from fastapi import Depends, FastAPI, HTTPException, status
from sqlalchemy.orm import Session
import schemas, models
from transformers import pipeline
import database

app = FastAPI()
models.database.Base.metadata.create_all(bind=database.engine)
classifier = pipeline("sentiment-analysis")

# Database session dependency
def get_db():
    db = database.SessionLocal()
    try:
        yield db
    finally:
        db.close()

@app.post("/analyze_sentiment", status_code=status.HTTP_201_CREATED)
def create_sentiment_result(sentiment_result: schemas.SentimentResultCreate, text_input: str, db: Session = Depends(get_db)):
    # Perform input validation
    if not isinstance(text_input, str) or not text_input.strip():
        raise HTTPException(status_code=status.HTTP_422_UNPROCESSABLE_ENTITY, detail="Invalid text input")

    try:
        text_content = text_input
        sentiment_analysis_result = classifier(text_content)

        # Create a new SentimentResult instance
        new_sentiment_result = models.SentimentResult(
            score=sentiment_analysis_result[0]['score'],
            label = sentiment_analysis_result[0]['label'],
            text_input=text_content
        )

        # Add the new SentimentResult to the database
        db.add(new_sentiment_result)
        db.commit()
        db.refresh(new_sentiment_result)

        return new_sentiment_result
    except Exception as e:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=f"An error occurred: {str(e)}")

@app.delete("/sentiment/{id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_sentiment_result(id: int, db: Session = Depends(get_db)):
    # Retrieve the sentiment result and check for existence
    sentiment_result_to_delete = db.query(models.SentimentResult).filter(models.SentimentResult.id == id).first()

    if sentiment_result_to_delete is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail=f"SentimentResult with ID {id} not found")

    # Delete the sentiment result
    db.delete(sentiment_result_to_delete)
    db.commit()