactory) : IRequestHandler<AddPackageItemCommand, Result<Guid>>
{
    public async ValueTask<Result<Guid>> Handle(AddPackageItemCommand request, CancellationToken cancellationToken)
    {
        try
        {
            using var context = await contextFactory.CreateDbContextAsync(cancellationToken);

            if (!await context.Packages.AnyAsync(p => p.Id == request.PackageId, cancellationToken))
                return Result.Fail($"Could not find package by ID {request.PackageId}");

            if (!await context.ProductPrices.AnyAsync(p => p.Id == request.ProductPriceId && p.Active == true, cancellationToken))
                return Result.Fail($"Could not find an active product price by ID {request.ProductPriceId}");

            if (await context.PackageItems.AnyAsync(p => p.ProductPriceId == request.ProductPriceId && p.PackageId == request.PackageId, cancellationToken))
                return Result.Fail<Guid>($"Product price {request.ProductPriceId} is already added to this package {request.PackageId}");

            var newPackageItem = context.PackageItems.Add(new Entities.PackageItem
            {
                PackageId = request.PackageId,
                ProductPriceId = request.ProductPriceId,
                Active = true
            });

            return await context.SaveChangesAsync(cancellationToken) > 0
                ? Result.Ok(newPackageItem.Entity.Id)
                : Result.Fail<Guid>($"Failed to add new package item by ID {request.ProductPriceId}");
        }
        catch (Exception ex)
        {
            return Result.Fail<Guid>(new Error(ex.Message).CausedBy(ex));
        }
    }
}