routers/openai_v1.py

from fastapi import APIRouter, Depends
from langchain_core.prompts import ChatPromptTemplate
from datetime import datetime
# import uuid

from global_state import get
from db.tbs_db import TbsDb
from auth import get_current_user
from db_model.user import UserModel
from db_model.chat import ChatModel

router = APIRouter()

db_module_filename = f"{get('project_root')}/db/cloudflare.py"

@router.post("/chat/completions")
async def chat_completions(chat_model:ChatModel, current_user: UserModel = Depends(get_current_user)):
    try:
        model = chat_model.model
    except:
        model = ''

    if (model=='')or(model is None):
        model = await get_default_model()

    api_key_info = await get_api_key(model)
    api_key = api_key_info.get('api_key', '')
    group_name = api_key_info.get('group_name', '')
    base_url = api_key_info.get('base_url', '')

    if group_name=='gemini': # google api，生成 gemini 的 llm
        from langchain_google_genai import ChatGoogleGenerativeAI    
        llm = ChatGoogleGenerativeAI(
            api_key = api_key,
            model = model,
        )
    else: # 下面就是 chatgpt 兼容 api
        from langchain_openai import ChatOpenAI
        # 初始化 ChatOpenAI 模型
        llm = ChatOpenAI(
            model = model,
            api_key = api_key,
            base_url = base_url,
        )
    
    # 生成prompt模板
    lc_messages = [(message.role, message.content) for message in chat_model.messages]
    prompt_template = ChatPromptTemplate.from_messages(lc_messages)
    chain = prompt_template | llm
    try:
        result = chain.invoke({}) # AIMessage 类对象
    except Exception as e:
        return {'error': str(e)}
    
    # 转换为OpenAI格式
    converted_data = convert_to_openai_format(result)
    return converted_data

# 从数据库获取默认模型
async def get_default_model():
    query = f"SELECT * FROM api_names order by default_order limit 1"
    response = TbsDb(db_module_filename, "Cloudflare").get_item(query)
    try:
        result = response['result'][0]['results'][0]['api_name']
    except:
        result = ''
    return result

async def get_api_key(model):
    query = f"""
SELECT an.api_name, ak.api_key, an.base_url, ag.group_name
FROM api_keys ak
JOIN api_groups ag ON ak.api_group_id = ag.id
JOIN api_names an ON an.api_group_id = ag.id
WHERE ak.category='LLM' and an.api_name='{model}' and disabled=0
ORDER BY ak.last_call_at
limit 1
"""
    response = TbsDb(db_module_filename, "Cloudflare").get_item(query)
    try:
        result = response['result'][0]['results'][0]
        api_key = result['api_key']
    except:
        api_key = ''
    
    query = f"update api_keys set last_call_at=datetime('now') where api_key='{api_key}'"
    TbsDb(db_module_filename, "Cloudflare").execute_query(query)
    return result

def convert_to_openai_format(original_json):
    # 创建新的JSON对象
    new_json = {
        "id": "chatcmpl-123",  # 这里可以生成一个唯一的ID，或者使用传入的id
        "object": "chat.completion",
        "created": int(datetime.now().timestamp()),  # 当前时间戳
        "choices": [
            {
                "index": 0,
                "message": {
                    "role": "assistant",
                    "content": original_json.content  # 使用原始内容
                },
                "finish_reason": "stop"
            }
        ],
        "usage": {
            "prompt_tokens": original_json.usage_metadata.get("input_tokens",0),
            "completion_tokens": original_json.usage_metadata.get("output_tokens", 0),
            "total_tokens": original_json.usage_metadata.get("total_tokens", 0)
        }
    }
    return new_json