"""
OpenAI/OpenRouter summarizer utility.

Uses OPENAI_API_KEY and OPENAI_URL from environment (via Config).
"""

from __future__ import annotations

import json
from typing import Dict, List

import requests

from config import Config


class SummarizationError(RuntimeError):
    """Raised when summarization fails."""


def summarize_text(text: str, max_points: int = 3) -> Dict[str, List[str] | str]:
    """
    Summarize text into a short summary and key points.

    Returns:
        {
            "summary": "string",
            "key_points": ["point 1", "point 2", ...]
        }
    """
    if not text or not text.strip():
        return {"summary": "", "key_points": []}

    if not Config.OPENAI_API_KEY:
        raise SummarizationError("OPENAI_API_KEY is not set")

    payload = {
        "model": Config.OPENAI_MODEL,
        "messages": [
            {
                "role": "system",
                "content": (
                    "You are a precise summarizer. Return JSON only with keys "
                    "`summary` and `key_points` (array of strings). Do not add extra keys."
                ),
            },
            {
                "role": "user",
                "content": (
                    "Summarize the following content in 2-4 sentences and provide "
                    f"{max_points} key points.\n\n"
                    f"CONTENT:\n{text}"
                ),
            },
        ],
        "temperature": 0.2,
        "max_tokens": 400,
    }

    headers = {
        "Authorization": f"Bearer {Config.OPENAI_API_KEY}",
        "Content-Type": "application/json",
    }

    try:
        response = requests.post(
            Config.OPENAI_URL,
            headers=headers,
            json=payload,
            timeout=Config.OPENAI_TIMEOUT,
        )
        response.raise_for_status()
        data = response.json()
    except Exception as exc:
        raise SummarizationError(f"Request failed: {exc}") from exc

    try:
        content = data["choices"][0]["message"]["content"].strip()
        result = json.loads(content)
        summary = result.get("summary", "").strip()
        key_points = [p.strip() for p in result.get("key_points", []) if p.strip()]
        return {"summary": summary, "key_points": key_points}
    except Exception as exc:
        raise SummarizationError(f"Invalid response format: {exc}") from exc