refactor: Rationalize SQL dialect and statement code, to simplify adding new dialects

sqrl-planner/src/main/java/com/datasqrl/calcite/SqrlConfigurations.java

@@ -20,7 +20,7 @@
 
 public class SqrlConfigurations {
 
-  public static final UnaryOperator<SqlWriterConfig> sqlToString =
+  public static final UnaryOperator<SqlWriterConfig> SQL_TO_STRING =
       c ->
           c.withAlwaysUseParentheses(false)
               .withSelectListItemsOnSeparateLines(false)

sqrl-planner/src/main/java/com/datasqrl/calcite/convert/AbstractSqlConverters.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright © 2021 DataSQRL (contact@datasqrl.com)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datasqrl.calcite.convert;
+
+import com.datasqrl.calcite.Dialect;
+import com.datasqrl.calcite.DynamicParamSqlPrettyWriter;
+import com.datasqrl.calcite.SqrlConfigurations;
+import java.util.Map;
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import org.apache.calcite.rel.RelNode;
+import org.apache.calcite.rel.rel2sql.RelToSqlConverterWithHints;
+import org.apache.calcite.sql.CalciteFixes;
+import org.apache.calcite.sql.SqlDialect;
+import org.apache.calcite.sql.SqlNode;
+import org.apache.calcite.sql.pretty.SqlPrettyWriter;
+
+@RequiredArgsConstructor(access = AccessLevel.PACKAGE)
+abstract class AbstractSqlConverters implements SqlConverters {
+
+  private final Dialect dialect;
+  private final SqlDialect calciteSqlDialect;
+  private final boolean appendSelectLists;
+
+  @Override
+  public final SqlNode convert(RelNode relNode, Map<String, String> tableNameMapping) {
+    var sqlNode =
+        new RelToSqlConverterWithHints(calciteSqlDialect, tableNameMapping)
+            .visitRoot(relNode)
+            .asStatement();
+
+    if (appendSelectLists) {
+      CalciteFixes.appendSelectLists(sqlNode);
+    }
+
+    return sqlNode;
+  }
+
+  @Override
+  public final String convert(SqlNode sqlNode) {
+    var writer = createWriter();
+    sqlNode.unparse(writer, 0, 0);
+
+    return writer.toSqlString().getSql();
+  }
+
+  @Override
+  public final Dialect getDialect() {
+    return dialect;
+  }
+
+  protected SqlPrettyWriter createWriter() {
+    var baseConfig = SqlPrettyWriter.config().withDialect(calciteSqlDialect);
+    var config = SqrlConfigurations.SQL_TO_STRING.apply(baseConfig);
+
+    return new DynamicParamSqlPrettyWriter(config);
+  }
+
+  protected final SqlDialect getCalciteSqlDialect() {
+    return calciteSqlDialect;
+  }
+}

sqrl-planner/src/main/java/com/datasqrl/calcite/convert/SqlNodeToString.java → sqrl-planner/src/main/java/com/datasqrl/calcite/convert/DuckDbSqlConverters.java

@@ -16,15 +16,13 @@
 package com.datasqrl.calcite.convert;
 
 import com.datasqrl.calcite.Dialect;
-import com.datasqrl.calcite.convert.RelToSqlNode.SqlNodes;
+import com.datasqrl.calcite.dialect.DuckDbSqlDialect;
+import com.google.auto.service.AutoService;
 
-/** Converts a SqlNode to a SQL string for a given dialect */
-public interface SqlNodeToString {
-  SqlStrings convert(SqlNodes sqlNode);
+@AutoService(SqlConverters.class)
+public class DuckDbSqlConverters extends AbstractSqlConverters {
 
-  Dialect getDialect();
-
-  interface SqlStrings {
-    String getSql();
+  public DuckDbSqlConverters() {
+    super(Dialect.DUCKDB, DuckDbSqlDialect.DEFAULT, true);
   }
 }

sqrl-planner/src/main/java/com/datasqrl/util/FlinkSqlNodeToString.java → sqrl-planner/src/main/java/com/datasqrl/calcite/convert/FlinkSqlConverters.java

