use crate::db::{ConnectionPool, DbError};
use crate::message_broker::MessageBroker;
use rand::distributions::{Distribution, Uniform};
use rand::rngs::StdRng;
use rand::SeedableRng;
use std::sync::atomic::Ordering;
use std::sync::Arc;
use std::time::{Duration, Instant};

use super::base::{BaseWorker, Worker, WorkerState};
use crate::worker::sql::{
    QUERY_GET_TOWNS,
    QUERY_INSERT_STOCK,
    QUERY_CLEANUP_STOCK,
    QUERY_GET_REGION_USERS,
};

pub struct StockageManager {
    base: BaseWorker,
}

impl StockageManager {
    pub fn new(pool: ConnectionPool, broker: MessageBroker) -> Self {
        Self {
            base: BaseWorker::new("StockageManager", pool, broker),
        }
    }

    fn run_loop(pool: ConnectionPool, broker: MessageBroker, state: Arc<WorkerState>) {
        let mut last_add_run: Option<Instant> = None;
        let mut last_cleanup_run: Option<Instant> = None;

        while state.running_worker.load(Ordering::Relaxed) {
            let now = Instant::now();

            // Entspricht addLocalStocks: alle 60 Sekunden prüfen & ggf. Stocks hinzufügen
            let should_add = match last_add_run {
                None => true,
                Some(last) => now.saturating_duration_since(last) >= Duration::from_secs(60),
            };

            if should_add {
                if let Err(err) = Self::add_local_stocks(&pool, &broker) {
                    eprintln!("[StockageManager] Fehler in addLocalStocks: {err}");
                }
                last_add_run = Some(now);
            }

            // Cleanup regelmäßig ausführen (z.B. ebenfalls im 60s-Rhythmus)
            let should_cleanup = match last_cleanup_run {
                None => true,
                Some(last) => now.saturating_duration_since(last) >= Duration::from_secs(60),
            };

            if should_cleanup {
                if let Err(err) = Self::cleanup_buyable_stock(&pool) {
                    eprintln!("[StockageManager] Fehler bei stock cleanup: {err}");
                }
                last_cleanup_run = Some(now);
            }

            std::thread::sleep(Duration::from_secs(1));
        }
    }

    fn add_local_stocks(pool: &ConnectionPool, broker: &MessageBroker) -> Result<(), DbError> {
        let mut rng = StdRng::from_entropy();
        let dist = Uniform::from(0.0..1.0);

        let town_ids = Self::get_town_ids(pool)?;

        for town_id in town_ids {
            // Wahrscheinlichkeit analog: round(dist * 2160) <= 1
            let roll: f64 = dist.sample(&mut rng) * 2160.0_f64;
            let chance = roll.round();
            if chance <= 1.0 {
                Self::add_stock_for_town(pool, broker, town_id)?;
            }
        }

        Ok(())
    }

    fn get_town_ids(pool: &ConnectionPool) -> Result<Vec<i32>, DbError> {
        let mut conn = pool
            .get()
            .map_err(|e| DbError::new(format!("[StockageManager] DB-Verbindung fehlgeschlagen: {e}")))?;

        conn.prepare("get_towns", QUERY_GET_TOWNS)?;
        let towns = conn.execute("get_towns", &[])?;

        let mut ids = Vec::with_capacity(towns.len());
        for row in towns {
            if let Some(id) = row.get("id").and_then(|v| v.parse::<i32>().ok()) {
                ids.push(id);
            }
        }

        Ok(ids)
    }

    fn add_stock_for_town(
        pool: &ConnectionPool,
        broker: &MessageBroker,
        town_id: i32,
    ) -> Result<(), DbError> {
        let mut conn = pool
            .get()
            .map_err(|e| DbError::new(format!("[StockageManager] DB-Verbindung fehlgeschlagen: {e}")))?;

        conn.prepare("add_stock", QUERY_INSERT_STOCK)?;
        conn.execute("add_stock", &[&town_id])?;

        // Benachrichtige alle User in der Region
        let users = Self::get_region_users(&mut conn, town_id)?;
        for user_id in users {
            let message = format!(
                r#"{{"event":"stock_change","user_id":{},"branch":{}}}"#,
                user_id, town_id
            );
            broker.publish(message);
        }

        Ok(())
    }

    fn get_region_users(conn: &mut crate::db::DbConnection, region_id: i32) -> Result<Vec<i32>, DbError> {
        conn.prepare("get_region_users", QUERY_GET_REGION_USERS)?;
        let rows = conn.execute("get_region_users", &[&region_id])?;

        let mut result = Vec::with_capacity(rows.len());
        for row in rows {
            if let Some(uid) = row.get("user_id").and_then(|v| v.parse::<i32>().ok()) {
                result.push(uid);
            }
        }
        Ok(result)
    }

    fn cleanup_buyable_stock(pool: &ConnectionPool) -> Result<(), DbError> {
        let mut conn = pool
            .get()
            .map_err(|e| DbError::new(format!("[StockageManager] DB-Verbindung fehlgeschlagen: {e}")))?;

        conn.prepare("cleanup_stock", QUERY_CLEANUP_STOCK)?;
        conn.execute("cleanup_stock", &[])?;
        Ok(())
    }
}

impl Worker for StockageManager {
    fn start_worker_thread(&mut self) {
        let pool = self.base.pool.clone();
        let broker = self.base.broker.clone();

        self.base
            .start_worker_with_loop(move |state: Arc<WorkerState>| {
                StockageManager::run_loop(pool.clone(), broker.clone(), state);
            });
    }

    fn stop_worker_thread(&mut self) {
        self.base.stop_worker();
    }

    fn enable_watchdog(&mut self) {
        self.base.start_watchdog();
    }
}