Refactor azalea-client (#205)

* start organizing packet_handling more by moving packet handlers into their own functions

* finish writing all the handler functions for packets

* use macro for generating match statement for packet handler functions

* fix set_entity_data

* update config state to also use handler functions

* organize az-client file structure by moving things into plugins directory

* fix merge issues

1 files changed, 109 insertions, 0 deletions

diff --git a/azalea-client/src/plugins/packet/mod.rs b/azalea-client/src/plugins/packet/mod.rs
new file mode 100644
index 00000000..cbd8a175
--- /dev/null
+++ b/azalea-client/src/plugins/packet/mod.rs
@@ -0,0 +1,109 @@
+use azalea_entity::{EntityUpdateSet, metadata::Health};
+use bevy_app::{App, First, Plugin, PreUpdate, Update};
+use bevy_ecs::{
+    prelude::*,
+    system::{SystemParam, SystemState},
+};
+
+use self::{
+    game::{
+        AddPlayerEvent, DeathEvent, InstanceLoadedEvent, KeepAliveEvent, RemovePlayerEvent,
+        ResourcePackEvent, UpdatePlayerEvent,
+    },
+    login::{LoginPacketEvent, SendLoginPacketEvent},
+};
+use crate::{chat::ChatReceivedEvent, events::death_listener};
+
+pub mod config;
+pub mod game;
+pub mod login;
+
+pub struct PacketPlugin;
+
+pub fn death_event_on_0_health(
+    query: Query<(Entity, &Health), Changed<Health>>,
+    mut death_events: EventWriter<DeathEvent>,
+) {
+    for (entity, health) in query.iter() {
+        if **health == 0. {
+            death_events.send(DeathEvent {
+                entity,
+                packet: None,
+            });
+        }
+    }
+}
+
+impl Plugin for PacketPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            First,
+            (game::send_receivepacketevent, config::send_packet_events),
+        )
+        .add_systems(
+            PreUpdate,
+            (
+                game::process_packet_events
+                    // we want to index and deindex right after
+                    .before(EntityUpdateSet::Deindex),
+                config::process_packet_events,
+                login::handle_send_packet_event,
+                login::process_packet_events,
+            ),
+        )
+        .add_systems(
+            Update,
+            (
+                (
+                    config::handle_send_packet_event,
+                    game::handle_outgoing_packets,
+                )
+                    .chain(),
+                death_event_on_0_health.before(death_listener),
+            ),
+        )
+        // we do this instead of add_event so we can handle the events ourselves
+        .init_resource::<Events<game::ReceivePacketEvent>>()
+        .init_resource::<Events<config::ReceiveConfigPacketEvent>>()
+        .add_event::<game::SendPacketEvent>()
+        .add_event::<config::SendConfigPacketEvent>()
+        .add_event::<AddPlayerEvent>()
+        .add_event::<RemovePlayerEvent>()
+        .add_event::<UpdatePlayerEvent>()
+        .add_event::<ChatReceivedEvent>()
+        .add_event::<DeathEvent>()
+        .add_event::<KeepAliveEvent>()
+        .add_event::<ResourcePackEvent>()
+        .add_event::<InstanceLoadedEvent>()
+        .add_event::<LoginPacketEvent>()
+        .add_event::<SendLoginPacketEvent>();
+    }
+}
+
+#[macro_export]
+macro_rules! declare_packet_handlers {
+    (
+        $packetenum:ident,
+        $packetvar:expr,
+        $handler:ident,
+        [$($packet:path),+ $(,)?]
+    ) => {
+        paste::paste! {
+           match $packetvar {
+                $(
+                    $packetenum::[< $packet:camel >](p) => $handler.$packet(p),
+                )+
+            }
+        }
+    };
+}
+
+pub(crate) fn as_system<T>(ecs: &mut World, f: impl FnOnce(T::Item<'_, '_>))
+where
+    T: SystemParam + 'static,
+{
+    let mut system_state = SystemState::<T>::new(ecs);
+    let values = system_state.get_mut(ecs);
+    f(values);
+    system_state.apply(ecs);
+}