from fastapi import FastAPI, Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from pydantic import BaseModel
from models.transformer.text_generator import TextGenerator
import os


app = FastAPI()

generator = TextGenerator(
    model_name="frantics-bot-model",
)

security = HTTPBearer()
BEARER_TOKEN = os.environ.get("BEARER_TOKEN")


async def validate_token(credentials: HTTPAuthorizationCredentials = Depends(security)):
    if credentials.credentials == BEARER_TOKEN:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )


class Message(BaseModel):
    author: str
    content: str


@app.post("/generate")
def generate_response(
    message: Message,
    token: str = Depends(validate_token)
):
    response = generator.generate_text(
        author=message.author,
        input_str=message.content,
        max_length=100,
        num_return_sequences=1,
        do_sample=True,
        temperature=0.8,
        top_k=100,
        top_p=0.95
    )["generated_texts"][0]
    response = response[:response.find("</s>")]
    return {"response": response}