"""DeepSeek API client - OpenAI-compatible, zero extra dependencies."""

import json
import logging
import time
import requests

logger = logging.getLogger(__name__)


class DeepSeekClient:
    """Client for DeepSeek API (OpenAI-compatible format)."""

    BASE_URL = "https://api.deepseek.com/v1/chat/completions"

    def __init__(self, api_key, model="deepseek-chat", temperature=0.7, max_retries=3):
        self.api_key = api_key
        self.model = model
        self.temperature = temperature
        self.max_retries = max_retries
        self.session = requests.Session()
        self.session.headers.update({
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json"
        })

    def ask(self, system_prompt, user_prompt, temperature=None):
        """Send a chat completion request. Returns response text."""
        messages = [
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": user_prompt}
        ]
        payload = {
            "model": self.model,
            "messages": messages,
            "temperature": temperature or self.temperature
        }

        last_error = None
        for attempt in range(self.max_retries):
            try:
                resp = self.session.post(self.BASE_URL, json=payload, timeout=60)
                resp.raise_for_status()
                data = resp.json()
                result = data["choices"][0]["message"]["content"]
                logger.info(
                    "DeepSeek API OK | model=%s | input=%d chars | output=%d chars",
                    self.model, len(user_prompt), len(result)
                )
                return result

            except requests.exceptions.Timeout:
                last_error = "Timeout"
                logger.warning("Attempt %d/%d timed out", attempt + 1, self.max_retries)
            except requests.exceptions.HTTPError as e:
                last_error = str(e)
                logger.warning("Attempt %d/%d HTTP error: %s", attempt + 1, self.max_retries, e)
                if "insufficient_quota" in str(e).lower() or "invalid_api_key" in str(e).lower():
                    raise  # don't retry these
            except (json.JSONDecodeError, KeyError) as e:
                last_error = f"Parse error: {e}"
                logger.warning("Attempt %d/%d parse error: %s", attempt + 1, self.max_retries, e)

            if attempt < self.max_retries - 1:
                sleep_time = 2 ** attempt
                logger.info("Retrying in %ds...", sleep_time)
                time.sleep(sleep_time)

        raise RuntimeError(
            f"DeepSeek API failed after {self.max_retries} retries. Last error: {last_error}"
        )