/// <summary>
/// Merges the changes from a single read-in bookmarkfile into the local database.
/// </summary>
/// <param name="bmf"></param>
/// <returns></returns>
private static async Task <int> MergeAsync(BookMarkFile bmf)
{
int nchanges = 0;
// Now let's be very smart about combining this file in with the original.
var bookdb = BookDataContext.Get();
var currbooks = CommonQueries.BookGetAllWhichHaveUserData(bookdb);
const int CHANGES_PER_SAVE = 1000;
int nextDbSaveChange = CHANGES_PER_SAVE;
foreach (var external in bmf.BookMarkList)
{
var book = currbooks.Find(b => b.BookId == external.BookId);
if (book == null)
{
book = CommonQueries.BookGet(bookdb, external.BookId);
}
if (book == null)
{
// Prepend the BookMarkSource so that the book is clearly labeled
// as being from a bookmark file (and therefore this is kind of a fake entry)
if (!external.BookSource.StartsWith(BookData.BookSourceBookMarkFile))
{
external.BookSource = BookData.BookSourceBookMarkFile + external.BookSource;
}
// Must set all these ids to zero so that they get re-set by EF.
if (external.Review != null)
{
external.Review.Id = 0;
}
if (external.Notes != null)
{
external.Notes.Id = 0;
foreach (var note in external.Notes.Notes)
{
note.Id = 0;
}
}
if (external.NavigationData != null)
{
external.NavigationData.Id = 0;
}
external.DownloadData = null; // on this computer, nothing has been downloaded.
CommonQueries.BookAdd(bookdb, external, CommonQueries.ExistHandling.IfNotExists);
nchanges++;
App.Error($"NOTE: adding external {external.BookId} name {external.Title}");
}
else
{
// Great -- now I can merge the UserReview, Notes, and BookNavigationData.
int nbookchanges = 0;
if (external.Review != null)
{
if (book.Review == null)
{
external.Review.Id = 0; // clear it out so that EF will set to the correct value.
book.Review = external.Review;
nbookchanges++;
}
else
{
nbookchanges += book.Review.Merge(external.Review);
}
}
if (external.NavigationData != null)
{
if (book.NavigationData == null)
{
external.NavigationData.Id = 0; // clear it out so that EF will set to the correct value.
book.NavigationData = external.NavigationData;
nbookchanges++;
}
else
{
nbookchanges += book.NavigationData.Merge(external.NavigationData);
}
}
if (external.Notes != null)
{
if (book.Notes == null)
{
// Copy them all over
book.Notes = new BookNotes()
{
BookId = external.Notes.BookId,
};
foreach (var note in external.Notes.Notes)
{
note.Id = 0; // reset to zero to insert into the currrent book.
book.Notes.Notes.Add(note);
}
nbookchanges++;
}
else
{
// Add in only the changed notes. The ids will not be the same
nbookchanges += book.Notes.Merge(external.Notes);
}
}
if (nbookchanges > 0)
{
; // hook to hang the debugger on.
}
nchanges += nbookchanges;
if (nchanges > nextDbSaveChange)
{
await bookdb.SaveChangesAsync();
nextDbSaveChange = nchanges + CHANGES_PER_SAVE;
}
}
}
// And save at the end!
if (nchanges > 0)
{
await bookdb.SaveChangesAsync();
}
return(nchanges);
}
