use std::collections::{BTreeMap, BTreeSet};
use std::time::SystemTime;
use redis::Commands;
use tracing::{info, warn};
use rayon::prelude::*;
use crate::client_manager::ClientManager;
use crate::models::{TrackerInfo, TrackerMap};

pub fn get_trackers(client_mgr: &ClientManager) -> color_eyre::Result<TrackerMap> {
    let mut con = client_mgr.get_master_connection()?;
    let trackers: BTreeMap<String, String> = con.hgetall("trackers")?;
    let mut errors = vec![];
    let trackers: BTreeMap<String, TrackerInfo> = trackers.into_iter()
        .map(|(name, info)| {
            let info: serde_json::Result<TrackerInfo> = serde_json::from_str(&info);
            (name, info)
        })
        .filter_map(|(n,v)| {
            v.map_err(|e| errors.push((n.clone(), e)))
                .ok()
                .map(|v| (n, v))
        })
        .collect();
    for (n, e) in errors {
        warn!("Unable to parse tracker data for {n}: {e}");
    }
    Ok(trackers)
}

pub fn determine_active_trackers(client_mgr: &ClientManager, trackers: &TrackerMap, inactive_minutes: u64) -> color_eyre::Result<BTreeSet<String>> {
    let start = SystemTime::now();
    let t = get_last_requests_time()?;
    let res: color_eyre::Result<Vec<Option<String>>> = trackers.par_iter().map(|(name, info)| {
        let mut con = client_mgr.get_connection_from_tracker(info)?;
        for i in 0..inactive_minutes {
            let tim = t.clone() - i * 60u64;
            let k = format!("{name}:requests_processed:{tim}");
            let ex: bool = con.exists(k)?;
            if ex {
                return Ok(Some(name.clone()))
            }
        }
        Ok(None)
    })
        .collect();
    let res = res?;
    let dur = SystemTime::now().duration_since(start).unwrap().as_secs_f32();
    info!("Determining active projects took {dur:.04} seconds.");
    Ok(res.into_iter().filter_map(|v| v).collect())
}

pub fn get_last_requests_time() -> color_eyre::Result<u64> {
    let now = SystemTime::now();
    let unix = now.duration_since(SystemTime::UNIX_EPOCH)?.as_secs();
    let unix = unix - 60;
    let d = unix.clone() % 60;
    Ok(unix - d)
}