use std::time::Duration;

use anyhow::Result;
use camper_widget_refresh::dbus::{
    PropertyType, start_service_at, update_connected_status, update_single_property,
};
use futures_util::StreamExt;
use tokio::time::timeout;
use zbus::{Connection, connection, proxy};

const TIMEOUT: Duration = Duration::from_secs(2);

// ---------- Client-side proxy definitions ----------

#[proxy(
    interface = "org.craftknight.CamperWidget.Status",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget"
)]
trait Status {
    #[zbus(property)]
    fn connected(&self) -> zbus::Result<bool>;
}

#[proxy(
    interface = "org.craftknight.CamperWidget.Battery",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget/Battery"
)]
trait Battery {
    #[zbus(property)]
    fn soc(&self) -> zbus::Result<f64>;

    #[zbus(property)]
    fn power(&self) -> zbus::Result<f64>;

    #[zbus(property)]
    fn state(&self) -> zbus::Result<String>;
}

#[proxy(
    interface = "org.craftknight.CamperWidget.Solar",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget/Solar"
)]
trait Solar {
    #[zbus(property)]
    fn power(&self) -> zbus::Result<f64>;
}

#[proxy(
    interface = "org.craftknight.CamperWidget.AcInput",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget/AcInput"
)]
trait AcInput {
    #[zbus(property)]
    fn power(&self) -> zbus::Result<f64>;
}

#[proxy(
    interface = "org.craftknight.CamperWidget.AcLoad",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget/AcLoad"
)]
trait AcLoad {
    #[zbus(property)]
    fn power(&self) -> zbus::Result<f64>;
}

#[proxy(
    interface = "org.craftknight.CamperWidget.Config",
    default_service = "org.craftknight.CamperWidget",
    default_path = "/org/craftknight/camper_widget"
)]
trait Config {
    fn reload(&self) -> zbus::Result<()>;
}

// ---------- Test fixture ----------

struct DbusTestFixture {
    _daemon: dbus_launch::Daemon,
    address: String,
}

impl DbusTestFixture {
    fn new() -> Self {
        let daemon = dbus_launch::Launcher::daemon()
            .launch()
            .expect("failed to launch dbus-daemon — is dbus-daemon installed?");
        let address = daemon.address().to_string();
        Self {
            _daemon: daemon,
            address,
        }
    }

    fn address(&self) -> &str {
        &self.address
    }

    async fn client_connection(&self) -> Result<Connection> {
        let conn = connection::Builder::address(self.address())?
            .build()
            .await?;
        Ok(conn)
    }
}

// ---------- Tests ----------

#[tokio::test]
async fn test_default_property_values() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (_conn, _state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let status = StatusProxy::new(&client).await?;
    let battery = BatteryProxy::new(&client).await?;
    let solar = SolarProxy::new(&client).await?;
    let ac_input = AcInputProxy::new(&client).await?;
    let ac_load = AcLoadProxy::new(&client).await?;

    assert!(!status.connected().await?);
    assert_eq!(battery.soc().await?, 0.0);
    assert_eq!(battery.power().await?, 0.0);
    assert_eq!(battery.state().await?, "idle");
    assert_eq!(solar.power().await?, 0.0);
    assert_eq!(ac_input.power().await?, 0.0);
    assert_eq!(ac_load.power().await?, 0.0);

    Ok(())
}

#[tokio::test]
async fn test_connected_status_update() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let status = StatusProxy::new(&client).await?;

    assert!(!status.connected().await?);

    // Subscribe to changes before mutating
    let mut stream = status.receive_connected_changed().await;

    update_connected_status(&conn, &state, true).await?;

    // Wait for a property-changed signal with the expected value.
    // The proxy may deliver a cached/initial signal first, so loop until
    // we see the value we expect or timeout.
    let deadline = tokio::time::Instant::now() + TIMEOUT;
    loop {
        let remaining = deadline.saturating_duration_since(tokio::time::Instant::now());
        if remaining.is_zero() {
            panic!("timed out waiting for connected=true signal");
        }
        let signal = timeout(remaining, stream.next()).await?;
        let changed = signal.expect("stream ended unexpectedly");
        if changed.get().await? {
            break; // got the expected value
        }
    }

