"""
Shared OpenAI HTTP client — single implementation of the chat-completions call.

Replaces duplicated urllib boilerplate in gpt_reasoning, relevance,
mission_parser, and threat_chat.
"""

import json
import logging
import os
import urllib.request
import urllib.error
from typing import Dict, Optional, Tuple

logger = logging.getLogger(__name__)

_API_URL = "https://api.openai.com/v1/chat/completions"


class OpenAIAPIError(Exception):
    """Raised when the OpenAI API call fails (HTTP or network error)."""

    def __init__(self, message: str, status_code: Optional[int] = None):
        self.status_code = status_code
        super().__init__(message)


def get_api_key() -> Optional[str]:
    """Return the OpenAI API key from the environment, or None."""
    return os.environ.get("OPENAI_API_KEY")


def chat_completion(payload: Dict, *, timeout: int = 30) -> Dict:
    """Send a chat-completion request and return the parsed JSON response.

    Args:
        payload: Full request body (model, messages, etc.).
        timeout: HTTP timeout in seconds.

    Returns:
        Parsed response dict.

    Raises:
        OpenAIAPIError: On HTTP or network failure.
    """
    api_key = get_api_key()
    if not api_key:
        raise OpenAIAPIError("OPENAI_API_KEY not set")

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

    try:
        req = urllib.request.Request(
            _API_URL,
            data=json.dumps(payload).encode("utf-8"),
            headers=headers,
            method="POST",
        )
        with urllib.request.urlopen(req, timeout=timeout) as response:
            return json.loads(response.read().decode("utf-8"))
    except urllib.error.HTTPError as e:
        raise OpenAIAPIError(
            f"HTTP {e.code}: {e.reason}", status_code=e.code
        ) from e
    except urllib.error.URLError as e:
        raise OpenAIAPIError(f"URL error: {e.reason}") from e


def extract_content(resp_data: Dict) -> Tuple[Optional[str], Optional[str]]:
    """Safely extract content and refusal from a chat-completion response.

    Returns:
        (content, refusal) — either may be None.
    """
    choice = resp_data.get("choices", [{}])[0]
    message = choice.get("message", {})
    return message.get("content"), message.get("refusal")