Fixed updating highlights

It seems like mariadb didn't like it that updating highlights just overwrites all of them with the new ones thus it threw an error. I have now added proper updating of highlights.

src/Application/Services/BookService.cs

@@ -2,6 +2,7 @@
 using Application.Common.DTOs.Bookmarks;
 using Application.Common.DTOs.Books;
 using Application.Common.DTOs.Tags;
+using Application.Common.DTOs.Highlights;
 using Application.Common.Exceptions;
 using Application.Interfaces.Managers;
 using Application.Interfaces.Repositories;
@@ -155,17 +156,8 @@ public async Task UpdateBookAsync(string email, BookForUpdateDto bookUpdateDto)
  MergeTags(bookUpdateDto.Tags, book, user);
  continue;
  case "Highlights":
- {
- Collection<Highlight> newHighlights = new();
- foreach (var highlightInDto in bookUpdateDto.Highlights)
- {
- var highlight = _mapper.Map<Highlight>(highlightInDto);
- newHighlights.Add(highlight);
- }
- book.Highlights = newHighlights;
-
- continue;
- }
+ MergeHighlights(bookUpdateDto.Highlights, book);
+ continue;
  case "Bookmarks":
  MergeBookmarks(bookUpdateDto.Bookmarks, book);
  continue;
@@ -347,21 +339,58 @@ private void RemoveBookTagsWhichDontExistInNewTags(Book book,
  foreach (var tag in tagsToRemove) { book.Tags.Remove(tag); }
  }
 
+ private void MergeHighlights(ICollection<HighlightInDto> newHighlights, Book book)
+ {
+ RemoveHighlightsWhichDontExistInNewHighlights(book, newHighlights);
+
+ foreach (var newHighlight in newHighlights)
+ {
+ // If book already has the highlight, update it
+ var existingHighlight = book.Highlights.SingleOrDefault(h => h.HighlightId == newHighlight.Guid);
+ if (existingHighlight != null)
+ {
+ if (existingHighlight.Color != newHighlight.Color)
+ existingHighlight.Color = newHighlight.Color;
+
+ continue;
+ }
+
+ // Else add the highlight to book
+ var highlight = _mapper.Map<Highlight>(newHighlight);
+ highlight.HighlightId = highlight.HighlightId;
+ book.Highlights.Add(highlight);
+ }
+ }
+
+ /// When a book is updated, a list of highlights is sent with it. This list of highlights
+ /// is the "source of truth" and contains all highlights that the book owns.
+ /// If the database book contains highlights that the updated list of highlights
+ /// does not contain, those old highlights shall be deleted.
+ private void RemoveHighlightsWhichDontExistInNewHighlights(Book book, 
+ ICollection<HighlightInDto> newHighlights)
+ {
+ var highlightsToRemove = new List<Highlight>();
+ foreach (var highlight in book.Highlights)
+ {
+ if (newHighlights.All(h => h.Guid != highlight.HighlightId))
+ highlightsToRemove.Add(highlight);
+ }
+
+ foreach (var highlight in highlightsToRemove) { book.Highlights.Remove(highlight); }
+ }
+
  private void MergeBookmarks(ICollection<BookmarkInDto> newBookmarks, Book book)
  {
  RemoveBookmarksWhichDontExistInNewBookmarks(book, newBookmarks);
 
  foreach (var newBookmark in newBookmarks)
  {
- // If book already has the tag, update it
+ // If book already has the bookmark, update it
  var existingBookmark = book.Bookmarks.SingleOrDefault(t => t.BookmarkId == newBookmark.Guid);
  if (existingBookmark != null)
  {
  if (existingBookmark.Name != newBookmark.Name)
- {
- string prevName = existingBookmark.Name;
  existingBookmark.Name = newBookmark.Name;
- }
 
  continue;
  }
@@ -373,7 +402,7 @@ private void MergeBookmarks(ICollection<BookmarkInDto> newBookmarks, Book book)
  }
  }
 
- /// When a book is updated, a list of bookmarks is sent with it. This list of tags
+ /// When a book is updated, a list of bookmarks is sent with it. This list of bookmarks
  /// is the "source of truth" and contains all bookmarks that the book owns.
  /// If the database book contains bookmarks that the updated list of bookmarks
  /// does not contain, those old bookmarks shall be deleted.
@@ -389,4 +418,4 @@ private void RemoveBookmarksWhichDontExistInNewBookmarks(Book book,
 
  foreach (var bookmark in bookmarksToRemove) { book.Bookmarks.Remove(bookmark); }
  }
-}
+}