#39 Avoid adding the same snippet version into index multiple times

This commit introduces a check during the re/indexing of manual
snippets. It verifies whether the processed version is already assigned
to a snippet within the index. If it is, the system will not add it again.

src/Repository/ElasticRepository.php

@@ -70,7 +70,12 @@ public function addOrUpdateDocument(array $snippet): void
         $urlFragment = str_replace('/', '-', $snippet['manual_title'] . '-' . $snippet['relative_url'] . '-' . $snippet['content_hash']);
         $documentId = $urlFragment . '-' . $snippet['fragment'];
 
-        $script = new Script('ctx._source.manual_version.add(params.manual_version)');
+        $scriptCode = <<<EOD
+if (!ctx._source.manual_version.contains(params.manual_version)) {
+    ctx._source.manual_version.add(params.manual_version);
+}
+EOD;
+        $script = new Script($scriptCode);
         $script->setParam('manual_version', $snippet['manual_version']);
         $snippet['manual_version'] = [$snippet['manual_version']];
         $script->setUpsert($snippet);
@@ -126,7 +131,11 @@ protected function getDeleteQueryScript(): string
     {
         $script = <<<EOD
 if (ctx._source.manual_version.contains(params.manual_version)) {
-   ctx._source.manual_version.remove(ctx._source.manual_version.indexOf(params.manual_version));
+    for (int i=ctx._source.manual_version.length-1; i>=0; i--) {
+        if (ctx._source.manual_version[i] == params.manual_version) {
+            ctx._source.manual_version.remove(i);
+        }
+    }
 }
 if (ctx._source.manual_version.size() == 0) {
     ctx.op = "delete";