server/backend.py

import re
import g4f
from g4f import ChatCompletion
from googletrans import Translator
from flask import request
from datetime import datetime
from requests import get
from server.auto_proxy import get_random_proxy, update_working_proxies
from server.config import special_instructions


class Backend_Api:
    def __init__(self, app, config: dict) -> None:
        """  
        Initialize the Backend_Api class.  

        :param app: Flask application instance  
        :param config: Configuration dictionary  
        """
        self.app = app
        self.use_auto_proxy = config['use_auto_proxy']
        self.routes = {
            '/backend-api/v2/conversation': {
                'function': self._conversation,
                'methods': ['POST']
            }
        }

        # if self.use_auto_proxy:
        #    update_proxies = threading.Thread(
        #        target=update_working_proxies, daemon=True)
        #    update_proxies.start()

    def _conversation(self):
        """  
        Handles the conversation route.  

        :return: Response object containing the generated conversation stream  
        """
        try:
            jailbreak = request.json['jailbreak']
            model = request.json['model']
            messages = build_messages(jailbreak)

            # Generate response
            response = ChatCompletion.create(model=model, stream=True,
                                             messages=messages, provider=g4f.Provider.Forefront)

            return self.app.response_class(generate_stream(response, jailbreak), mimetype='text/event-stream')

        except Exception as e:
            print(e)
            print(e.__traceback__.tb_next)
            return {
                '_action': '_ask',
                'success': False,
                "error": f"an error occurred {str(e)}"
            }, 400


def build_messages(jailbreak):
    """  
    Build the messages for the conversation.  

    :param jailbreak: Jailbreak instruction string  
    :return: List of messages for the conversation  
    """
    _conversation = request.json['meta']['content']['conversation']
    internet_access = request.json['meta']['content']['internet_access']
    prompt = request.json['meta']['content']['parts'][0]

    # Generate system message
    current_date = datetime.now().strftime("%Y-%m-%d")
    system_message = (
        f'You are ChatGPT also known as ChatGPT, a large language model trained by OpenAI. '
        f'Strictly follow the users instructions. '
        f'Knowledge cutoff: 2021-09-01 Current date: {current_date}. '
        f'{set_response_language(prompt)}'
    )

    # Initialize the conversation with the system message
    conversation = [{'role': 'system', 'content': system_message}]

    # Add the existing conversation
    conversation += _conversation

    # Add web results if enabled
    conversation += fetch_search_results(
        prompt["content"]) if internet_access else []

    # Add jailbreak instructions if enabled
    if jailbreak_instructions := isJailbreak(jailbreak):
        conversation += jailbreak_instructions

    # Add the prompt
    conversation += [prompt]

    # Reduce conversation size to avoid API Token quantity error
    conversation = conversation[-4:] if len(conversation) > 3 else conversation

    return conversation


def fetch_search_results(query):
    """  
    Fetch search results for a given query.  

    :param query: Search query string  
    :return: List of search results  
    """
    search = get('https://ddg-api.herokuapp.com/search',
                 params={
                     'query': query,
                     'limit': 5,
                 })

    results = []
    snippets = ""
    for index, result in enumerate(search.json()):
        snippet = f'[{index + 1}] "{result["snippet"]}" URL:{result["link"]}.'
        snippets += snippet
    results.append({'role': 'system', 'content': snippets})
    
    return results


def generate_stream(response, jailbreak):
    """  
    Generate the conversation stream.  

    :param response: Response object from ChatCompletion.create  
    :param jailbreak: Jailbreak instruction string  
    :return: Generator object yielding messages in the conversation  
    """
    if isJailbreak(jailbreak):
        response_jailbreak = ''
        unlocked = False
        for message in response:
            response_jailbreak += message
            if unlocked:
                yield message
            if response_jailbroken_success(response_jailbreak):
                unlocked = True
            if response_jailbroken_failed(response_jailbreak):
                yield "Error: jailbreak failed. Try again."
                break
    else:
        yield from response


def response_jailbroken_success(response: str) -> bool:
    """Check if the response has been jailbroken.

    :param response: Response string
    :return: Boolean indicating if the response has been jailbroken
    """
    act_match = re.search(r'ACT:', response, flags=re.DOTALL)
    return bool(act_match)


def response_jailbroken_failed(response):
    """  
    Check if the response has not been jailbroken.  

    :param response: Response string  
    :return: Boolean indicating if the response has not been jailbroken  
    """
    return False if len(response) < 4 else not response.startswith("GPT:")


def set_response_language(prompt):
    """  
    Set the response language based on the prompt content.  

    :param prompt: Prompt dictionary  
    :return: String indicating the language to be used for the response  
    """
    translator = Translator()
    detected_language = translator.detect(prompt['content']).lang
    return f"You will respond in the language: {detected_language}. "


def isJailbreak(jailbreak):
    """  
    Check if jailbreak instructions are provided.  

    :param jailbreak: Jailbreak instruction string  
    :return: Jailbreak instructions if provided, otherwise None  
    """
    if jailbreak != "Default":
        return special_instructions[jailbreak] if jailbreak in special_instructions else None
    else:
        return None