# #region DictionaryUtils [C:1] [TYPE Module] [SEMANTICS translate, term, normalize, delimiter, csv]
# @BRIEF Utility helpers for dictionary management (term normalization and delimiter detection).
# @LAYER: Domain

import unicodedata


# #region _normalize_term [TYPE Function]
# @BRIEF Normalize a term for case-insensitive unique constraint lookup.
# @RATIONALE: NFC normalization is applied before lowercasing to ensure consistent
#             comparison of Unicode characters (e.g. precomposed vs decomposed forms).
# @REJECTED: Lowercasing without NFC normalization — would cause duplicate entries
#            for semantically identical Unicode strings in different normalization forms.
def _normalize_term(term: str) -> str:
    """Normalize a term by NFC, lowercasing, and removing extra whitespace."""
    if not term:
        return ""
    term = unicodedata.normalize('NFC', term)
    return " ".join(term.lower().split())
# #endregion _normalize_term


# #region _detect_delimiter [TYPE Function]
# @BRIEF Detect the delimiter used in a CSV/TSV header line.
def _detect_delimiter(header_line: str) -> str:
    """Detect delimiter by counting tabs vs commas in the first line."""
    if not header_line:
        return ","
    tab_count = header_line.count("\t")
    comma_count = header_line.count(",")
    return "\t" if tab_count > comma_count else ","
# #endregion _detect_delimiter
# #endregion DictionaryUtils