Prevent the user from converting messages and warn them, if there are no puzzles

app/views/contests/show.html.slim

@@ -9,13 +9,13 @@
 
 .row
   .col.alert.alert-success
-      = t("contests.show.public_scoreboard")
-      = link_to root_url + "public/#{@contest.slug}", root_url + "public/#{@contest.slug}"
+    = t("contests.show.public_scoreboard")
+    = link_to root_url + "public/#{@contest.slug}", root_url + "public/#{@contest.slug}"
 
 .row.mb-4
   .col.alert.alert-success
-      |> URL for the public scoreboard extension:
-      = link_to "#{message_url}?token=#{@contest.generate_token_for(:token)}"
+    |> URL for the public scoreboard extension:
+    = link_to "#{message_url}?token=#{@contest.generate_token_for(:token)}"
     
 .row.mb-4
   .col-6
@@ -50,6 +50,10 @@
       .row.mt-5
         .col
           h4 = t("messages.plural").capitalize
+      - if !@puzzles.size
+        .row
+          .col.alert.alert-danger
+            | You first need to add a puzzle before converting messages to completions
       table.table.table-striped.table-hover
         thead
           tr
@@ -69,8 +73,12 @@
               td
                 = message.text
               td
-                a.btn.btn-sm.btn-secondary href=contest_message_convert_path(@contest, message) style="white-space: nowrap;"
-                  = t("helpers.buttons.add_completion")
+                - if @puzzles.size
+                  a.btn.btn-sm.btn-secondary href=contest_message_convert_path(@contest, message) style="white-space: nowrap;"
+                    = t("helpers.buttons.add_completion")
+                - else
+                  a.btn.btn-sm.btn-secondary.disabled href=contest_message_convert_path(@contest, message) style="white-space: nowrap;"
+                    = t("helpers.buttons.add_completion")
               td
                 = link_to t("helpers.buttons.delete"), contest_message_path(@contest, message), data: { turbo_method: :delete }, class: "btn btn-sm btn-danger"
   .col-6