rename root to library and add home with on deck WIP

src/library.cr

@@ -324,6 +324,29 @@ class Title
     return nil if idx.nil? || idx == @entries.size - 1
     @entries[idx + 1]
   end
+
+  def get_on_deck_entry(username)
+    # this assumes @entries is in order (low to high), otherwise we would need to sort first
+    # TODO: what happens if no entry has progress > 0
+    idx_latest_read_entry_reverse = -99 # hack to set var, refactor this and `return nil if` below
+    @entries.reverse.each_with_index do |e, i|
+      if load_progress(username, e.title) > 0
+        idx_latest_read_entry_reverse = i
+        break
+      end
+    end
+    return nil if idx_latest_read_entry_reverse == -99 
+    latest_read_entry = @entries.reverse[idx_latest_read_entry_reverse]
+    if load_progress(username, latest_read_entry.title) == latest_read_entry.pages
+      # return next entry (if exists)
+      if idx_latest_read_entry_reverse - 1 >= 0
+        return @entries.reverse[idx_latest_read_entry_reverse - 1]
+      end
+    else # return in progress entry
+      return latest_read_entry
+    end
+    return nil
+  end
 end
 
 class TitleInfo