"""
MigMan ETL Transform Module.

This module handles the transformation phase of the MigMan ETL pipeline.
It processes the extracted data, applies business rules, data cleaning, and formatting
to prepare the data for loading into the target system.

The transformation process typically includes:
1. Data validation and quality checks
2. Data type conversions and formatting
3. Business rule application
4. Data enrichment and calculated fields
5. Data structure normalization
6. Comprehensive logging throughout the process

Classes:
    MigManTransform: Main class handling MigMan data transformation.
"""

import logging
from typing import Union
from nemo_library_etl.adapter._utils.db_handler_local import ETLDuckDBHandler
from nemo_library_etl.adapter.migman.config_models_migman import (
    ConfigMigMan,
)
from nemo_library_etl.adapter._utils.file_handler import ETLFileHandler
from nemo_library import NemoLibrary


class MigManTransformMapping:
    """
    Handles transformation of extracted MigMan data.

    This class manages the transformation phase of the MigMan ETL pipeline,
    providing methods to process, clean, and format the extracted data for loading
    into the target system.

    The transformer:
    - Uses NemoLibrary for core functionality and configuration
    - Integrates with Prefect logging for pipeline visibility
    - Applies business rules and data validation
    - Handles data type conversions and formatting
    - Provides data enrichment and calculated fields
    - Ensures data quality and consistency

    Attributes:
        nl (NemoLibrary): Core Nemo library instance for system integration.
        config: Configuration object from the Nemo library.
        logger: Prefect logger for pipeline execution tracking.
        cfg (PipelineMigMan): Pipeline configuration with transformation settings.
    """

    def __init__(
        self,
        nl: NemoLibrary,
        cfg: ConfigMigMan,
        logger: Union[logging.Logger, object],
        fh: ETLFileHandler,
        local_database: ETLDuckDBHandler,
    ) -> None:
        """
        Initialize the MigMan Transform instance.

        Sets up the transformer with the necessary library instances, configuration,
        and logging capabilities for the transformation process.

        Args:
            nl (NemoLibrary): Core Nemo library instance for system integration.
            cfg (PipelineMigMan): Pipeline configuration object containing
                                                          transformation settings and rules.
            logger (Union[logging.Logger, object]): Logger instance for recording execution details.
                                                   Can be a standard Python logger or Prefect logger.
        """
        self.nl = nl
        self.cfg = cfg
        self.logger = logger
        self.fh = fh
        self.local_database = local_database

        super().__init__()

    def mappings(self) -> None:
        """
        Apply mappings to the MigMan data.

        This method processes the MigMan data by applying predefined mappings
        to transform the data according to business rules and requirements.
        It ensures that the data is correctly formatted and enriched for
        subsequent loading into the target system.

        Note:
            The actual mapping logic needs to be implemented based on
            the specific MigMan system requirements and mapping definitions.
        """
        self.logger.info("Applying mappings to MigMan data")

        if not self.cfg.transform.mapping.active:
            self.logger.info("Mapping configuration is inactive, skipping mappings")
            return

        for mapping in self.cfg.transform.mapping.mappings:

            if not mapping.active:
                self.logger.info(f"Mapping {mapping} is inactive, skipping")
                continue

            self.logger.info(f"Processing mapping: {mapping}")

            # Implement mapping logic here
