handle enum during vstream copy

Enable support for enums during vstream copy phase.

There are two reasons that the connector does not handle `enum` for PSDB branches.

 1. The upstream debezium-connector-vitess simply does not support
    `enum` during the VStream copy phase. It tries to cast the row value
    to an integer, but the value is a string. It seems support for
    `enum` landed in 2021
    debezium#20, and
    support for snapshots (VStream Copy) landed in 2022
    debezium#112,
    without taking the former into account. This is easily fixed by
    finding finding the index of the string
    value in the list of values obtained from `column_type` during the
    schema discovery phase at the beginning of the VStream.
 2. However, this isn't working on some PSDB branches which don't have
    the fix vitessio/vitess#13045 for this bug
    vitessio/vitess#12981. Fixable by
    backporting the bugfix or upgrading those branches.

Signed-off-by: Max Englander <max@planetscale.com>

Author: maxenglander

src/main/java/io/debezium/connector/vitess/VitessType.java

@@ -41,10 +41,32 @@ public int getJdbcId() {
         return jdbcId;
     }
 
+    public Integer getEnumOrdinal(String value) {
+        int index = enumValues.indexOf(value);
+        if (index == -1) {
+            return Integer.valueOf(value);
+        }
+        return Integer.valueOf(index + 1);
+    }
+
     public List<String> getEnumValues() {
         return enumValues;
     }
 
+    public Long getSetNumeral(String value) {
+        String[] members = value.split(",");
+        Long result = 0L;
+        for (String member : members) {
+            long index = enumValues.indexOf(member);
+            if (index == -1) {
+                index = Long.valueOf(member);
+            }
+            Double power = Math.pow(2, index);
+            result = result + Long.valueOf(power.longValue());
+        }
+        return result;
+    }
+
     public boolean isEnum() {
         return !enumValues.isEmpty();
     }

src/main/java/io/debezium/connector/vitess/connection/ReplicationMessageColumnValueResolver.java

@@ -22,8 +22,14 @@ public static Object resolveValue(
             case Types.SMALLINT:
                 return value.asShort();
             case Types.INTEGER:
+                if (vitessType.isEnum()) {
+                    return vitessType.getEnumOrdinal(value.asString());
+                }
                 return value.asInteger();
             case Types.BIGINT:
+                if (vitessType.isEnum()) {
+                    return vitessType.getSetNumeral(value.asString());
+                }
                 return value.asLong();
             case Types.BLOB:
             case Types.BINARY:

src/test/java/io/debezium/connector/vitess/VitessConnectorIT.java

@@ -972,6 +972,28 @@ public void testInitialOnlySnapshot() throws Exception {
         stopConnector();
     }
 
+    @Test
+    public void shouldHandleEnumAndSetDuringTableCopy() throws Exception {
+        TestHelper.executeDDL("vitess_create_tables.ddl");
+
+        TestHelper.execute(INSERT_ENUM_TYPE_STMT, TEST_UNSHARDED_KEYSPACE);
+        TestHelper.execute(INSERT_SET_TYPE_STMT, TEST_UNSHARDED_KEYSPACE);
+
+        final String enumTableName = "enum_table";
+        final String setTableName = "set_table";
+
+        String tableInclude = TEST_UNSHARDED_KEYSPACE + "." + enumTableName + "," + TEST_UNSHARDED_KEYSPACE + "." + setTableName;
+        startConnector(Function.identity(), false, false, 1,
+                -1, -1, tableInclude, VitessConnectorConfig.SnapshotMode.INITIAL, TestHelper.TEST_SHARD);
+
+        int expectedRecordsCount = 2;
+        consumer = testConsumer(expectedRecordsCount);
+
+        consumer.await(TestHelper.waitTimeForRecords(), TimeUnit.SECONDS);
+
+        stopConnector();
+    }
+
     private void testOffsetStorage(boolean offsetStoragePerTask) throws Exception {
         TestHelper.executeDDL("vitess_create_tables.ddl", TEST_UNSHARDED_KEYSPACE);