"""CSV column definitions and requirements."""

from enum import Enum


class CsvColumn(str, Enum):
    """CSV file column headers.

    Values are the exact header strings expected in the input CSV.
    Used as pydantic aliases in ContractRow and for header validation.
    """

    ACCOUNT_ID = 'Account ID'
    CONTRACT_NAME = 'Contract Name'
    CONTRACT_TYPE = 'Contract Type'
    SIGNING_ENTITY = 'Signing Entity'
    RUN_CONTROLLER = 'Run Controller'
    EXECUTION_DATE = 'Execution Date'
    IS_EXCLUDED = 'Is Excluded From Accounting Run'
    IS_PRIMARY = 'Is Primary Contract'
    CURRENT_PERIOD_START = 'Current Period Start Date'
    RENEWAL_RULES = 'Renewal Rules'
    TERMINATION_INTERVAL = 'Termination Notice Period (Interval)'
    TERMINATION_TYPE = 'Termination Notice Period (Type)'
    RENEW_AFTER_INTERVAL = 'Renew After (Interval)'
    RENEW_AFTER_TYPE = 'Renew After (Type)'
    CURRENT_PERIOD_END = 'Current Period End Date'
    COLLECTION_INTERVAL = 'Collection Period (Interval)'
    COLLECTION_TYPE = 'Collection Period (Type)'


class ResultColumn(str, Enum):
    """Output CSV column headers added to success/failure CSVs."""

    CONTRACT_ID = 'Contract ID'
    STATUS = 'Status'
    REASON = 'Reason'


DRY_RUN_CONTRACT_ID = 'DRY_RUN'


class ProcessingStatus(str, Enum):
    """Status of a contract creation attempt."""

    SUCCESS = 'success'
    DRY_RUN = 'dry_run'
    ERROR = 'error'


class ResultStatus(str, Enum):
    """Status values written to the output CSV Status column."""

    ERROR = 'ERROR'
    SKIPPED = 'SKIPPED'


class SkipReason(str, Enum):
    """Reasons a row may be skipped during processing."""

    ALREADY_PROCESSED = 'Already processed'
    DUPLICATE_IN_INPUT = 'Duplicate in input file'
    INVALID_DATA = 'Invalid data or missing required fields'


class MissingFieldPolicy(str, Enum):
    """Policy for handling missing optional fields during build."""

    DEFAULT = 'default'  # Apply business defaults (today's date, 30-day term, etc.)
    SKIP = 'skip'  # Skip the row entirely


REQUIRED_COLUMNS: frozenset[CsvColumn] = frozenset(
    {
        CsvColumn.ACCOUNT_ID,
        CsvColumn.CONTRACT_NAME,
        CsvColumn.CONTRACT_TYPE,
    }
)