from fastapi import FastAPI
import streamlit as st
from transformers import (
      AutoTokenizer,
      AutoConfig,
      AutoModelForCausalLM,
      StoppingCriteriaList,
      MaxLengthCriteria,
  )

app = FastAPI()

#input_prompt = "Heart is in love"

def song_generator(input_prompt):
  tokenizer = AutoTokenizer.from_pretrained("./TaylorSwiftFineTunedModel/")


  model = AutoModelForCausalLM.from_pretrained("./TaylorSwiftFineTunedModel/")
  # set pad_token_id to eos_token_id because OPT does not have a PAD token
  model.config.pad_token_id = model.config.eos_token_id
  input_ids = tokenizer(input_prompt, return_tensors="pt")
  stopping_criteria = StoppingCriteriaList([MaxLengthCriteria(max_length=300)])
  outputs = model.contrastive_search(
      **input_ids, penalty_alpha=0.6, top_k=15, stopping_criteria=stopping_criteria, pad_token_id=tokenizer.eos_token_id,
  )
  song_generated = tokenizer.batch_decode(outputs, skip_special_tokens=True)
  return song_generated
    

st.header('Taylor-swift style song generator')
query = st.text_input("Enter 2 or 3 verses ", "")
submit = st.button('Generate') 
input_song = query

if submit:
  st.subheader('Song generated is ')
  
  with st.spinner(text='This may take a moment...'):
    output_sentence = song_generator(input_song)
  st.write(output_sentence[0])