//! End-effector traits — abstract operations that touch real hardware
//! (SSH, Home Assistant, Docker).  Control logic in [`cluster_state`]
//! and [`orchestrate`] works with these traits so it can be tested
//! without live infrastructure.

use anyhow::Result;

use crate::cluster_state::ClusterState;
use crate::config::{Cluster, Config, Node};

/// Probe nodes and return their aggregate state.
pub trait NodeProber {
    /// Probe all unique nodes across the config.
    fn probe(&self, config: &Config) -> impl std::future::Future<Output = ClusterState> + Send;
}

/// Power on/off smart plugs via Home Assistant.
///
/// Intentionally models only the **power-on** path (`entity_is_on` /
/// `turn_on`): orchestrate's `prepare_cluster` auto-powers-on a cluster
/// when nodes are unreachable, and that is the only place the trait is
/// used. `power off` is a direct user command (`power.rs`) that talks to
/// `HaClient` directly — it does not flow through orchestrate, so it has
/// no need of the trait abstraction. If orchestrate ever needs to power
/// off, add `turn_off` here and route `power_off` through it.
pub trait PowerController {
    /// Check whether a HA entity is currently in state `"on"`.
    fn entity_is_on(&self, entity: &str) -> impl std::future::Future<Output = Option<bool>> + Send;

    /// Turn on a HA entity (power on the node/switch).
    fn turn_on(&self, entity: &str) -> impl std::future::Future<Output = Result<()>> + Send;
}

/// Ping a node via SSH to test reachability.
pub trait NodePinger {
    /// Whether the node accepts SSH connections.
    fn is_reachable(
        &self,
        config: &Config,
        node: &Node,
    ) -> impl std::future::Future<Output = bool> + Send;
}

// ---------------------------------------------------------------------------
// Real implementations
// ---------------------------------------------------------------------------

use crate::home_assistant::Client as HaClient;
use crate::home_assistant::warn_if_token_looks_short;
use crate::ssh::run_ssh;
use tracing::warn;

pub struct SshProber;

impl NodeProber for SshProber {
    async fn probe(&self, config: &Config) -> ClusterState {
        ClusterState::probe(config).await
    }
}

pub struct HaPowerController {
    ha: HaClient,
    config: Config,
}

impl HaPowerController {
    pub fn new(ha: HaClient, config: Config) -> Self {
        Self { ha, config }
    }
}

impl PowerController for HaPowerController {
    async fn entity_is_on(&self, entity: &str) -> Option<bool> {
        // `[mikrotik]` device: liveness through the RouterOS API login
        // (logged in = on; unreachable/rejected = off, like a dead switch).
        if let Some(dev) = self
            .config
            .mikrotik
            .as_ref()
            .and_then(|m| m.devices.iter().find(|d| d.name == entity))
        {
            return Some(crate::mikrotik::ping_device(dev).await.is_ok());
        }
        self.ha.get_state(entity).await.map(|s| s == "on")
    }

    async fn turn_on(&self, entity: &str) -> Result<()> {
        // RouterOS has no power-ON API: route through the device's
        // `on_entity` HA relay if configured; otherwise the operator plugs
        // it in manually (same semantics as `power on`), never an error.
        if let Some(dev) = self
            .config
            .mikrotik
            .as_ref()
            .and_then(|m| m.devices.iter().find(|d| d.name == entity))
        {
            match &dev.on_entity {
                Some(relay) => self.ha.turn_on(relay).await?,
                None => {
                    warn!("RouterOS {entity} has no on_entity relay — power it on manually");
                }
            }
            return Ok(());
        }
        self.ha.turn_on(entity).await
    }
}

pub struct SshNodePinger;

impl NodePinger for SshNodePinger {
    async fn is_reachable(&self, config: &Config, node: &Node) -> bool {
        run_ssh(config, node, "echo ok".into(), false).await.is_ok()
    }
}

/// Build a [`HaPowerController`] from config, returning `None` if HA is
/// not configured.
pub fn ha_controller_from_config(config: &Config) -> Option<HaPowerController> {
    let ha_cfg = config.home_assistant.as_ref()?;
    let ha = match HaClient::new(ha_cfg) {
        Ok(c) => c,
        Err(e) => {
            warn!("Failed to construct HA client: {}", e);
            return None;
        }
    };
    warn_if_token_looks_short(&ha_cfg.token);
    Some(HaPowerController::new(ha, config.clone()))
}

/// Collect all entity IDs (per-node + cluster extras) for a cluster.
pub fn cluster_entities(cluster: &Cluster) -> Vec<String> {
    let mut entities: Vec<String> = Vec::new();
    for node in &cluster.nodes {
        if let Some(entity) = &node.entity {
            entities.push(entity.clone());
        }
    }
    entities.extend(
        cluster
            .extra_entities
            .iter()
            .map(|e| e.entity().to_string()),
    );
    entities
}