Catalog Integration

/**
 * Catalog manager integration (from flink-table-api-java)
 * Provides centralized catalog and database management
 */
public interface CatalogManager {
  
  /**
   * Registers a catalog with the catalog manager
   * @param catalogName Name of the catalog
   * @param catalog Catalog instance to register
   */
  void registerCatalog(String catalogName, Catalog catalog);
  
  /**
   * Gets a registered catalog by name
   * @param catalogName Name of the catalog
   * @return Optional catalog instance
   */
  Optional<Catalog> getCatalog(String catalogName);
  
  /**
   * Lists all registered catalog names
   * @return Set of catalog names
   */
  Set<String> listCatalogs();
  
  /**
   * Sets the current catalog
   * @param catalogName Name of catalog to set as current
   */
  void setCurrentCatalog(String catalogName);
  
  /**
   * Gets the current catalog name
   * @return Current catalog name
   */
  String getCurrentCatalog();
  
  /**
   * Sets the current database within current catalog
   * @param databaseName Database name to set as current
   */
  void setCurrentDatabase(String databaseName);
  
  /**
   * Gets the current database name
   * @return Current database name
   */
  String getCurrentDatabase();
  
  /**
   * Resolves object identifier to qualified name
   * @param identifier Object identifier to resolve
   * @return Fully qualified object identifier
   */
  ObjectIdentifier qualifyIdentifier(UnresolvedIdentifier identifier);
}

/**
 * Function catalog integration (from flink-table-api-java)
 * Manages function registration, lookup, and resolution
 */
public interface FunctionCatalog {
  
  /**
   * Registers a temporary system function
   * @param name Function name
   * @param functionDefinition Function definition
   */
  void registerTemporarySystemFunction(String name, FunctionDefinition functionDefinition);
  
  /**
   * Registers a temporary catalog function
   * @param objectIdentifier Function identifier with catalog/database/name
   * @param functionDefinition Function definition
   * @param ignoreIfExists Whether to ignore if function already exists
   */
  void registerTemporaryCatalogFunction(
    ObjectIdentifier objectIdentifier,
    FunctionDefinition functionDefinition,
    boolean ignoreIfExists
  );
  
  /**
   * Drops a temporary system function
   * @param name Function name to drop
   * @return True if function was dropped, false if not found
   */
  boolean dropTemporarySystemFunction(String name);
  
  /**
   * Drops a temporary catalog function
   * @param identifier Function identifier
   * @param ignoreIfNotExist Whether to ignore if function doesn't exist
   * @return True if function was dropped
   */
  boolean dropTemporaryCatalogFunction(ObjectIdentifier identifier, boolean ignoreIfNotExist);
  
  /**
   * Looks up function by identifier
   * @param objectIdentifier Function identifier
   * @return Optional function lookup result
   */
  Optional<FunctionLookup.Result> lookupFunction(ObjectIdentifier objectIdentifier);
  
  /**
   * Lists user-defined functions in given catalog and database
   * @param catalogName Catalog name
   * @param databaseName Database name
   * @return Array of function names
   */
  String[] listFunctions(String catalogName, String databaseName);
  
  /**
   * Lists temporary functions
   * @return Array of temporary function names
   */
  String[] listTemporaryFunctions();
}

/**
 * Table source utilities for catalog integration
 */
object TableSourceUtil {
  
  /**
   * Validates table source capabilities and configuration
   * @param tableSource Table source to validate
   * @param schema Expected table schema
   * @throws ValidationException if source is invalid
   */
  def validateTableSource(tableSource: TableSource[_], schema: TableSchema): Unit
  
  /**
   * Creates dynamic table source from catalog table
   * @param catalogTable Catalog table definition
   * @param context Dynamic table context
   * @return Dynamic table source instance
   */
  def createDynamicTableSource(
    catalogTable: CatalogBaseTable,
    context: DynamicTableSource.Context
  ): DynamicTableSource
  
  /**
   * Extracts watermark strategy from table source
   * @param tableSource Table source with watermark information
   * @return Optional watermark strategy
   */
  def extractWatermarkStrategy(tableSource: TableSource[_]): Option[WatermarkStrategy[_]]
  
  /**
   * Validates partition information for partitioned sources
   * @param partitions Partition specifications
   * @param tableSchema Table schema with partition keys
   * @throws ValidationException if partitions are invalid
   */
  def validatePartitions(
    partitions: java.util.List[CatalogPartitionSpec],
    tableSchema: TableSchema
  ): Unit
  
  /**
   * Creates table source from legacy table factory
   * @param properties Table properties from catalog
   * @param isTemporary Whether this is a temporary table
   * @return Legacy table source instance
   */
  def createTableSource(
    properties: java.util.Map[String, String],
    isTemporary: Boolean
  ): TableSource[_]
}

