"""
Booktitle normalizer: maps verbose venue names to standard abbreviations.

Loads rules from data/abbr.tsv (regex → abbreviation).
"""
import re
import csv
from pathlib import Path
from typing import Optional


class BooktitleNormalizer:
    """Normalizes booktitle/journal names to standard abbreviations."""

    def __init__(self, tsv_path: str = None):
        if tsv_path is None:
            tsv_path = str(Path(__file__).resolve().parent.parent / "data" / "abbr.tsv")
        self.rules: list[tuple[re.Pattern, str]] = []
        self._load_rules(tsv_path)

    def _load_rules(self, tsv_path: str):
        """Load regex → abbreviation rules from TSV file."""
        path = Path(tsv_path)
        if not path.exists():
            return

        with open(path, 'r', encoding='utf-8') as f:
            reader = csv.reader(f, delimiter='\t')
            for row in reader:
                if len(row) >= 2:
                    pattern_str = row[0].strip()
                    abbr = row[1].strip()
                    # Skip comments and empty lines
                    if not pattern_str or pattern_str.startswith('#'):
                        continue
                    try:
                        self.rules.append((re.compile(pattern_str, re.IGNORECASE), abbr))
                    except re.error:
                        pass  # Skip invalid regex

    def normalize(self, booktitle: str) -> Optional[str]:
        """
        Normalize a booktitle to its standard abbreviation.
        Returns the abbreviation if matched, None if no match found.
        """
        if not booktitle:
            return None
        for pattern, abbr in self.rules:
            if pattern.search(booktitle):
                return abbr
        return None