Add TicksAlive component (#229)

* Add TicksAlive component

* Rename TicksAlive to TicksConnected

* Move component to plugins/tick_counter.rs and add doc comment

4 files changed, 45 insertions, 16 deletions

diff --git a/azalea-client/src/plugins/disconnect.rs b/azalea-client/src/plugins/disconnect.rs
index 80993476..ab39ba5e 100644
--- a/azalea-client/src/plugins/disconnect.rs
+++ b/azalea-client/src/plugins/disconnect.rs
@@ -11,7 +11,7 @@ use tracing::info;
 use super::login::IsAuthenticated;
 use crate::{
     chat_signing, client::JoinedClientBundle, connection::RawConnection, loading::HasClientLoaded,
-    local_player::InstanceHolder,
+    local_player::InstanceHolder, tick_counter::TicksConnected,
 };
 
 pub struct DisconnectPlugin;
@@ -72,6 +72,8 @@ pub struct RemoveOnDisconnectBundle {
     pub is_authenticated: IsAuthenticated,
     // send ServerboundPlayerLoaded next time we join.
     pub has_client_loaded: HasClientLoaded,
+    // TickCounter is reset on reconnect
+    pub ticks_alive: TicksConnected,
 }
 
 /// A system that removes the several components from our clients when they get
diff --git a/azalea-client/src/plugins/mod.rs b/azalea-client/src/plugins/mod.rs
index 7c5cd3a3..2319f6fc 100644
--- a/azalea-client/src/plugins/mod.rs
+++ b/azalea-client/src/plugins/mod.rs
@@ -22,6 +22,7 @@ pub mod pong;
 pub mod respawn;
 pub mod task_pool;
 pub mod tick_broadcast;
+pub mod tick_counter;
 pub mod tick_end;
 
 /// This plugin group will add all the default plugins necessary for Azalea to
@@ -54,6 +55,7 @@ impl PluginGroup for DefaultPlugins {
             .add(loading::PlayerLoadedPlugin)
             .add(brand::BrandPlugin)
             .add(tick_broadcast::TickBroadcastPlugin)
+            .add(tick_counter::TickCounterPlugin)
             .add(pong::PongPlugin)
             .add(connection::ConnectionPlugin)
             .add(login::LoginPlugin)
diff --git a/azalea-client/src/plugins/packet/game/mod.rs b/azalea-client/src/plugins/packet/game/mod.rs
index fd6b712c..b7886208 100644
--- a/azalea-client/src/plugins/packet/game/mod.rs
+++ b/azalea-client/src/plugins/packet/game/mod.rs
@@ -22,22 +22,9 @@ pub use events::*;
 use tracing::{debug, error, trace, warn};
 
 use crate::{
-    ClientInformation,
-    block_update::QueuedServerBlockUpdates,
-    chat::{ChatPacket, ChatReceivedEvent},
-    chunks,
-    connection::RawConnection,
-    declare_packet_handlers,
-    disconnect::DisconnectEvent,
-    interact::BlockStatePredictionHandler,
-    inventory::{
+    block_update::QueuedServerBlockUpdates, chat::{ChatPacket, ChatReceivedEvent}, chunks, connection::RawConnection, declare_packet_handlers, disconnect::DisconnectEvent, interact::BlockStatePredictionHandler, inventory::{
         ClientSideCloseContainerEvent, Inventory, MenuOpenedEvent, SetContainerContentEvent,
-    },
-    loading::HasClientLoaded,
-    local_player::{Hunger, InstanceHolder, LocalGameMode, PlayerAbilities, TabList},
-    movement::{KnockbackEvent, KnockbackType},
-    packet::as_system,
-    player::{GameProfileComponent, PlayerInfo},
+    }, loading::HasClientLoaded, local_player::{Hunger, InstanceHolder, LocalGameMode, PlayerAbilities, TabList}, movement::{KnockbackEvent, KnockbackType}, packet::as_system, player::{GameProfileComponent, PlayerInfo}, tick_counter::TicksConnected, ClientInformation
 };
 
 pub fn process_packet(ecs: &mut World, player: Entity, packet: &ClientboundGamePacket) {
@@ -299,6 +286,7 @@ impl GamePacketHandler<'_> {
                         previous: p.common.previous_game_type.into(),
                     },
                     entity_bundle,
+                    TicksConnected(0),
                 ));
 
                 azalea_entity::indexing::add_entity_to_indexes(
diff --git a/azalea-client/src/plugins/tick_counter.rs b/azalea-client/src/plugins/tick_counter.rs
new file mode 100644
index 00000000..21515959
--- /dev/null
+++ b/azalea-client/src/plugins/tick_counter.rs
@@ -0,0 +1,37 @@
+use azalea_core::tick::GameTick;
+use azalea_physics::PhysicsSet;
+use azalea_world::InstanceName;
+
+use bevy_app::{App, Plugin};
+use bevy_ecs::prelude::*;
+
+use crate::{mining::MiningSet, movement::send_position, tick_broadcast::send_tick_broadcast};
+
+/// Counts the number of game ticks elapsed on the **local client** since the
+/// `login` packet was received.
+#[derive(Component, Clone, Debug, Default)]
+pub struct TicksConnected(pub u64);
+
+/// Inserts the counter-increment system into the `GameTick` schedule **before**
+/// physics, mining and movement.
+pub struct TickCounterPlugin;
+
+impl Plugin for TickCounterPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            GameTick,
+            increment_counter
+                .before(PhysicsSet)
+                .before(MiningSet)
+                .before(send_position)
+                .before(send_tick_broadcast),
+        );
+    }
+}
+
+/// Increment the [`GameTickCounter`] on every entity that lives in an instance.
+fn increment_counter(mut query: Query<&mut TicksConnected, With<InstanceName>>) {
+    for mut counter in &mut query {
+        counter.0 += 1;
+    }
+}