Mining (#95)

* more mining stuff

* initialize azalea-tags crate

* more mining stuff 2

* mining in ecs

* well technically mining works but

no codegen for how long it takes to mine each block yet

* rename downloads to __cache__

it was bothering me since it's not *just* downloads

* codegen block behavior

* fix not sending packet to finish breaking block

* mining animation 🎉

* clippy

* cleanup, move Client::mine into a client extension

* add azalea/src/mining.rs

---------

Co-authored-by: mat <git@matdoes.dev>

1 files changed, 306 insertions, 0 deletions

diff --git a/azalea-entity/src/info.rs b/azalea-entity/src/info.rs
new file mode 100644
index 00000000..18021d36
--- /dev/null
+++ b/azalea-entity/src/info.rs
@@ -0,0 +1,306 @@
+//! Implement things relating to entity datas, like an index of uuids to
+//! entities.
+
+use azalea_core::ChunkPos;
+use azalea_world::{InstanceContainer, InstanceName, MinecraftEntityId, PartialInstance};
+use bevy_app::{App, Plugin, PostUpdate, PreUpdate, Update};
+use bevy_ecs::{
+    component::Component,
+    entity::Entity,
+    query::{Added, Changed, With, Without},
+    schedule::{IntoSystemConfigs, SystemSet},
+    system::{Commands, EntityCommand, Query, Res, ResMut, Resource},
+    world::{EntityMut, World},
+};
+use derive_more::{Deref, DerefMut};
+use log::{debug, warn};
+use parking_lot::RwLock;
+use std::{
+    collections::{HashMap, HashSet},
+    fmt::Debug,
+    sync::Arc,
+};
+use uuid::Uuid;
+
+use crate::{
+    add_dead,
+    systems::{
+        deduplicate_entities, deduplicate_local_entities, update_entity_by_id_index,
+        update_fluid_on_eyes, update_uuid_index,
+    },
+    update_bounding_box, EntityUuid, LastSentPosition, Position,
+};
+
+use super::{Local, LookDirection};
+
+/// A Bevy [`SystemSet`] for various types of entity updates.
+#[derive(SystemSet, Debug, Hash, Eq, PartialEq, Clone)]
+pub enum EntityUpdateSet {
+    /// Remove ECS entities that refer to an entity that was already in the ECS
+    /// before.
+    Deduplicate,
+    /// Create search indexes for entities.
+    Index,
+    /// Remove despawned entities from search indexes.
+    Deindex,
+}
+
+/// Plugin handling some basic entity functionality.
+pub struct EntityPlugin;
+impl Plugin for EntityPlugin {
+    fn build(&self, app: &mut App) {
+        // entities get added pre-update
+        // added to indexes during update (done by this plugin)
+        // modified during update
+        // despawned post-update (done by this plugin)
+        app.add_systems(
+            PreUpdate,
+            remove_despawned_entities_from_indexes.in_set(EntityUpdateSet::Deindex),
+        )
+        .add_systems(
+            PostUpdate,
+            (deduplicate_entities, deduplicate_local_entities).in_set(EntityUpdateSet::Deduplicate),
+        )
+        .add_systems(
+            Update,
+            (
+                (
+                    update_entity_chunk_positions,
+                    update_uuid_index,
+                    update_entity_by_id_index,
+                )
+                    .in_set(EntityUpdateSet::Index),
+                (
+                    add_updates_received,
+                    debug_new_entity,
+                    debug_detect_updates_received_on_local_entities,
+                    add_dead,
+                    update_bounding_box,
+                    clamp_look_direction,
+                    update_fluid_on_eyes,
+                ),
+            ),
+        )
+        .init_resource::<EntityInfos>();
+    }
+}
+
+fn debug_new_entity(query: Query<(Entity, Option<&Local>), Added<MinecraftEntityId>>) {
+    for (entity, local) in query.iter() {
+        if local.is_some() {
+            debug!("new local entity: {:?}", entity);
+        } else {
+            debug!("new entity: {:?}", entity);
+        }
+    }
+}
+
+// How entity updates are processed (to avoid issues with shared worlds)
+// - each bot contains a map of { entity id: updates received }
+// - the shared world also contains a canonical "true" updates received for each
