private static async Task <Product> TrackPriceAndSaveProductAsync(WebProduct webProduct)
{
using (var dbContext = new DiscountMonitorContext())
{
var product = dbContext.Products
.Include(i => i.HistoryPrices)
.SingleOrDefault(i => i.Url.Equals(webProduct.Url));
product ??= new Product(
webProduct.Name,
webProduct.Price,
webProduct.Description,
webProduct.Url
);
product.VerifyAndTrackPrice(webProduct.Price);
if (product.PriceWasChanged)
{
Console.WriteLine("O preço do produto foi alterado.");
}
dbContext.Products.Update(product);
await dbContext.SaveChangesAsync();
return(product);
}
}
private static async Task <WebProduct> GetProductFromWebAsync(string url)
{
Console.WriteLine($"Obtendo dados do produto da página { url }.");
using (var httpClient = new HttpClient())
{
var htmlContent = await httpClient.GetStringAsync(url);
var htmlDocument = new HtmlDocument();
htmlDocument.LoadHtml(htmlContent);
var productName = htmlDocument.DocumentNode.SelectSingleNode("//h1");
var productPrice = htmlDocument.DocumentNode.SelectSingleNode("//span[@class=\"price-template__text\"]");
var ignoredTags = new[] { "h2", "table" };
var productDescription = htmlDocument.DocumentNode
.SelectSingleNode("//div[@class=\"description__container-text\"]")
.ChildNodes
.Where(i => !ignoredTags.Contains(i.OriginalName) && !string.IsNullOrWhiteSpace(i.InnerText))
.FirstOrDefault();
var product = new WebProduct
{
Name = productName.InnerText,
Price = Convert.ToDouble(productPrice.InnerText),
Description = productDescription.InnerText,
Url = url
};
return(product);
}
}