feat(inventory): implement lore methods for item stack (#3025)

crates/pumpkin-data/src/data_component_impl/basic.rs

@@ -177,8 +177,33 @@ impl DataComponentImpl for ItemModelImpl {
 }
 
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
-pub struct LoreImpl;
+pub struct LoreImpl {
+    pub lines: Vec<TextComponent>,
+}
+impl LoreImpl {
+    pub fn read_data(data: &NbtTag) -> Option<Self> {
+        let NbtTag::List(lines) = data else {
+            return None;
+        };
+
+        Some(Self {
+            lines: lines
+                .iter()
+                .filter_map(NbtTag::extract_string)
+                .map(|line| TextComponent::text(line.to_owned()))
+                .collect(),
+        })
+    }
+}
 impl DataComponentImpl for LoreImpl {
+    fn write_data(&self) -> NbtTag {
+        NbtTag::List(
+            self.lines
+                .iter()
+                .map(|line| NbtTag::String(line.clone().get_text().into_boxed_str()))
+                .collect(),
+        )
+    }
     default_impl!(Lore);
 }
 

crates/pumpkin-data/src/data_component_impl/mod.rs

@@ -539,6 +539,7 @@ pub fn read_data(id: DataComponent, data: &NbtTag) -> Option<Box<dyn DataCompone
         DataComponent::Fireworks => Some(FireworksImpl::read_data(data)?.to_dyn()),
         DataComponent::FireworkExplosion => Some(FireworkExplosionImpl::read_data(data)?.to_dyn()),
         DataComponent::CustomName => Some(CustomNameImpl::read_data(data)?.to_dyn()),
+        DataComponent::Lore => Some(LoreImpl::read_data(data)?.to_dyn()),
         DataComponent::ItemName => Some(ItemNameImpl::read_data(data)?.to_dyn()),
         DataComponent::ItemModel => Some(ItemModelImpl::read_data(data)?.to_dyn()),
         DataComponent::Consumable => Some(ConsumableImpl::read_data(data)?.to_dyn()),

crates/pumpkin-data/src/item_stack/mod.rs

@@ -206,6 +206,27 @@ impl ItemStack {
         }
     }
 
+    pub fn set_lore(&mut self, lines: Vec<pumpkin_util::text::TextComponent>) {
+        let lore = Some(Box::new(crate::data_component_impl::LoreImpl { lines }) as _);
+        if let Some((_, component)) = self
+            .patch
+            .iter_mut()
+            .find(|(id, _)| *id == DataComponent::Lore)
+        {
+            *component = lore;
+        } else {
+            self.patch.push((DataComponent::Lore, lore));
+        }
+    }
+
+    pub fn add_lore(&mut self, line: pumpkin_util::text::TextComponent) {
+        let mut lines = self
+            .get_data_component::<crate::data_component_impl::LoreImpl>()
+            .map_or_else(Vec::new, |lore| lore.lines.clone());
+        lines.push(line);
+        self.set_lore(lines);
+    }
+
     pub const EMPTY: &'static Self = &Self {
         item_count: 0,
         item: &Item::AIR,
@@ -745,7 +766,7 @@ mod tests {
     use crate::data_component::DataComponent;
     use crate::data_component_impl::{
         CustomDataImpl, CustomNameImpl, DataComponentImpl, EnchantmentsImpl, ItemNameImpl,
-        UnbreakableImpl,
+        LoreImpl, UnbreakableImpl,
     };
 
     /// Helper: creates a fresh Iron Sword (max_damage 250, damage 0).
@@ -906,6 +927,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn lore_can_be_set_and_appended() {
+        let mut stack = ItemStack::new(1, &Item::WOODEN_AXE);
+        stack.set_lore(vec![pumpkin_util::text::TextComponent::text("First line")]);
+        stack.add_lore(pumpkin_util::text::TextComponent::text("Second line"));
+
+        let lore = stack
+            .get_data_component::<LoreImpl>()
+            .expect("lore component should be present");
+        assert_eq!(lore.lines.len(), 2);
+        assert_eq!(lore.lines[0].clone().get_text(), "First line");
+        assert_eq!(lore.lines[1].clone().get_text(), "Second line");
+    }
+
     #[test]
     fn custom_data_survives_item_stack_nbt_roundtrip() {
         let mut stack = ItemStack::new(1, &Item::WOODEN_AXE);