"""Interpretation review engine (spec Modus 4).

Evaluates whether a customer's legal interpretation is plausible, too narrow,
too broad, etc. Matches the interpretation against a curated pattern library;
no match -> `uncertain` plus a request for the missing context (never invent a
verdict, spec §6.3).
"""

from __future__ import annotations

import hashlib
from typing import Optional

from .enums import Confidence, InterpretationVerdict
from .schemas import InterpretationAssessment, ProductProfile
from .taxonomy_interpretations import INTERPRETATION_PATTERNS, InterpretationPattern


def _interpretation_id(raw: str) -> str:
    digest = hashlib.sha1(raw.strip().lower().encode("utf-8")).hexdigest()
    return "interp_%s" % digest[:10]


def _best_match(text: str) -> Optional[InterpretationPattern]:
    low = text.lower()
    best: Optional[InterpretationPattern] = None
    best_score = 0
    for pattern in INTERPRETATION_PATTERNS:
        score = sum(1 for t in pattern.triggers if t in low)
        if score > best_score:
            best, best_score = pattern, score
    return best


def assess_interpretation(
    raw_interpretation: str, profile: Optional[ProductProfile] = None
) -> InterpretationAssessment:
    interp_id = _interpretation_id(raw_interpretation)
    pattern = _best_match(raw_interpretation)

    if pattern is None:
        return InterpretationAssessment(
            interpretation_id=interp_id,
            raw_interpretation=raw_interpretation,
            assessment=InterpretationVerdict.UNCERTAIN,
            corrected_interpretation=(
                "Diese Auslegung lässt sich ohne weitere Angaben nicht bewerten. Bitte Produkt, "
                "Rolle, Marktzugang und die konkret betroffene Pflicht benennen."
            ),
            explanation="Kein bekanntes Auslegungsmuster erkannt — bewusst keine Scheinsicherheit.",
            confidence=Confidence.LOW,
        )

    return InterpretationAssessment(
        interpretation_id=interp_id,
        raw_interpretation=raw_interpretation,
        affected_regulations=pattern.affected_regulations,
        affected_obligations=pattern.affected_obligations,
        assessment=pattern.verdict,
        risks=pattern.risks,
        corrected_interpretation=pattern.corrected_interpretation,
        legal_basis_refs=pattern.legal_basis_refs,
        explanation=pattern.explanation,
        confidence=pattern.confidence,
    )