protected bool Equals(ConnectedCourse other)
{
return(string.Equals(CourseId, other.CourseId) && string.Equals(CourseId2, other.CourseId2));
}
/// <summary>
/// This method updates the (more detailed) properties of a given course such as dates, connected courses, description etc.
/// </summary>
/// <param name="course">Course for which the information should be updated</param>
/// <param name="db">Database context</param>
/// <param name="list">List of existing courses</param>
/// <param name="catalog">Course catalog</param>
/// <param name="isConnectedCourse">Determines if the current parsing happens for a connected course (is used to prevent cirular parsing)</param>
/// <returns></returns>
public async Task GetCourseDetailAsync(Course course, DatabaseContext db, List <Course> list, CourseCatalog catalog, bool isConnectedCourse = false)
{
HtmlDocument doc = await GetHtmlDocumentForCourse(course, db);
if (doc == null)
{
return;
}
var changed = false;
//case of isConnectedCourse is set to false (on PAUL website) is not handled
if (isConnectedCourse)
{
if (course.ParsedConnectedCourses.All(c => c.Name.Length > course.Name.Length))
{
var valueBefore = course.IsConnectedCourse;
course.IsConnectedCourse = false;
if (course.IsConnectedCourse != valueBefore)
{
changed = true;
}
}
else if (course.IsConnectedCourse != isConnectedCourse)
{
course.IsConnectedCourse = isConnectedCourse;
changed = true;
}
}
//Update InternalID if not set before (migration code)
if (course.InternalCourseID == null)
{
course.InternalCourseID = course.Id.Split(',')[1];
changed = true;
}
//Get Shortname
var descr = doc.DocumentNode.GetDescendantsByName("shortdescription").FirstOrDefault();
if (descr != null && course.ShortName != descr.Attributes["value"].Value)
{
course.ShortName = descr.Attributes["value"].Value;
changed = true;
}
try
{
//Termine parsen
var dates = GetDates(doc, db).ToList();
await UpdateDatesInDatabase(course, dates, db);
await UpdateExamDates(doc, db, course);
}
catch
{
//if the updating of dates fails, not the whole update should crash
PaulRepository.AddLog($"Date parsing failed for course {course.CourseId}", FatalityLevel.Error, "Date parsing");
}
//Verbundene Veranstaltungen parsen
var divs = doc.DocumentNode.GetDescendantsByClass("dl-ul-listview");
var courses = divs.FirstOrDefault(l => l.InnerHtml.Contains("Veranstaltung anzeigen"))?.ChildNodes.Where(l => l.Name == "li" && l.InnerHtml.Contains("Veranstaltung anzeigen"));
if (courses != null)
{
foreach (var c in courses)
{
var text = c.Descendants().First(n => n.Name == "strong")?.InnerText;
var name = text.Split(new[] { ' ' }, 2)[1];
var id = text.Split(new[] { ' ' }, 2)[0];
var url = c.Descendants().First(n => n.Name == "a")?.Attributes["href"].Value;
var docent = c.Descendants().Where(n => n.Name == "p").Skip(2).First().InnerText;
await _writeLock.WaitAsync();
Course c2 = list.FirstOrDefault(co => co.Id == $"{course.Catalogue.InternalID},{id}");
if (c2 == null)
{
c2 = new Course {
Name = name, TrimmedUrl = url, Catalogue = course.Catalogue, Id = $"{course.Catalogue.InternalID},{id}"
};
//db.Courses.Add(c2);
db.Entry(c2).State = EntityState.Added;
list.Add(c2);
}
//prevent that two separate threads add the connected courses
if (course.Id != c2.Id &&
!course.ParsedConnectedCourses.Any(co => co.Id == c2.Id) &&
!c2.ParsedConnectedCourses.Any(co => co.Id == course.Id))
{
var con1 = new ConnectedCourse {
CourseId = course.Id, CourseId2 = c2.Id
};
course.ParsedConnectedCourses.Add(c2);
db.ConnectedCourses.Add(con1);
var con2 = new ConnectedCourse {
CourseId = c2.Id, CourseId2 = course.Id
};
c2.ParsedConnectedCourses.Add(course);
db.ConnectedCourses.Add(con2);
}
_writeLock.Release();
}
}
//Gruppen parsen
var groups = divs.FirstOrDefault(l => l.InnerHtml.Contains("Kleingruppe anzeigen"))?.ChildNodes.Where(l => l.Name == "li");
if (groups != null)
{
var parsedTutorials = groups.Select(group =>
{
var name = group.Descendants().First(n => n.Name == "strong")?.InnerText;
var url = group.Descendants().First(n => n.Name == "a")?.Attributes["href"].Value;
return(new Course {
Id = course.Id + $",{name}", Name = name, TrimmedUrl = url, CourseId = course.Id, IsTutorial = true, Catalogue = catalog
});
});
foreach (var parsedTutorial in parsedTutorials)
{
var tutorial = course.ParsedTutorials.FirstOrDefault(t => t == parsedTutorial);
if (tutorial != null)
{
tutorial.NewUrl = parsedTutorial.TrimmedUrl;
}
}
var newTutorials = parsedTutorials.Except(course.ParsedTutorials).ToList();
if (newTutorials.Any())
{
await _writeLock.WaitAsync();
//db.Courses.AddRange(newTutorials);
foreach (var t in newTutorials)
{
var entry = db.Entry(t);
if (entry.State != EntityState.Added)
{
entry.State = EntityState.Added;
}
}
course.ParsedTutorials.AddRange(newTutorials);
_writeLock.Release();
}
var oldTutorials = course.ParsedTutorials.Except(parsedTutorials).ToList();
if (oldTutorials.Any() && parsedTutorials.Any())
{
await _writeLock.WaitAsync();
await db.Database.ExecuteSqlCommandAsync($"DELETE FROM Date Where CourseId IN ({string.Join(",", oldTutorials.Select(o => "'" + o.Id + "'"))})");
var selectedCourses = db.SelectedCourses.Where(p => oldTutorials.Any(o => o.Id == p.CourseId)).Include(s => s.Users).ThenInclude(u => u.User).ToList();
foreach (var selectedCourseUser in selectedCourses.SelectMany(s => s.Users))
{
await db.Database.ExecuteSqlCommandAsync($"DELETE FROM SelectedCourseUser Where UserId IN ({selectedCourseUser.User.Id}) And SelectedCourseId IN ({string.Join(",", selectedCourses.Select(s => "'" + s.Id + "'"))}) ");
}
await db.Database.ExecuteSqlCommandAsync($"DELETE FROM SelectedCourse Where CourseId IN ({string.Join(",", oldTutorials.Select(o => "'" + o.Id + "'"))})");
await db.Database.ExecuteSqlCommandAsync($"DELETE FROM Course Where Id IN ({string.Join(",", oldTutorials.Select(o => "'" + o.Id + "'"))})");
foreach (var old in oldTutorials)
{
course.ParsedTutorials.Remove(old);
}
_writeLock.Release();
}
}
//mark course as modified
if (changed)
{
await _writeLock.WaitAsync();
db.ChangeTracker.TrackObject(course);
_writeLock.Release();
}
}
