[WIP][SPARK-51395][SQL] Refine handling of default values in procedures

sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/DefaultValue.java

@@ -0,0 +1,74 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.spark.sql.connector.catalog;
+
+import java.util.Objects;
+import javax.annotation.Nullable;
+
+import org.apache.spark.annotation.Evolving;
+import org.apache.spark.sql.connector.expressions.Expression;
+
+@Evolving
+public class DefaultValue {
+  private final String sql;
+  private final Expression expr;
+
+  public DefaultValue(String sql) {
+    this(sql, null /* no expression */);
+  }
+
+  public DefaultValue(Expression expr) {
+    this(null /* no sql */, expr);
+  }
+
+  public DefaultValue(String sql, Expression expr) {
+    if (sql == null && expr == null) {
+      throw new IllegalArgumentException("SQL and expression can't be both null");
+    }
+    this.sql = sql;
+    this.expr = expr;
+  }
+
+  @Nullable
+  public String getSql() {
+    return sql;
+  }
+
+  @Nullable
+  public Expression getExpression() {
+    return expr;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) return true;
+    if (other == null || getClass() != other.getClass()) return false;
+    DefaultValue that = (DefaultValue) other;
+    return Objects.equals(sql, that.sql) && Objects.equals(expr, that.expr);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(sql, expr);
+  }
+
+  @Override
+  public String toString() {
+    return String.format("DefaultValue{sql=%s, expression=%s}", sql, expr);
+  }
+}

sql/catalyst/src/main/java/org/apache/spark/sql/connector/catalog/procedures/ProcedureParameter.java

@@ -20,6 +20,8 @@
 import javax.annotation.Nullable;
 
 import org.apache.spark.annotation.Evolving;
+import org.apache.spark.sql.connector.catalog.DefaultValue;
+import org.apache.spark.sql.connector.expressions.Expression;
 import org.apache.spark.sql.internal.connector.ProcedureParameterImpl;
 import org.apache.spark.sql.types.DataType;
 
@@ -68,7 +70,7 @@ static Builder in(String name, DataType dataType) {
    * null if not provided.
    */
   @Nullable
-  String defaultValueExpression();
+  DefaultValue defaultValue();
 
   /**
    * Returns the comment of this parameter or null if not provided.
@@ -89,7 +91,7 @@ class Builder {
     private final Mode mode;
     private final String name;
     private final DataType dataType;
-    private String defaultValueExpression;
+    private DefaultValue defaultValue;
     private String comment;
 
     private Builder(Mode mode, String name, DataType dataType) {
@@ -99,10 +101,26 @@ private Builder(Mode mode, String name, DataType dataType) {
     }
 
     /**
-     * Sets the default value expression of the parameter.
+     * Sets the default value of the parameter using SQL.
      */
-    public Builder defaultValue(String defaultValueExpression) {
-      this.defaultValueExpression = defaultValueExpression;
+    public Builder defaultValue(String sql) {
+      this.defaultValue = new DefaultValue(sql);
+      return this;
+    }
+
+    /**
+     * Sets the default value of the parameter using an expression.
+     */
+    public Builder defaultValue(Expression expression) {
+      this.defaultValue = new DefaultValue(expression);
+      return this;
+    }
+
+    /**
+     * Sets the default value of the parameter.
+     */
+    public Builder defaultValue(DefaultValue defaultValue) {
+      this.defaultValue = defaultValue;
       return this;
     }
 
@@ -118,7 +136,7 @@ public Builder comment(String comment) {
      * Builds the stored procedure parameter.
      */
     public ProcedureParameter build() {
-      return new ProcedureParameterImpl(mode, name, dataType, defaultValueExpression, comment);
+      return new ProcedureParameterImpl(mode, name, dataType, defaultValue, comment);
     }
   }
 }

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/FunctionBuilderBase.scala

@@ -135,10 +135,11 @@ object NamedParametersSupport {
   }
 
   private def toInputParameter(param: ProcedureParameter): InputParameter = {
-    val defaultValue = Option(param.defaultValueExpression).map { expr =>
-      ResolveDefaultColumns.analyze(param.name, param.dataType, expr, "CALL")
+    val defaultValueExpr = Option(param.defaultValue).map { defaultValue =>
+      val sql = ResolveDefaultColumns.generateSQL(defaultValue)
+      ResolveDefaultColumns.analyze(param.name, param.dataType, sql, "CALL")
     }
-    InputParameter(param.name, defaultValue)
+    InputParameter(param.name, defaultValueExpr)
   }
 
   private def defaultRearrange(