Enchantments (#286)

* start implementing enchants

* store parsed registries

* more work on enchants

* implement deserializer for some entity effects

* mostly working definitions for enchants

* fix tests

* detect equipment changes

* fix errors

* update changelog

* fix some imports

* remove outdated todo

* add basic test for enchants applying attributes

* use git simdnbt

4 files changed, 84 insertions, 30 deletions

diff --git a/azalea-inventory/src/components/mod.rs b/azalea-inventory/src/components/mod.rs
index 9c27db8c..87d4256b 100644
--- a/azalea-inventory/src/components/mod.rs
+++ b/azalea-inventory/src/components/mod.rs
@@ -4,6 +4,7 @@ use core::f64;
 use std::{
     any::Any,
     collections::HashMap,
+    fmt::{self, Display},
     io::{self, Cursor},
     mem::ManuallyDrop,
 };
@@ -11,12 +12,13 @@ use std::{
 use azalea_buf::{AzBuf, AzaleaRead, AzaleaWrite, BufReadError};
 use azalea_chat::FormattedText;
 use azalea_core::{
+    attribute_modifier_operation::AttributeModifierOperation,
     checksum::{Checksum, get_checksum},
     codec_utils::*,
     filterable::Filterable,
     identifier::Identifier,
     position::GlobalPos,
-    registry_holder::{DamageTypeElement, RegistryHolder},
+    registry_holder::{RegistryHolder, dimension_type::DamageTypeElement},
     sound::CustomSound,
 };
 use azalea_registry::{
@@ -115,7 +117,7 @@ macro_rules! define_data_components {
                 }
             }
             pub fn azalea_read_as(
-                kind: registry::DataComponentKind,
+                kind: DataComponentKind,
                 buf: &mut Cursor<&[u8]>,
             ) -> Result<Self, BufReadError> {
                 trace!("Reading data component {kind}");
@@ -131,7 +133,7 @@ macro_rules! define_data_components {
             /// `kind` must be the correct value for this union.
             pub unsafe fn azalea_write_as(
                 &self,
-                kind: registry::DataComponentKind,
+                kind: DataComponentKind,
                 buf: &mut impl std::io::Write,
             ) -> io::Result<()> {
                 let mut value = Vec::new();
@@ -147,7 +149,7 @@ macro_rules! define_data_components {
             /// `kind` must be the correct value for this union.
             pub unsafe fn clone_as(
                 &self,
-                kind: registry::DataComponentKind,
+                kind: DataComponentKind,
             ) -> Self {
                 match kind {
                     $( DataComponentKind::$x => {
@@ -161,7 +163,7 @@ macro_rules! define_data_components {
             pub unsafe fn eq_as(
                 &self,
                 other: &Self,
-                kind: registry::DataComponentKind,
+                kind: DataComponentKind,
             ) -> bool {
                 match kind {
                     $( DataComponentKind::$x => unsafe { self.$x.eq(&other.$x) }, )*
@@ -353,11 +355,12 @@ pub enum Rarity {
     Epic,
 }
 
-#[derive(Clone, PartialEq, AzBuf, Serialize)]
+#[derive(Clone, PartialEq, AzBuf, Serialize, Default)]
 #[serde(transparent)]
 pub struct Enchantments {
+    /// Enchantment levels here are 1-indexed, level 0 does not exist.
     #[var]
-    pub levels: HashMap<Enchantment, u32>,
+    pub levels: HashMap<Enchantment, i32>,
 }
 
 #[derive(Clone, PartialEq, AzBuf, Debug, Serialize)]
@@ -421,14 +424,6 @@ pub enum EquipmentSlotGroup {
     Body,
 }
 
-#[derive(Clone, Copy, PartialEq, AzBuf, Debug, Serialize)]
-#[serde(rename_all = "snake_case")]
-pub enum AttributeModifierOperation {
-    AddValue,
-    AddMultipliedBase,
-    AddMultipliedTotal,
-}
-
 // this is duplicated in azalea-entity, BUT the one there has a different
 // protocol format (and we can't use it anyways because it would cause a
 // circular dependency)
@@ -450,7 +445,7 @@ pub struct AttributeModifiersEntry {
     pub display: AttributeModifierDisplay,
 }
 
-#[derive(Clone, PartialEq, AzBuf, Debug, Serialize)]
+#[derive(Clone, PartialEq, AzBuf, Debug, Serialize, Default)]
 #[serde(transparent)]
 pub struct AttributeModifiers {
     pub modifiers: Vec<AttributeModifiersEntry>,
@@ -1108,7 +1103,8 @@ impl Default for Equippable {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, AzBuf, Serialize)]
+/// An enum that represents inventory slots that can hold items.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, AzBuf, Serialize)]
 #[serde(rename_all = "snake_case")]
 pub enum EquipmentSlot {
     Mainhand,
@@ -1117,9 +1113,55 @@ pub enum EquipmentSlot {
     Legs,
     Chest,
     Head,
+    /// This is for animal armor, use [`Self::Chest`] for the chestplate slot.
     Body,
     Saddle,
 }
+impl EquipmentSlot {
+    #[must_use]
+    pub fn from_byte(byte: u8) -> Option<Self> {
+        let value = match byte {
+            0 => Self::Mainhand,
+            1 => Self::Offhand,
+            2 => Self::Feet,
+            3 => Self::Legs,
+            4 => Self::Chest,
+            5 => Self::Head,
+            _ => return None,
+        };
+        Some(value)
+    }
+    pub fn values() -> [Self; 8] {
+        [
+            Self::Mainhand,
+            Self::Offhand,
+            Self::Feet,
+            Self::Legs,
+            Self::Chest,
+            Self::Head,
+            Self::Body,
+            Self::Saddle,
+        ]
+    }
+    /// Get the display name for the equipment slot, like "mainhand".
+    pub fn name(self) -> &'static str {
+        match self {
+            Self::Mainhand => "mainhand",
+            Self::Offhand => "offhand",
+            Self::Feet => "feet",
+            Self::Legs => "legs",
+            Self::Chest => "chest",
+            Self::Head => "head",
+            Self::Body => "body",
+            Self::Saddle => "saddle",
+        }
+    }
+}
+impl Display for EquipmentSlot {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.name())
+    }
+}
 
