use std::time::Instant;

use godot::prelude::*;
use teanet::stats::NetStats;

#[derive(GodotClass)]
#[class(base=Object, singleton)]
pub struct Stats {
    pub statistics: Statistics,
    last_update: Instant,

    base: Base<Object>,
}

#[godot_api]
impl IObject for Stats {
    fn init(base: Base<Object>) -> Self {
        Stats {
            statistics: Default::default(),
            last_update: Instant::now(),
            base,
        }
    }
}

impl Stats {
    pub fn update_stats(&mut self, stats: NetStats) {
        let now = Instant::now();

        let tx_diff =
            stats.bytes_tx.max(self.statistics.total_bytes_tx) - self.statistics.total_bytes_tx;
        let rx_diff =
            stats.bytes_rx.max(self.statistics.total_bytes_rx) - self.statistics.total_bytes_rx;

        self.statistics.total_bytes_rx = stats.bytes_rx;
        self.statistics.total_bytes_tx = stats.bytes_tx;
        self.statistics.packet_loss =
            1. - ((stats.messages_received as f64) / (stats.messages_expected as f64));

        let duration = now - self.last_update;
        let tx_bps = tx_diff as f64 / duration.as_secs_f64();
        let rx_bps = rx_diff as f64 / duration.as_secs_f64();
        self.statistics.tx_bps = tx_bps as usize;
        self.statistics.rx_bps = rx_bps as usize;

        self.last_update = now;
    }
}

#[derive(Default)]
pub struct Statistics {
    pub total_bytes_tx: usize,
    pub total_bytes_rx: usize,
    pub tx_bps: usize,
    pub rx_bps: usize,
    pub packet_loss: f64,
}