fix replacing asset while copying past data

Attempting to update the existing SponsorshipAssetFile by URL containing
target conference slug would result into 404. Luckily it resulted
into 404, it could overwrite existing data which is unhappy for organizers
if we lack conference_slug in asset files controller.

This patch properly handles 4 differenct scenario that
sponsorships/_form can see:

1. new: sponsorship and asset_file is new, and not submitted yet.

2. copy: sponsorship is new and asset_file belongs to other conference.
   Happens when a sponsorship is sourced using past data. Never happens
   after #create, as it does s3:CopyObject and inserts new
   unclaimed SponsorshipAssetFile.

3. unclaimed: sponsorship is new. asset_file is persisted but unclaimed.
   Happens when a sponsorship is not valid on #create.

4. existing: sponsorship and asset_file are both persisted.

> Level: Error Non-Error promise rejection captured with value: Uploader getSession failed: status=404

https://rubykaigi.sentry.io/issues/7053573751/events/5966851ed69e42fd9a976f807d7f2a69/

Author: sorah

app/views/sponsorships/_form.html.haml

@@ -199,18 +199,42 @@
       %p= t('.logo_help')
       %p= t('.logo_zip_help')
 
-    .form-group.sponsorships_form_asset_file{data: {session_endpoint: sponsorship.asset_file&.persisted? ? initiate_update_user_conference_sponsorship_asset_file_path(conference, sponsorship.asset_file) : user_conference_sponsorship_asset_files_path, session_endpoint_method: 'POST'}}
-      = form.hidden_field :asset_file_id
-      .sponsorships_form_asset_file_form (Loading)
-
-    - if sponsorship.asset_file
       :ruby
-        asset_file_url = user_conference_sponsorship_asset_file_path(conference, sponsorship.asset_file)
-        unless sponsorship.persisted? # possibly copying from another sponsorship
-          asset_file = SponsorshipAssetFile.includes(:sponsorship).find(sponsorship.asset_file_id)
-          asset_file_url = user_conference_sponsorship_asset_file_path(asset_file.sponsorship&.conference || conference, asset_file)
+        asset_file_state = :new
+        if sponsorship.asset_file&.persisted?
+          asset_file_state = :existing
+          asset_file_url = user_conference_sponsorship_asset_file_path(conference, sponsorship.asset_file)
+          # Copying from another sponsorship (:copy) or failed validation (:unclaimed)
+          if sponsorship.new_record?
+            # We need to query it again as foo.assoc=other rewrites other.foo
+            asset_sponsorship = Sponsorship.includes(:asset_file, :conference).select(:id, :conference_id).where(asset_file: {id: sponsorship.asset_file_id}).first
+            claimed_asset_file = asset_sponsorship&.asset_file
+            if claimed_asset_file
+              asset_file_state = :copy
+              asset_file_url = user_conference_sponsorship_asset_file_path(asset_sponsorship.conference, claimed_asset_file)
+              raise "asset_file_state=:copy, assertion failed, conference_id must differ when copy; asset_file_id=#{sponsorship.asset_file.id}" unless asset_sponsorship.conference_id != conference.id
+            else
+              asset_file_state = :unclaimed
+              asset_file_url = user_conference_sponsorship_asset_file_path(conference, sponsorship.asset_file)
+            end
+          end
+        end
+
+        form_params = case asset_file_state
+        when :new, :copy
+          {session_endpoint: user_conference_sponsorship_asset_files_path, session_endpoint_method: 'POST', asset_file_state: asset_file_state.to_s}
+        when :existing, :unclaimed
+          {session_endpoint: initiate_update_user_conference_sponsorship_asset_file_path(conference, sponsorship.asset_file), session_endpoint_method: 'POST', asset_file_state: asset_file_state.to_s}
+        else
+          raise "Unknown asset_file_state: #{asset_file_state}, sponsorship_asset_file_id: #{sponsorship.asset_file.id}"
         end
-      %small.form-text= link_to t('.download_logo'), asset_file_url
+
+      .form-group.sponsorships_form_asset_file{data: form_params}
+        = form.hidden_field :asset_file_id
+        .sponsorships_form_asset_file_form (Loading)
+
+        - if sponsorship.asset_file
+          %small.form-text= link_to t('.download_logo'), asset_file_url
 
     %div.py-3.sponsorships_form_asset_file_form__warning.d-none{data: {warning_kind: 'zip_asset'}}
       .card