import logging
import json
from flask import request, Flask
from typing import Generator
from g4f import version, models
from g4f import get_last_provider, ChatCompletion
from g4f.image import is_allowed_extension, to_image
from g4f.errors import VersionNotFoundError
from g4f.Provider import __providers__
from g4f.Provider.bing.create_images import patch_provider
from .internet import get_search_message
class Backend_Api:
"""
Handles various endpoints in a Flask application for backend operations.
This class provides methods to interact with models, providers, and to handle
various functionalities like conversations, error handling, and version management.
Attributes:
app (Flask): A Flask application instance.
routes (dict): A dictionary mapping API endpoints to their respective handlers.
"""
def __init__(self, app: Flask) -> None:
"""
Initialize the backend API with the given Flask application.
Args:
app (Flask): Flask application instance to attach routes to.
"""
self.app: Flask = app
self.routes = {
'/backend-api/v2/models': {
'function': self.get_models,
'methods': ['GET']
},
'/backend-api/v2/providers': {
'function': self.get_providers,
'methods': ['GET']
},
'/backend-api/v2/version': {
'function': self.get_version,
'methods': ['GET']
},
'/backend-api/v2/conversation': {
'function': self.handle_conversation,
'methods': ['POST']
},
'/backend-api/v2/gen.set.summarize:title': {
'function': self.generate_title,
'methods': ['POST']
},
'/backend-api/v2/error': {
'function': self.handle_error,
'methods': ['POST']
}
}
def handle_error(self):
"""
Initialize the backend API with the given Flask application.
Args:
app (Flask): Flask application instance to attach routes to.
"""
print(request.json)
return 'ok', 200
def get_models(self):
"""
Return a list of all models.
Fetches and returns a list of all available models in the system.
Returns:
List[str]: A list of model names.
"""
return models._all_models
def get_providers(self):
"""
Return a list of all working providers.
"""
return [provider.__name__ for provider in __providers__ if provider.working]
def get_version(self):
"""
Returns the current and latest version of the application.
Returns:
dict: A dictionary containing the current and latest version.
"""
try:
current_version = version.utils.current_version
except VersionNotFoundError:
current_version = None
return {
"version": current_version,
"latest_version": version.get_latest_version(),
}
def generate_title(self):
"""
Generates and returns a title based on the request data.
Returns:
dict: A dictionary with the generated title.
"""
return {'title': ''}
def handle_conversation(self):
"""
Handles conversation requests and streams responses back.
Returns:
Response: A Flask response object for streaming.
"""
kwargs = self._prepare_conversation_kwargs()
return self.app.response_class(
self._create_response_stream(kwargs),
mimetype='text/event-stream'
)
def _prepare_conversation_kwargs(self):
"""
Prepares arguments for chat completion based on the request data.
Reads the request and prepares the necessary arguments for handling
a chat completion request.
Returns:
dict: Arguments prepared for chat completion.
"""
kwargs = {}
if "image" in request.files:
file = request.files['image']
if file.filename != '' and is_allowed_extension(file.filename):
kwargs['image'] = to_image(file.stream, file.filename.endswith('.svg'))
if "json" in request.form:
json_data = json.loads(request.form['json'])
else:
json_data = request.json
provider = json_data.get('provider', '').replace('g4f.Provider.', '')
provider = provider if provider and provider != "Auto" else None
if "image" in kwargs and not provider:
provider = "Bing"
if provider == 'OpenaiChat':
kwargs['auto_continue'] = True
messages = json_data['messages']
if json_data.get('web_search'):
if provider == "Bing":
kwargs['web_search'] = True
else:
messages[-1]["content"] = get_search_message(messages[-1]["content"])
model = json_data.get('model')
model = model if model else models.default
patch = patch_provider if json_data.get('patch_provider') else None
return {
"model": model,
"provider": provider,
"messages": messages,
"stream": True,
"ignore_stream": True,
"patch_provider": patch,
**kwargs
}
def _create_response_stream(self, kwargs) -> Generator[str, None, None]:
"""
Creates and returns a streaming response for the conversation.
Args:
kwargs (dict): Arguments for creating the chat completion.
Yields:
str: JSON formatted response chunks for the stream.
Raises:
Exception: If an error occurs during the streaming process.
"""
try:
first = True
for chunk in ChatCompletion.create(**kwargs):
if first:
first = False
yield self._format_json('provider', get_last_provider(True))
if isinstance(chunk, Exception):
logging.exception(chunk)
yield self._format_json('message', get_error_message(chunk))
else:
yield self._format_json('content', str(chunk))
except Exception as e:
logging.exception(e)
yield self._format_json('error', get_error_message(e))
def _format_json(self, response_type: str, content) -> str:
"""
Formats and returns a JSON response.
Args:
response_type (str): The type of the response.
content: The content to be included in the response.
Returns:
str: A JSON formatted string.
"""
return json.dumps({
'type': response_type,
response_type: content
}) + "\n"
def get_error_message(exception: Exception) -> str:
"""
Generates a formatted error message from an exception.
Args:
exception (Exception): The exception to format.
Returns:
str: A formatted error message string.
"""
return f"{get_last_provider().__name__}: {type(exception).__name__}: {exception}"
