From a9730af656f633bca04e6452815ddd92f2f2d178 Mon Sep 17 00:00:00 2001
From: Greg Weisbrod <greg.weisbrod@gmail.com>
Date: Thu, 21 Oct 2021 00:35:13 -0400
Subject: [PATCH] add NFTokenCreateOffer

---
 src/models/transactions/NFTokenCreateOffer.ts | 116 ++++++++++++++++++
 src/models/transactions/index.ts              |   5 +
 src/models/transactions/transaction.ts        |   9 ++
 3 files changed, 130 insertions(+)
 create mode 100644 src/models/transactions/NFTokenCreateOffer.ts

diff --git a/src/models/transactions/NFTokenCreateOffer.ts b/src/models/transactions/NFTokenCreateOffer.ts
new file mode 100644
index 00000000..b8274273
--- /dev/null
+++ b/src/models/transactions/NFTokenCreateOffer.ts
@@ -0,0 +1,116 @@
+import { ValidationError } from '../../errors'
+import { Amount } from '../common'
+
+import {
+  BaseTransaction,
+  GlobalFlags,
+  validateBaseTransaction,
+  isAmount,
+} from './common'
+
+/**
+ * Transaction Flags for an NFTokenCreateOffer Transaction.
+ *
+ * @category Transaction Flags
+ */
+export enum NFTokenCreateOfferFlags {
+  /**
+   * If set, indicates that the offer is a sell offer.
+   * Otherwise, it is a buy offer.
+   */
+  tfSellToken = 0x00000001,
+}
+
+/**
+ * Map of flags to boolean values representing {@link NFTokenCreateOffer} transaction
+ * flags.
+ *
+ * @category Transaction Flags
+ */
+export interface NFTokenCreateOfferFlagsInterface extends GlobalFlags {
+  tfSellToken?: boolean
+}
+
+/**
+ * The NFTokenCreateOffer transaction creates an NFToken object and adds it to the
+ * relevant NFTokenPage object of the minter. If the transaction is
+ * successful, the newly minted token will be owned by the minter account
+ * specified by the transaction.
+ */
+export interface NFTokenCreateOffer extends BaseTransaction {
+  TransactionType: 'NFTokenCreateOffer'
+  /**
+   * Indicates the AccountID of the account that initiated the
+   * transaction.
+   */
+  Account: string
+  /**
+   * Identifies the TokenID of the NFToken object that the
+   * offer references.
+   */
+  TokenID: string
+  /**
+   * Indicates the amount expected or offered for the Token.
+   *
+   * The amount must be non-zero, except where this is an
+   * offer is an offer to sell and the asset is XRP; then it
+   * is legal to specify an amount of zero, which means that
+   * the current owner of the token is giving it away, gratis,
+   * either to anyone at all, or to the account identified by
+   * the Destination field.
+   */
+  Amount: Amount
+  /**
+   * Indicates the AccountID of the account that owns the
+   * corresponding NFToken.
+   *
+   * If the offer is to buy a token, this field must be present
+   * and it must be different than Account (since an offer to
+   * buy a token one already holds is meaningless).
+   *
+   * If the offer is to sell a token, this field must not be
+   * present, as the owner is, implicitly, the same as Account
+   * (since an offer to sell a token one doesn't already hold
+   * is meaningless).
+   */
+  Owner?: string
+  /**
+   * Indicates the time after which the offer will no longer
+   * be valid. The value is the number of seconds since the
+   * Ripple Epoch.
+   */
+  Expiration?: number
+  /**
+   * If present, indicates that this offer may only be
+   * accepted by the specified account. Attempts by other
+   * accounts to accept this offer MUST fail.
+   */
+  Destination?: string
+  Flags?: number | NFTokenCreateOfferFlagsInterface
+}
+
+/**
+ * Verify the form and type of an NFTokenCreateOffer at runtime.
+ *
+ * @param tx - An NFTokenCreateOffer Transaction.
+ * @throws When the NFTokenCreateOffer is Malformed.
+ */
+export function validateNFTokenCreateOffer(tx: Record<string, unknown>): void {
+  validateBaseTransaction(tx)
+
+  if (tx.Account == null) {
+    throw new ValidationError('NFTokenCreateOffer: missing field Account')
+  }
+
+  if (tx.TokenID == null) {
+    throw new ValidationError('NFTokenCreateOffer: missing field TokenID')
+  }
+
+  if (tx.Amount == null) {
+    throw new ValidationError('NFTokenCreateOffer: missing field Amount')
+  }
+
+  if (typeof tx.Amount !== 'string' && !isAmount(tx.Amount)) {
+    throw new ValidationError('NFTokenCreateOffer: invalid Amount')
+  }
+}
diff --git a/src/models/transactions/index.ts b/src/models/transactions/index.ts
index 7af68ffc..b9af0cb7 100644
--- a/src/models/transactions/index.ts
+++ b/src/models/transactions/index.ts
@@ -15,6 +15,11 @@ export { EscrowCancel } from './escrowCancel'
 export { EscrowCreate } from './escrowCreate'
 export { EscrowFinish } from './escrowFinish'
 export { NFTokenBurn } from './NFTokenBurn'
+export {
+  NFTokenCreateOffer,
+  NFTokenCreateOfferFlags,
+  NFTokenCreateOfferFlagsInterface,
+} from './NFTokenCreateOffer'
 export {
   NFTokenMint,
   NFTokenMintFlags,
diff --git a/src/models/transactions/transaction.ts b/src/models/transactions/transaction.ts
index 4a899b5b..ea4c6c80 100644
--- a/src/models/transactions/transaction.ts
+++ b/src/models/transactions/transaction.ts
@@ -18,6 +18,10 @@ import { EscrowCreate, validateEscrowCreate } from './escrowCreate'
 import { EscrowFinish, validateEscrowFinish } from './escrowFinish'
 import { TransactionMetadata } from './metadata'
 import { NFTokenBurn, validateNFTokenBurn } from './NFTokenBurn'
+import {
+  NFTokenCreateOffer,
+  validateNFTokenCreateOffer,
+} from './NFTokenCreateOffer'
 import { NFTokenMint, validateNFTokenMint } from './NFTokenMint'
 import { OfferCancel, validateOfferCancel } from './offerCancel'
 import { OfferCreate, validateOfferCreate } from './offerCreate'
@@ -53,6 +57,7 @@ export type Transaction =
   | EscrowCreate
   | EscrowFinish
   | NFTokenBurn
+  | NFTokenCreateOffer
   | NFTokenMint
   | OfferCancel
   | OfferCreate
@@ -132,6 +137,10 @@ export function validate(transaction: Record<string, unknown>): void {
       validateNFTokenBurn(tx)
       break
 
+    case 'NFTokenCreateOffer':
+      validateNFTokenCreateOffer(tx)
+      break
+
     case 'NFTokenMint':
       validateNFTokenMint(tx)
       break