feat(emails): validate tags in notification emails

app/validators/tags_validator.rb

@@ -0,0 +1,64 @@
+class TagsValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    procedure = record.procedure
+    tags = record.used_type_de_champ_tags(value || '')
+
+    invalid_tags = tags.filter_map do |(tag, stable_id)|
+      tag if stable_id.nil?
+    end
+
+    invalid_for_draft_revision = invalid_tags_for_revision(record, attribute, tags, procedure.draft_revision_id)
+
+    invalid_for_published_revision = if procedure.published_revision_id.present?
+      invalid_tags_for_revision(record, attribute, tags, procedure.published_revision_id)
+    else
+      []
+    end
+
+    invalid_for_previous_revision = procedure
+      .revision_ids_with_pending_dossiers
+      .flat_map do |revision_id|
+        invalid_tags_for_revision(record, attribute, tags, revision_id)
+      end.uniq
+
+    # champ is added in draft revision but not yet published
+    champ_missing_in_published_revision = (invalid_for_published_revision - invalid_for_draft_revision)
+    add_errors(record, attribute, :champ_missing_in_published_revision, champ_missing_in_published_revision)
+
+    # champ is removed but the removal is not yet published
+    champ_missing_in_draft_revision = (invalid_for_draft_revision - invalid_for_published_revision)
+    add_errors(record, attribute, :champ_missing_in_draft_revision, champ_missing_in_draft_revision)
+
+    # champ is removed and the removal is published
+    champ_missing_in_published_and_draft_revision = invalid_for_published_revision.intersection(invalid_for_draft_revision)
+    add_errors(record, attribute, :champ_missing_in_published_and_draft_revision, champ_missing_in_published_and_draft_revision)
+
+    # champ is missing from one of the revisions in pending dossiers
+    add_errors(record, attribute, :champ_missing_in_previous_revision, invalid_for_previous_revision)
+
+    # unknown champ
+    add_errors(record, attribute, :champ_missing, invalid_tags)
+  end
+
+  private
+
+  def add_errors(record, attribute, message, tags)
+    tags.each do |tag|
+      record.errors.add(attribute, message, tag: tag)
+    end
+  end
+
+  def invalid_tags_for_revision(record, attribute, tags, revision_id)
+    revision_stable_ids = TypeDeChamp
+      .joins(:revision_types_de_champ)
+      .where(procedure_revision_types_de_champ: { revision_id: revision_id, parent_id: nil })
+      .distinct(:stable_id)
+      .pluck(:stable_id)
+
+    tags.filter_map do |(tag, stable_id)|
+      if stable_id.present? && !stable_id.in?(revision_stable_ids)
+        tag
+      end
+    end
+  end
+end