Handle entity metadata

protocol/packets.py

@@ -4,10 +4,11 @@ from minecraft.networking.packets import Packet, PacketBuffer
 from minecraft.networking.types import (
     VarInt, Integer, UnsignedByte, Position, Vector, MutableRecord,
     attribute_alias, multi_attribute_alias, Long, Boolean, VarLong,
-    Short, UnsignedLong, Byte, BlockFace, String
+    Short, UnsignedLong, Byte, BlockFace, String, UUID, Angle, Double,
+    Float,
 )
 
-from protocol.types import Nbt, Slot
+from protocol.types import Nbt, Slot, Entry
 
 
 class ChunkDataPacket(Packet):
@@ -286,3 +287,23 @@ class ServerWindowConfirmationPacket(Packet):
         {'action_number': Short},
         {'accepted': Boolean},
     ]
+
+
+class EntityMetadataPacket(Packet):
+    # Updates one or more metadata properties for an existing entity
+    # https://wiki.vg/Protocol#Entity_Metadata
+
+    id = 0x44
+    packet_name = 'entity metadata'
+    fields = 'entity_id', 'metadata'
+
+    class Entry:
+        __slots__ = 'index', 'type', 'value'
+
+    def read(self, file_object):
+        self.entity_id = VarInt.read(file_object)
+        self.metadata = []
+        for _ in range(99):
+            entry = Entry.read(file_object)
+            if not entry: break
+            self.metadata.append(entry)

protocol/types.py

@@ -4,7 +4,8 @@ import struct
 
 from minecraft.networking.types.basic import (
     Type, Byte, Short, Integer, Long, Float, Double,
-    ShortPrefixedByteArray, Boolean, VarInt, TrailingByteArray
+    ShortPrefixedByteArray, Boolean, VarInt, TrailingByteArray,
+    Position, String, UnsignedByte
 )
 from minecraft.networking.types.utility import Vector
 
@@ -39,6 +40,8 @@ class Nbt(Type):
     @staticmethod
     def read(file_object):
         type_id = Byte.read(file_object)
+        if type_id == TAG_End:
+            return None
         if type_id != TAG_Compound:
             raise Exception("Invalid NBT header")
         name = ShortPrefixedByteArray.read(file_object).decode('utf-8')
@@ -118,7 +121,8 @@ class Slot(Type):
         present = Boolean.read(file_object)
         item_id = VarInt.read(file_object) if present else None
         item_count = Byte.read(file_object) if present else None
-        nbt = TrailingByteArray.read(file_object) if present else None
+        print('slot read', present, item_id, item_count)
+        nbt = Nbt.read(file_object) if present else None
         return Slot(present, item_id, item_count, nbt)
 
     @staticmethod
@@ -127,3 +131,37 @@ class Slot(Type):
         VarInt.send(value.item_id, socket)
         Byte.send(value.item_count, socket)
         TrailingByteArray.send(value.nbt, socket)
+
+
+class Entry(Type):
+    types = {
+        0: Byte,
+        1: VarInt,
+        2: Float,
+        3: String,
+        6: Slot,
+        7: Boolean,
+        9: Position,
+    }
+
+    def __init__(self, index, type, value):
+        self.index = index
+        self.type = type
+        self.value = value
+
+    def __str__(self):
+        return str(self.__dict__)
+    def __repr__(self):
+        return 'Entry(index={}, type={}, value={}'.format(
+            self.index, self.type, self.value)
+
+    @staticmethod
+    def read(file_object):
+        index = UnsignedByte.read(file_object)
+        if index == 0xff: return None
+        type = VarInt.read(file_object)
+        try:
+            value = Entry.types[type].read(file_object)
+        except KeyError:
+            return None
+        return Entry(index, type, value)