Metadata & Schema

class Metadata:
    def __init__(self):
        """Container for cluster metadata including keyspaces, tables, and hosts."""

    def get_keyspace(self, keyspace):
        """
        Get metadata for a specific keyspace.

        Parameters:
        - keyspace (str): Name of the keyspace

        Returns:
        KeyspaceMetadata: Keyspace metadata or None if not found
        """

    def get_table(self, keyspace, table):
        """
        Get metadata for a specific table.

        Parameters:
        - keyspace (str): Name of the keyspace
        - table (str): Name of the table

        Returns:
        TableMetadata: Table metadata or None if not found
        """

    def get_user_type(self, keyspace, user_type):
        """
        Get metadata for a user-defined type.

        Parameters:
        - keyspace (str): Name of the keyspace
        - user_type (str): Name of the user-defined type

        Returns:
        UserType: User-defined type metadata or None if not found
        """

    def get_function(self, keyspace, function, signature):
        """
        Get metadata for a user-defined function.

        Parameters:
        - keyspace (str): Name of the keyspace
        - function (str): Name of the function
        - signature (list): Function signature (argument types)

        Returns:
        Function: Function metadata or None if not found
        """

    def get_aggregate(self, keyspace, aggregate, signature):
        """
        Get metadata for a user-defined aggregate.

        Parameters:
        - keyspace (str): Name of the keyspace
        - aggregate (str): Name of the aggregate
        - signature (list): Aggregate signature (argument types)

        Returns:
        Aggregate: Aggregate metadata or None if not found
        """

    def get_host(self, address):
        """
        Get host metadata by address.

        Parameters:
        - address (str): Host IP address

        Returns:
        Host: Host metadata or None if not found
        """

    def all_hosts(self):
        """
        Get all known hosts in the cluster.

        Returns:
        list: List of Host objects
        """

    def rebuild_schema(self, keyspace=None):
        """
        Rebuild schema metadata from the cluster.

        Parameters:
        - keyspace (str): Specific keyspace to rebuild, or None for all
        """

    @property
    def keyspaces(self):
        """dict: Dictionary mapping keyspace names to KeyspaceMetadata objects"""

    @property
    def cluster_name(self):
        """str: Name of the cluster"""

    @property
    def partitioner(self):
        """str: Partitioner used by the cluster"""

    @property
    def token_map(self):
        """TokenMap: Token mapping for the cluster"""

    @property
    def hosts(self):
        """dict: Dictionary mapping host addresses to Host objects"""

class KeyspaceMetadata:
    def __init__(self, name, durable_writes, strategy_class, strategy_options):
        """
        Metadata for a Cassandra keyspace.

        Parameters:
        - name (str): Keyspace name
        - durable_writes (bool): Whether durable writes are enabled
        - strategy_class (str): Replication strategy class
        - strategy_options (dict): Replication strategy options
        """

    @property
    def name(self):
        """str: Name of the keyspace"""

    @property
    def durable_writes(self):
        """bool: Whether durable writes are enabled"""

    @property
    def replication_strategy(self):
        """ReplicationStrategy: Replication strategy instance"""

    @property
    def tables(self):
        """dict: Dictionary mapping table names to TableMetadata objects"""

    @property
    def user_types(self):
        """dict: Dictionary mapping type names to UserType objects"""

    @property
    def functions(self):
        """dict: Dictionary mapping function signatures to Function objects"""

    @property
    def aggregates(self):
        """dict: Dictionary mapping aggregate signatures to Aggregate objects"""

    def export_as_string(self):
        """
        Export keyspace definition as CQL string.

        Returns:
        str: CQL CREATE KEYSPACE statement
        """

class TableMetadata:
    def __init__(self, keyspace, name, columns, partition_key, clustering_key, options, triggers, indexes):
        """
        Metadata for a Cassandra table.

