Slot type

pumpkin-protocol/src/lib.rs

@@ -11,6 +11,7 @@ pub mod packet_encoder;
 pub mod position;
 pub mod server;
 pub mod uuid;
+pub mod slot;
 
 pub const CURRENT_MC_PROTOCOL: u32 = 767;
 

pumpkin-protocol/src/slot.rs

@@ -0,0 +1,76 @@
+use serde::{
+    de::{self, SeqAccess, Visitor},
+    Deserialize,
+};
+
+use crate::VarInt;
+
+#[derive(Debug, Clone)]
+pub struct Slot {
+    item_count: VarInt,
+    item_id: Option<VarInt>,
+    num_components_to_add: Option<VarInt>,
+    num_components_to_remove: Option<VarInt>,
+    components_to_add: Option<Vec<(VarInt, ())>>, // The second type depends on the varint
+    components_to_remove: Option<Vec<VarInt>>,
+}
+
+impl<'de> Deserialize<'de> for Slot {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: de::Deserializer<'de>,
+    {
+        struct VarIntVisitor;
+        impl<'de> Visitor<'de> for VarIntVisitor {
+            type Value = Slot;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a valid VarInt encoded in a byte sequence")
+            }
+
+            fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+            where
+                A: SeqAccess<'de>,
+            {
+                let item_count = seq
+                    .next_element::<VarInt>()?
+                    .ok_or(de::Error::custom("Failed to decode VarInt"))?;
+                if item_count.0 == 0 {
+                    return Ok(Slot {
+                        item_count: 0.into(),
+                        item_id: None,
+                        num_components_to_add: None,
+                        num_components_to_remove: None,
+                        components_to_add: None,
+                        components_to_remove: None,
+                    });
+                }
+                let item_id = seq
+                    .next_element::<VarInt>()?
+                    .ok_or(de::Error::custom("Failed to decode VarInt"))?;
+                let num_components_to_add = seq
+                    .next_element::<VarInt>()?
+                    .ok_or(de::Error::custom("Failed to decode VarInt"))?;
+                let num_components_to_remove = seq
+                    .next_element::<VarInt>()?
+                    .ok_or(de::Error::custom("Failed to decode VarInt"))?;
+                if num_components_to_add.0 != 0 || num_components_to_remove.0 != 0 {
+                    return Err(de::Error::custom(
+                        "Slot components are currently unsupported",
+                    ));
+                }
+
+                Ok(Slot {
+                    item_count,
+                    item_id: Some(item_id),
+                    num_components_to_add: Some(num_components_to_add),
+                    num_components_to_remove: Some(num_components_to_remove),
+                    components_to_add: None,
+                    components_to_remove: None,
+                })
+            }
+        }
+
+        deserializer.deserialize_seq(VarIntVisitor)
+    }
+}