"""Italian → English vocabulary normalisation."""

from __future__ import annotations

from pathlib import Path

import yaml

from pipeline.errors import PipelineError


class Vocabulary:
    """Lookup table loaded from a vocab YAML file."""

    def __init__(self, path: Path) -> None:
        with path.open(encoding="utf-8") as fh:
            raw = yaml.safe_load(fh) or {}
        self.canonical_values: set[str] = set(raw.get("canonical_values", []) or [])
        normalize = raw.get("normalize", {}) or {}
        self._normalize: dict[str, str] = {
            str(key).strip().lower(): str(value).strip() for key, value in normalize.items()
        }

    def to_english(self, italian_name: str, *, kind: str) -> str:
        """Map an Italian (or already-English) term to its canonical English form."""
        key = italian_name.strip().lower()
        if not key:
            raise PipelineError(f"Empty {kind} name cannot be normalised.")

        if key in self._normalize:
            return self._normalize[key]

        # Already a canonical English value (case-insensitive match).
        for value in self.canonical_values:
            if value.lower() == key:
                return value

        raise PipelineError(
            f"No English mapping found for {kind} '{italian_name}'. "
            f"Add it to the vocabulary file."
        )


def load_crop_vocab(path: Path) -> Vocabulary:
    return Vocabulary(path)


def load_disease_vocab(path: Path) -> Vocabulary:
    return Vocabulary(path)