import streamlit as st
import numpy as np
from scipy.integrate import odeint
import matplotlib.pyplot as plt

class Pendulum:
    def __init__(self, length, gravity):
        self.L = length
        self.g = gravity
    
    def derivatives(self, state, t):
        theta, omega = state
        dydt = [omega, -self.g/self.L * np.sin(theta)]
        return dydt
    
    def simulate(self, initial_angle, duration, time_points):
        initial_state = [initial_angle, 0]  # angle and angular velocity
        t = np.linspace(0, duration, time_points)
        solution = odeint(self.derivatives, initial_state, t)
        return t, solution

def main():
    st.title("Simulación Simple del Mecanismo del Péndulo")
    
    # User inputs
    length = st.slider("Amplitud del Péndulo (m)", 0.1, 5.0, 1.0)
    initial_angle = st.slider("Angulo Inicial (grados)", -90.0, 90.0, 45.0)
    
    # Convert to radians
    initial_angle_rad = np.deg2rad(initial_angle)
    
    # Create and simulate pendulum
    pendulum = Pendulum(length=length, gravity=9.81)
    t, solution = pendulum.simulate(initial_angle_rad, duration=10, time_points=1000)
    
    # Plot results
    fig, ax = plt.subplots()
    ax.plot(t, np.rad2deg(solution[:, 0]))
    ax.set_xlabel('Tiempo (s)')
    ax.set_ylabel('Angulo (grados)')
    ax.grid(True)
    st.pyplot(fig)
    
    # Display energy conservation
    E_kinetic = 0.5 * length * solution[:, 1]**2
    E_potential = 9.81 * length * (1 - np.cos(solution[:, 0]))
    E_total = E_kinetic + E_potential
    
    st.write("### Conservación de la Energía")
    st.line_chart({"Energía Total": E_total, 
                   "Energía Cinética": E_kinetic,
                   "Energía Potencial": E_potential})

if __name__ == "__main__":
    main()