src/streamlit_app.py

import os

# # 1. Create the folder if it doesn't exist
# cache_root = "/mnt/data/huggingface"
# os.makedirs(cache_root, exist_ok=True)

# # 2. Redirect Hugging Face Hub, Transformers & Datasets caches
# os.environ["HF_HOME"]            = cache_root
# os.environ["TRANSFORMERS_CACHE"] = os.path.join(cache_root, "transformers")
# os.environ["HF_DATASETS_CACHE"]  = os.path.join(cache_root, "datasets")

import streamlit as st
# Import the high-level pipeline API from Hugging Face Transformers
# It simplifies loading models/tokenizers and running common tasks
from transformers import pipeline

#hf_token = st.secrets["HF_HUB_TOKEN"]
hf_token= os.getenv("HUGGING_FACE_HUB_TOKEN")

# 1. Cache the pipeline so it loads once
@st.cache_resource
def get_generator():
    # Initialize a text-to-text generation pipeline:
    # - "text2text-generation" tells the pipeline we want a seq2seq model (T5 family)
    # - model="google/flan-t5-small" specifies which pretrained model to load
    # The pipeline object wraps both tokenizer and model for you.
    return pipeline("text2text-generation", model="google/flan-t5-small", use_auth_token=hf_token)

generator = get_generator()

st.title("📝 FLAN-T5 Text-to-Text Generator")
st.write("Enter a prompt below and hit Generate to see the model’s output.")

# 2. Prompt the user for input
user_input = st.text_area("Your prompt:", height=120)

# 3. Generation settings in the sidebar
with st.sidebar:
    st.header("Generation Settings")
    max_length = st.slider("Max output length",  min_value=16, max_value=200, value=50)
    num_beams  = st.slider("Beam search width",  min_value=1,  max_value=8,   value=4)
    do_sample  = st.checkbox("Enable sampling",  value=False)
    top_k      = st.slider("Top-k sampling",    min_value=0,  max_value=100, value=50)
    temperature= st.slider("Temperature",       min_value=0.1, max_value=2.0, value=1.0, step=0.1)

# 4. Generate button
if st.button("🔄 Generate"):
    if not user_input.strip():
        st.error("Please enter a prompt first.")
    else:
        with st.spinner("Generating…"):
            outputs = generator(user_input)
        # pipeline returns list of dicts with key "generated_text"
        result = outputs[0]["generated_text"]
        st.subheader("Output")
        st.write(result)