Interactivity in Streamlit Intermediate

import streamlit as st

# Button
if st.button("Click me", type="primary"):
    st.write("Button clicked!")

# Text input
name = st.text_input("Enter your name", placeholder="John Doe")

# Text area
bio = st.text_area("Tell us about yourself", height=150)

# Number input
age = st.number_input("Age", min_value=0, max_value=120, value=25)

# Slider
temperature = st.slider("Temperature", 0.0, 2.0, 0.7, step=0.1)

# Range slider
values = st.slider("Range", 0, 100, (25, 75))

# Selectbox (dropdown)
option = st.selectbox("Choose a model", ["GPT-4", "Claude", "Gemini"])

# Multi-select
colors = st.multiselect("Favorite colors", ["Red", "Green", "Blue"])

# Radio buttons
genre = st.radio("Genre", ["Comedy", "Drama", "Sci-Fi"], horizontal=True)

# Checkbox
agree = st.checkbox("I agree to the terms")

# Toggle
dark_mode = st.toggle("Dark mode")

# Date input
date = st.date_input("Select a date")

# Color picker
color = st.color_picker("Pick a color", "#00f900")

# Single file upload
uploaded_file = st.file_uploader("Upload a CSV", type=["csv"])
if uploaded_file:
    df = pd.read_csv(uploaded_file)
    st.dataframe(df)

# Multiple file upload
files = st.file_uploader("Upload images", type=["png", "jpg"], accept_multiple_files=True)
for file in files:
    st.image(file, caption=file.name)

# Initialize session state
if "counter" not in st.session_state:
    st.session_state.counter = 0

# Increment on button click
if st.button("Increment"):
    st.session_state.counter += 1

st.write(f"Counter: {st.session_state.counter}")

# Store chat messages
if "messages" not in st.session_state:
    st.session_state.messages = []

# Widget with session state key
st.text_input("Name", key="user_name")
# Access via: st.session_state.user_name

with st.form("my_form"):
    st.write("Configure your model:")

    model = st.selectbox("Model", ["GPT-4", "Claude", "Gemini"])
    temperature = st.slider("Temperature", 0.0, 2.0, 0.7)
    max_tokens = st.number_input("Max Tokens", 100, 4000, 1000)
    prompt = st.text_area("Prompt")

    submitted = st.form_submit_button("Generate", type="primary")

    if submitted:
        st.write(f"Generating with {model} at temperature {temperature}...")

# Initialize chat history
if "messages" not in st.session_state:
    st.session_state.messages = []

# Display chat history
for msg in st.session_state.messages:
    with st.chat_message(msg["role"]):
        st.write(msg["content"])

# Chat input
if prompt := st.chat_input("Say something..."):
    st.session_state.messages.append({"role": "user", "content": prompt})
    with st.chat_message("user"):
        st.write(prompt)

    # Generate response (replace with actual LLM call)
    response = f"Echo: {prompt}"
    st.session_state.messages.append({"role": "assistant", "content": response})
    with st.chat_message("assistant"):
        st.write(response)

# Run a function when a widget value changes
def on_change():
    st.session_state.greeting = f"Hello, {st.session_state.name_input}!"

st.text_input("Name", key="name_input", on_change=on_change)

if "greeting" in st.session_state:
    st.write(st.session_state.greeting)