use chrono::{DateTime, Utc};
use serde::{Deserialize, Serialize};
use serde_json::Error;
use crate::metrics::Metrics;

pub const STATUS_TOPIC: &str = "system/metrics";

#[derive(Debug, Serialize, Deserialize)]
pub struct StatusMessage<'a> {
    pub agent: &'a str,
    pub metrics: Metrics,
    pub timestamp: DateTime<Utc>,
}

impl<'a> StatusMessage<'a> {
    pub fn new(agent: &'a str, metrics: Metrics) -> Self {
        Self {
            agent,
            metrics,
            timestamp: Utc::now(),
        }
    }

    pub fn to_string(&self) -> Result<String, Error> {
        serde_json::to_string_pretty(&self)
    }
}

impl<'a> TryFrom<&'a [u8]> for StatusMessage<'a> {
    type Error = serde_json::Error;

    fn try_from(value: &'a [u8]) -> Result<Self, Self::Error> {
        serde_json::from_slice(value)
    }
}