    Ok(())
}

#[tokio::test]
async fn test_battery_soc_update() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let battery = BatteryProxy::new(&client).await?;

    let mut stream = battery.receive_soc_changed().await;

    update_single_property(&conn, &state, &PropertyType::BatterySoc, 85.5).await?;

    let signal = timeout(TIMEOUT, stream.next()).await?;
    assert!(signal.is_some());
    assert!((signal.unwrap().get().await? - 85.5).abs() < f64::EPSILON);

    Ok(())
}

#[tokio::test]
async fn test_battery_power_and_state_derivation() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let battery = BatteryProxy::new(&client).await?;

    let mut state_stream = battery.receive_state_changed().await;

    // Positive power above threshold -> charging
    update_single_property(&conn, &state, &PropertyType::BatteryPower, 12.0).await?;
    update_single_property(&conn, &state, &PropertyType::BatteryState, 12.0).await?;

    let signal = timeout(TIMEOUT, state_stream.next()).await?;
    assert!(signal.is_some());
    assert_eq!(signal.unwrap().get().await?, "charging");

    // Negative power below threshold -> discharging
    update_single_property(&conn, &state, &PropertyType::BatteryPower, -12.0).await?;
    update_single_property(&conn, &state, &PropertyType::BatteryState, -12.0).await?;

    let signal = timeout(TIMEOUT, state_stream.next()).await?;
    assert!(signal.is_some());
    assert_eq!(signal.unwrap().get().await?, "discharging");

    // Small power within threshold -> idle
    update_single_property(&conn, &state, &PropertyType::BatteryPower, 3.0).await?;
    update_single_property(&conn, &state, &PropertyType::BatteryState, 3.0).await?;

    let signal = timeout(TIMEOUT, state_stream.next()).await?;
    assert!(signal.is_some());
    assert_eq!(signal.unwrap().get().await?, "idle");

    Ok(())
}

#[tokio::test]
async fn test_solar_power_update() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let solar = SolarProxy::new(&client).await?;

    let mut stream = solar.receive_power_changed().await;

    update_single_property(&conn, &state, &PropertyType::SolarPower, 250.0).await?;

    let signal = timeout(TIMEOUT, stream.next()).await?;
    assert!(signal.is_some());
    assert!((signal.unwrap().get().await? - 250.0).abs() < f64::EPSILON);

    Ok(())
}

#[tokio::test]
async fn test_ac_input_power_update() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let ac_input = AcInputProxy::new(&client).await?;

    let mut stream = ac_input.receive_power_changed().await;

    update_single_property(&conn, &state, &PropertyType::AcInputPower, 82.0).await?;

    let signal = timeout(TIMEOUT, stream.next()).await?;
    assert!(signal.is_some());
    assert!((signal.unwrap().get().await? - 82.0).abs() < f64::EPSILON);

    Ok(())
}

#[tokio::test]
async fn test_ac_load_power_update() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let ac_load = AcLoadProxy::new(&client).await?;

    let mut stream = ac_load.receive_power_changed().await;

    update_single_property(&conn, &state, &PropertyType::AcLoadPower, 77.0).await?;

    let signal = timeout(TIMEOUT, stream.next()).await?;
    assert!(signal.is_some());
    assert!((signal.unwrap().get().await? - 77.0).abs() < f64::EPSILON);

    Ok(())
}

#[tokio::test]
async fn test_config_reload_method() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (_conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let config = ConfigProxy::new(&client).await?;

    // Spawn a listener for the notify signal
    let notify = state.config_reload_notify.clone();
    let listener = tokio::spawn(async move { notify.notified().await });

    // Call reload via D-Bus
    config.reload().await?;

    // The listener should complete within the timeout
    timeout(TIMEOUT, listener).await??;

    Ok(())
}

#[tokio::test]
async fn test_property_change_signal_emitted() -> Result<()> {
    let fixture = DbusTestFixture::new();
    let (conn, state) = start_service_at(fixture.address()).await?;

    let client = fixture.client_connection().await?;
    let battery = BatteryProxy::new(&client).await?;

    // Subscribe to soc property changes before making updates
    let mut stream = battery.receive_soc_changed().await;

    // Update the property
    update_single_property(&conn, &state, &PropertyType::BatterySoc, 50.0).await?;

    // Should receive the change signal
    let signal = timeout(TIMEOUT, stream.next()).await?;
    assert!(signal.is_some());
    let changed = signal.unwrap();
    assert!((changed.get().await? - 50.0).abs() < f64::EPSILON);

    Ok(())
}