API, Core: Add sqlFor API to views to handle resolving a representati…

…on for a dialect(#9247)

api/src/main/java/org/apache/iceberg/view/View.java

@@ -121,4 +121,15 @@ default UpdateLocation updateLocation() {
   default UUID uuid() {
     throw new UnsupportedOperationException("Retrieving a view's uuid is not supported");
   }
+
+  /**
+   * Returns the view representation for the given SQL dialect
+   *
+   * @return the view representation for the given SQL dialect, or null if no representation could
+   *     be resolved
+   */
+  default SQLViewRepresentation sqlFor(String dialect) {
+    throw new UnsupportedOperationException(
+        "Resolving a sql with a given dialect is not supported");
+  }
 }

core/src/main/java/org/apache/iceberg/view/BaseView.java

@@ -24,6 +24,7 @@
 import java.util.UUID;
 import org.apache.iceberg.Schema;
 import org.apache.iceberg.UpdateLocation;
+import org.apache.iceberg.relocated.com.google.common.base.Preconditions;
 
 public class BaseView implements View, Serializable {
 
@@ -103,4 +104,28 @@ public UpdateLocation updateLocation() {
   public UUID uuid() {
     return UUID.fromString(ops.current().uuid());
   }
+
+  /**
+   * This implementation of sqlFor will resolve what is considered the "closest" dialect. If an
+   * exact match is found, then that is returned. Otherwise, the first representation would be
+   * returned. If no SQL representation is found, null is returned.
+   */
+  @Override
+  public SQLViewRepresentation sqlFor(String dialect) {
+    Preconditions.checkArgument(dialect != null, "Invalid dialect: null");
+    Preconditions.checkArgument(!dialect.isEmpty(), "Invalid dialect: (empty string)");
+    SQLViewRepresentation closest = null;
+    for (ViewRepresentation representation : currentVersion().representations()) {
+      if (representation instanceof SQLViewRepresentation) {
+        SQLViewRepresentation sqlViewRepresentation = (SQLViewRepresentation) representation;
+        if (sqlViewRepresentation.dialect().equals(dialect)) {
+          return sqlViewRepresentation;
+        } else if (closest == null) {
+          closest = sqlViewRepresentation;
+        }
+      }
+    }
+
+    return closest;
+  }
 }

core/src/test/java/org/apache/iceberg/view/ViewCatalogTests.java

@@ -1669,4 +1669,52 @@ public void concurrentReplaceViewVersion() {
                   .build());
     }
   }
+
+  @Test
+  public void testSqlForMultipleDialects() {
+    TableIdentifier identifier = TableIdentifier.of("ns", "view");
+
+    if (requiresNamespaceCreate()) {
+      catalog().createNamespace(identifier.namespace());
+    }
+
+    View view =
+        catalog()
+            .buildView(identifier)
+            .withSchema(SCHEMA)
+            .withDefaultNamespace(identifier.namespace())
+            .withDefaultCatalog(catalog().name())
+            .withQuery("spark", "select * from ns.tbl")
+            .withQuery("trino", "select * from ns.tbl using X")
+            .create();
+
+    assertThat(view.sqlFor("spark").sql()).isEqualTo("select * from ns.tbl");
+    assertThat(view.sqlFor("trino").sql()).isEqualTo("select * from ns.tbl using X");
+    assertThat(view.sqlFor("unknown-dialect").sql()).isEqualTo("select * from ns.tbl");
+  }
+
+  @Test
+  public void testSqlForInvalidArguments() {
+    TableIdentifier identifier = TableIdentifier.of("ns", "view");
+
+    if (requiresNamespaceCreate()) {
+      catalog().createNamespace(identifier.namespace());
+    }
+
+    View view =
+        catalog()
+            .buildView(identifier)
+            .withSchema(SCHEMA)
+            .withDefaultNamespace(identifier.namespace())
+            .withDefaultCatalog(catalog().name())
+            .withQuery("spark", "select * from ns.tbl")
+            .create();
+
+    assertThatThrownBy(() -> view.sqlFor(null))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Invalid dialect: null");
+    assertThatThrownBy(() -> view.sqlFor(""))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Invalid dialect: (empty string)");
+  }
 }