+//   entity
+// - when a client loads an entity, its "updates received" is set to the same as
+//   the global "updates received"
+// - when the shared world sees an entity for the first time, the "updates
+//   received" is set to 1.
+// - clients can force the shared "updates received" to 0 to make it so certain
+//   entities (i.e. other bots in our swarm) don't get confused and updated by
+//   other bots
+// - when a client gets an update to an entity, we check if our "updates
+//   received" is the same as the shared world's "updates received": if it is,
+//   then process the update and increment the client's and shared world's
+//   "updates received" if not, then we simply increment our local "updates
+//   received" and do nothing else
+
+/// An [`EntityCommand`] that applies a "relative update" to an entity, which
+/// means this update won't be run multiple times by different clients in the
+/// same world.
+///
+/// This is used to avoid a bug where when there's multiple clients in the same
+/// world and an entity sends a relative move packet to all clients, its
+/// position gets desynced since the relative move is applied multiple times.
+///
+/// Don't use this unless you actually got an entity update packet that all
+/// other clients within render distance will get too. You usually don't need
+/// this when the change isn't relative either.
+pub struct RelativeEntityUpdate {
+    pub partial_world: Arc<RwLock<PartialInstance>>,
+    // a function that takes the entity and updates it
+    pub update: Box<dyn FnOnce(&mut EntityMut) + Send + Sync>,
+}
+impl EntityCommand for RelativeEntityUpdate {
+    fn apply(self, entity: Entity, world: &mut World) {
+        let partial_entity_infos = &mut self.partial_world.write().entity_infos;
+
+        let mut entity_mut = world.entity_mut(entity);
+
+        if Some(entity) == partial_entity_infos.owner_entity {
+            // if the entity owns this partial world, it's always allowed to update itself
+            (self.update)(&mut entity_mut);
+            return;
+        };
+
+        let entity_id = *entity_mut.get::<MinecraftEntityId>().unwrap();
+        let Some(updates_received) = entity_mut.get_mut::<UpdatesReceived>() else {
+            // a client tried to update another client, which isn't allowed
+            return;
+        };
+
+        let this_client_updates_received = partial_entity_infos
+            .updates_received
+            .get(&entity_id)
+            .copied();
+
+        let can_update = this_client_updates_received.unwrap_or(1) == **updates_received;
+        if can_update {
+            let new_updates_received = this_client_updates_received.unwrap_or(0) + 1;
+            partial_entity_infos
+                .updates_received
+                .insert(entity_id, new_updates_received);
+
+            **entity_mut.get_mut::<UpdatesReceived>().unwrap() = new_updates_received;
+
+            let mut entity = world.entity_mut(entity);
+            (self.update)(&mut entity);
+        }
+    }
+}
+
+/// Things that are shared between all the partial worlds.
+#[derive(Resource, Default)]
+pub struct EntityInfos {
+    /// An index of entities by their UUIDs
+    pub(crate) entity_by_uuid: HashMap<Uuid, Entity>,
+}
+
+impl EntityInfos {
+    pub fn new() -> Self {
+        Self {
+            entity_by_uuid: HashMap::default(),
+        }
+    }
+
+    pub fn get_entity_by_uuid(&self, uuid: &Uuid) -> Option<Entity> {
+        self.entity_by_uuid.get(uuid).copied()
+    }
+}
+
+/// Update the chunk position indexes in [`EntityInfos`].
+fn update_entity_chunk_positions(
+    mut query: Query<(Entity, &Position, &mut LastSentPosition, &InstanceName), Changed<Position>>,
+    instance_container: Res<InstanceContainer>,
+) {
+    for (entity, pos, last_pos, world_name) in query.iter_mut() {
+        let world_lock = instance_container.get(world_name).unwrap();
+        let mut world = world_lock.write();
+
+        let old_chunk = ChunkPos::from(*last_pos);
