From aedccaa1784cb1cf3596ebf4dcb15fac4ffc335b Mon Sep 17 00:00:00 2001
From: Jeff Cruikshank <jeff@chia.net>
Date: Wed, 13 Jul 2022 11:55:28 -0700
Subject: [PATCH] Calculate NFT royalty amount

---
 chia/cmds/wallet_funcs.py             | 63 ++++++++++++++++++++++++++-
 chia/wallet/nft_wallet/nft_puzzles.py |  1 +
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/chia/cmds/wallet_funcs.py b/chia/cmds/wallet_funcs.py
index 88dac2bd8a..18daad4840 100644
--- a/chia/cmds/wallet_funcs.py
+++ b/chia/cmds/wallet_funcs.py
@@ -20,6 +20,7 @@ from chia.util.config import load_config
 from chia.util.default_root import DEFAULT_ROOT_PATH
 from chia.util.ints import uint16, uint32, uint64, uint128
 from chia.wallet.did_wallet.did_info import DID_HRP
+from chia.wallet.nft_wallet.nft_puzzles import NFT_METADATA_UPDATER_PUZZLE_HASH
 from chia.wallet.nft_wallet.nft_info import NFT_HRP, NFTInfo
 from chia.wallet.trade_record import TradeRecord
 from chia.wallet.trading.offer import Offer
@@ -515,13 +516,33 @@ async def take_offer(args: dict, wallet_client: WalletRpcClient, fingerprint: in
         print("Please enter a valid offer file or hex blob")
         return
 
-    offered, requested, _ = offer.summary()
+    offered, requested, driver_dict = offer.summary()
     cat_name_resolver = wallet_client.cat_asset_id_to_name
     print("Summary:")
     print("  OFFERED:")
     await print_offer_summary(cat_name_resolver, offered)
     print("  REQUESTED:")
     await print_offer_summary(cat_name_resolver, requested)
+
+    nft_coin_id: Optional[bytes32] = nft_coin_id_from_offer(driver_dict)
+    nft_royalty_percentage: int = (
+        0 if nft_coin_id is None else await get_nft_royalty_percentage(nft_coin_id, wallet_client)
+    )
+    if nft_royalty_percentage > 0:
+        print("NFT Royalty Amount:")
+        nft_royalty_asset_id, nft_royalty_amount = calculate_nft_royalty_amount(
+            offered, requested, nft_coin_id, nft_royalty_percentage
+        )
+        nft_royalty_currency = (
+            "XCH"
+            if nft_royalty_asset_id == "xch"
+            else (await cat_name_resolver(bytes32.fromhex(nft_royalty_asset_id)))[1]
+        )
+        nft_royalty_divisor = units["chia"] if nft_royalty_asset_id == "xch" else units["cat"]
+        print(
+            f"      {Decimal(nft_royalty_amount) / nft_royalty_divisor} {nft_royalty_currency} ({nft_royalty_amount} mojos)"
+        )
+
     print(f"Included Fees: {Decimal(offer.bundle.fees()) / units['chia']}")
 
     if not examine_only:
@@ -929,3 +950,43 @@ async def get_nft_info(args: Dict, wallet_client: WalletRpcClient, fingerprint:
         print_nft_info(nft_info)
     except Exception as e:
         print(f"Failed to get NFT info: {e}")
+
+
+async def get_nft_royalty_percentage(nft_coin_id: bytes32, wallet_client: WalletRpcClient) -> int:
+    info = NFTInfo.from_json_dict((await wallet_client.get_nft_info(nft_coin_id.hex()))["nft_info"])
+    return info.royalty_percentage
+
+
+def calculate_nft_royalty_amount(
+    offered: Dict[str, Any], requested: Dict[str, Any], nft_coin_id: bytes32, nft_royalty_percentage: int
+) -> Tuple[str, int]:
+    nft_asset_id = nft_coin_id.hex()
+    amount_dict: Dict[str, Any] = requested if nft_asset_id in offered else offered
+    amounts: List[Tuple[str, int]] = list(amount_dict.items())
+
+    if len(amounts) != 1 or not isinstance(amounts[0][1], int):
+        raise ValueError("Royalty enabled NFTs only support offering/requesting one NFT for one currency")
+
+    royalty_amount: uint64 = uint64(amounts[0][1] * nft_royalty_percentage / 10000)
+    royalty_asset_id = amounts[0][0]
+    return royalty_asset_id, royalty_amount
+
+
+def driver_dict_asset_is_nft(driver_dict: Dict[str, Any], asset_id: str) -> bool:
+    asset_dict: Dict[str, Any] = driver_dict[asset_id]
+    if asset_dict.get("type") == "singleton":
+        updater_hash_hexstr: Optional[str] = asset_dict.get("also", {}).get("updater_hash")
+        try:
+            updater_hash = bytes32.from_hexstr(updater_hash_hexstr)
+            return updater_hash == NFT_METADATA_UPDATER_PUZZLE_HASH
+        except ValueError:
+            # Failed to construct bytes32 from updater_hash_hexstr
+            pass
+    return False
+
+
+def nft_coin_id_from_offer(driver_dict: Dict[str, Any]) -> Optional[bytes32]:
+    nft_asset_id: Optional[str] = next(
+        (key for key in driver_dict.keys() if driver_dict_asset_is_nft(driver_dict, key)), None
+    )
+    return bytes32.fromhex(nft_asset_id) if nft_asset_id is not None else None
diff --git a/chia/wallet/nft_wallet/nft_puzzles.py b/chia/wallet/nft_wallet/nft_puzzles.py
index c25ac6e836..01b6b7985a 100644
--- a/chia/wallet/nft_wallet/nft_puzzles.py
+++ b/chia/wallet/nft_wallet/nft_puzzles.py
@@ -20,6 +20,7 @@ LAUNCHER_PUZZLE_HASH = LAUNCHER_PUZZLE.get_tree_hash()
 SINGLETON_MOD_HASH = SINGLETON_TOP_LAYER_MOD.get_tree_hash()
 NFT_STATE_LAYER_MOD_HASH = NFT_STATE_LAYER_MOD.get_tree_hash()
 NFT_METADATA_UPDATER = load_clvm("nft_metadata_updater_default.clvm")
+NFT_METADATA_UPDATER_PUZZLE_HASH = NFT_METADATA_UPDATER.get_tree_hash()
 NFT_OWNERSHIP_LAYER = load_clvm("nft_ownership_layer.clvm")
 NFT_TRANSFER_PROGRAM_DEFAULT = load_clvm("nft_ownership_transfer_program_one_way_claim_with_royalties.clvm")
 STANDARD_PUZZLE_MOD = load_clvm("p2_delegated_puzzle_or_hidden_puzzle.clvm")