static string DownloadWebpage(string link)
{
//Check if in cache
var fname = "html_cache/" + BuildAnswerCache.CalculateMD5Hash(link) + ".txt";
Directory.CreateDirectory("html_cache");
if (File.Exists(fname))
{
//CONSOLE WRITE
Console.WriteLine("\t(already in new cache)");
return(File.ReadAllText(fname));
}
try
{
var wc = new System.Net.WebClient();
//COMMENT THIS TO ALLOW DOWNLOADS -- right now it won't actually download anything new
return(null);
string downloaded = wc.DownloadString(link);
//And save
File.WriteAllText(fname, downloaded);
return(downloaded);
}
catch
{
return(null);
}
}
static bool BuildFromCache(string link, Test test)
{
var fromCache = BuildAnswerCache.FetchCached(link);
if (fromCache == null)
{
return(false);
}
test.Questions = fromCache;
return(true);
}
public static void BuildDatabase(string[][] csvFile)
{
int totalQuestionCount = 0;
foreach (var line in csvFile)
{
Console.Title = "Parsing... Total Questions: " + totalQuestionCount + $", Skipped: {skippedQuestionCount}";
if (line.Length != 5)
{
continue;
}
//Parse CSV to useful
var link = line[0];
var category = line[1];
var subcategory = line[2];
var redownload = line[3] == "yes";
var defaultSelect = line[4] == "yes";
//Allow for dupes
if (alreadyDone.Contains(link))
{
Console.WriteLine("Duplicate link: " + link);
continue;
}
alreadyDone.Add(link);
//first, try and retreive from cache
List <QANode> nodes = BuildAnswerCache.FetchCached(link);
if (!redownload && nodes != null)
{
totalQuestionCount += nodes.Count;
//quick scan to remove any nodes that have no answers or garbage answers
var nNodes = nodes.Where(a => a.Correct.Length > 0 && a.Correct.Count(b => b < 0 || b >= a.Answers.Length) == 0).Where(a => a.Answers.Length > 0).ToList();
skippedQuestionCount += nodes.Count - nNodes.Count;
if (nodes.Count - nNodes.Count > 0)
{
Console.WriteLine($"\tDeleting {nodes.Count - nNodes.Count} questions without answers");
}
//Add UIDs
foreach (var q in nNodes)
{
q.QuestionId = BuildAnswerCache.CalculateMD5Hash(q.Question);
}
Insert(category, subcategory, defaultSelect, nNodes);
continue;
}
//Otherwise, we have to redownload
var pageData = DownloadWebpage(link);
if (pageData == null)
{
Console.WriteLine("404 Not Found: " + link);
continue;
}
Console.WriteLine($" Downloading and parsing: {link}");
var html = new HtmlAgilityPack.HtmlDocument();
html.LoadHtml(Encoding.UTF7.GetString(Encoding.UTF7.GetBytes(pageData)));
//Figure out which parser
if (link.ToLower().Contains("currentnursing"))
{
nodes = ParseCurrentNursing(link, html);
}
if (link.ToLower().Contains("nurseslabs"))
{
nodes = ParseNursesLabs(link, html);
}
//Delete questions with no answers
if (nodes != null)
{
var newNodes = nodes.Where(a => a.Correct.Length > 0 && a.Correct.Count(b => b < 0 || b >= a.Answers.Length) == 0).Where(a => a.Answers.Length > 0).ToList();
skippedQuestionCount += nodes.Count - newNodes.Count;
if (nodes.Count - newNodes.Count > 0)
{
Console.WriteLine($"\tDeleting {nodes.Count - newNodes.Count} questions without answers");
}
nodes = newNodes;
//Add UIDs
foreach (var q in nodes)
{
q.QuestionId = BuildAnswerCache.CalculateMD5Hash(q.Question);
}
}
//If not null, insert it, otherwise warn
if (nodes == null)
{
Console.WriteLine("\tFailed to Parse");
}
else
{
Insert(category, subcategory, defaultSelect, nodes);
}
if (nodes != null)
{
totalQuestionCount += nodes.Count;
}
}
//Finally, save the database
File.WriteAllText("question_db.json", Newtonsoft.Json.JsonConvert.SerializeObject(categories, Newtonsoft.Json.Formatting.Indented));
}