        Parameters:
        - keyspace (str): Keyspace name
        - name (str): Table name
        - columns (list): List of ColumnMetadata objects
        - partition_key (list): Partition key columns
        - clustering_key (list): Clustering key columns
        - options (dict): Table options
        - triggers (dict): Table triggers
        - indexes (dict): Secondary indexes
        """

    @property
    def keyspace_name(self):
        """str: Name of the keyspace containing this table"""

    @property
    def name(self):
        """str: Name of the table"""

    @property
    def columns(self):
        """dict: Dictionary mapping column names to ColumnMetadata objects"""

    @property
    def partition_key(self):
        """list: List of ColumnMetadata objects forming the partition key"""

    @property
    def clustering_key(self):
        """list: List of ColumnMetadata objects forming the clustering key"""

    @property
    def primary_key(self):
        """list: Complete primary key (partition key + clustering key)"""

    @property
    def options(self):
        """dict: Table options (compaction, compression, etc.)"""

    @property
    def triggers(self):
        """dict: Dictionary mapping trigger names to TriggerMetadata objects"""

    @property
    def indexes(self):
        """dict: Dictionary mapping index names to IndexMetadata objects"""

    def export_as_string(self):
        """
        Export table definition as CQL string.

        Returns:
        str: CQL CREATE TABLE statement
        """

    def is_cql_compatible(self):
        """
        Check if table is compatible with CQL.

        Returns:
        bool: True if table can be used with CQL
        """

class ColumnMetadata:
    def __init__(self, table, name, cql_type, is_static=False, is_reversed=False):
        """
        Metadata for a table column.

        Parameters:
        - table (TableMetadata): Parent table
        - name (str): Column name
        - cql_type: CQL type of the column
        - is_static (bool): Whether column is static
        - is_reversed (bool): Whether column has reversed order
        """

    @property
    def table(self):
        """TableMetadata: Parent table metadata"""

    @property
    def name(self):
        """str: Name of the column"""

    @property
    def cql_type(self):
        """_CassandraType: CQL type of the column"""

    @property
    def is_static(self):
        """bool: Whether this is a static column"""

    @property
    def is_reversed(self):
        """bool: Whether this column has reversed clustering order"""

    @property
    def is_partition_key(self):
        """bool: Whether this column is part of the partition key"""

    @property
    def is_clustering_key(self):
        """bool: Whether this column is part of the clustering key"""

    @property
    def is_primary_key(self):
        """bool: Whether this column is part of the primary key"""

class IndexMetadata:
    def __init__(self, table, name, kind, options):
        """
        Metadata for a secondary index.

        Parameters:
        - table (TableMetadata): Parent table
        - name (str): Index name
        - kind (str): Index type/kind
        - options (dict): Index options
        """

    @property
    def table(self):
        """TableMetadata: Parent table metadata"""

    @property
    def name(self):
        """str: Name of the index"""

    @property
    def kind(self):
        """str: Type of index (COMPOSITES, KEYS, CUSTOM)"""

    @property
    def options(self):
        """dict: Index configuration options"""

    def export_as_string(self):
        """
        Export index definition as CQL string.

        Returns:
        str: CQL CREATE INDEX statement
        """

class UserType:
    def __init__(self, keyspace, name, field_names, field_types):
        """
        Metadata for a user-defined type.

        Parameters:
        - keyspace (str): Keyspace name
        - name (str): Type name
        - field_names (list): Field names
        - field_types (list): Field types
        """

    @property
    def keyspace(self):
        """str: Keyspace containing this type"""

    @property
    def name(self):
        """str: Name of the type"""

    @property
    def field_names(self):
        """list: Names of fields in this type"""

    @property
    def field_types(self):
        """list: Types of fields in this type"""

    def export_as_string(self):
        """
        Export type definition as CQL string.

        Returns:
        str: CQL CREATE TYPE statement
        """

class Function:
    def __init__(self, keyspace, name, argument_names, argument_types, body, called_on_null_input, language, return_type):
        """
        Metadata for a user-defined function.

        Parameters:
        - keyspace (str): Keyspace name
        - name (str): Function name
        - argument_names (list): Parameter names
        - argument_types (list): Parameter types
        - body (str): Function body code
        - called_on_null_input (bool): Whether function is called on null input
        - language (str): Implementation language
        - return_type: Return type
        """

    @property
    def keyspace_name(self):
        """str: Keyspace containing this function"""

    @property
    def name(self):
        """str: Name of the function"""

    @property
    def argument_names(self):
        """list: Names of function parameters"""

    @property
    def argument_types(self):
        """list: Types of function parameters"""

    @property
    def signature(self):
        """str: Function signature string"""

    @property
    def body(self):
        """str: Function implementation code"""

    @property
    def called_on_null_input(self):
        """bool: Whether function is called when input is null"""

    @property
    def language(self):
        """str: Implementation language (java, javascript, etc.)"""

