# src/rhosocial/activerecord/backend/base/sql_building.py
"""
SQL building operations mixin for backend implementations.

This mixin provides utility methods for preparing SQL statements and parameters
before execution.
"""

from typing import Optional, Tuple


class SQLBuildingMixin:
    """
    Mixin for SQL building operations.

    This mixin provides methods for preparing SQL statements and parameters
    for database execution. It works with the dialect system to ensure proper
    SQL formatting and handles database-specific transformations of SQL and parameters.
    The default implementation provides pass-through behavior, but subclasses can
    override methods to implement database-specific SQL and parameter preparation.
    """

    def _prepare_sql_and_params(self, sql: str, params: Optional[Tuple]) -> Tuple[str, Optional[Tuple]]:
        """
        Prepare SQL and parameters for database execution.

        This method performs any necessary transformations on the SQL statement
        and parameter tuple before they are passed to the database driver.
        The default implementation provides pass-through behavior, returning
        the original SQL and parameters unchanged. Subclasses should override
        this method to implement database-specific transformations such as:

        - Placeholder format conversion (e.g., '?' to '%s' or '$N')
        - SQL syntax adjustments for specific database systems
        - Parameter format adjustments for specific database drivers
        - Escaping or quoting adjustments based on database requirements

        The method is called by the execution pipeline just before passing
        the SQL and parameters to the database driver's execution method.

        Args:
            sql: The raw SQL statement string to be prepared
            params: Optional tuple of parameter values to be prepared,
                   or None if no parameters are provided

        Returns:
            A tuple containing:
            - str: The prepared SQL statement string, potentially modified
            - Optional[Tuple]: The prepared parameters tuple, potentially modified,
                             or None if no parameters were provided

        Example:
            # Default implementation (pass-through)
            return sql, params

            # PostgreSQL implementation might convert placeholders:
            prepared_sql = sql.replace('?', '$%d' % (i+1) for i in range(len(params)))
            return prepared_sql, params
        """
        return sql, params