 #[derive(Clone, PartialEq, AzBuf, Debug, Serialize)]
 pub struct Glider;
diff --git a/azalea-inventory/src/default_components/generated.rs b/azalea-inventory/src/default_components/generated.rs
index 7daa545e..11f8d160 100644
--- a/azalea-inventory/src/default_components/generated.rs
+++ b/azalea-inventory/src/default_components/generated.rs
@@ -6,6 +6,7 @@
 use std::collections::HashMap;
 
 use azalea_chat::translatable_component::TranslatableComponent;
+use azalea_core::attribute_modifier_operation::AttributeModifierOperation;
 use azalea_registry::{
     Attribute, Block, DataRegistry, EntityKind, HolderSet, Item, MobEffect, SoundEvent,
 };
diff --git a/azalea-inventory/src/lib.rs b/azalea-inventory/src/lib.rs
index 4a15ea31..87cd61e4 100644
--- a/azalea-inventory/src/lib.rs
+++ b/azalea-inventory/src/lib.rs
@@ -49,10 +49,16 @@ impl Menu {
     ///
     /// Will panic if the menu isn't `Menu::Player`.
     pub fn as_player(&self) -> &Player {
+        self.try_as_player()
+            .expect("Called `Menu::as_player` on a menu that wasn't `Player`.")
+    }
+    /// Get the [`Player`] from this [`Menu`], or returns `None` if the menu
+    /// isn't a player menu.
+    pub fn try_as_player(&self) -> Option<&Player> {
         if let Menu::Player(player) = &self {
-            player
+            Some(player)
         } else {
-            unreachable!("Called `Menu::as_player` on a menu that wasn't `Player`.")
+            None
         }
     }
 
@@ -63,10 +69,16 @@ impl Menu {
     ///
     /// Will panic if the menu isn't `Menu::Player`.
     pub fn as_player_mut(&mut self) -> &mut Player {
+        self.try_as_player_mut()
+            .expect("Called `Menu::as_player_mut` on a menu that wasn't `Player`.")
+    }
+    /// Same as [`Menu::try_as_player`], but returns a mutable reference to the
+    /// [`Player`].
+    pub fn try_as_player_mut(&mut self) -> Option<&mut Player> {
         if let Menu::Player(player) = self {
-            player
+            Some(player)
         } else {
-            unreachable!("Called `Menu::as_player_mut` on a menu that wasn't `Player`.")
+            None
         }
     }
 }
diff --git a/azalea-inventory/src/slot.rs b/azalea-inventory/src/slot.rs
index d19ab177..c3134214 100644
--- a/azalea-inventory/src/slot.rs
+++ b/azalea-inventory/src/slot.rs
@@ -1,7 +1,7 @@
 use std::{
     any::Any,
     borrow::Cow,
-    fmt,
+    fmt::{self, Debug},
     io::{self, Cursor, Write},
 };
 
@@ -79,11 +79,10 @@ impl ItemStack {
         }
     }
 
-    /// Get the `kind` of the item in this slot, or
-    /// [`azalea_registry::Item::Air`]
-    pub fn kind(&self) -> azalea_registry::Item {
+    /// Get the `kind` of the item in this slot, or [`Item::Air`]
+    pub fn kind(&self) -> Item {
         match self {
-            ItemStack::Empty => azalea_registry::Item::Air,
+            ItemStack::Empty => Item::Air,
             ItemStack::Present(i) => i.kind,
         }
     }
@@ -152,7 +151,7 @@ impl Serialize for ItemStack {
 #[derive(Debug, Clone, PartialEq, Serialize)]
 pub struct ItemStackData {
     #[serde(rename = "id")]
-    pub kind: azalea_registry::Item,
+    pub kind: Item,
     /// The amount of the item in this slot.
     ///
     /// The count can be zero or negative, but this is rare.
@@ -184,7 +183,7 @@ impl ItemStackData {
 
     /// Check if the count of the item is <= 0 or if the item is air.
     pub fn is_empty(&self) -> bool {
-        self.count <= 0 || self.kind == azalea_registry::Item::Air
+        self.count <= 0 || self.kind == Item::Air
     }
 
     /// Whether this item is the same as another item, ignoring the count.
@@ -222,7 +221,7 @@ impl AzaleaRead for ItemStack {
         if count <= 0 {
             Ok(ItemStack::Empty)
         } else {
-            let kind = azalea_registry::Item::azalea_read(buf)?;
+            let kind = Item::azalea_read(buf)?;
             let component_patch = DataComponentPatch::azalea_read(buf)?;
             Ok(ItemStack::Present(ItemStackData {
                 count,
@@ -449,7 +448,7 @@ impl Clone for DataComponentPatch {
         DataComponentPatch { components }
     }
 }
-impl fmt::Debug for DataComponentPatch {
+impl Debug for DataComponentPatch {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_set().entries(self.components.keys()).finish()
     }