import streamlit as st

st.title("Self Learn Kinematics")

# Display introduction
st.write("If velocity value is positive, the object is travelling to the right.")
st.write("If velocity value is negative, the object is travelling in the opposite direction to the left.")

# State variables to hold input values and results
if 'u' not in st.session_state:
    st.session_state.u = 0.0
if 'v' not in st.session_state:
    st.session_state.v = 0.0

# Input for initial velocity, u
u = st.number_input("Enter the initial velocity (u) in metres per second:", value=st.session_state.u, step=0.1, format="%.1f")

# Input for final velocity, v
v = st.number_input("Enter the final velocity (v) in metres per second:", value=st.session_state.v, step=0.1, format="%.1f")

# Buttons for submitting and clearing inputs
if st.button("Submit"):
    st.session_state.u = u
    st.session_state.v = v

    # Determine the initial direction
    if st.session_state.u < 0:
        initial_direction = "travelling to the left"
    elif st.session_state.u > 0:
        initial_direction = "travelling to the right"
    else:
        initial_direction = "at rest"

    # Determine the final direction
    if st.session_state.v < 0:
        final_direction = "travelling to the left"
    elif st.session_state.v > 0:
        final_direction = "travelling to the right"
    else:
        final_direction = "at rest"

    # Display initial and final velocities information
    st.write(f"Initial velocity (u): {st.session_state.u} m/s means object is {initial_direction} with a speed of {abs(st.session_state.u)} m/s.")
    st.write(f"Final velocity (v): {st.session_state.v} m/s means object is {final_direction} with a speed of {abs(st.session_state.v)} m/s.")

    # Determine and display the motion description based on the conditions
    if st.session_state.u < 0:
        if st.session_state.v == st.session_state.u:
            st.write("u < 0, v = u")
            st.write("Object was initially travelling to the left.")
            st.write("Object continued travelling to the left with constant speed.")
        elif st.session_state.v < st.session_state.u:
            st.write("u < 0, v < u")
            st.write("Object was initially travelling to the left.")
            st.write("Object continued travelling to the left, accelerated and increased its speed.")
        elif st.session_state.v == 0:
            st.write("u < 0, v = 0")
            st.write("Object was initially travelling to the left.")
            st.write("Object continued travelling to the left, decelerated, decreased its speed and stopped.")
        elif st.session_state.v > st.session_state.u and st.session_state.v < 0:
            st.write("u < 0, v > u and v < 0")
            st.write("Object was initially travelling to the left.")
            st.write("Object continued travelling to the left, decelerated and decreased its speed.")
        elif st.session_state.v > st.session_state.u and st.session_state.v > 0:
            st.write("u < 0, v > u and v > 0")
            st.write("Object was initially travelling to the left.")
            st.write("Object continued travelling to the left, decelerated, decreased its speed and stopped.")
            st.write("Object then accelerated and travelled to the right.")
    elif st.session_state.u > 0:
        if st.session_state.v == st.session_state.u:
            st.write("u > 0, v = u")
            st.write("Object was initially travelling to the right.")
            st.write("Object continued travelling to the right with constant speed.")
        elif st.session_state.v > st.session_state.u:
            st.write("u > 0, v > u")
            st.write("Object was initially travelling to the right.")
            st.write("Object continued travelling to the right, accelerated and increased its speed.")
        elif st.session_state.v == 0:
            st.write("u > 0, v = 0")
            st.write("Object was initially travelling to the right.")
            st.write("Object continued travelling to the right, decelerated, decreased its speed and stopped.")
        elif st.session_state.v < st.session_state.u and st.session_state.v > 0:
            st.write("u > 0, v < u and v > 0")
            st.write("Object was initially travelling to the right.")
            st.write("Object continued travelling to the right, decelerated and decreased its speed.")
        elif st.session_state.v < st.session_state.u and st.session_state.v < 0:
            st.write("u > 0, v < u and v < 0")
            st.write("Object was initially travelling to the right.")
            st.write("Object continued travelling to the right, decelerated, decreased its speed and stopped.")
            st.write("Object then accelerated and travelled to the left.")
    elif st.session_state.u == 0:
        if st.session_state.v == st.session_state.u:
            st.write("Object was initially at rest.")
            st.write("u = 0, v = u")
            st.write("Object continued resting.")
        elif st.session_state.v > st.session_state.u:
            st.write("Object was initially at rest.")
            st.write("u = 0, v > u")
            st.write("Object accelerated and increased its speed to travel to the right.")
        elif st.session_state.v < st.session_state.u:
            st.write("Object was initially at rest.")
            st.write("u = 0, v < u and v < 0")
            st.write("Object accelerated and increased its speed to travel to the left.")

# Clear button
if st.button("Clear"):
    st.session_state.u = 0.0
    st.session_state.v = 0.0
    st.experimental_rerun()  # Rerun the script to reset the input fields and clear the output