upload limits: show how upload limits are calculated in profiles.

* Allow mousing over the upload limit on profile pages to show the full
  formula for the upload limit calculation. In particular, show how the
  upload limit multiplier is derived from the deletion confidence.

* Refactor to avoid duplicating upload limit calculations in the
  presenter, as much as possible.

app/models/user.rb

@@ -549,6 +549,28 @@ class User < ApplicationRecord
       is_moderator? || flagger_id == id
     end
 
+    def upload_limit
+      @upload_limit ||= [max_upload_limit - used_upload_slots, 0].max
+    end
+
+    def used_upload_slots
+      uploaded_count = Post.for_user(id).where("created_at >= ?", 24.hours.ago).count
+      uploaded_comic_count = Post.for_user(id).tag_match("comic").where("created_at >= ?", 24.hours.ago).count / 3
+      uploaded_count - uploaded_comic_count
+    end
+
+    def max_upload_limit
+      [(base_upload_limit * upload_limit_multiplier).ceil, 10].max
+    end
+
+    def upload_limit_multiplier
+      (1 - (adjusted_deletion_confidence / 15.0))
+    end
+
+    def adjusted_deletion_confidence
+      [deletion_confidence(60), 15].min
+    end
+
     def base_upload_limit
       if created_at >= 1.month.ago
         10
@@ -563,25 +585,6 @@ class User < ApplicationRecord
       end
     end
 
-    def max_upload_limit
-      dcon = [deletion_confidence(60), 15].min
-      [(base_upload_limit * (1 - (dcon / 15.0))).ceil, 10].max
-    end
-
-    def upload_limit
-      @upload_limit ||= begin
-        uploaded_count = Post.for_user(id).where("created_at >= ?", 24.hours.ago).count
-        uploaded_comic_count = Post.for_user(id).tag_match("comic").where("created_at >= ?", 24.hours.ago).count / 3
-        limit = max_upload_limit - (uploaded_count - uploaded_comic_count)
-
-        if limit < 0
-          limit = 0
-        end
-
-        limit
-      end
-    end
-
     def tag_query_limit
       if is_platinum?
         Danbooru.config.base_tag_query_limit * 2

app/presenters/user_presenter.rb

@@ -68,13 +68,14 @@ class UserPresenter
       return "none"
     end
 
-    dcon = [user.deletion_confidence(60), 15].min
-    multiplier = (1 - (dcon / 15.0))
-    max_count = [(user.base_upload_limit * multiplier).ceil, 5].max
-    uploaded_count = Post.for_user(user.id).where("created_at >= ?", 24.hours.ago).count
-    uploaded_comic_count = Post.for_user(user.id).tag_match("comic").where("created_at >= ?", 24.hours.ago).count / 3
+    limit_tooltip = <<-EOS.strip_heredoc
+      Base: #{user.base_upload_limit}
+      Del. Rate: #{"%.2f" % user.adjusted_deletion_confidence}
+      Multiplier: (1 - (#{"%.2f" % user.adjusted_deletion_confidence} / 15)) = #{user.upload_limit_multiplier}
+      Upload Limit: #{user.base_upload_limit} * #{"%.2f" % user.upload_limit_multiplier} = #{user.max_upload_limit}
+    EOS
 
-    "(#{user.base_upload_limit} * #{'%0.2f' % multiplier}) - #{uploaded_count - uploaded_comic_count} = #{user.upload_limit}"
+    %{#{user.used_upload_slots} / <abbr title="#{limit_tooltip}">#{user.upload_limit}</abbr>}.html_safe
   end
 
   def uploads

app/views/users/_statistics.html.erb

@@ -31,7 +31,7 @@
 
       <tr>
         <th>Upload Limit</th>
-        <td><%= presenter.upload_limit %></td>
+        <td><%= presenter.upload_limit %> (<%= link_to "help", wiki_pages_path(title: "about:upload_limits") %>)</td>
       </tr>
 
       <tr>