import logging
import json
import uvicorn
import nest_asyncio

from fastapi import FastAPI, Response, Request
from fastapi.responses import StreamingResponse, RedirectResponse, HTMLResponse, JSONResponse
from fastapi.exceptions import RequestValidationError
from starlette.status import HTTP_422_UNPROCESSABLE_ENTITY
from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel
from typing import List, Union

import g4f
import g4f.debug
from g4f.client import Client
from g4f.typing import Messages

class ChatCompletionsConfig(BaseModel):
    messages: Messages
    model: str
    provider: Union[str, None] = None
    stream: bool = False
    temperature: Union[float, None] = None
    max_tokens: Union[int, None] = None
    stop: Union[list[str], str, None] = None
    api_key: Union[str, None] = None

class Api:
    def __init__(self, engine: g4f, debug: bool = True, sentry: bool = False,
                 list_ignored_providers: List[str] = None) -> None:
        self.engine = engine
        self.debug = debug
        self.sentry = sentry
        self.list_ignored_providers = list_ignored_providers

        if debug:
            g4f.debug.logging = True

        self.n = 10
        self.mkclient()

        nest_asyncio.apply()
        self.app = FastAPI()

        self.routes()
        self.register_validation_exception_handler()

    def mkclient(self):
        if self.n >= 5:
            self.client = Client()
            self.n = 0
        
        self.n += 1

    def register_validation_exception_handler(self):
        @self.app.exception_handler(RequestValidationError)
        async def validation_exception_handler(request: Request, exc: RequestValidationError):
            details = exc.errors()
            modified_details = []
            for error in details:
                modified_details.append(
                    {
                        "loc": error["loc"],
                        "message": error["msg"],
                        "type": error["type"],
                    }
                )
            return JSONResponse(
                status_code=HTTP_422_UNPROCESSABLE_ENTITY,
                content=jsonable_encoder({"detail": modified_details}),
            )

    def routes(self):
        @self.app.get("/")
        async def read_root():
            return RedirectResponse("/v1", 302)

        @self.app.get("/v1")
        async def read_root_v1():
            return HTMLResponse('g4f API: Go to '
                                '<a href="/v1/chat/completions">chat/completions</a> '
                                'or <a href="/v1/models">models</a>.')

        @self.app.get("/v1/models")
        async def models():
            model_list = dict(
                (model, g4f.ModelUtils.convert[model])
                for model in g4f.Model.__all__()
            )
            model_list = [{
                'id': model_id,
                'object': 'model',
                'created': 0,
                'owned_by': model.base_provider
            } for model_id, model in model_list.items()]
            return JSONResponse(model_list)

        @self.app.get("/v1/models/{model_name}")
        async def model_info(model_name: str):
            try:
                model_info = g4f.ModelUtils.convert[model_name]
                return JSONResponse({
                    'id': model_name,
                    'object': 'model',
                    'created': 0,
                    'owned_by': model_info.base_provider
                })
            except:
                return JSONResponse({"error": "The model does not exist."})

        @self.app.post("/v1/chat/completions")
        async def chat_completions(config: ChatCompletionsConfig = None, request: Request = None, provider: str = None):
            self.mkclient() # if reached, change the client
            try:
                config.provider = provider if config.provider is None else config.provider
                if config.api_key is None and request is not None:
                    auth_header = request.headers.get("Authorization")
                    if auth_header is not None:
                        auth_header = auth_header.split(None, 1)[-1]
                        if auth_header and auth_header != "Bearer":
                            config.api_key = auth_header
                response = self.client.chat.completions.create(
                    **config.dict(exclude_none=True),
                    ignored=self.list_ignored_providers
                )
            except Exception as e:
                logging.exception(e)
                return Response(content=format_exception(e, config), status_code=500, media_type="application/json")

            if not config.stream:
                return JSONResponse(response.to_json())

            def streaming():
                try:
                    for chunk in response:
                        yield f"data: {json.dumps(chunk.to_json())}\n\n"
                except GeneratorExit:
                    pass
                except Exception as e:
                    logging.exception(e)
                    yield f'data: {format_exception(e, config)}'

            return StreamingResponse(streaming(), media_type="text/event-stream")

        @self.app.post("/v1/completions")
        async def completions():
            return Response(content=json.dumps({'info': 'Not working yet.'}, indent=4), media_type="application/json")

    def run(self, ip, use_colors : bool = False):
        split_ip = ip.split(":")
        uvicorn.run(app=self.app, host=split_ip[0], port=int(split_ip[1]), use_colors=use_colors)

def format_exception(e: Exception, config: ChatCompletionsConfig) -> str:
    last_provider = g4f.get_last_provider(True)
    return json.dumps({
        "error": {"message": f"{e.__class__.__name__}: {e}"},
        "model": last_provider.get("model") if last_provider else config.model,
        "provider": last_provider.get("name") if last_provider else config.provider
    })

def run_api(host: str = '0.0.0.0', port: int = 1337, debug: bool = False, use_colors=True) -> None:
    print(f'Starting server... [g4f v-{g4f.version.utils.current_version}]')
    app = Api(engine=g4f, debug=debug)
    app.run(f"{host}:{port}", use_colors=use_colors)

run_api(host="0.0.0.0", port=7860)