"""Application constants and business rule definitions.

Defines immutable constants used throughout the adjustment file preparation pipeline,
including business validation rules and schema definitions for input and staging tables.

Constants:
    - ValidationRules: Business logic constraints (UPC lengths, distribution types)
    - AdjustmentInputSchema: Input file schema with column mappings
    - AdjustmentStagingSchema: MySQL staging table schema

Data Transformation Flow:
    File (external columns) → DuckDB (normalized) → MySQL staging (final schema)
"""

from typing import Final

from src.enums import AdjustmentColumn, AdjustmentFileColumn, DuckDBTable
from src.schemas import ColumnMapping


class ValidationRules:
    """Business validation rules."""

    ACCOUNT_EXPENSE_ADJUSTMENT_TYPE: Final[str] = 'account expense'
    ACTION_STATUS_COMPLETE: Final[str] = 'complete'
    DISTRIBUTION_TYPES: Final[frozenset[str]] = frozenset({'digital', 'physical'})
    STATEMENT_PERIOD_STATUS: Final[str] = 'current'
    UPC_MIN_LENGTH: Final[int] = 12
    UPC_MAX_LENGTH: Final[int] = 13


class AdjustmentInputSchema:
    """Input file schema mapping external columns to internal database columns."""

    TABLE = DuckDBTable.ADJUSTMENT_FILE

    COLUMNS: Final[tuple[ColumnMapping, ...]] = (
        ColumnMapping(
            column_name=AdjustmentColumn.ACCOUNT_ID,
            display_name=AdjustmentFileColumn.ACCOUNT_ID,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.ACCOUNT_NAME,
            display_name=AdjustmentFileColumn.ACCOUNT_NAME,
            required=False,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.ACTIVITY_MONTH,
            display_name=AdjustmentFileColumn.ACTIVITY_MONTH,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.ACTIVITY_YEAR,
            display_name=AdjustmentFileColumn.ACTIVITY_YEAR,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.ADJUSTMENT_TYPE,
            display_name=AdjustmentFileColumn.ADJUSTMENT_TYPE,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.AMOUNT,
            display_name=AdjustmentFileColumn.AMOUNT,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.APPLY_TO_FLOWTHROUGH,
            display_name=AdjustmentFileColumn.APPLY_TO_FLOWTHROUGH,
            required=False,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.CLIENT_FACING_COMMENT,
            display_name=AdjustmentFileColumn.CLIENT_FACING_COMMENT,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.CONTRACT_ID,
            display_name=AdjustmentFileColumn.CONTRACT_ID,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.CONTRACT_NAME,
            display_name=AdjustmentFileColumn.CONTRACT_NAME,
            required=False,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.CURRENCY,
            display_name=AdjustmentFileColumn.CURRENCY,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.DISTRIBUTION_TYPE,
            display_name=AdjustmentFileColumn.DISTRIBUTION_TYPE,
            required=False,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.INTERNAL_NOTE,
            display_name=AdjustmentFileColumn.INTERNAL_NOTE,
            required=False,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.STATEMENT_MONTH,
            display_name=AdjustmentFileColumn.STATEMENT_MONTH,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.STATEMENT_YEAR,
            display_name=AdjustmentFileColumn.STATEMENT_YEAR,
            required=True,
        ),
        ColumnMapping(
            column_name=AdjustmentColumn.UPC,
            display_name=AdjustmentFileColumn.UPC,
            required=False,
        ),
    )


class AdjustmentStagingSchema:
    """MySQL staging table schema for validated adjustment data."""

    TABLE: Final[str] = 'worksheet_flowthrough'

    COLUMNS: Final[list[str]] = [
        'worksheet_flowthrough_batch_id',
        'batch_row_index',
        'account_id',
        'activity_statement_period_id',
        # 'apply_to_statement_period_id',  # TODO: Add back
        # 'reference_adjustment_type_id',  # TODO: Add back
        'contract_id',
        # 'currency_code',  # TODO: Add back
        'amount',
        'amount_raw',
        # 'upc',  # TODO: Add back
        # 'distribution_type',  # TODO: Add back
        'note',
        'internal_note',
        # 'apply_to_flowthrough_payment',  # TODO: Add back
        'errors',
        'source_data',
    ]