components/LiteCharms.Features/Refunds/Commands/Handlers/RefundCustomerCommandHandler.cs

using LiteCharms.Infrastructure.Database;

namespace LiteCharms.Features.Refunds.Commands.Handlers;

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

            if(!await context.Orders.AnyAsync(o => o.Id == request.OrderId, cancellationToken))
                return Result.Fail<Guid>(new Error($"Order with Id: {request.OrderId} does not exist"));

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

            if(!await context.Orders.AnyAsync(o => o.Id == request.OrderId && o.CustomerId == request.CustomerId, cancellationToken))
                return Result.Fail<Guid>(new Error($"Order with Id: {request.OrderId} does not belong to Customer with Id: {request.CustomerId}"));

            var refund = context.OrderRefunds.Add(new Entities.OrderRefund
            {
                OrderId = request.OrderId,
                Reason = request.Reason,
                Amount = request.Amount
            });

            return await context.SaveChangesAsync(cancellationToken) > 0
                ? Result.Ok(refund.Entity.Id)
                : Result.Fail<Guid>(new Error($"Failed to create refund for OrderId: {request.OrderId}"));
        }
		catch (Exception ex)
		{
            return Result.Fail<Guid>(new Error(ex.Message).CausedBy(ex));
        }
    }
}