gno.land/p/nt/grc721/enumerable/v0⧉

1package enumerable23import (4	"gno.land/p/nt/grc721/v0"5)67const Kind = "enumerable"89// NewEnumerable attaches an enumerable extension and registers it as a core10// Extension. Attach it before the first mint so every token is indexed.11func NewEnumerable(coreLedger *grc721.PrivateLedger) (*Enumerable, *Ledger) {12	if coreLedger == nil {13		panic("enumerable: nil core ledger")14	}1516	st := &storage{}17	core := coreLedger.ReadToken()18	led := &Ledger{core: core, st: st}19	coreLedger.RegisterExtension(led)2021	return &Enumerable{core: core, st: st}, led22}2324func (e *Enumerable) ExtensionKind() string {25	return Kind26}2728func (e *Enumerable) TokenID() string {29	return e.core.ID()30}3132func (e *Enumerable) TotalSupply() int64 {33	return int64(len(e.st.allTokens))34}3536func (e *Enumerable) TokenByIndex(index int64) (grc721.TokenID, error) {37	if index < 0 || index >= int64(len(e.st.allTokens)) {38		return "", ErrIndexOutOfRange39	}4041	return e.st.allTokens[index], nil42}4344func (e *Enumerable) TokenOfOwnerByIndex(owner address, index int64) (grc721.TokenID, error) {45	list := e.ownedList(owner)46	if list == nil || index < 0 || index >= int64(len(list.ids)) {47		return "", ErrIndexOutOfRange48	}4950	return list.ids[index], nil51}5253func (e *Enumerable) ownedList(owner address) *tokenList {54	v := e.st.owned.Get(owner.String())55	if v == nil {56		return nil57	}5859	return v.(*tokenList)60}6162func (led *Ledger) ExtensionKind() string { return Kind }6364func (led *Ledger) OnMint(to address, tid grc721.TokenID) {65	led.addToAll(tid)66	led.addToOwner(to, tid)67}6869func (led *Ledger) OnTransfer(from, to address, tid grc721.TokenID) {70	led.removeFromOwner(from, tid)71	led.addToOwner(to, tid)72}7374func (led *Ledger) OnBurn(tid grc721.TokenID) {75	if v := led.st.owner.Get(tid.String()); v != nil {76		led.removeFromOwner(v.(address), tid)77	}7879	led.removeFromAll(tid)80}8182func (led *Ledger) addToAll(tid grc721.TokenID) {83	led.st.allIndex.Set(tid.String(), len(led.st.allTokens))84	led.st.allTokens = append(led.st.allTokens, tid)85}8687// Swap-and-pop: move the last id into the freed slot, then truncate.88func (led *Ledger) removeFromAll(tid grc721.TokenID) {89	tidStr := tid.String()9091	v := led.st.allIndex.Get(tidStr)92	if v == nil {93		return94	}9596	idx := v.(int)9798	last := len(led.st.allTokens) - 199	if idx != last {100		moved := led.st.allTokens[last]101		led.st.allTokens[idx] = moved102		led.st.allIndex.Set(moved.String(), idx)103	}104105	led.st.allTokens = led.st.allTokens[:last]106107	led.st.allIndex.Remove(tidStr)108}109110func (led *Ledger) addToOwner(owner address, tid grc721.TokenID) {111	ownerStr := owner.String()112113	var list *tokenList114	if v := led.st.owned.Get(ownerStr); v != nil {115		list = v.(*tokenList)116	} else {117		list = &tokenList{}118		led.st.owned.Set(ownerStr, list)119	}120121	led.st.ownedIndex.Set(tid.String(), len(list.ids))122	list.ids = append(list.ids, tid)123	led.st.owner.Set(tid.String(), owner)124}125126// Swap-and-pop within the owner list; drops the owner entry when it empties.127func (led *Ledger) removeFromOwner(owner address, tid grc721.TokenID) {128	ownerStr := owner.String()129130	v := led.st.owned.Get(ownerStr)131	if v == nil {132		return133	}134135	list := v.(*tokenList)136	tidStr := tid.String()137138	iv := led.st.ownedIndex.Get(tidStr)139	if iv == nil {140		return141	}142143	idx := iv.(int)144145	last := len(list.ids) - 1146	if idx != last {147		moved := list.ids[last]148		list.ids[idx] = moved149		led.st.ownedIndex.Set(moved.String(), idx)150	}151152	list.ids = list.ids[:last]153154	led.st.ownedIndex.Remove(tidStr)155156	if len(list.ids) == 0 {157		led.st.owned.Remove(ownerStr)158	}159160	led.st.owner.Remove(tidStr)161}162