main.py

import json
import logging
import os
import uuid
from datetime import datetime
from typing import Any, Dict, List, Optional

import httpx
from dotenv import load_dotenv
from fastapi import FastAPI, HTTPException, Depends
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from pydantic import BaseModel
from starlette.middleware.cors import CORSMiddleware
from starlette.responses import StreamingResponse, Response

# Configure Logging
logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
logger = logging.getLogger(__name__)

# Load Environment Variables
load_dotenv()
APP_SECRET = os.getenv("APP_SECRET", "786")
ACCESS_TOKEN = os.getenv("SD_ACCESS_TOKEN", "")

# Initialize FastAPI
app = FastAPI()

# Define Allowed Models
ALLOWED_MODELS = [
    {"id": "claude-3.5-sonnet", "name": "Claude 3.5 Sonnet"},
    {"id": "claude-3-opus", "name": "Claude 3 Opus"},
    {"id": "gemini-1.5-pro", "name": "Gemini 1.5 Pro"},
    {"id": "gpt-4o", "name": "GPT-4o"},
    {"id": "o1-preview", "name": "O1 Preview"},
    {"id": "o1-mini", "name": "O1 Mini"},
    {"id": "gpt-4o-mini", "name": "GPT-4o Mini"},
]

# Configure CORS Middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Replace with your trusted domains
    allow_credentials=True,
    allow_methods=["POST", "OPTIONS"],
    allow_headers=["Content-Type", "Authorization"],
)

# Security Scheme
security = HTTPBearer()

# Pydantic Models
class Message(BaseModel):
    role: str
    content: str

class ChatRequest(BaseModel):
    model: str
    messages: List[Message]
    stream: Optional[bool] = False

# Helper Functions
def create_chat_completion_data(content: str, model: str, finish_reason: Optional[str] = None) -> Dict[str, Any]:
    return {
        "id": f"chatcmpl-{uuid.uuid4()}",
        "object": "chat.completion.chunk",
        "created": int(datetime.now().timestamp()),
        "model": model,
        "choices": [
            {
                "index": 0,
                "delta": {"content": content, "role": "assistant"},
                "finish_reason": finish_reason,
            }
        ],
        "usage": None,
    }

def verify_app_secret(credentials: HTTPAuthorizationCredentials = Depends(security)):
    if credentials.credentials != APP_SECRET:
        raise HTTPException(status_code=403, detail="Invalid APP_SECRET")
    return credentials.credentials

# Routes
@app.options("/hf/v1/chat/completions")
async def chat_completions_options():
    return Response(
        status_code=200,
        headers={
            "Access-Control-Allow-Origin": "*",
            "Access-Control-Allow-Methods": "POST, OPTIONS",
            "Access-Control-Allow-Headers": "Content-Type, Authorization",
        },
    )

@app.get("/hf/v1/models")
async def list_models():
    return {"object": "list", "data": ALLOWED_MODELS}

@app.post("/hf/v1/chat/completions")
async def chat_completions(
    request: ChatRequest, app_secret: str = Depends(verify_app_secret)
):
    logger.info(f"Received chat completion request for model: {request.model}")

    if request.model not in [model['id'] for model in ALLOWED_MODELS]:
        allowed = ', '.join(model['id'] for model in ALLOWED_MODELS)
        raise HTTPException(
            status_code=400,
            detail=f"Model '{request.model}' is not allowed. Allowed models are: {allowed}",
        )

    # Generate a UUID
    uuid_str = str(uuid.uuid4()).replace("-", "")

    # Prepare Headers (Move sensitive data to environment variables or secure storage)
    headers = {
        'accept': '*/*',
        'accept-language': 'en-US,en;q=0.9',
        'authorization': f'Bearer {ACCESS_TOKEN}',
        'cache-control': 'no-cache',
        'origin': 'chrome-extension://difoiogjjojoaoomphldepapgpbgkhkb',
        'pragma': 'no-cache',
        'priority': 'u=1, i',
        'sec-fetch-dest': 'empty',
        'sec-fetch-mode': 'cors',
        'sec-fetch-site': 'none',
        'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36',
    }

    # Prepare JSON Payload
    json_data = {
        'prompt': "\n".join(
            [
                f"{'User' if msg.role == 'user' else 'Assistant'}: {msg.content}"
                for msg in request.messages
            ]
        ),
        'stream': True,
        'app_name': 'ChitChat_Edge_Ext',
        'app_version': '4.28.0',
        'tz_name': 'Asia/Karachi',
        'cid': 'C092SEMXM9BJ',
        'model': request.model,
        'search': False,
        'auto_search': False,
        'from': 'chat',
        'group_id': 'default',
        'prompt_template': {
            'key': 'artifacts',
            'attributes': {
                'lang': 'original',
            },
        },
        'tools': {
            'auto': ['text_to_image', 'data_analysis'],
        },
        'extra_info': {
            'origin_url': 'chrome-extension://difoiogjjojoaoomphldepapgpbgkhkb/standalone.html?from=sidebar',
            'origin_title': 'Sider',
        },
    }

    async def generate():
        async with httpx.AsyncClient() as client:
            try:
                async with client.stream(
                    'POST',
                    'https://sider.ai/api/v3/completion/text',
                    headers=headers,
                    json=json_data,
                    timeout=120.0
                ) as response:
                    response.raise_for_status()
                    async for line in response.aiter_lines():
                        if line and ("[DONE]" not in line):
                            try:
                                # Adjust the slicing based on the actual response format
                                data = json.loads(line[5:]) if len(line) > 5 else None
                                if data and "data" in data and "text" in data["data"]:
                                    content = data["data"].get("text", "")
                                    yield f"data: {json.dumps(create_chat_completion_data(content, request.model))}\n\n"
                                else:
                                    logger.warning(f"Unexpected data format: {line}")
                            except json.JSONDecodeError as e:
                                logger.error(f"JSON decode error for line: {line} - {e}")
                            except Exception as e:
                                logger.error(f"Error processing line: {line} - {e}")
                    # Indicate the end of the stream
                    yield f"data: {json.dumps(create_chat_completion_data('', request.model, 'stop'))}\n\n"
                    yield "data: [DONE]\n\n"
            except httpx.HTTPStatusError as e:
                logger.error(f"HTTP error occurred: {e}")
                raise HTTPException(status_code=e.response.status_code, detail=str(e))
            except httpx.RequestError as e:
                logger.error(f"An error occurred while requesting: {e}")
                raise HTTPException(status_code=500, detail=str(e))

    if request.stream:
        logger.info("Streaming response")
        return StreamingResponse(generate(), media_type="text/event-stream")
    else:
        logger.info("Non-streaming response")
        full_response = ""
        async for chunk in generate():
            if chunk.startswith("data: ") and not chunk[6:].startswith("[DONE]"):
                try:
                    data = json.loads(chunk[6:])
                    if data["choices"][0]["delta"].get("content"):
                        full_response += data["choices"][0]["delta"]["content"]
                except json.JSONDecodeError as e:
                    logger.error(f"JSON decode error in non-streaming response: {chunk} - {e}")
                except Exception as e:
                    logger.error(f"Error processing chunk in non-streaming response: {chunk} - {e}")

        return {
            "id": f"chatcmpl-{uuid.uuid4()}",
            "object": "chat.completion",
            "created": int(datetime.now().timestamp()),
            "model": request.model,
            "choices": [
                {
                    "index": 0,
                    "message": {"role": "assistant", "content": full_response},
                    "finish_reason": "stop",
                }
            ],
            "usage": None,
        }