    @property
    def return_type(self):
        """_CassandraType: Return type of the function"""

class Aggregate:
    def __init__(self, keyspace, name, argument_types, state_func, state_type, final_func, initial_condition, return_type):
        """
        Metadata for a user-defined aggregate.

        Parameters:
        - keyspace (str): Keyspace name
        - name (str): Aggregate name
        - argument_types (list): Input types
        - state_func (str): State function name
        - state_type: State type
        - final_func (str): Final function name
        - initial_condition: Initial state value
        - return_type: Return type
        """

    @property
    def keyspace_name(self):
        """str: Keyspace containing this aggregate"""

    @property
    def name(self):
        """str: Name of the aggregate"""

    @property
    def argument_types(self):
        """list: Types of aggregate input"""

    @property
    def signature(self):
        """str: Aggregate signature string"""

    @property
    def state_func(self):
        """str: Name of the state function"""

    @property
    def state_type(self):
        """_CassandraType: Type of the state value"""

    @property
    def final_func(self):
        """str: Name of the final function"""

    @property
    def initial_condition(self):
        """Initial state value"""

    @property
    def return_type(self):
        """_CassandraType: Return type of the aggregate"""

class ReplicationStrategy:
    """Base class for replication strategies."""

    @property
    def name(self):
        """str: Name of the replication strategy"""

    @property
    def options(self):
        """dict: Strategy configuration options"""

class SimpleStrategy(ReplicationStrategy):
    def __init__(self, replication_factor):
        """
        Simple replication strategy for single-datacenter clusters.

        Parameters:
        - replication_factor (int): Number of replicas
        """

    @property
    def replication_factor(self):
        """int: Number of replicas"""

class NetworkTopologyStrategy(ReplicationStrategy):
    def __init__(self, dc_replication_factors):
        """
        Network topology replication strategy for multi-datacenter clusters.

        Parameters:
        - dc_replication_factors (dict): Replication factors by datacenter
        """

    @property
    def dc_replication_factors(self):
        """dict: Replication factors by datacenter name"""

class LocalStrategy(ReplicationStrategy):
    def __init__(self):
        """Local replication strategy (for system keyspaces)."""

class TokenMap:
    def __init__(self, token_to_host_owner, tokens_to_host_owners, ring):
        """
        Token mapping for cluster routing.

        Parameters:
        - token_to_host_owner (dict): Mapping of tokens to primary hosts
        - tokens_to_host_owners (dict): Mapping of tokens to replica sets
        - ring (list): Ordered list of tokens in the ring
        """

    def get_replicas(self, keyspace, token):
        """
        Get replica hosts for a token in a keyspace.

        Parameters:
        - keyspace (str): Keyspace name
        - token: Token to look up

        Returns:
        set: Set of Host objects that are replicas for the token
        """

    @property
    def ring(self):
        """list: Ordered list of tokens in the cluster ring"""

class Token:
    """Base class for partition tokens."""

    @property
    def value(self):
        """Token value"""

class Murmur3Token(Token):
    def __init__(self, value):
        """
        Murmur3 hash token (default partitioner).

        Parameters:
        - value (int): Token value
        """

class MD5Token(Token):
    def __init__(self, value):
        """
        MD5 hash token (legacy partitioner).

        Parameters:
        - value (int): Token value
        """

class BytesToken(Token):
    def __init__(self, value):
        """
        Bytes-based token (byte order partitioner).

        Parameters:
        - value (bytes): Token value
        """

def protect_names(names):
    """
    Quote CQL identifiers that need protection.

    Parameters:
    - names (list): List of CQL identifiers

    Returns:
    list: List of quoted identifiers
    """

def protect_name(name):
    """
    Quote a CQL identifier if it needs protection.

    Parameters:
    - name (str): CQL identifier

    Returns:
    str: Quoted identifier if needed, otherwise original name
    """

def protect_value(value):
    """
    Quote a CQL value for safe inclusion in queries.

