from typing import Optional
from sqlalchemy.orm import Session
from openai import AsyncOpenAI

from providers.base_provider import LLMProvider
from services.api_key_service import ApiKeyService


class DeepSeekProvider(LLMProvider):
    """
    DeepSeek API provider implementation using OpenAI-compatible API
    """

    def __init__(self, db: Session, api_key: Optional[str] = None):
        if not api_key:
            api_key = ApiKeyService.get_api_key(db, "deepseek")

        if not api_key:
            raise ValueError("DeepSeek API key not found in database or provided")

        self.client = AsyncOpenAI(
            api_key=api_key,
            base_url="https://api.deepseek.com"
        )

    def supports_tools(self) -> bool:
        return False

    async def generate_response(self, model: str, prompt: str, max_tokens: Optional[int] = None) -> str:
        try:
            is_reasoner = "reasoner" in model or "r1" in model.lower()

            messages = [{"role": "user", "content": prompt}]
            # deepseek-reasoner 不支持 system message，把指令放进 user message
            if not is_reasoner:
                messages.insert(0, {
                    "role": "system",
                    "content": "你正在参与一场结构化辩论。请按照用户消息中的规则进行辩论，直接给出你的论点，不要重复提示词或历史记录。"
                })

            kwargs = {
                "model": model,
                "messages": messages,
            }
            # reasoner 模型不支持 max_tokens，使用 max_completion_tokens
            if is_reasoner:
                kwargs["max_completion_tokens"] = max_tokens or 4096
            else:
                kwargs["max_tokens"] = max_tokens or 500

            response = await self.client.chat.completions.create(**kwargs)

            message = response.choices[0].message
            content = message.content or ""

            # deepseek-reasoner 的主要内容可能在 reasoning_content 中
            if not content.strip() and is_reasoner:
                reasoning = getattr(message, "reasoning_content", None)
                if reasoning:
                    content = reasoning

            return content.strip()
        except Exception as e:
            raise Exception(f"Error calling DeepSeek API: {str(e)}")