import numpy as np
import streamlit as st

from .streamlit_utils import SessionState

session_state = SessionState.get(page=1)


def main():
    # Render the readme as markdown using st.markdown.
    readme_text = st.markdown('''
    # Instructions

    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed vel lorem tincidunt, 
    congue orci id, pretium augue. Curabitur facilisis malesuada justo. Sed tincidunt 
    metus sed arcu blandit efficitur. Vestibulum ut neque sed diam dapibus imperdiet 
    id sit amet ante. In in sollicitudin est, ut bibendum lectus. Curabitur posuere 
    cursus dui. Nullam interdum eu nunc ac bibendum. Etiam id dolor laoreet nulla euismod 
    tristique. Nulla mollis condimentum auctor. Mauris ut diam ante. Maecenas at mauris 
    vulputate, hendrerit erat in, viverra libero. Nulla viverra lacus vitae urna hendrerit 
    fringilla. Aliquam pharetra justo vitae neque semper, a consequat lorem varius.
    ''')

    # Add a selector for the app mode on the sidebar.
    st.sidebar.title("What to do")
    app_mode = st.sidebar.selectbox(
        "Choose the app mode",
        ["Instructions", "Show paginated content"]
    )
    if app_mode == "Instructions":
        st.sidebar.success('To continue select an option in the dropdown menu.')
    elif app_mode == "Show paginated content":
        readme_text.empty()
        prev_page = st.button('prev')
        if prev_page:
            session_state.page -= 1
        next_page = st.button('next')
        if next_page:
            session_state.page += 1
        st.write(f'page: {session_state.page}')
        load_data(page=session_state.page)


def load_data(page=1):
    data = np.arange(1, 100)
    page = max(page, 1)
    per_page = 10
    start = (page - 1) * per_page
    end = page * per_page
    results = data[start:end]

    for i in results:
        st.subheader(i)
        st.text('Lorem ipsum dolor sit amet, consectetur adipiscing elit.')


if __name__ == "__main__":
    main()