Swarm (#36)

* make azalea-pathfinder dir

* start writing d* lite impl

* more work on d* lite

* work more on implementing d* lite

* full d* lite impl

* updated edges

* add next() function

* add NoPathError

* why does dstar lite not work

* fix d* lite implementation

* make the test actually check the coords

* replace while loop with if statement

* fix clippy complaints

* make W only have to be PartialOrd

* fix PartialOrd issues

* implement mtd* lite

* add a test to mtd* lite

* remove normal d* lite

* make heuristic only take in one arg

* add `success` function

* Update README.md

* evil black magic to make .entity not need dimension

* start adding moves

* slightly improve the vec3/position situation

new macro that implements all the useful functions

* moves stuff

* make it compile

* update deps in az-pathfinder

* make it compile again

* more pathfinding stuff

* add Bot::look_at

* replace EntityMut and EntityRef with just Entity

* block pos pathfinding stuff

* rename movedirection to walkdirection

* execute path every tick

* advance path

* change az-pf version

* make azalea_client keep plugin state

* fix Plugins::get

* why does it think there is air

* start debugging incorrect air

* update some From methods to use rem_euclid

* start adding swarm

* fix deadlock

i still don't understand why it was happening but the solution was to keep the Client::player lock for shorter so it didn't overlap with the Client::dimension lock

* make lookat actually work probably

* fix going too fast

* Update main.rs

* make a thing immutable

* direction_looking_at

* fix rotations

* import swarm in an example

* fix stuff from merge

* remove azalea_pathfinder import

* delete azalea-pathfinder crate

already in azalea::pathfinder module

* swarms

* start working on shared dimensions

* Shared worlds work

* start adding Swarm::add_account

* add_account works

* change "client" to "bot" in some places

* Fix issues from merge

* Update world.rs

* add SwarmEvent::Disconnect(Account)

* almost add SwarmEvent::Chat and new plugin system

it panics rn

* make plugins have to provide the State associated type

* improve comments

* make fn build slightly cleaner

* fix SwarmEvent::Chat

* change a println in bot/main.rs

* Client::shutdown -> disconnect

* polish

fix clippy warnings + improve some docs a bit

* fix shared worlds*

*there's a bug that entities and bots will have their positions exaggerated because the relative movement packet is applied for every entity once per bot

* i am being trolled by rust

for some reason some stuff is really slow for literally no reason and it makes no sense i am going insane

