initial commit

mapping/custom_blocks.go

@@ -0,0 +1,84 @@
+package mapping
+
+import (
+	"github.com/akmalfairuz/legacy-version/internal"
+	"github.com/df-mc/worldupgrader/blockupgrader"
+	"github.com/sandertv/gophertunnel/minecraft/protocol"
+	"golang.org/x/exp/maps"
+)
+
+func convert(entries []protocol.BlockEntry) (states []blockupgrader.BlockState) {
+	for _, entry := range entries {
+		propertiesMap := map[string][]any{}
+		if props := jsonCheck[[]any](entry.Properties, "properties"); props != nil {
+			for _, prop := range *props {
+				prop := prop.(map[string]any)
+				name := jsonCheck[string](prop, "name")
+				enum := jsonCheck[[]any](prop, "enum")
+				if enum == nil {
+					int32Enum := jsonCheck[[]int32](prop, "enum")
+					if int32Enum != nil {
+						enum = &[]any{}
+						for _, i := range *int32Enum {
+							*enum = append(*enum, i)
+						}
+					}
+				}
+				if name == nil || enum == nil {
+					panic("could not find field `name` and `enum`")
+				}
+				propertiesMap[*name] = *enum
+			}
+		}
+
+		combinations := make([]map[string]any, 0)
+		generateCombinationsRecursively(propertiesMap, internal.NewIterator(maps.Keys(propertiesMap)), map[string]any{}, &combinations)
+		if len(combinations) == 0 {
+			combinations = append(combinations, map[string]any{})
+		}
+
+		for _, combination := range combinations {
+			blockState := blockupgrader.BlockState{
+				Name:       entry.Name,
+				Properties: combination,
+			}
+
+			states = append(states, blockState)
+		}
+	}
+	return
+}
+
+func generateCombinationsRecursively[K comparable, V any](all map[K][]V, iterator *internal.Iterator[K], current map[K]V, output *[]map[K]V) {
+	if !iterator.HasNext() {
+		entry := map[K]V{}
+		for k, v := range current {
+			entry[k] = v
+		}
+		out := append(*output, entry)
+		*output = out
+	} else {
+		key := iterator.Next()
+		set := all[key]
+
+		for _, value := range set {
+			current[key] = value
+			generateCombinationsRecursively(all, iterator, current, output)
+			delete(current, key)
+		}
+
+		iterator.Previous()
+	}
+}
+
+func jsonCheck[T any](json map[string]any, field string) *T {
+	fieldValue, found := json[field]
+	if !found {
+		return nil
+	}
+	castedValue, ok := fieldValue.(T)
+	if !ok {
+		return nil
+	}
+	return &castedValue
+}