+        let new_chunk = ChunkPos::from(*pos);
+
+        if old_chunk != new_chunk {
+            // move the entity from the old chunk to the new one
+            if let Some(entities) = world.entities_by_chunk.get_mut(&old_chunk) {
+                entities.remove(&entity);
+            }
+            world
+                .entities_by_chunk
+                .entry(new_chunk)
+                .or_default()
+                .insert(entity);
+        }
+    }
+}
+/// A component that lists all the local player entities that have this entity
+/// loaded. If this is empty, the entity will be removed from the ECS.
+#[derive(Component, Clone, Deref, DerefMut)]
+pub struct LoadedBy(pub HashSet<Entity>);
+
+/// A component that counts the number of times this entity has been modified.
+/// This is used for making sure two clients don't do the same relative update
+/// on an entity.
+///
+/// If an entity is local (i.e. it's a client/localplayer), this component
+/// should NOT be present in the entity.
+#[derive(Component, Debug, Deref, DerefMut)]
+pub struct UpdatesReceived(u32);
+
+#[allow(clippy::type_complexity)]
+pub fn add_updates_received(
+    mut commands: Commands,
+    query: Query<
+        Entity,
+        (
+            Changed<MinecraftEntityId>,
+            (Without<UpdatesReceived>, Without<Local>),
+        ),
+    >,
+) {
+    for entity in query.iter() {
+        // entities always start with 1 update received
+        commands.entity(entity).insert(UpdatesReceived(1));
+    }
+}
+
+/// The [`UpdatesReceived`] component should never be on [`Local`] entities.
+/// This warns if an entity has both components.
+fn debug_detect_updates_received_on_local_entities(
+    query: Query<Entity, (With<Local>, With<UpdatesReceived>)>,
+) {
+    for entity in &query {
+        warn!("Entity {:?} has both Local and UpdatesReceived", entity);
+    }
+}
+
+/// Despawn entities that aren't being loaded by anything.
+fn remove_despawned_entities_from_indexes(
+    mut commands: Commands,
+    mut entity_infos: ResMut<EntityInfos>,
+    instance_container: Res<InstanceContainer>,
+    query: Query<(Entity, &EntityUuid, &Position, &InstanceName, &LoadedBy), Changed<LoadedBy>>,
+) {
+    for (entity, uuid, position, world_name, loaded_by) in &query {
+        let world_lock = instance_container.get(world_name).unwrap();
+        let mut world = world_lock.write();
+
+        // if the entity has no references left, despawn it
+        if !loaded_by.is_empty() {
+            continue;
+        }
+
+        // remove the entity from the chunk index
+        let chunk = ChunkPos::from(*position);
+        if let Some(entities_in_chunk) = world.entities_by_chunk.get_mut(&chunk) {
+            if entities_in_chunk.remove(&entity) {
+                // remove the chunk if there's no entities in it anymore
+                if entities_in_chunk.is_empty() {
+                    world.entities_by_chunk.remove(&chunk);
+                }
+            } else {
+                warn!("Tried to remove entity from chunk {chunk:?} but the entity was not there.");
+            }
+        } else {
+            warn!("Tried to remove entity from chunk {chunk:?} but the chunk was not found.");
+        }
+        // remove it from the uuid index
+        if entity_infos.entity_by_uuid.remove(uuid).is_none() {
+            warn!("Tried to remove entity {entity:?} from the uuid index but it was not there.");
+        }
+        // and now remove the entity from the ecs
+        commands.entity(entity).despawn();
+        debug!("Despawned entity {entity:?} because it was not loaded by anything.");
+        return;
+    }
+}
+
+pub fn clamp_look_direction(mut query: Query<&mut LookDirection>) {
+    for mut look_direction in &mut query {
+        look_direction.y_rot %= 360.0;
+        look_direction.x_rot = look_direction.x_rot.clamp(-90.0, 90.0) % 360.0;
+    }
+}
+
+impl Debug for EntityInfos {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("EntityInfos").finish()
+    }
+}