"""Streamlit dashboard application for physics simulation visualisation.

This module provides an interactive dashboard for visualising the physics
engine directly, demonstrating thermal-electrical coupling in real-time.
"""

from collections import deque
from dataclasses import dataclass, field

import streamlit as st

from py_dvt_ate.simulation.physics.engine import PhysicsEngine


# History buffer size for charts
HISTORY_SIZE = 500


@dataclass
class SimulationHistory:
    """Stores time series data for visualisation."""

    time: deque[float] = field(default_factory=lambda: deque(maxlen=HISTORY_SIZE))
    chamber_temp: deque[float] = field(
        default_factory=lambda: deque(maxlen=HISTORY_SIZE)
    )
    case_temp: deque[float] = field(default_factory=lambda: deque(maxlen=HISTORY_SIZE))
    junction_temp: deque[float] = field(
        default_factory=lambda: deque(maxlen=HISTORY_SIZE)
    )
    output_voltage: deque[float] = field(
        default_factory=lambda: deque(maxlen=HISTORY_SIZE)
    )
    power_dissipation: deque[float] = field(
        default_factory=lambda: deque(maxlen=HISTORY_SIZE)
    )


def init_session_state() -> None:
    """Initialise Streamlit session state."""
    if "engine" not in st.session_state:
        st.session_state.engine = PhysicsEngine(update_rate_hz=100.0)
    if "history" not in st.session_state:
        st.session_state.history = SimulationHistory()
    if "running" not in st.session_state:
        st.session_state.running = False


def step_simulation(steps: int = 10) -> None:
    """Advance the simulation by the given number of steps."""
    engine: PhysicsEngine = st.session_state.engine
    history: SimulationHistory = st.session_state.history

    for _ in range(steps):
        engine.step()

    # Record current state in history
    thermal = engine.get_thermal_state()
    electrical = engine.get_electrical_state()

    history.time.append(thermal.timestamp)
    history.chamber_temp.append(thermal.chamber_temperature)
    history.case_temp.append(thermal.case_temperature)
    history.junction_temp.append(thermal.junction_temperature)
    history.output_voltage.append(electrical.output_voltage)
    history.power_dissipation.append(electrical.power_dissipation)


def display_thermal_chart() -> None:
    """Display temperature chart."""
    history: SimulationHistory = st.session_state.history

    if len(history.time) < 2:
        st.info("Start the simulation to see temperature data")
        return

    chart_data = {
        "Time (s)": list(history.time),
        "Chamber": list(history.chamber_temp),
        "Case": list(history.case_temp),
        "Junction": list(history.junction_temp),
    }

    st.line_chart(
        chart_data,
        x="Time (s)",
        y=["Chamber", "Case", "Junction"],
        color=["#1f77b4", "#ff7f0e", "#d62728"],
    )


def display_current_state() -> None:
    """Display current simulation state metrics."""
    engine: PhysicsEngine = st.session_state.engine
    thermal = engine.get_thermal_state()
    electrical = engine.get_electrical_state()

    col1, col2, col3, col4 = st.columns(4)

    with col1:
        st.metric("Chamber Temp", f"{thermal.chamber_temperature:.2f} °C")
    with col2:
        st.metric("Case Temp", f"{thermal.case_temperature:.2f} °C")
    with col3:
        st.metric("Junction Temp", f"{thermal.junction_temperature:.2f} °C")
    with col4:
        st.metric("Output Voltage", f"{electrical.output_voltage:.4f} V")

    col5, col6, col7, col8 = st.columns(4)

    with col5:
        st.metric("Input Voltage", f"{electrical.input_voltage:.2f} V")
    with col6:
        st.metric("Load Current", f"{electrical.load_current * 1000:.1f} mA")
    with col7:
        st.metric("Power Diss.", f"{electrical.power_dissipation * 1000:.2f} mW")
    with col8:
        st.metric("Sim Time", f"{engine.simulation_time:.2f} s")


def display_controls() -> None:
    """Display simulation control panel in sidebar."""
    engine: PhysicsEngine = st.session_state.engine

    st.sidebar.header("Simulation Controls")

    # Start/Stop button
    if st.session_state.running:
        if st.sidebar.button("Stop Simulation", type="primary", use_container_width=True):
            st.session_state.running = False
            st.rerun()
    else:
        if st.sidebar.button(
            "Start Simulation", type="primary", use_container_width=True
        ):
            st.session_state.running = True
            st.rerun()

    # Reset button
    if st.sidebar.button("Reset", use_container_width=True):
        st.session_state.engine = PhysicsEngine(update_rate_hz=100.0)
        st.session_state.history = SimulationHistory()
        st.session_state.running = False
        st.rerun()

    st.sidebar.divider()

    # Temperature setpoint
    st.sidebar.subheader("Thermal Chamber")
    temp_setpoint = st.sidebar.slider(
        "Temperature Setpoint (°C)",
        min_value=-40.0,
        max_value=125.0,
        value=25.0,
        step=5.0,
        key="temp_setpoint",
    )
    engine.set_chamber_setpoint(temp_setpoint)

    st.sidebar.divider()

    # Power supply controls
    st.sidebar.subheader("Power Supply")
    input_voltage = st.sidebar.slider(
        "Input Voltage (V)",
        min_value=0.0,
        max_value=12.0,
        value=5.0,
        step=0.1,
        key="input_voltage",
    )
    engine.set_input_voltage(input_voltage)

    output_enabled = st.sidebar.toggle(
        "Output Enabled",
        value=engine.is_output_enabled,
        key="output_enabled",
    )
    engine.set_output_enabled(output_enabled)

    st.sidebar.divider()

    # Load controls
    st.sidebar.subheader("Electronic Load")
    load_current_ma = st.sidebar.slider(
        "Load Current (mA)",
        min_value=0.0,
        max_value=500.0,
        value=100.0,
        step=10.0,
        key="load_current",
    )
    engine.set_load_current(load_current_ma / 1000.0)


def main() -> None:
    """Main entry point for the Streamlit dashboard."""
    st.set_page_config(
        page_title="py-dvt-ate Virtual Lab Bench",
        page_icon="🔬",
        layout="wide",
    )

    st.title("py-dvt-ate Virtual Lab Bench")
    st.markdown(
        """
        Interactive physics simulation demonstrating coupled thermal-electrical
        behaviour of an LDO voltage regulator.
        """
    )

    init_session_state()

    # Sidebar controls
    display_controls()

    # Current state display
    st.subheader("Current State")
    display_current_state()

    # Temperature chart
    st.subheader("Temperature History")
    display_thermal_chart()

    # Auto-refresh when running
    if st.session_state.running:
        step_simulation(steps=10)
        st.rerun()


if __name__ == "__main__":
    main()