item/stack.go: Add new WithItem method to replace session/handler_cra…

…fting.go duplicateStack function.

server/item/stack.go

@@ -2,6 +2,7 @@ package item
 
 import (
 	"fmt"
+	"maps"
 	"reflect"
 	"slices"
 	"sort"
@@ -210,7 +211,7 @@ func (s Stack) Lore() []string {
 // WithValue stores Values by encoding them using the encoding/gob package. Users of WithValue must ensure
 // that their value is valid for encoding with this package.
 func (s Stack) WithValue(key string, val any) Stack {
-	s.data = copyMap(s.data)
+	s.data = maps.Clone(s.data)
 	if val != nil {
 		s.data[key] = val
 	} else {
@@ -232,7 +233,7 @@ func (s Stack) WithEnchantments(enchants ...Enchantment) Stack {
 	if _, ok := s.item.(Book); ok {
 		s.item = EnchantedBook{}
 	}
-	s.enchantments = copyEnchantments(s.enchantments)
+	s.enchantments = maps.Clone(s.enchantments)
 	for _, enchant := range enchants {
 		if _, ok := s.Item().(EnchantedBook); !ok && !enchant.t.CompatibleWithItem(s.item) {
 			// Enchantment is not compatible with the item.
@@ -245,7 +246,7 @@ func (s Stack) WithEnchantments(enchants ...Enchantment) Stack {
 
 // WithoutEnchantments returns the current stack but with the passed enchantments removed.
 func (s Stack) WithoutEnchantments(enchants ...EnchantmentType) Stack {
-	s.enchantments = copyEnchantments(s.enchantments)
+	s.enchantments = maps.Clone(s.enchantments)
 	for _, enchant := range enchants {
 		delete(s.enchantments, enchant)
 	}
@@ -265,10 +266,7 @@ func (s Stack) Enchantment(enchant EnchantmentType) (Enchantment, bool) {
 // Enchantments returns an array of all Enchantments on the item. Enchantments returns the enchantments of a Stack in a
 // deterministic order.
 func (s Stack) Enchantments() []Enchantment {
-	e := make([]Enchantment, 0, len(s.enchantments))
-	for _, ench := range s.enchantments {
-		e = append(e, ench)
-	}
+	e := slices.Collect(maps.Values(s.enchantments))
 	sort.Slice(e, func(i, j int) bool {
 		id1, _ := EnchantmentID(e[i].t)
 		id2, _ := EnchantmentID(e[j].t)
@@ -296,6 +294,20 @@ func (s Stack) WithAnvilCost(anvilCost int) Stack {
 	return s
 }
 
+// WithItem returns a Stack with the item type passed, copying all the
+// properties from s to the new stack. Damage to an item, enchantments and anvil
+// costs are only copied if they are still applicable to the new item type.
+func (s Stack) WithItem(t world.Item) Stack {
+	cp := NewStack(t, s.count).
+		Damage(s.damage).
+		WithCustomName(s.customName).
+		WithLore(s.lore...).
+		WithEnchantments(s.Enchantments()...).
+		WithAnvilCost(s.anvilCost)
+	cp.data = s.data
+	return cp
+}
+
 // AddStack adds another stack to the stack and returns both stacks. The first stack returned will have as
 // many items in it as possible to fit in the stack, according to a max count of either 64 or otherwise as
 // returned by Item.MaxCount(). The second stack will have the leftover items: It may be empty if the count of
@@ -371,7 +383,7 @@ func (s Stack) String() string {
 // Values returns all values associated with the stack by users. The map returned is a copy of the original:
 // Modifying it will not modify the item stack.
 func (s Stack) Values() map[string]any {
-	return copyMap(s.data)
+	return maps.Clone(s.data)
 }
 
 // stackID is a counter for unique stack IDs.
@@ -398,21 +410,3 @@ func id(s Stack) int32 {
 func format(a []any) string {
 	return strings.TrimSuffix(fmt.Sprintln(a...), "\n")
 }
-
-// copyMap makes a copy of the map passed. It does not recursively copy the map.
-func copyMap(m map[string]any) map[string]any {
-	cp := make(map[string]any, len(m))
-	for k, v := range m {
-		cp[k] = v
-	}
-	return cp
-}
-
-// copyEnchantments makes a copy of the enchantments map passed. It does not recursively copy the map.
-func copyEnchantments(m map[EnchantmentType]Enchantment) map[EnchantmentType]Enchantment {
-	cp := make(map[EnchantmentType]Enchantment, len(m))
-	for k, v := range m {
-		cp[k] = v
-	}
-	return cp
-}

server/session/handler_book_edit.go

@@ -68,9 +68,9 @@ func (b BookEditHandler) Handle(p packet.Packet, s *Session, _ *world.Tx, _ Cont
 		}
 		book = book.SwapPages(page, int(pk.SecondaryPageNumber))
 	case packet.BookActionSign:
-		_ = s.inv.SetItem(slot, duplicateStack(it, item.WrittenBook{Title: pk.Title, Author: pk.Author, Pages: book.Pages, Generation: item.OriginalGeneration()}))
+		_ = s.inv.SetItem(slot, it.WithItem(item.WrittenBook{Title: pk.Title, Author: pk.Author, Pages: book.Pages, Generation: item.OriginalGeneration()}))
 		return nil
 	}
-	_ = s.inv.SetItem(slot, duplicateStack(it, book))
+	_ = s.inv.SetItem(slot, it.WithItem(book))
 	return nil
 }

server/session/handler_crafting.go

@@ -184,20 +184,6 @@ func (s *Session) craftingOffset() uint32 {
 	return craftingGridSmallOffset
 }
 
-// duplicateStack duplicates an item.Stack with the new item type given.
-func duplicateStack(input item.Stack, newType world.Item) item.Stack {
-	outputStack := item.NewStack(newType, input.Count()).
-		Damage(input.MaxDurability() - input.Durability()).
-		WithCustomName(input.CustomName()).
-		WithLore(input.Lore()...).
-		WithEnchantments(input.Enchantments()...).
-		WithAnvilCost(input.AnvilCost())
-	for k, v := range input.Values() {
-		outputStack = outputStack.WithValue(k, v)
-	}
-	return outputStack
-}
-
 // matchingStacks returns true if the two stacks are the same in a crafting scenario.
 func matchingStacks(has, expected recipe.Item) bool {
 	switch expected := expected.(type) {

server/session/handler_loom.go

@@ -93,5 +93,5 @@ func (h *ItemStackRequestHandler) handleLoomCraft(a *protocol.CraftLoomRecipeSta
 		Container: protocol.FullContainerName{ContainerID: protocol.ContainerLoomDye},
 		Slot:      loomDyeSlot,
 	}, dye.Grow(-timesCrafted), s, tx)
-	return h.createResults(s, tx, duplicateStack(input, b))
+	return h.createResults(s, tx, input.WithItem(b))
 }

server/session/handler_smithing.go

@@ -85,7 +85,7 @@ func (h *ItemStackRequestHandler) handleSmithing(a *protocol.CraftRecipeStackReq
 		if !ok {
 			return fmt.Errorf("input item is not trimmable")
 		}
-		return h.createResults(s, tx, duplicateStack(input, trimmable.WithTrim(trim)))
+		return h.createResults(s, tx, input.WithItem(trimmable.WithTrim(trim)))
 	}
-	return h.createResults(s, tx, duplicateStack(input, craft.Output()[0].Item()))
+	return h.createResults(s, tx, input.WithItem(craft.Output()[0].Item()))
 }