"""
Helper functions for file reading and writing
"""
import re
from typing import Set, Tuple, List

from masque.pattern import Pattern


def mangle_name(pattern: Pattern, dose_multiplier: float=1.0) -> str:
    """
    Create a name using `pattern.name`, `id(pattern)`, and the dose multiplier.

    Args:
        pattern: Pattern whose name we want to mangle.
        dose_multiplier: Dose multiplier to mangle with.

    Returns:
        Mangled name.
    """
    expression = re.compile('[^A-Za-z0-9_\?\$]')
    full_name = '{}_{}_{}'.format(pattern.name, dose_multiplier, id(pattern))
    sanitized_name = expression.sub('_', full_name)
    return sanitized_name


def make_dose_table(patterns: List[Pattern], dose_multiplier: float=1.0) -> Set[Tuple[int, float]]:
    """
    Create a set containing `(id(pat), written_dose)` for each pattern (including subpatterns)

    Args:
        pattern: Source Patterns.
        dose_multiplier: Multiplier for all written_dose entries.

    Returns:
        `{(id(subpat.pattern), written_dose), ...}`
    """
    dose_table = {(id(pattern), dose_multiplier) for pattern in patterns}
    for pattern in patterns:
        for subpat in pattern.subpatterns:
            subpat_dose_entry = (id(subpat.pattern), subpat.dose * dose_multiplier)
            if subpat_dose_entry not in dose_table:
                subpat_dose_table = make_dose_table([subpat.pattern], subpat.dose * dose_multiplier)
                dose_table = dose_table.union(subpat_dose_table)
    return dose_table