use crate::{
    GameState,
    config::NetworkingConfig,
    protocol::{
        ClientEnteredPlaying, TbMapEntityId, TbMapEntityMapping, messages::DespawnTbMapEntity,
    },
    tb_entities::{Movable, Platform, PlatformTarget},
};
use avian3d::prelude::{
    Collider, ColliderAabb, ColliderDensity, ColliderMarker, ColliderOf, ColliderTransform,
    CollisionEventsEnabled, CollisionLayers, Sensor,
};
use bevy::{ecs::bundle::BundleFromComponents, prelude::*, scene::SceneInstance};
use bevy_replicon::{
    client::{ClientSystems, confirm_history::ConfirmHistory},
    prelude::{ClientState, ClientTriggerExt, RepliconChannels},
};
use bevy_replicon_renet::{
    RenetChannelsExt,
    netcode::{ClientAuthentication, NetcodeClientTransport, NetcodeError},
    renet::{ConnectionConfig, RenetClient},
};
use bevy_trenchbroom::geometry::Brushes;
use std::{
    net::{Ipv4Addr, UdpSocket},
    time::SystemTime,
};

pub mod audio;
pub mod backpack;
pub mod control;
pub mod debug;
pub mod enemy;
pub mod heal_effect;
pub mod player;
mod settings;
pub mod setup;
pub mod steam;
pub mod ui;

pub fn plugin(app: &mut App) {
    app.add_plugins((
        backpack::plugin,
        control::plugin,
        debug::plugin,
        enemy::plugin,
        heal_effect::plugin,
        player::plugin,
        setup::plugin,
        audio::plugin,
        steam::plugin,
        ui::plugin,
        settings::plugin,
    ));

    app.add_systems(
        OnEnter(GameState::Connecting),
        connect_to_server.run_if(|config: Res<NetworkingConfig>| config.server.is_some()),
    );
    app.add_systems(Update, despawn_absent_map_entities);
    app.add_systems(
        PreUpdate,
        (migrate_remote_entities, ApplyDeferred)
            .chain()
            .after(ClientSystems::Receive),
    );

    app.add_systems(OnEnter(ClientState::Connected), on_connected_state);
    app.add_systems(OnExit(ClientState::Connected), on_disconnect);
}

//
// Client logic
//

fn on_connected_state(mut commands: Commands, mut game_state: ResMut<NextState<GameState>>) {
    info!("sent entered playing signal");
    commands.client_trigger(ClientEnteredPlaying);
    game_state.set(GameState::Playing);
}

fn on_disconnect() {
    info!("disconnected from the server");
}

//
// Renet
//

fn connect_to_server(
    mut commands: Commands,
    config: Res<NetworkingConfig>,
    channels: Res<RepliconChannels>,
) -> Result {
    let server_channels_config = channels.server_configs();
    let client_channels_config = channels.client_configs();

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

    commands.insert_resource(client);
    commands.insert_resource(client_transport(&config)?);

    Ok(())
}

fn client_transport(config: &NetworkingConfig) -> Result<NetcodeClientTransport, NetcodeError> {
    let current_time = SystemTime::now()
        .duration_since(SystemTime::UNIX_EPOCH)
        .unwrap();
    let client_id = current_time.as_millis() as u64;
    let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, 0))?;
    let server_addr = config
        .server
        .flatten()
        .unwrap_or_else(|| "127.0.0.1:31111".parse().unwrap());
    let authentication = ClientAuthentication::Unsecure {
        client_id,
        protocol_id: 0,
        server_addr,
        user_data: None,
    };

    info!("attempting connection to {server_addr}");
    NetcodeClientTransport::new(current_time, authentication, socket)
}

#[allow(clippy::type_complexity)]
fn migrate_remote_entities(
    query: Query<(Entity, &TbMapEntityId), (Added<TbMapEntityId>, With<ConfirmHistory>)>,
    children: Query<&Children>,
    mut commands: Commands,
    mut mapping: ResMut<TbMapEntityMapping>,
) {
    for (serverside, tb_id) in query.iter() {
        received_remote_map_entity(serverside, tb_id.id, &children, &mut mapping, &mut commands);
    }
}

fn received_remote_map_entity(
    serverside: Entity,
    tb_id: u64,
    children: &Query<&Children>,
    mapping: &mut TbMapEntityMapping,
    commands: &mut Commands,
) {
    let Some(clientside) = mapping.0.remove(&tb_id) else {
        warn!("received unknown MapEntity ID `{tb_id:?}`");
        return;
    };

    // cannot just use `take` directly with a bundle because then any missing component would cause
    // the entire bundle to fail
    move_component::<Brushes>(commands, clientside, serverside);
    move_component::<(
        Collider,
        ColliderAabb,
        ColliderDensity,
        ColliderMarker,
        CollisionLayers,
    )>(commands, clientside, serverside);
    move_component::<ColliderOf>(commands, clientside, serverside);
    move_component::<ColliderTransform>(commands, clientside, serverside);
    move_component::<CollisionEventsEnabled>(commands, clientside, serverside);
    move_component::<Movable>(commands, clientside, serverside);
    move_component::<Platform>(commands, clientside, serverside);
    move_component::<PlatformTarget>(commands, clientside, serverside);
    move_component::<SceneInstance>(commands, clientside, serverside);
    move_component::<SceneRoot>(commands, clientside, serverside);
    move_component::<Sensor>(commands, clientside, serverside);

    if let Ok(children) = children.get(clientside) {
        for child in children.iter() {
            commands.entity(child).insert(ChildOf(serverside));
        }
    }

    commands.entity(clientside).despawn();
}

fn move_component<B: Bundle + BundleFromComponents>(
    commands: &mut Commands,
    from: Entity,
    to: Entity,
) {
    commands.queue(move |world: &mut World| {
        let comp = world.entity_mut(from).take::<B>();
        if let Some(comp) = comp {
            world.entity_mut(to).insert(comp);
        }
    });
}

fn despawn_absent_map_entities(
    mut commands: Commands,
    mut messages: MessageReader<DespawnTbMapEntity>,
    mut map: ResMut<TbMapEntityMapping>,
) {
    for msg in messages.read() {
        // the server may double-send DespawnTbMapEntity for a given ID, so ignore it if the entity
        // was already despawned.
        let Some(entity) = map.0.remove(&msg.0) else {
            continue;
        };

        commands.entity(entity).despawn();
    }
}