Implement spath command with field resolution

common/src/main/java/org/opensearch/sql/common/utils/DebugUtils.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.common.utils;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.stream.Collectors;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/**
+ * Utility class for debugging operations. This class is only for debugging purpose, and not
+ * intended to be used in production code.
+ */
+public class DebugUtils {
+  // Update this to true while you are debugging. (Safe guard to avoid usage in production code. )
+  private static final boolean IS_DEBUG = false;
+  private static final Logger logger = LogManager.getLogger(DebugUtils.class);
+
+  public static <T> T debug(T obj, String message) {
+    verifyDebug();
+    print("### %s: %s (at %s)", message, stringify(obj), getCalledFrom(1));
+    return obj;
+  }
+
+  public static <T> T debug(T obj) {
+    verifyDebug();
+    print("### %s (at %s)", stringify(obj), getCalledFrom(1));
+    return obj;
+  }
+
+  private static void verifyDebug() {
+    if (!IS_DEBUG) {
+      throw new RuntimeException("DebugUtils can be used only for local debugging.");
+    }
+  }
+
+  private static void print(String format, Object... args) {
+    logger.info(String.format(format, args));
+  }
+
+  private static String getCalledFrom(int pos) {
+    RuntimeException e = new RuntimeException();
+    StackTraceElement item = e.getStackTrace()[pos + 1];
+    return item.getClassName() + "." + item.getMethodName() + ":" + item.getLineNumber();
+  }
+
+  private static String stringify(Collection<?> items) {
+    if (items == null) {
+      return "null";
+    }
+
+    if (items.isEmpty()) {
+      return "()";
+    }
+
+    String result = items.stream().map(i -> stringify(i)).collect(Collectors.joining(","));
+
+    return "(" + result + ")";
+  }
+
+  private static String stringify(Map<?, ?> map) {
+    if (map == null) {
+      return "[[null]]";
+    }
+
+    if (map.isEmpty()) {
+      return "[[EMPTY]]";
+    }
+
+    String result =
+        map.entrySet().stream()
+            .map(entry -> entry.getKey() + ": " + stringify(entry.getValue()))
+            .collect(Collectors.joining(","));
+    return "{" + result + "}";
+  }
+
+  private static String stringify(Object obj) {
+    if (obj instanceof Collection) {
+      return stringify((Collection) obj);
+    } else if (obj instanceof Map) {
+      return stringify((Map) obj);
+    }
+    return String.valueOf(obj);
+  }
+}

common/src/test/java/org/opensearch/sql/common/utils/DebugUtilsTest.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.common.utils;
+
+import static org.junit.Assert.assertThrows;
+
+import org.junit.Test;
+
+public class DebugUtilsTest {
+
+  @Test
+  public void testDebugThrowsRuntimeException() {
+    assertThrows(RuntimeException.class, () -> DebugUtils.debug("test", "test message"));
+  }
+
+  @Test
+  public void testDebugWithoutMessageThrowsRuntimeException() {
+    assertThrows(RuntimeException.class, () -> DebugUtils.debug("test"));
+  }
+}

core/src/main/java/org/opensearch/sql/analysis/Analyzer.java

@@ -104,6 +104,7 @@
 import org.opensearch.sql.ast.tree.Values;
 import org.opensearch.sql.ast.tree.Window;
 import org.opensearch.sql.common.antlr.SyntaxCheckException;
+import org.opensearch.sql.common.patterns.PatternUtils;
 import org.opensearch.sql.data.model.ExprMissingValue;
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.datasource.DataSourceService;
@@ -953,10 +954,10 @@ private Aggregation analyzePatternsAgg(Patterns node) {
     List<UnresolvedExpression> aggExprs =
         Stream.of(
                 new Alias(
-                    "pattern_count",
+                    PatternUtils.PATTERN_COUNT,
                     new AggregateFunction(BuiltinFunctionName.COUNT.name(), AllFields.of())),
                 new Alias(
-                    "sample_logs",
+                    PatternUtils.SAMPLE_LOGS,
                     new AggregateFunction(
                         BuiltinFunctionName.TAKE.name(),
                         node.getSourceField(),

core/src/main/java/org/opensearch/sql/ast/AstNodeUtils.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.ast;
+
+import lombok.experimental.UtilityClass;
+import org.opensearch.sql.ast.expression.Let;
+import org.opensearch.sql.ast.expression.subquery.SubqueryExpression;
+
+/** Utility class for AST node operations shared among visitor classes. */
+@UtilityClass
+public class AstNodeUtils {
+
+  /**
+   * Checks if an AST node contains a subquery expression.
+   *
+   * @param expr The AST node to check
+   * @return true if the node or any of its children contains a subquery expression
+   */
+  public static boolean containsSubqueryExpression(Node expr) {
+    if (expr == null) {
+      return false;
+    }
+    if (expr instanceof SubqueryExpression) {
+      return true;
+    }
+    if (expr instanceof Let l) {
+      return containsSubqueryExpression(l.getExpression());
+    }
+    for (Node child : expr.getChild()) {
+      if (containsSubqueryExpression(child)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}

core/src/main/java/org/opensearch/sql/ast/analysis/FieldResolutionContext.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.ast.analysis;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import lombok.Getter;
+import org.opensearch.sql.ast.tree.Relation;
+import org.opensearch.sql.ast.tree.UnresolvedPlan;
+
+/** Context for field resolution using stack-based traversal. */
+public class FieldResolutionContext {
+
+  @Getter private final Map<UnresolvedPlan, FieldResolutionResult> results;
+  private final Deque<FieldResolutionResult> requirementsStack;
+
+  public FieldResolutionContext() {
+    this.results = new IdentityHashMap<>();
+    this.requirementsStack = new ArrayDeque<>();
+    this.requirementsStack.push(new FieldResolutionResult(Set.of(), "*"));
+  }
+
+  public void pushRequirements(FieldResolutionResult result) {
+    requirementsStack.push(result);
+  }
+
+  public FieldResolutionResult popRequirements() {
+    return requirementsStack.pop();
+  }
+
+  public FieldResolutionResult getCurrentRequirements() {
+    if (requirementsStack.isEmpty()) {
+      throw new RuntimeException("empty stack");
+    } else {
+      return requirementsStack.peek();
+    }
+  }
+
+  public void setResult(UnresolvedPlan relation, FieldResolutionResult result) {
+    results.put(relation, result);
+  }
+
+  public Set<Relation> getRelations() {
+    return results.keySet().stream()
+        .filter(k -> k instanceof Relation)
+        .map(k -> (Relation) k)
+        .collect(Collectors.toSet());
+  }
+
+  public static String mergeWildcardPatterns(Set<String> patterns) {
+    if (patterns == null || patterns.isEmpty()) {
+      return null;
+    }
+    if (patterns.size() == 1) {
+      return patterns.iterator().next();
+    }
+    return String.join(" | ", patterns.stream().sorted().toList());
+  }
+
+  @Override
+  public String toString() {
+    return "FieldResolutionContext{relationResults=" + results + "}";
+  }
+}