app.cs

namespace StockPriceWriter
{
    public class Application
    {
        private readonly IGetStockService _getStockService;
        private readonly IPublishService _publishService;

        public Application(IGetStockService getStockService, IPublishService publishService)
        {
            _getStockService = getStockService;
            _publishService = publishService;
        }

        public async Task ExecuteAsync()
        {
            var stockData = await _getStockService.GetStockDataAsync();

            foreach (var stock in stockData)
            {
                _publishService.SendMessage(new PriceChange
                {
                    Symbol = stock.Symbol,
                    Price = stock.StockPrice
                }.ToString());
            }
        }
    }
}