// Ce module regroupe la publication Home Assistant discovery.
use anyhow::{Context, Result};
use rumqttc::AsyncClient;
use serde::Serialize;

use crate::config::{base_device_topic, Config};

#[derive(Clone, Serialize)]
struct DeviceInfo {
    identifiers: Vec<String>,
    name: String,
    manufacturer: String,
    model: String,
    sw_version: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    suggested_area: Option<String>,
}

#[derive(Serialize)]
struct EntityConfig<'a> {
    name: &'a str,
    unique_id: String,
    state_topic: String,
    availability_topic: String,
    payload_available: &'a str,
    payload_not_available: &'a str,
    device: DeviceInfo,
    #[serde(skip_serializing_if = "Option::is_none")]
    command_topic: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    payload_on: Option<&'a str>,
    #[serde(skip_serializing_if = "Option::is_none")]
    payload_off: Option<&'a str>,
    #[serde(skip_serializing_if = "Option::is_none")]
    unit_of_measurement: Option<&'a str>,
    #[serde(skip_serializing_if = "Option::is_none")]
    device_class: Option<&'a str>,
    #[serde(skip_serializing_if = "Option::is_none")]
    icon: Option<&'a str>,
}

// Publie les entites HA discovery pour les capteurs et commandes standard.
pub async fn publish_all(client: &AsyncClient, cfg: &Config) -> Result<()> {
    let base = base_device_topic(cfg);
    let prefix = cfg.mqtt.discovery_prefix.trim_end_matches('/');
    let device = DeviceInfo {
        identifiers: cfg.device.identifiers.clone(),
        name: cfg.device.name.clone(),
        manufacturer: cfg.device.manufacturer.clone(),
        model: cfg.device.model.clone(),
        sw_version: cfg.device.sw_version.clone(),
        suggested_area: cfg.device.suggested_area.clone(),
    };


    let sensors = vec![
        ("cpu_usage", "CPU Usage", Some("%"), None, Some("mdi:chip")),
        ("memory_used_mb", "Memory Used", Some("MB"), None, Some("mdi:memory")),
        ("memory_total_mb", "Memory Total", Some("MB"), None, Some("mdi:memory")),
        ("ip_address", "IP Address", None, None, Some("mdi:ip")),
        ("power_state", "Power State", None, None, Some("mdi:power")),
        ("battery_level", "Battery Level", Some("%"), Some("battery"), Some("mdi:battery")),
        ("battery_state", "Battery State", None, None, Some("mdi:battery-charging")),
    ];

    for (key, name, unit, class, icon) in sensors {
        let entity_name = format!("{}_{}", key, cfg.device.name);
        let entity = EntityConfig {
            name: &entity_name,
            unique_id: format!("{}_{}", cfg.device.name, key),
            state_topic: format!("{}/{}", base, key),
            availability_topic: format!("{}/{}/available", base, key),
            payload_available: "online",
            payload_not_available: "offline",
            device: DeviceInfo { ..device.clone() },
            command_topic: None,
            payload_on: None,
            payload_off: None,
            unit_of_measurement: unit,
            device_class: class,
            icon,
        };
        let topic = format!("{}/sensor/{}/{}/config", prefix, cfg.device.name, entity_name);
        publish_discovery(client, &topic, &entity).await?;
    }

    let switches = vec![
        ("shutdown", "Shutdown", "cmd/shutdown/set"),
        ("reboot", "Reboot", "cmd/reboot/set"),
        ("sleep", "Sleep", "cmd/sleep/set"),
        ("screen", "Screen", "cmd/screen/set"),
    ];

    for (key, name, cmd) in switches {
        let entity_name = format!("{}_{}", key, cfg.device.name);
        let entity = EntityConfig {
            name: &entity_name,
            unique_id: format!("{}_{}", cfg.device.name, key),
            state_topic: format!("{}/{}/state", base, key),
            availability_topic: format!("{}/{}/available", base, key),
            payload_available: "online",
            payload_not_available: "offline",
            device: DeviceInfo { ..device.clone() },
            command_topic: Some(format!("{}/{}", base, cmd)),
            payload_on: Some("ON"),
            payload_off: Some("OFF"),
            unit_of_measurement: None,
            device_class: Some("switch"),
            icon: Some("mdi:power"),
        };
        let topic = format!("{}/switch/{}/{}/config", prefix, cfg.device.name, entity_name);
        publish_discovery(client, &topic, &entity).await?;
    }

    Ok(())
}

async fn publish_discovery<T: Serialize>(client: &AsyncClient, topic: &str, payload: &T) -> Result<()> {
    let data = serde_json::to_vec(payload).context("serialize discovery")?;
    client
        .publish(topic, rumqttc::QoS::AtLeastOnce, true, data)
        .await
        .context("publish discovery")?;
    Ok(())
}