"""
@file utils/name_gen.py
@brief Obfuscated identifier name generator.
@details Provides NameGenerator that yields high-entropy-looking identifiers
         and ensures uniqueness across a transformation session.
"""
import itertools
from typing import Iterator, Set

class NameGenerator:
    """
    @brief Generates unique obfuscated identifiers.
    @details Uses patterned Cartesian products to create long, confusing names and
             tracks used names to avoid collisions.
    """
    def __init__(self):
        """
        @brief Initialize internal iterator and used-name set.
        """
        self._name_iterator = self._create_iterator()
        self.used_names = set()
    
    def _create_iterator(self) -> Iterator[str]:
        """
        @brief Iterator producing obfuscated identifier candidates.
        @return Iterator[str] Infinite stream of names such as vIl1lO0o0Z2z2...
        """
        patterns = ['Il1l', 'O0o0', 'Z2z2', 'S5s5', 'B8b8', 'Q9q9']
        for length in itertools.count(2):  # Start with length=2, continue forever
            for combo in itertools.product(patterns, repeat=length):
                yield 'v' + ''.join(combo)

    def generate_name(self) -> str:
        """
        @brief Produce a fresh, unique obfuscated name.
        @return str Name guaranteed not to have been produced before by this instance.
        """
        while True:
            candidate = next(self._name_iterator)
            if candidate not in self.used_names:
                self.used_names.add(candidate)
                return candidate