up3

server/internal/iteminternal/builder.go

@@ -0,0 +1,72 @@
+package iteminternal
+
+import (
+	"github.com/df-mc/dragonfly/server/item/category"
+	"maps"
+)
+
+// 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{
+		"textures": map[string]any{
+			"default": builder.identifier,
+		},
+	}
+	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,
+	}
+}

server/internal/iteminternal/components.go

@@ -0,0 +1,82 @@
+package iteminternal
+
+import (
+	"github.com/df-mc/dragonfly/server/item"
+	"github.com/df-mc/dragonfly/server/world"
+	"strings"
+)
+
+// Components returns all the components of the given custom item. If the item has no components, a nil map and false
+// are returned.
+func Components(it world.CustomItem) map[string]any {
+	category := it.Category()
+	identifier, _ := it.EncodeItem()
+	name := strings.Split(identifier, ":")[1]
+
+	builder := NewComponentBuilder(it.Name(), identifier, category)
+
+	if x, ok := it.(item.Armour); ok {
+		builder.AddComponent("minecraft:armor", map[string]any{
+			"protection": int32(x.DefencePoints()),
+		})
+
+		var slot string
+		switch it.(type) {
+		case item.HelmetType:
+			slot = "slot.armor.head"
+		case item.ChestplateType:
+			slot = "slot.armor.chest"
+		case item.LeggingsType:
+			slot = "slot.armor.legs"
+		case item.BootsType:
+			slot = "slot.armor.feet"
+		}
+		builder.AddComponent("minecraft:wearable", map[string]any{
+			"slot": slot,
+		})
+	}
+	if x, ok := it.(item.Consumable); ok {
+		builder.AddProperty("use_duration", int32(x.ConsumeDuration().Seconds()*20))
+		builder.AddComponent("minecraft:food", map[string]any{
+			"can_always_eat": x.AlwaysConsumable(),
+		})
+
+		if y, ok := it.(item.Drinkable); ok && y.Drinkable() {
+			builder.AddProperty("use_animation", int32(2))
+		} else {
+			builder.AddProperty("use_animation", int32(1))
+		}
+	}
+	if x, ok := it.(item.Cooldown); ok {
+		builder.AddComponent("minecraft:cooldown", map[string]any{
+			"category": name,
+			"duration": float32(x.Cooldown().Seconds()),
+		})
+	}
+	if x, ok := it.(item.Durable); ok {
+		builder.AddComponent("minecraft:durability", map[string]any{
+			"max_durability": int32(x.DurabilityInfo().MaxDurability),
+		})
+	}
+	if x, ok := it.(item.MaxCounter); ok {
+		builder.AddProperty("max_stack_size", int32(x.MaxCount()))
+	}
+	if x, ok := it.(item.OffHand); ok {
+		builder.AddProperty("allow_off_hand", x.OffHand())
+	}
+	if x, ok := it.(item.Throwable); ok {
+		// The data in minecraft:projectile is only used by vanilla server-side, but we must send at least an empty map
+		// so the client will play the throwing animation.
+		builder.AddComponent("minecraft:projectile", map[string]any{})
+		builder.AddComponent("minecraft:throwable", map[string]any{
+			"do_swing_animation": x.SwingAnimation(),
+		})
+	}
+	if x, ok := it.(item.Glinted); ok {
+		builder.AddProperty("foil", x.Glinted())
+	}
+	if x, ok := it.(item.HandEquipped); ok {
+		builder.AddProperty("hand_equipped", x.HandEquipped())
+	}
+	return builder.Construct()
+}