/// <summary>
/// Gets a list of posts from the provided pages from a quest.
/// </summary>
/// <param name="quest">The quest being tallied.</param>
/// <param name="adapter">The quest's forum adapter.</param>
/// <param name="rangeInfo">The thread range info for the tally.</param>
/// <param name="pages">The pages that are being loaded.</param>
/// <param name="token">The cancellation token.</param>
/// <returns>Returns a list of PostComponents comprising the posts from the threads that fall within the specified range.</returns>
private async Task <List <PostComponents> > GetPostsFromPagesAsync(
IQuest quest, IForumAdapter adapter, ThreadRangeInfo rangeInfo, List <Task <HtmlDocument> > pages, CancellationToken token)
{
List <PostComponents> postsList = new List <PostComponents>();
var firstPageTask = pages.First();
while (pages.Any())
{
var finishedPage = await Task.WhenAny(pages).ConfigureAwait(false);
pages.Remove(finishedPage);
if (finishedPage.IsCanceled)
{
throw new OperationCanceledException();
}
// This will throw any pending exceptions that occurred while trying to load the page.
// This removes the need to check for finishedPage.IsFaulted.
var page = await finishedPage.ConfigureAwait(false);
if (page == null)
{
Exception ae = new Exception("Not all pages loaded. Rerun tally.");
ae.Data["Application"] = true;
throw ae;
}
var posts = from post in adapter.GetPosts(page, quest)
where post != null && post.IsVote && post.IsAfterStart(rangeInfo) &&
(quest.ReadToEndOfThread || rangeInfo.IsThreadmarkSearchResult || post.Number <= quest.EndPost)
select post;
postsList.AddRange(posts);
}
var firstPage = firstPageTask.Result;
ThreadInfo threadInfo = adapter.GetThreadInfo(firstPage);
ViewModelService.MainViewModel.VoteCounter.Title = threadInfo.Title;
// Get all posts that are not filtered out, either explicitly, or (for the thread author) implicity.
postsList = postsList
.Where(p => (
(quest.UseCustomUsernameFilters && !quest.UsernameFilter.Match(p.Author)) || (!quest.UseCustomUsernameFilters && p.Author != threadInfo.Author)) &&
(!quest.UseCustomPostFilters || !(quest.PostsToFilter.Contains(p.Number) || quest.PostsToFilter.Contains(p.IDValue))
)
)
.Distinct().OrderBy(p => p.Number).ToList();
return(postsList);
}
/// <summary>
/// Determines the page number range that will be loaded for the quest.
/// Returns a tuple of first page number, last page number, and pages to scan.
/// </summary>
/// <param name="quest">The quest being tallied.</param>
/// <param name="adapter">The forum adapter for the quest.</param>
/// <param name="threadRangeInfo">The thread range info, as provided by the adapter.</param>
/// <param name="token">The cancellation token.</param>
/// <returns>Returns a tuple of the page number info that was determined.</returns>
private async Task <Tuple <int, int, int> > GetPagesToScanAsync(
IQuest quest, IForumAdapter adapter, ThreadRangeInfo threadRangeInfo, CancellationToken token)
{
IPageProvider pageProvider = ViewModels.ViewModelService.MainViewModel.PageProvider;
int firstPageNumber = threadRangeInfo.GetStartPage(quest);
int lastPageNumber = 0;
int pagesToScan = 0;
if (threadRangeInfo.Pages > 0)
{
// If the startInfo obtained the thread pages info, just use that.
lastPageNumber = threadRangeInfo.Pages;
}
else if (quest.ReadToEndOfThread || threadRangeInfo.IsThreadmarkSearchResult)
{
// If we're reading to the end of the thread (end post 0, or based on a threadmark),
// then we need to load the first page to find out how many pages there are in the thread.
// Make sure to bypass the cache, since it may have changed since the last load.
string firstPageUrl = adapter.GetUrlForPage(firstPageNumber, quest.PostsPerPage);
HtmlDocument page = await pageProvider.GetPage(firstPageUrl, $"Page {firstPageNumber}",
CachingMode.BypassCache, ShouldCache.Yes, SuppressNotifications.No, token)
.ConfigureAwait(false);
if (page == null)
{
throw new InvalidOperationException($"Unable to load web page: {firstPageUrl}");
}
lastPageNumber = adapter.GetThreadInfo(page).Pages;
}
else
{
// If we're not reading to the end of the thread, just calculate
// what the last page number will be. Pages to scan will be the
// difference in pages +1.
lastPageNumber = quest.GetPageNumberOf(quest.EndPost);
}
pagesToScan = lastPageNumber - firstPageNumber + 1;
Tuple <int, int, int> result = new Tuple <int, int, int>(firstPageNumber, lastPageNumber, pagesToScan);
return(result);
}