* make world an RwLock again

* remove debug messages

* fix skipping event ticks

unfortunately now sending events is `.send().await?` instead of just `.send()`

* fix deadlock + warnings

* turns out my floor_mod impl was wrong

and i32::rem_euclid has the correct behavior LOL

* still errors with lots of bots

* make swarm iter & fix new chunks not loading

* improve docs

* start fixing tests

* fix all the tests

except the examples i don't know how to exclude them from the tests

* improve docs some more

1 files changed, 134 insertions, 0 deletions

diff --git a/azalea/src/swarm/plugins.rs b/azalea/src/swarm/plugins.rs
new file mode 100644
index 00000000..0c7cf2ae
--- /dev/null
+++ b/azalea/src/swarm/plugins.rs
@@ -0,0 +1,134 @@
+use crate::{Swarm, SwarmEvent};
+use async_trait::async_trait;
+use nohash_hasher::NoHashHasher;
+use std::{
+    any::{Any, TypeId},
+    collections::HashMap,
+    hash::BuildHasherDefault,
+};
+
+type U64Hasher = BuildHasherDefault<NoHashHasher<u64>>;
+
+// kind of based on https://docs.rs/http/latest/src/http/extensions.rs.html
+/// A map of plugin ids to [`SwarmPlugin`] trait objects. The client stores
+/// this so we can keep the state for our [`Swarm`] plugins.
+///
+/// If you're using azalea, you should generate this from the `swarm_plugins!` macro.
+#[derive(Clone, Default)]
+pub struct SwarmPlugins<S> {
+    map: Option<HashMap<TypeId, Box<dyn SwarmPlugin<S>>, U64Hasher>>,
+}
+
+#[derive(Clone)]
+pub struct SwarmPluginStates<S> {
+    map: Option<HashMap<TypeId, Box<dyn SwarmPluginState<S>>, U64Hasher>>,
+}
+
+impl<S> SwarmPluginStates<S> {
+    pub fn get<T: SwarmPluginState<S>>(&self) -> Option<&T> {
+        self.map
+            .as_ref()
+            .and_then(|map| map.get(&TypeId::of::<T>()))
+            .and_then(|boxed| (boxed.as_ref() as &dyn Any).downcast_ref::<T>())
+    }
+}
+
+impl<S> SwarmPlugins<S>
+where
+    S: 'static,
+{
+    /// Create a new empty set of plugins.
+    pub fn new() -> Self {
+        Self { map: None }
+    }
+
+    /// Add a new plugin to this set.
+    pub fn add<T: SwarmPlugin<S>>(&mut self, plugin: T) {
+        if self.map.is_none() {
+            self.map = Some(HashMap::with_hasher(BuildHasherDefault::default()));
+        }
+        self.map
+            .as_mut()
+            .unwrap()
+            .insert(TypeId::of::<T>(), Box::new(plugin));
+    }
+
+    /// Build our plugin states from this set of plugins. Note that if you're
+    /// using `azalea` you'll probably never need to use this as it's called
+    /// for you.
+    pub fn build(self) -> SwarmPluginStates<S> {
+        if self.map.is_none() {
+            return SwarmPluginStates { map: None };
+        }
+        let mut map = HashMap::with_hasher(BuildHasherDefault::default());
+        for (id, plugin) in self.map.unwrap().into_iter() {
+            map.insert(id, plugin.build());
+        }
+        SwarmPluginStates { map: Some(map) }
+    }
+}
+
+impl<S> IntoIterator for SwarmPluginStates<S> {
+    type Item = Box<dyn SwarmPluginState<S>>;
+    type IntoIter = std::vec::IntoIter<Self::Item>;
+
+    /// Iterate over the plugin states.
+    fn into_iter(self) -> Self::IntoIter {
+        self.map
+            .map(|map| map.into_values().collect::<Vec<_>>())
+            .unwrap_or_default()
+            .into_iter()
+    }
+}
+
+/// A `SwarmPluginState` keeps the current state of a plugin for a client. All
+/// the fields must be atomic. Unique `SwarmPluginState`s are built from
+/// [`SwarmPlugin`]s.
+#[async_trait]
+pub trait SwarmPluginState<S>: Send + Sync + SwarmPluginStateClone<S> + Any + 'static {
+    async fn handle(self: Box<Self>, event: SwarmEvent, swarm: Swarm<S>);
+}
+
+/// Swarm plugins can keep their own personal state ([`SwarmPluginState`]),
+/// listen to [`SwarmEvent`]s, and add new functions to [`Swarm`].
+pub trait SwarmPlugin<S>: Send + Sync + SwarmPluginClone<S> + Any + 'static {
+    fn build(&self) -> Box<dyn SwarmPluginState<S>>;
+}
+
+/// An internal trait that allows SwarmPluginState to be cloned.
+#[doc(hidden)]
+pub trait SwarmPluginStateClone<S> {
+    fn clone_box(&self) -> Box<dyn SwarmPluginState<S>>;
+}
+impl<T, S> SwarmPluginStateClone<S> for T
+where
+    T: 'static + SwarmPluginState<S> + Clone,
+{
+    fn clone_box(&self) -> Box<dyn SwarmPluginState<S>> {
+        Box::new(self.clone())
+    }
+}
+impl<S> Clone for Box<dyn SwarmPluginState<S>> {
+    fn clone(&self) -> Self {
+        self.clone_box()
+    }
+}
+
+/// An internal trait that allows SwarmPlugin to be cloned.
+#[doc(hidden)]
+pub trait SwarmPluginClone<S> {
+    fn clone_box(&self) -> Box<dyn SwarmPlugin<S>>;
+}
+impl<T, S> SwarmPluginClone<S> for T
+where
+    T: 'static + SwarmPlugin<S> + Clone,
+{
+    fn clone_box(&self) -> Box<dyn SwarmPlugin<S>> {
+        Box::new(self.clone())
+    }
+}
+impl<S> Clone for Box<dyn SwarmPlugin<S>> {
+    fn clone(&self) -> Self {
+        self.clone_box()
+    }
+}