/**
 * Schema evolution utilities for catalog integration
 */
public class SchemaEvolutionUtil {
  
  /**
   * Checks schema compatibility between versions
   * @param oldSchema Previous schema version
   * @param newSchema New schema version
   * @return Compatibility check result
   */
  public static CompatibilityResult checkCompatibility(
    TableSchema oldSchema,
    TableSchema newSchema
  );
  
  /**
   * Evolves schema with backward compatibility
   * @param currentSchema Current schema
   * @param evolutionSpec Schema evolution specification
   * @return Evolved schema
   * @throws SchemaEvolutionException if evolution is not compatible
   */
  public static TableSchema evolveSchema(
    TableSchema currentSchema,
    SchemaEvolutionSpec evolutionSpec
  ) throws SchemaEvolutionException;
  
  /**
   * Validates column changes for compatibility
   * @param oldColumn Old column definition
   * @param newColumn New column definition
   * @return True if change is compatible
   */
  public static boolean isColumnChangeCompatible(
    TableColumn oldColumn,
    TableColumn newColumn
  );
  
  /**
   * Creates schema projection for subset of columns
   * @param originalSchema Original table schema
   * @param selectedFields Selected field names
   * @return Projected schema with selected fields only
   */
  public static TableSchema projectSchema(
    TableSchema originalSchema,
    List<String> selectedFields
  );
}

/**
 * Built-in catalog types supported by Flink
 */
public enum CatalogType {
  GENERIC_IN_MEMORY,    // GenericInMemoryCatalog - for testing and temporary use
  HIVE,                 // HiveCatalog - Apache Hive Metastore integration
  JDBC,                 // JdbcCatalog - JDBC-based catalog storage
  ELASTICSEARCH,        // ElasticsearchCatalog - for Elasticsearch integration
  CUSTOM                // Custom catalog implementations
}

/**
 * Catalog configuration properties
 */
public class CatalogProperties {
  public static final String CATALOG_TYPE = "type";
  public static final String CATALOG_DEFAULT_DATABASE = "default-database";
  public static final String CATALOG_HIVE_CONF_DIR = "hive-conf-dir";
  public static final String CATALOG_HIVE_VERSION = "hive-version";
  public static final String CATALOG_JDBC_URL = "default-database.jdbc.url";
  public static final String CATALOG_JDBC_USERNAME = "default-database.jdbc.username";
  public static final String CATALOG_JDBC_PASSWORD = "default-database.jdbc.password";
}

/**
 * Catalog factory for creating catalog instances
 */
public interface CatalogFactory extends Factory {
  
  /**
   * Creates catalog instance from configuration
   * @param context Factory context with configuration
   * @return Created catalog instance
   */
  Catalog createCatalog(Context context);
  
  /**
   * Returns factory identifier
   * @return Unique factory identifier
   */
  String factoryIdentifier();
  
  /**
   * Returns required configuration options
   * @return Set of required options
   */
  Set<ConfigOption<?>> requiredOptions();
  
  /**
   * Returns optional configuration options
   * @return Set of optional options
   */
  Set<ConfigOption<?>> optionalOptions();
}

// Create table through catalog
CatalogTable catalogTable = CatalogTable.of(
  Schema.newBuilder()
    .column("id", DataTypes.BIGINT())
    .column("name", DataTypes.STRING())
    .column("ts", DataTypes.TIMESTAMP(3))
    .watermark("ts", "ts - INTERVAL '5' SECOND")
    .primaryKey("id")
    .build(),
  "Table for user data",
  Collections.emptyList(),
  tableProperties
);

ObjectPath tablePath = new ObjectPath("default_database", "users");
catalog.createTable(tablePath, catalogTable, false);

// Query table metadata
CatalogBaseTable table = catalog.getTable(tablePath);
TableSchema schema = table.getUnresolvedSchema().resolve(typeFactory);

// Create database
CatalogDatabase database = new CatalogDatabaseImpl(
  Collections.singletonMap("location", "/path/to/database"),
  "User database for analytics"
);

catalog.createDatabase("analytics_db", database, false);

// List databases and tables
List<String> databases = catalog.listDatabases();
List<String> tables = catalog.listTables("analytics_db");

/**
 * Partition management through catalog integration
 */
public interface PartitionManager {
  
  /**
   * Creates partition in catalog table
   * @param tablePath Table object path
   * @param partitionSpec Partition specification
   * @param partition Partition metadata
   * @param ignoreIfExists Whether to ignore if partition exists
   */
  void createPartition(
    ObjectPath tablePath,
    CatalogPartitionSpec partitionSpec,
    CatalogPartition partition,
    boolean ignoreIfExists
  );
  
