Try: fix bwc tests

Author: pawankartik-elastic

x-pack/plugin/esql/qa/server/multi-clusters/src/javaRestTest/java/org/elasticsearch/xpack/esql/ccq/MultiClusterSpecIT.java

@@ -258,10 +258,12 @@ static CsvSpecReader.CsvTestCase convertToRemoteIndices(CsvSpecReader.CsvTestCas
             String[] localIndices = fromStatement.substring("FROM ".length()).split(",");
             final String remoteIndices;
             if (canUseRemoteIndicesOnly() && randomBoolean()) {
-                remoteIndices = Arrays.stream(localIndices).map(index -> "*:" + index.trim()).collect(Collectors.joining(","));
+                remoteIndices = Arrays.stream(localIndices)
+                    .map(index -> unquoteAndRequoteAsRemote(index.trim(), true))
+                    .collect(Collectors.joining(","));
             } else {
                 remoteIndices = Arrays.stream(localIndices)
-                    .map(index -> "*:" + index.trim() + "," + index.trim())
+                    .map(index -> unquoteAndRequoteAsRemote(index.trim(), false))
                     .collect(Collectors.joining(","));
             }
             var newFrom = "FROM " + remoteIndices + " " + commands[0].substring(fromStatement.length());
@@ -272,9 +274,13 @@ static CsvSpecReader.CsvTestCase convertToRemoteIndices(CsvSpecReader.CsvTestCas
             assert parts.length >= 2 : commands[0];
             String[] indices = parts[1].split(",");
             if (canUseRemoteIndicesOnly() && randomBoolean()) {
-                parts[1] = Arrays.stream(indices).map(index -> "*:" + index.trim()).collect(Collectors.joining(","));
+                parts[1] = Arrays.stream(indices)
+                    .map(index -> unquoteAndRequoteAsRemote(index.trim(), true))
+                    .collect(Collectors.joining(","));
             } else {
-                parts[1] = Arrays.stream(indices).map(index -> "*:" + index.trim() + "," + index.trim()).collect(Collectors.joining(","));
+                parts[1] = Arrays.stream(indices)
+                    .map(index -> unquoteAndRequoteAsRemote(index.trim(), false))
+                    .collect(Collectors.joining(","));
             }
             String newNewMetrics = String.join(" ", parts);
             testCase.query = newNewMetrics + query.substring(first.length());
@@ -307,6 +313,40 @@ static boolean hasIndexMetadata(String query) {
         return false;
     }
 
+    /**
+     * Since partial quoting is prohibited, we need to take the index name, unquote it,
+     * convert it to a remote index, and then requote it. For example, "employees" is unquoted,
+     * turned into the remote index *:employees, and then requoted to get "*:employees".
+     * @param index Name of the index.
+     * @param asRemoteIndexOnly If the return needs to be in the form of "*:idx,idx" or "*:idx".
+     * @return A remote index pattern that's requoted.
+     */
+    private static String unquoteAndRequoteAsRemote(String index, boolean asRemoteIndexOnly) {
+        index = index.trim();
+
+        int numOfQuotes = 0;
+        for (; numOfQuotes < index.length(); numOfQuotes++) {
+            if (index.charAt(numOfQuotes) != '"') {
+                break;
+            }
+        }
+
+        String unquoted = unquote(index, numOfQuotes);
+        if (asRemoteIndexOnly) {
+            return quote("*:" + unquoted, numOfQuotes);
+        } else {
+            return quote("*:" + unquoted + "," + unquoted, numOfQuotes);
+        }
+    }
+
+    private static String quote(String index, int numOfQuotes) {
+        return "\"".repeat(numOfQuotes) + index + "\"".repeat(numOfQuotes);
+    }
+
+    private static String unquote(String index, int numOfQuotes) {
+        return index.substring(numOfQuotes, index.length() - numOfQuotes);
+    }
+
     @Override
     protected boolean enableRoundingDoubleValuesOnAsserting() {
         return true;