initial commit

mapping/item.go

@@ -0,0 +1,109 @@
+package mapping
+
+import (
+	"encoding/json"
+	"github.com/sandertv/gophertunnel/minecraft/nbt"
+	"sync"
+)
+
+type Item interface {
+	// ItemRuntimeIDToName converts an item runtime ID to a string ID.
+	ItemRuntimeIDToName(int32) (string, bool)
+	// ItemNameToRuntimeID converts a string ID to an item runtime ID.
+	ItemNameToRuntimeID(string) (int32, bool)
+	RegisterEntry(string) int32
+	Air() int32
+	ItemVersion() uint16
+}
+
+type DefaultItemMapping struct {
+	mu sync.Mutex
+	// itemRuntimeIDsToNames holds a map to translate item runtime IDs to string IDs.
+	itemRuntimeIDsToNames map[int32]string
+	// itemNamesToRuntimeIDs holds a map to translate item string IDs to runtime IDs.
+	itemNamesToRuntimeIDs map[string]int32
+	airRID                int32
+	itemVersion           uint16
+}
+
+func NewItemMapping(itemRuntimeIDData []byte, requiredItemList []byte, itemVersion uint16, direct bool) *DefaultItemMapping {
+	itemRuntimeIDsToNames := make(map[int32]string)
+	itemNamesToRuntimeIDs := make(map[string]int32)
+	var airRID *int32
+
+	if direct {
+		var items map[string]int32
+		if err := nbt.Unmarshal(itemRuntimeIDData, &items); err != nil {
+			panic(err)
+		}
+		for name, rid := range items {
+			if name == "minecraft:air" {
+				airRID = &rid
+			}
+
+			itemNamesToRuntimeIDs[name] = rid
+			itemRuntimeIDsToNames[rid] = name
+		}
+	} else {
+		var m map[string]struct {
+			RuntimeID      int16 `json:"runtime_id"`
+			ComponentBased bool  `json:"component_based"`
+		}
+		if err := json.Unmarshal(requiredItemList, &m); err != nil {
+			panic(err)
+		}
+		for name, data := range m {
+			rid := int32(data.RuntimeID)
+			if name == "minecraft:air" {
+				airRID = &rid
+			}
+
+			itemNamesToRuntimeIDs[name] = rid
+			itemRuntimeIDsToNames[rid] = name
+		}
+	}
+
+	if airRID == nil {
+		panic("couldn't find air")
+	}
+
+	return &DefaultItemMapping{itemRuntimeIDsToNames: itemRuntimeIDsToNames, itemNamesToRuntimeIDs: itemNamesToRuntimeIDs, itemVersion: itemVersion}
+}
+
+func (m *DefaultItemMapping) ItemRuntimeIDToName(runtimeID int32) (name string, found bool) {
+	defer m.mu.Unlock()
+	m.mu.Lock()
+	name, ok := m.itemRuntimeIDsToNames[runtimeID]
+	return name, ok
+}
+
+func (m *DefaultItemMapping) ItemNameToRuntimeID(name string) (runtimeID int32, found bool) {
+	defer m.mu.Unlock()
+	m.mu.Lock()
+	rid, ok := m.itemNamesToRuntimeIDs[name]
+	return rid, ok
+}
+
+func (m *DefaultItemMapping) RegisterEntry(name string) int32 {
+	defer m.mu.Unlock()
+	m.mu.Lock()
+	if rid, ok := m.itemNamesToRuntimeIDs[name]; ok {
+		return rid
+	}
+	nextRID := int32(len(m.itemRuntimeIDsToNames))
+	m.itemNamesToRuntimeIDs[name] = nextRID
+	m.itemRuntimeIDsToNames[nextRID] = name
+	return nextRID
+}
+
+func (m *DefaultItemMapping) Air() int32 {
+	defer m.mu.Unlock()
+	m.mu.Lock()
+	return m.airRID
+}
+
+func (m *DefaultItemMapping) ItemVersion() uint16 {
+	defer m.mu.Unlock()
+	m.mu.Lock()
+	return m.itemVersion
+}