app.py

import streamlit as st
import web3
import requests
import pandas

# Connect to the Sepolia Ethereum blockchain
w3 = web3.Web3(web3.HTTPProvider(st.secrets["infura"]))

# Variables
ABI = '[ { "anonymous": false, "inputs": [ { "indexed": false, "internalType": "string", "name": "data", "type": "string" } ], "name": "Store", "type": "event" }, { "inputs": [ { "internalType": "string", "name": "_IPFSHash", "type": "string" } ], "name": "storeHash", "outputs": [], "stateMutability": "nonpayable", "type": "function" } ]'

# Page title and styling
st.set_page_config(page_title="Survey Data Retriever")
st.markdown("<style>.row-widget.stButton {text-align: center;}</style>", unsafe_allow_html=True)

# Title
st.title('Survey Data Retriever')
st.write("# ")

# Text input
contract_address = st.text_input(r"$\textsf{\Large Smart Contract Address}$")

# Retrieve button
button = st.button("Retrieve Survey Responses")

# On click
if button:
    my_bar = st.progress(0, text="Operation in progress. Please wait.")
    df = pandas.DataFrame()

    try:
        contract = w3.eth.contract(address=w3.to_checksum_address(contract_address), abi=ABI)
        logs = contract.events.Store.get_logs(from_block=4635673)
    except Exception as e:
        st.error("Error retrieving logs from the contract.")
        st.stop()

    st.write(r"$\textsf{\normalsize \textbf{IPFS Hashes}}$")

    for i, log in enumerate(logs):
        my_bar.progress((i+1)/len(logs), text="Retrieving responses...")

        ipfs_hash = log.args.data
        st.write(f"**Hash**: {ipfs_hash}; **Block number**: {log.blockNumber}")

        # Use Pinata to retrieve data
        response = requests.get(
            f"https://gateway.pinata.cloud/ipfs/{ipfs_hash}",
            headers={"Authorization": f"Bearer {st.secrets['pinata_jwt']}"}
        )

        if response.status_code == 200:
            try:
                json_to_row = pandas.json_normalize(response.json())
                df = pandas.concat([df, json_to_row], ignore_index=True)
            except Exception as e:
                st.error(f"Invalid JSON for hash: {ipfs_hash}")
                st.text(f"Error: {e}\nRaw content:\n{response.text}")
        else:
            st.error(f"Failed to retrieve data from IPFS for hash: {ipfs_hash}")
            st.text(f"Status Code: {response.status_code}\nContent: {response.text}")

    st.write("# ")
    st.write(r"$\textsf{\normalsize \textbf{Response Data}}$")
    st.write(df)

    st.download_button("Press to Download",
                       df.to_csv(index=False).encode('utf-8'),
                       "responses.csv",
                       "text/csv",
                       key='download-csv')

    my_bar.empty()