public static async Task LoadImage(SciHubData data)
{
var doc = new HtmlDocument();
doc.LoadHtml(data.Html);
data.Id = doc.DocumentNode
.SelectSingleNode(".//input[@type='hidden']")
.GetAttributeValue("value", string.Empty);
var img = doc.DocumentNode
.SelectSingleNode(".//img")
.GetAttributeValue("src", string.Empty);
var shortUrl = data.Url;
shortUrl = shortUrl.Substring(0, shortUrl.IndexOf('/', 10));
shortUrl += img;
try
{
data.ImageData = await WebUtility.SimpleByteRequest(shortUrl);
if (data.ImageData == null)
{
throw new Exception("Somehow no image data was loaded");
}
}
catch (Exception e)
{
throw new SciHubException(SciHubExceptionType.Captcha, e);
}
}
public static async Task PostCaptcha(SciHubData data, string solved)
{
var body = $"id={data.Id}&answer={solved}";
using (var res = await WebUtility.SimpleRequest(data.Url, HttpMethod.Post, body, CancellationToken.None))
{
var bytes = await res.Content.ReadAsByteArrayAsync();
if (!IsHtml(bytes))
{
data.ArticleData = bytes;
}
}
}
private static async Task <byte[]> LoadArticleInternal(SciHubData data, ICaptchaSolvingStrategy solvingStrategy)
{
var bytes = await WebUtility.SimpleByteRequest(data.Url);
if (bytes == null || bytes.Length < 6)
{
throw new SciHubException(SciHubExceptionType.Article);
}
if (!IsHtml(bytes))
{
return(bytes);
}
var fullHtml = Encoding.UTF8.GetString(bytes);
data.Html = fullHtml;
await LoadImage(data);
do
{
var solved = await solvingStrategy.Solve(data.ImageData);
if (solved.Aborted)
{
return(null);
}
if (solved.Reload)
{
return(await LoadArticleInternal(data, solvingStrategy));
}
await PostCaptcha(data, solved.Captcha);
if (data.ArticleData == null)
{
await solvingStrategy.Invalidate(solved.Captcha);
}
}while (data.ArticleData == null);
return(data.ArticleData);
}
public static async Task <byte[]> LoadArticle(string url, ICaptchaSolvingStrategy strategy)
{
var data = new SciHubData
{
Url = url
};
try
{
await strategy.Initialize();
var result = await LoadArticleInternal(data, strategy);
return(result);
}
catch
{
throw;
}
finally
{
await strategy.Finish();
}
}