use std::{
    net::{Ipv4Addr, SocketAddr, UdpSocket},
    time::SystemTime,
};

use bevy::prelude::*;
use bevy_renet::renet::{
    transport::{
        ClientAuthentication, NetcodeClientTransport, NetcodeServerTransport, ServerAuthentication,
        ServerConfig,
    },
    ConnectionConfig, RenetClient, RenetServer,
};
use bevy_replicon::prelude::*;
use bevy_replicon_renet::{RenetChannelsExt, RepliconRenetPlugins};
use serde::{Deserialize, Serialize};

#[test]
fn connect_disconnect() {
    let mut server_app = App::new();
    let mut client_app = App::new();
    for app in [&mut server_app, &mut client_app] {
        app.add_plugins((
            MinimalPlugins,
            RepliconPlugins.set(ServerPlugin {
                tick_policy: TickPolicy::EveryFrame,
                ..Default::default()
            }),
            RepliconRenetPlugins,
        ));
    }

    setup(&mut server_app, &mut client_app);

    let mut renet_client = client_app.world_mut().resource_mut::<RenetClient>();
    assert!(renet_client.is_connected());
    renet_client.disconnect();

    client_app.update();
    server_app.update();

    let renet_server = server_app.world().resource::<RenetServer>();
    assert_eq!(renet_server.connected_clients(), 0);

    let connected_clients = server_app.world().resource::<ConnectedClients>();
    assert_eq!(connected_clients.len(), 0);

    let replicon_client = client_app.world().resource::<RepliconClient>();
    assert!(replicon_client.is_disconnected());

    server_app.world_mut().remove_resource::<RenetServer>();
    server_app.update();
    assert!(!server_app.world().resource::<RepliconServer>().is_running());
}

#[test]
fn replication() {
    let mut server_app = App::new();
    let mut client_app = App::new();
    for app in [&mut server_app, &mut client_app] {
        app.add_plugins((
            MinimalPlugins,
            RepliconPlugins.set(ServerPlugin {
                tick_policy: TickPolicy::EveryFrame,
                ..Default::default()
            }),
            RepliconRenetPlugins,
        ));
    }

    setup(&mut server_app, &mut client_app);

    server_app.world_mut().spawn(Replicated);

    server_app.update();
    client_app.update();

    assert_eq!(client_app.world().entities().len(), 1);
}

#[test]
fn server_event() {
    let mut server_app = App::new();
    let mut client_app = App::new();
    for app in [&mut server_app, &mut client_app] {
        app.add_plugins((
            MinimalPlugins,
            RepliconPlugins.set(ServerPlugin {
                tick_policy: TickPolicy::EveryFrame,
                ..Default::default()
            }),
            RepliconRenetPlugins,
        ))
        .add_server_event::<DummyEvent>(ChannelKind::Ordered);
    }

    setup(&mut server_app, &mut client_app);

    server_app.world_mut().send_event(ToClients {
        mode: SendMode::Broadcast,
        event: DummyEvent,
    });

    server_app.update();
    client_app.update();

    let dummy_events = client_app.world().resource::<Events<DummyEvent>>();
    assert_eq!(dummy_events.len(), 1);
}

#[test]
fn client_event() {
    let mut server_app = App::new();
    let mut client_app = App::new();
    for app in [&mut server_app, &mut client_app] {
        app.add_plugins((
            MinimalPlugins,
            RepliconPlugins.set(ServerPlugin {
                tick_policy: TickPolicy::EveryFrame,
                ..Default::default()
            }),
            RepliconRenetPlugins,
        ))
        .add_client_event::<DummyEvent>(ChannelKind::Ordered);
    }

    setup(&mut server_app, &mut client_app);

    client_app.world_mut().send_event(DummyEvent);

    client_app.update();
    server_app.update();

    let client_events = server_app
        .world_mut()
        .resource::<Events<FromClient<DummyEvent>>>();
    assert_eq!(client_events.len(), 1);
}

fn setup(server_app: &mut App, client_app: &mut App) {
    const CLIENT_ID: u64 = 1;
    let port = setup_server(server_app, 1);
    setup_client(client_app, CLIENT_ID, port);
    wait_for_connection(server_app, client_app);
}

fn setup_client(app: &mut App, client_id: u64, port: u16) {
    let channels = app.world().resource::<RepliconChannels>();

    let server_channels_config = channels.get_server_configs();
    let client_channels_config = channels.get_client_configs();

    let client = RenetClient::new(ConnectionConfig {
        server_channels_config,
        client_channels_config,
        ..Default::default()
    });
    let transport = create_client_transport(client_id, port);

    app.insert_resource(client).insert_resource(transport);
}

fn setup_server(app: &mut App, max_clients: usize) -> u16 {
    let channels = app.world().resource::<RepliconChannels>();

    let server_channels_config = channels.get_server_configs();
    let client_channels_config = channels.get_client_configs();

    let server = RenetServer::new(ConnectionConfig {
        server_channels_config,
        client_channels_config,
        ..Default::default()
    });
    let transport = create_server_transport(max_clients);
    let port = transport.addresses().first().unwrap().port();

    app.insert_resource(server).insert_resource(transport);

    port
}

const PROTOCOL_ID: u64 = 0;

fn create_server_transport(max_clients: usize) -> NetcodeServerTransport {
    let current_time = SystemTime::now()
        .duration_since(SystemTime::UNIX_EPOCH)
        .unwrap();
    let server_addr = SocketAddr::new(Ipv4Addr::LOCALHOST.into(), 0);
    let socket = UdpSocket::bind(server_addr).expect("localhost should be bindable");
    let public_addr = socket
        .local_addr()
        .expect("socket should autodetect local address");
    let server_config = ServerConfig {
        current_time,
        max_clients,
        protocol_id: PROTOCOL_ID,
        public_addresses: vec![public_addr],
        authentication: ServerAuthentication::Unsecure,
    };

    NetcodeServerTransport::new(server_config, socket).unwrap()
}

fn create_client_transport(client_id: u64, port: u16) -> NetcodeClientTransport {
    let current_time = SystemTime::now()
        .duration_since(SystemTime::UNIX_EPOCH)
        .unwrap();
    let ip = Ipv4Addr::LOCALHOST.into();
    let server_addr = SocketAddr::new(ip, port);
    let socket = UdpSocket::bind((ip, 0)).expect("localhost should be bindable");
    let authentication = ClientAuthentication::Unsecure {
        client_id,
        protocol_id: PROTOCOL_ID,
        server_addr,
        user_data: None,
    };

    NetcodeClientTransport::new(current_time, authentication, socket).unwrap()
}

fn wait_for_connection(server_app: &mut App, client_app: &mut App) {
    loop {
        client_app.update();
        server_app.update();
        if client_app.world().resource::<RenetClient>().is_connected() {
            break;
        }
    }
}

#[derive(Deserialize, Event, Serialize)]
struct DummyEvent;