"""Shared AI response parsing utilities — used by all provider implementations."""
from __future__ import annotations

import json
import re

from ai.base import ClassificationResult


def strip_code_fences(text: str) -> str:
    """Remove markdown code fences (```json ... ```) from *text*."""
    text = re.sub(r"```(?:json)?\s*", "", text)
    text = re.sub(r"```", "", text)
    return text.strip()


def parse_classification(raw: str) -> ClassificationResult:
    """Parse a classification JSON response into a ClassificationResult.

    Tolerates markdown code fences and extracts the first JSON object found.
    Returns an empty ClassificationResult on any parse failure.
    """
    raw = strip_code_fences(raw)
    match = re.search(r"\{.*\}", raw, re.DOTALL)
    if match:
        try:
            data = json.loads(match.group())
            return ClassificationResult(
                topics=data.get("assigned_topics", []),
                suggested_new_topics=data.get("new_topic_suggestions", []),
                reasoning=data.get("reasoning", ""),
            )
        except json.JSONDecodeError:
            pass
    return ClassificationResult()


def parse_suggestions(raw: str) -> list[str]:
    """Parse a topic-suggestion JSON response into a list of topic name strings.

    Tolerates markdown code fences. Returns an empty list on parse failure.
    """
    raw = strip_code_fences(raw)
    match = re.search(r"\{.*\}", raw, re.DOTALL)
    if match:
        try:
            data = json.loads(match.group())
            return data.get("suggested_topics", [])
        except json.JSONDecodeError:
            pass
    return []