initial commit

packbuilder/builder.go

@@ -0,0 +1,71 @@
+package packbuilder
+
+import (
+	"github.com/df-mc/dragonfly/server/item/category"
+	"golang.org/x/exp/maps"
+	"strings"
+)
+
+// ComponentBuilder represents a builder that can be used to construct an item components map to be sent to a client.
+type ComponentBuilder struct {
+	name       string
+	identifier string
+	category   category.Category
+
+	properties map[string]any
+	components map[string]any
+}
+
+// NewComponentBuilder returns a new component builder with the provided item data.
+func NewComponentBuilder(name, identifier string, category category.Category) *ComponentBuilder {
+	return &ComponentBuilder{
+		name:       name,
+		identifier: identifier,
+		category:   category,
+
+		properties: make(map[string]any),
+		components: make(map[string]any),
+	}
+}
+
+// AddProperty adds the provided property to the builder.
+func (builder *ComponentBuilder) AddProperty(name string, value any) {
+	builder.properties[name] = value
+}
+
+// AddComponent adds the provided component to the builder.
+func (builder *ComponentBuilder) AddComponent(name string, value any) {
+	builder.components[name] = value
+}
+
+// Construct constructs the final item components map and returns it. It also applies the default properties required
+// for the item to work without modifying the original maps in the builder.
+func (builder *ComponentBuilder) Construct() map[string]any {
+	properties := maps.Clone(builder.properties)
+	components := maps.Clone(builder.components)
+	builder.applyDefaultProperties(properties)
+	builder.applyDefaultComponents(components, properties)
+	return map[string]any{"components": components}
+}
+
+// applyDefaultProperties applies the default properties to the provided map. It is important that this method does
+// not modify the builder's properties map directly otherwise Empty() will return false in future use of the builder.
+func (builder *ComponentBuilder) applyDefaultProperties(x map[string]any) {
+	x["minecraft:icon"] = map[string]any{
+		"texture": strings.Split(builder.identifier, ":")[1],
+	}
+	x["creative_group"] = builder.category.Group()
+	x["creative_category"] = int32(builder.category.Uint8())
+	if _, ok := x["max_stack_size"]; !ok {
+		x["max_stack_size"] = int32(64)
+	}
+}
+
+// applyDefaultComponents applies the default components to the provided map. It is important that this method does not
+// modify the builder's components map directly otherwise Empty() will return false in future use of the builder.
+func (builder *ComponentBuilder) applyDefaultComponents(x, properties map[string]any) {
+	x["item_properties"] = properties
+	x["minecraft:display_name"] = map[string]any{
+		"value": builder.name,
+	}
+}