use crate::auth_client::AuthClient;
use crate::bufferpool::BufferPool;
use crate::metrics::{ACTIVE_CONNECTIONS, PACKETS_RECEIVED};
use crate::packet::Packet;
use dotenv::dotenv;
use std::collections::HashMap;
use std::env;
use std::error::Error;
use std::net::ToSocketAddrs;
use std::str::FromStr;
use std::sync::Arc;
use tokio::io::AsyncReadExt;
use tokio::net::{TcpListener, TcpStream};
use tokio::sync::{Mutex, Semaphore};
use tokio::{select, signal};
use tracing::Level;
use tracing::{debug, error, info, warn};
use utils::consul_registration;
use utils::service_discovery::get_service_address;
use warp::Filter;
use crate::connection_service::ConnectionService;

mod packet_type;
mod packet;
mod router;
mod packets;
mod enums;
mod dataconsts;
mod types;
mod handlers;
mod bufferpool;
mod metrics;
mod auth_client;
mod connection_state;
mod connection_service;

pub mod auth {
    tonic::include_proto!("auth"); // Path matches the package name in auth.proto
}

const BUFFER_POOL_SIZE: usize = 1000;
const MAX_CONCURRENT_CONNECTIONS: usize = 100;


async fn handle_connection(stream: &mut TcpStream, pool: Arc<BufferPool>, auth_client: Arc<Mutex<AuthClient>>, connection_service: Arc<ConnectionService>, connection_id: String) -> Result<(), Box<dyn Error + Send + Sync>> {
    ACTIVE_CONNECTIONS.inc();
    while let Some(mut buffer) = pool.acquire().await {
        // Read data into the buffer
        let n = stream.read(&mut buffer).await?;
        if n == 0 {
            break; // Connection closed
        }
        PACKETS_RECEIVED.inc();

        // Process the packet
        match Packet::from_raw(&buffer[..n]) {
            Ok(packet) => {
                debug!("Parsed Packet: {:?}", packet);
                // Handle the parsed packet (route it, process it, etc.)
                router::route_packet(stream, packet, auth_client.clone(), connection_service.clone(), connection_id.clone()).await?;
            }
            Err(e) => warn!("Failed to parse packet: {}", e),
        }

        pool.release(buffer).await;
    }

    if let Some(state) = connection_service.get_connection(&connection_id) {
        let session_id = state.session_id.unwrap();
        let mut auth_client = auth_client.lock().await;
        auth_client.logout(&session_id).await?;
    }
    ACTIVE_CONNECTIONS.dec();
    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    dotenv().ok();
    tracing_subscriber::fmt()
        .with_max_level(Level::from_str(&env::var("LOG_LEVEL").unwrap_or_else(|_| "info".to_string())).unwrap_or_else(|_| Level::INFO))
        .init();

    // Set the gRPC server address
    let addr = env::var("LISTEN_ADDR").unwrap_or_else(|_| "0.0.0.0".to_string());
    let port = env::var("PACKET_SERVICE_PORT").unwrap_or_else(|_| "4000".to_string());
    let health_port = env::var("HEALTH_CHECK_PORT").unwrap_or_else(|_| "8082".to_string());

    let consul_url = env::var("CONSUL_URL").unwrap_or_else(|_| "http://127.0.0.1:8500".to_string());
    let service_name = env::var("SERVICE_NAME").unwrap_or_else(|_| "packet-service".to_string());
    let service_address = env::var("PACKET_SERVICE_ADDR").unwrap_or_else(|_| "127.0.0.1".to_string());
    let service_port = port.clone();
    let health_check_url = format!("http://{}:{}/health", service_address, health_port);
    let health_check_endpoint_addr = format!("{}:{}", service_address, health_port);
    let auth_node = get_service_address(&consul_url, "auth-service").await?;

    // Register service with Consul
    let service_id = consul_registration::get_or_generate_service_id();
    let tags = vec!["version-1.0".to_string()];
    let mut meta = HashMap::new();
    consul_registration::register_service(
        &consul_url,
        service_id.as_str(),
        service_name.as_str(),
        service_address.as_str(),
        service_port.parse().unwrap_or(50052),
        tags,
        meta,
        &health_check_url,
    )
        .await?;

    // Start health-check endpoint
    consul_registration::start_health_check(addr.as_str()).await?;

    let auth_address = auth_node.get(0).unwrap();
    let auth_url = format!("http://{}:{}", auth_address.ServiceAddress, auth_address.ServicePort);
    let auth_client = Arc::new(Mutex::new(AuthClient::connect(&auth_url).await?));

    let full_addr = format!("{}:{}", &addr, port);

    tokio::spawn(async move {
        let semaphore = Arc::new(Semaphore::new(MAX_CONCURRENT_CONNECTIONS));
        let listener = TcpListener::bind(full_addr.clone()).await.unwrap();
        let buffer_pool = BufferPool::new(BUFFER_POOL_SIZE);
        let connection_service = Arc::new(ConnectionService::new());

        info!("Packet service listening on {}", full_addr);

        loop {
            let (mut socket, addr) = listener.accept().await.unwrap();
            let auth_client = auth_client.clone();
            let connection_service = connection_service.clone();
            info!("New connection from {}", addr);

            let pool = buffer_pool.clone();
            let permit = semaphore.clone().acquire_owned().await.unwrap();

            // Spawn a new task for each connection
            tokio::spawn(async move {
                let _permit = permit;
                let connection_id = connection_service.add_connection();
                if let Err(e) = handle_connection(&mut socket, pool, auth_client, connection_service.clone(), connection_id.clone()).await {
                    error!("Error handling connection: {}", e);
                }
                connection_service.remove_connection(&connection_id);
            });
        }
    });

    let mut sigterm_stream = signal::unix::signal(signal::unix::SignalKind::terminate())?;
    select! {
        _ = signal::ctrl_c() => {
            info!("Received SIGINT (Ctrl+C), shutting down...");
        },
        _ = sigterm_stream.recv() => {
            info!("Received SIGTERM, shutting down...");
        },
    }

    consul_registration::deregister_service(&consul_url, service_id.as_str()).await.expect("");
    info!("service {} deregistered", service_name);
    Ok(())
}