  /**
   * Lists partitions for table
   * @param tablePath Table object path
   * @return List of partition specifications
   */
  List<CatalogPartitionSpec> listPartitions(ObjectPath tablePath);
  
  /**
   * Gets partition metadata
   * @param tablePath Table object path
   * @param partitionSpec Partition specification
   * @return Partition metadata
   */
  CatalogPartition getPartition(ObjectPath tablePath, CatalogPartitionSpec partitionSpec);
  
  /**
   * Drops partition from table
   * @param tablePath Table object path
   * @param partitionSpec Partition specification
   * @param ignoreIfNotExists Whether to ignore if partition doesn't exist
   */
  void dropPartition(
    ObjectPath tablePath,
    CatalogPartitionSpec partitionSpec,
    boolean ignoreIfNotExists
  );
}

/**
 * Statistics management through catalog
 */
public interface StatisticsManager {
  
  /**
   * Gets table statistics from catalog
   * @param objectPath Table path
   * @return Table statistics or empty if not available
   */
  Optional<CatalogTableStatistics> getTableStatistics(ObjectPath objectPath);
  
  /**
   * Gets column statistics from catalog
   * @param objectPath Table path
   * @return Column statistics or empty if not available
   */
  Optional<CatalogColumnStatistics> getTableColumnStatistics(ObjectPath objectPath);
  
  /**
   * Updates table statistics in catalog
   * @param objectPath Table path
   * @param tableStatistics Updated table statistics
   * @param ignoreIfNotExists Whether to ignore if table doesn't exist
   */
  void alterTableStatistics(
    ObjectPath objectPath,
    CatalogTableStatistics tableStatistics,
    boolean ignoreIfNotExists
  );
  
  /**
   * Updates column statistics in catalog
   * @param objectPath Table path
   * @param columnStatistics Updated column statistics
   * @param ignoreIfNotExists Whether to ignore if table doesn't exist
   */
  void alterTableColumnStatistics(
    ObjectPath objectPath,
    CatalogColumnStatistics columnStatistics,
    boolean ignoreIfNotExists
  );
}

// Create view through catalog
CatalogView catalogView = CatalogView.of(
  Schema.newBuilder()
    .column("user_id", DataTypes.BIGINT())
    .column("user_name", DataTypes.STRING())
    .build(),
  "Active users view",
  "SELECT id as user_id, name as user_name FROM users WHERE active = true",
  Collections.emptyList(),
  "Comment for active users view"
);

ObjectPath viewPath = new ObjectPath("default_database", "active_users");
catalog.createTable(viewPath, catalogView, false);

try {
  // Catalog operations that may fail
  catalog.createTable(tablePath, catalogTable, false);
} catch (TableAlreadyExistException e) {
  // Handle table already exists
} catch (DatabaseNotExistException e) {
  // Handle database doesn't exist
} catch (CatalogException e) {
  // Handle general catalog errors
}

// Function catalog error handling
try {
  functionCatalog.registerTemporaryCatalogFunction(identifier, functionDef, false);
} catch (FunctionAlreadyExistException e) {
  // Handle function already exists
} catch (ValidationException e) {
  // Handle function validation errors
}

Map<String, String> hiveProperties = new HashMap<>();
hiveProperties.put(CatalogProperties.CATALOG_TYPE, "hive");
hiveProperties.put(CatalogProperties.CATALOG_DEFAULT_DATABASE, "default");
hiveProperties.put(CatalogProperties.CATALOG_HIVE_CONF_DIR, "/opt/hive/conf");
hiveProperties.put(CatalogProperties.CATALOG_HIVE_VERSION, "3.1.2");

HiveCatalog hiveCatalog = new HiveCatalog("hive_catalog", "default", hiveConfDir);
catalogManager.registerCatalog("hive_catalog", hiveCatalog);
catalogManager.setCurrentCatalog("hive_catalog");

Map<String, String> jdbcProperties = new HashMap<>();
jdbcProperties.put(CatalogProperties.CATALOG_TYPE, "jdbc");
jdbcProperties.put(CatalogProperties.CATALOG_DEFAULT_DATABASE, "analytics");
jdbcProperties.put(CatalogProperties.CATALOG_JDBC_URL, "jdbc:postgresql://localhost:5432/metadata");
jdbcProperties.put(CatalogProperties.CATALOG_JDBC_USERNAME, "catalog_user");
jdbcProperties.put(CatalogProperties.CATALOG_JDBC_PASSWORD, "catalog_password");

JdbcCatalog jdbcCatalog = new JdbcCatalog("jdbc_catalog", "analytics", jdbcUrl, username, password);
catalogManager.registerCatalog("jdbc_catalog", jdbcCatalog);