@@ -13,19 +13,25 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.datasqrl.util;
+package com.datasqrl.calcite.convert;
 
 import com.datasqrl.calcite.Dialect;
-import com.datasqrl.calcite.convert.RelToSqlNode.SqlNodes;
-import com.datasqrl.calcite.convert.SqlNodeToString;
 import com.datasqrl.engine.stream.flink.sql.RelToFlinkSql;
 import com.google.auto.service.AutoService;
+import java.util.Map;
+import org.apache.calcite.rel.RelNode;
+import org.apache.calcite.sql.SqlNode;
 
-@AutoService(SqlNodeToString.class)
-public class FlinkSqlNodeToString implements SqlNodeToString {
+@AutoService(SqlConverters.class)
+public class FlinkSqlConverters implements SqlConverters {
 
   @Override
-  public SqlStrings convert(SqlNodes sqlNode) {
+  public SqlNode convert(RelNode relNode, Map<String, String> tableNameMapping) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public String convert(SqlNode sqlNode) {
     // TODO: Migrate remaining FlinkRelToSqlConverter to this paradigm
     return RelToFlinkSql.convertToString(sqlNode);
   }

sqrl-planner/src/main/java/com/datasqrl/calcite/convert/RelToSqlNode.java → sqrl-planner/src/main/java/com/datasqrl/calcite/convert/PostgresSqlConverters.java

@@ -16,18 +16,13 @@
 package com.datasqrl.calcite.convert;
 
 import com.datasqrl.calcite.Dialect;
-import java.util.Map;
-import org.apache.calcite.rel.RelNode;
-import org.apache.calcite.sql.SqlNode;
+import com.datasqrl.calcite.dialect.ExtendedPostgresSqlDialect;
+import com.google.auto.service.AutoService;
 
-/** Converts a RelNode to a SqlNode for a given dialect */
-public interface RelToSqlNode {
+@AutoService(SqlConverters.class)
+public class PostgresSqlConverters extends AbstractSqlConverters {
 
-  SqlNodes convert(RelNode relNode, Map<String, String> tableNameMapping);
-
-  Dialect getDialect();
-
-  interface SqlNodes {
-    SqlNode getSqlNode();
+  public PostgresSqlConverters() {
+    super(Dialect.POSTGRES, ExtendedPostgresSqlDialect.DEFAULT, false);
   }
 }

sqrl-planner/src/main/java/com/datasqrl/calcite/convert/SnowflakeSqlNodeToString.java → sqrl-planner/src/main/java/com/datasqrl/calcite/convert/SnowflakeSqlConverters.java

@@ -16,28 +16,25 @@
 package com.datasqrl.calcite.convert;
 
 import com.datasqrl.calcite.Dialect;
-import com.datasqrl.calcite.convert.RelToSqlNode.SqlNodes;
 import com.datasqrl.calcite.dialect.ExtendedSnowflakeSqlDialect;
 import com.google.auto.service.AutoService;
 import org.apache.calcite.sql.pretty.SqlPrettyWriter;
 
-@AutoService(SqlNodeToString.class)
-public class SnowflakeSqlNodeToString implements SqlNodeToString {
+@AutoService(SqlConverters.class)
+public class SnowflakeSqlConverters extends AbstractSqlConverters {
+
+  public SnowflakeSqlConverters() {
+    super(Dialect.SNOWFLAKE, ExtendedSnowflakeSqlDialect.DEFAULT, true);
+  }
 
   @Override
-  public SqlStrings convert(SqlNodes sqlNode) {
+  protected SqlPrettyWriter createWriter() {
     var config =
         SqlPrettyWriter.config()
-            .withDialect(ExtendedSnowflakeSqlDialect.DEFAULT)
+            .withDialect(getCalciteSqlDialect())
             .withQuoteAllIdentifiers(false)
             .withIndentation(0);
-    var prettyWriter = new SqlPrettyWriter(config);
-    sqlNode.getSqlNode().unparse(prettyWriter, 0, 0);
-    return () -> prettyWriter.toSqlString().getSql();
-  }
 
-  @Override
-  public Dialect getDialect() {
-    return Dialect.SNOWFLAKE;
+    return new SqlPrettyWriter(config);
   }
 }