    Parameters:
    - value: Value to quote

    Returns:
    str: Quoted value suitable for CQL
    """

def is_valid_name(name):
    """
    Check if a name is a valid unquoted CQL identifier.

    Parameters:
    - name (str): Identifier to check

    Returns:
    bool: True if the name is valid unquoted
    """

def escape_name(name):
    """
    Escape a CQL identifier for use in quoted form.

    Parameters:
    - name (str): Identifier to escape

    Returns:
    str: Escaped identifier
    """

# Get cluster metadata
metadata = cluster.metadata

print(f"Cluster name: {metadata.cluster_name}")
print(f"Partitioner: {metadata.partitioner}")
print(f"Total hosts: {len(metadata.all_hosts())}")

# List all keyspaces
print("\nKeyspaces:")
for keyspace_name in metadata.keyspaces:
    keyspace = metadata.keyspaces[keyspace_name]
    print(f"  {keyspace_name}: {keyspace.replication_strategy}")

# Explore a specific keyspace
keyspace = metadata.get_keyspace('my_app')
if keyspace:
    print(f"\nKeyspace '{keyspace.name}':")
    print(f"  Durable writes: {keyspace.durable_writes}")
    print(f"  Tables: {list(keyspace.tables.keys())}")
    print(f"  User types: {list(keyspace.user_types.keys())}")
    print(f"  Functions: {len(keyspace.functions)}")

# Get table metadata
table = metadata.get_table('my_app', 'users')
if table:
    print(f"Table: {table.keyspace_name}.{table.name}")
    
    # Show partition key
    print(f"Partition key: {[col.name for col in table.partition_key]}")
    
    # Show clustering key
    if table.clustering_key:
        print(f"Clustering key: {[col.name for col in table.clustering_key]}")
    
    # Show all columns
    print("\nColumns:")
    for col_name, column in table.columns.items():
        key_type = ""
        if column.is_partition_key:
            key_type = " (partition key)"
        elif column.is_clustering_key:
            key_type = " (clustering key)"
        elif column.is_static:
            key_type = " (static)"
        
        print(f"  {col_name}: {column.cql_type}{key_type}")
    
    # Show indexes
    if table.indexes:
        print("\nIndexes:")
        for index_name, index in table.indexes.items():
            print(f"  {index_name}: {index.kind}")
    
    # Show table options
    print(f"\nTable options: {table.options}")
    
    # Export as CQL
    print(f"\nCQL Definition:\n{table.export_as_string()}")

# Get UDT metadata
address_type = metadata.get_user_type('my_app', 'address')
if address_type:
    print(f"User type: {address_type.keyspace}.{address_type.name}")
    print("Fields:")
    for field_name, field_type in zip(address_type.field_names, address_type.field_types):
        print(f"  {field_name}: {field_type}")
    
    print(f"\nCQL Definition:\n{address_type.export_as_string()}")

# Find tables using this UDT
print(f"\nTables using {address_type.name}:")
keyspace = metadata.get_keyspace('my_app')
for table_name, table in keyspace.tables.items():
    for col_name, column in table.columns.items():
        if hasattr(column.cql_type, 'typename') and column.cql_type.typename == 'address':
            print(f"  {table_name}.{col_name}")

# Examine hosts and datacenters
print("Cluster topology:")
hosts_by_dc = {}
for host in metadata.all_hosts():
    dc = host.datacenter or 'unknown'
    if dc not in hosts_by_dc:
        hosts_by_dc[dc] = []
    hosts_by_dc[dc].append(host)

for dc, hosts in hosts_by_dc.items():
    print(f"\nDatacenter: {dc}")
    for host in hosts:
        status = "UP" if host.is_up else "DOWN"
        print(f"  {host.address} ({host.rack}): {status} - {host.release_version}")

# Examine token distribution
token_map = metadata.token_map
if token_map:
    print(f"\nToken ring has {len(token_map.ring)} tokens")
    
