"""
Ollama LLM API 服務
"""
import json
from typing import Optional, List, Generator

import requests

from app.core.config import settings


class LLMService:
    """Ollama LLM API 服務"""

    def __init__(self):
        self.api_url = settings.OLLAMA_API_URL
        self.default_model = settings.OLLAMA_DEFAULT_MODEL

    def list_models(self) -> List[str]:
        """
        列出可用模型

        Returns:
            模型 ID 列表
        """
        try:
            response = requests.get(f"{self.api_url}/v1/models", timeout=10)
            response.raise_for_status()
            models = response.json()
            return [m["id"] for m in models.get("data", [])]
        except Exception as e:
            return [f"Error: {str(e)}"]

    def chat(
        self,
        messages: List[dict],
        model: Optional[str] = None,
        temperature: float = 0.7,
        max_tokens: Optional[int] = None,
    ) -> str:
        """
        聊天完成請求

        Args:
            messages: 對話訊息列表 [{"role": "user", "content": "..."}]
            model: 模型名稱，預設使用設定檔中的模型
            temperature: 溫度參數 (0-1)
            max_tokens: 最大 token 數

        Returns:
            AI 回應內容
        """
        chat_request = {
            "model": model or self.default_model,
            "messages": messages,
            "temperature": temperature,
        }

        if max_tokens:
            chat_request["max_tokens"] = max_tokens

        try:
            response = requests.post(
                f"{self.api_url}/v1/chat/completions",
                json=chat_request,
                timeout=60,
            )
            response.raise_for_status()
            result = response.json()
            return result["choices"][0]["message"]["content"]
        except Exception as e:
            return f"Error: {str(e)}"

    def chat_stream(
        self,
        messages: List[dict],
        model: Optional[str] = None,
        temperature: float = 0.7,
    ) -> Generator[str, None, None]:
        """
        串流聊天請求

        Args:
            messages: 對話訊息列表
            model: 模型名稱
            temperature: 溫度參數

        Yields:
            AI 回應內容片段
        """
        chat_request = {
            "model": model or self.default_model,
            "messages": messages,
            "temperature": temperature,
            "stream": True,
        }

        try:
            response = requests.post(
                f"{self.api_url}/v1/chat/completions",
                json=chat_request,
                stream=True,
                timeout=120,
            )
            response.raise_for_status()

            for line in response.iter_lines():
                if line:
                    if line.startswith(b"data: "):
                        data_str = line[6:].decode("utf-8")
                        if data_str.strip() != "[DONE]":
                            try:
                                data = json.loads(data_str)
                                if "choices" in data:
                                    delta = data["choices"][0].get("delta", {})
                                    if "content" in delta:
                                        yield delta["content"]
                            except json.JSONDecodeError:
                                continue
        except Exception as e:
            yield f"Error: {str(e)}"

    def simple_ask(
        self,
        question: str,
        system_prompt: str = "You are a helpful assistant.",
        model: Optional[str] = None,
    ) -> str:
        """
        簡單問答

        Args:
            question: 使用者問題
            system_prompt: 系統提示詞
            model: 模型名稱

        Returns:
            AI 回應
        """
        messages = [
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": question},
        ]
        return self.chat(messages, model=model)

    def analyze_kpi(self, kpi_data: dict) -> str:
        """
        分析 KPI 數據

        Args:
            kpi_data: KPI 相關數據

        Returns:
            AI 分析結果
        """
        system_prompt = """你是一位專業的 KPI 分析師。
請根據提供的 KPI 數據，給出專業的分析和建議。
回應請使用繁體中文，並保持專業且易懂。"""

        question = f"""請分析以下 KPI 數據：

{json.dumps(kpi_data, ensure_ascii=False, indent=2)}

請提供：
1. 數據摘要
2. 表現評估
3. 改善建議"""

        return self.simple_ask(question, system_prompt)


# 單例
llm_service = LLMService()