components/sidebar.py

import streamlit as st

def render_sidebar():
    """
    Render the sidebar controls for the research companion app.

    Returns:
        query (str): The user's search query.
        num_results (int): Maximum number of papers to display.
        theme (str): UI theme selection ('Light' or 'Dark').
        search_clicked (bool): True if the Search button was pressed.
    """
    st.sidebar.title("🔍 Research Companion")

    # Input for research topic
    query = st.sidebar.text_input(
        label="Enter your research topic:",
        value="",
        placeholder="e.g. CRISPR delivery"
    )

    # Slider for number of results
    num_results = st.sidebar.slider(
        label="Max papers to display", 
        min_value=1, 
        max_value=20, 
        value=5
    )

    # Theme selection
    theme = st.sidebar.selectbox(
        label="Theme:", 
        options=["Light", "Dark"], 
        index=0
    )

    # Search action button
    search_clicked = st.sidebar.button("Search")

    return query, num_results, theme, search_clicked