    # Show token ownership for a keyspace
    keyspace_name = 'my_app'
    if keyspace_name in metadata.keyspaces:
        print(f"\nReplica distribution for keyspace '{keyspace_name}':")
        sample_tokens = token_map.ring[:5]  # Sample first 5 tokens
        for token in sample_tokens:
            replicas = token_map.get_replicas(keyspace_name, token)
            replica_addresses = [host.address for host in replicas]
            print(f"  Token {token.value}: {replica_addresses}")

def compare_schemas(old_metadata, new_metadata, keyspace_name):
    """Compare two metadata snapshots to detect schema changes."""
    
    old_ks = old_metadata.get_keyspace(keyspace_name)
    new_ks = new_metadata.get_keyspace(keyspace_name)
    
    if not old_ks or not new_ks:
        print("Keyspace not found in one of the metadata snapshots")
        return
    
    # Compare tables
    old_tables = set(old_ks.tables.keys())
    new_tables = set(new_ks.tables.keys())
    
    added_tables = new_tables - old_tables
    removed_tables = old_tables - new_tables
    common_tables = old_tables & new_tables
    
    if added_tables:
        print(f"Added tables: {added_tables}")
    if removed_tables:
        print(f"Removed tables: {removed_tables}")
    
    # Compare columns in common tables
    for table_name in common_tables:
        old_table = old_ks.tables[table_name]
        new_table = new_ks.tables[table_name]
        
        old_columns = set(old_table.columns.keys())
        new_columns = set(new_table.columns.keys())
        
        added_columns = new_columns - old_columns
        removed_columns = old_columns - new_columns
        
        if added_columns:
            print(f"Table {table_name} - Added columns: {added_columns}")
        if removed_columns:
            print(f"Table {table_name} - Removed columns: {removed_columns}")

# Usage
old_metadata = cluster.metadata
# ... time passes, schema changes occur ...
cluster.metadata.rebuild_schema()
new_metadata = cluster.metadata

compare_schemas(old_metadata, new_metadata, 'my_app')

from cassandra.metadata import protect_name, protect_value

def generate_insert_query(table_metadata, data):
    """Generate INSERT query from table metadata and data."""
    
    table_name = f"{table_metadata.keyspace_name}.{protect_name(table_metadata.name)}"
    
    # Filter data to only include existing columns
    valid_columns = []
    valid_values = []
    placeholders = []
    
    for col_name, value in data.items():
        if col_name in table_metadata.columns:
            valid_columns.append(protect_name(col_name))
            valid_values.append(value)
            placeholders.append('?')
    
    if not valid_columns:
        raise ValueError("No valid columns found in data")
    
    query = f"""
        INSERT INTO {table_name} ({', '.join(valid_columns)})
        VALUES ({', '.join(placeholders)})
    """
    
    return query.strip(), valid_values

# Usage
table = metadata.get_table('my_app', 'users')
data = {
    'id': uuid.uuid4(),
    'name': 'Alice Smith',
    'email': 'alice@example.com',
    'invalid_column': 'ignored'  # This will be filtered out
}

query, values = generate_insert_query(table, data)
print(f"Generated query: {query}")
print(f"Values: {values}")

session.execute(query, values)

def analyze_keyspace_complexity(keyspace_metadata):
    """Analyze complexity metrics for a keyspace."""
    
    metrics = {
        'total_tables': len(keyspace_metadata.tables),
        'total_columns': 0,
        'total_indexes': 0,
        'tables_with_clustering': 0,
        'tables_with_static_columns': 0,
        'user_types': len(keyspace_metadata.user_types),
        'functions': len(keyspace_metadata.functions),
        'column_types': set()
    }
    
    for table in keyspace_metadata.tables.values():
        metrics['total_columns'] += len(table.columns)
        metrics['total_indexes'] += len(table.indexes)
        
        if table.clustering_key:
            metrics['tables_with_clustering'] += 1
        
        has_static = any(col.is_static for col in table.columns.values())
        if has_static:
            metrics['tables_with_static_columns'] += 1
        
        for column in table.columns.values():
            metrics['column_types'].add(type(column.cql_type).__name__)
    
    return metrics

# Usage
keyspace = metadata.get_keyspace('my_app')
if keyspace:
    complexity = analyze_keyspace_complexity(keyspace)
    print(f"Keyspace complexity analysis:")
    for metric, value in complexity.items():
        if metric == 'column_types':
            print(f"  {metric}: {sorted(value)}")
        else:
            print(f"  {metric}: {value}")