from __future__ import annotations

import re

from app.modules.rag.intent_router_v2.normalization_terms import KeyTermCanonicalizer

_WORD_RE = re.compile(r"[A-Za-zА-Яа-яЁё-]+")


class RuEnTermMapper:
    _CANONICAL_MAP = {
        "класс": ["class"],
        "метод": ["method"],
        "функция": ["function", "def"],
        "модуль": ["module"],
        "пакет": ["package"],
        "файл": ["file"],
        "тест": ["test", "unit test"],
        "документация": ["documentation", "docs"],
        "readme": ["readme"],
    }
    _ENGLISH_SOURCES = {
        "class": ["class"],
        "method": ["method"],
        "function": ["function", "def"],
        "module": ["module"],
        "package": ["package"],
        "file": ["file"],
        "test": ["test", "unit test"],
        "tests": ["test", "unit test"],
        "documentation": ["documentation", "docs"],
        "docs": ["documentation", "docs"],
        "readme": ["readme"],
        "def": ["def"],
    }

    def __init__(self, canonicalizer: KeyTermCanonicalizer | None = None) -> None:
        self._canonicalizer = canonicalizer or KeyTermCanonicalizer()

    def expand(self, text: str) -> list[str]:
        expansions: list[str] = []
        lowered = (text or "").lower()
        for token in _WORD_RE.findall(lowered):
            canonical = self._canonicalizer.canonicalize(token) or token
            self._extend(expansions, self._CANONICAL_MAP.get(canonical, []))
            self._extend(expansions, self._ENGLISH_SOURCES.get(token, []))
        if "unit test" in lowered or "unit tests" in lowered:
            self._extend(expansions, self._ENGLISH_SOURCES["test"])
        return expansions

    def key_terms(self) -> tuple[str, ...]:
        return tuple(self._CANONICAL_MAP.keys())

    def all_literal_terms(self) -> tuple[str, ...]:
        values = set(self._canonicalizer.aliases())
        values.update(self._CANONICAL_MAP.keys())
        values.update(self._ENGLISH_SOURCES.keys())
        for targets in self._CANONICAL_MAP.values():
            values.update(target.lower() for target in targets)
        for targets in self._ENGLISH_SOURCES.values():
            values.update(target.lower() for target in targets)
        return tuple(sorted(values))

    def _extend(self, result: list[str], values: list[str]) -> None:
        for value in values:
            if value not in result:
                result.append(value)