Correct proxied/aliased currencies to use native Cryptocurrency's decimals

pjkundert · pjkundert · commit 2fc8edefd9c3 · 2023-02-02T13:58:09.000-07:00
diff --git a/slip39/api.py b/slip39/api.py
@@ -299,6 +299,23 @@ class Account:
         BNB		= 'Binance',
         XRP		= 'Ripple',
     )
+    CRYPTO_DECIMALS		= dict(
+        # Ethereum-related Cryptocurrencies are denominated 10^18, typically default 6 decimals
+        # precision.  Bitcoin-related cryptocurrencies are typically 8 decimals precision (1 Sat is
+        # 1/10^8 Bitcoin).  For XRP 1 Drop = 1/10^6 Ripple: https://xrpl.org/currency-formats.html
+        # For formatting, we'll typically default to decimals//3, which works out fairly well for
+        # most Cryptocurrencies and ERC-20 Tokens.  The exception are eg. WBTC (8 decimals) vs. BTC
+        # (24 decimals); using the default 8 // 3 = 2 for WBTC would be dramatically too few
+        # decimals of precision for practical use.  So, we recommend defaulting to the underlying
+        # known cryptocurrency, when a proxy Token is used for price calculations.
+        ETH		= 18,
+        BTC		= 24,
+        LTC		= 24,
+        DOGE		= 24,
+        CRO		= 18,
+        BNB		= 18,
+        XRP		= 6,
+    )
     CRYPTO_NAMES		= dict(
         # Currently supported (in order of visibility), and conversion of known Names to Symbol.  By
         # convention, Cryptocurrency names are lower-cased to avoid collisions with symbols.
diff --git a/slip39/invoice/artifact.py b/slip39/invoice/artifact.py
@@ -37,7 +37,7 @@
 from ..util		import commas, is_listlike, is_mapping
 from ..defaults		import INVOICE_CURRENCY, INVOICE_ROWS, INVOICE_STRFTIME, INVOICE_DUE, MM_IN, FILENAME_FORMAT
 from ..layout		import Region, Text, Image, Box, Coordinate, layout_pdf
-from .ethereum		import tokeninfo, tokenprices, TokenInfo  # , tokenratio
+from .ethereum		import tokeninfo, tokenprices, tokenknown
 
 """
 Invoice artifacts:
@@ -215,27 +215,7 @@ def cryptocurrency_proxy( name, decimals=None, chain=None, w3_url=None, use_prov
     except Exception as exc:
         log.info( f"Could not identify currency {name!r} as an ERC-20 Token: {exc}" )
     # Not a known Token; a core known Cryptocurrency?
-    return cryptocurrency_known( name, decimals=decimals )
-
-
-def cryptocurrency_known( name, decimals=None ):
-    """If it is a recognized core supported Cryptocurrency, return a TokenInfo useful for formatting.
-    Since Bitcoin (and other similar cryptocurrencies) are typically assumed to have 8 decimal
-    places (the Sat(oshi) is 1/10^8 of a Bitcoin), we'll make the default decimals//3 precision work
-    out to 8).
-
-    """
-    try:
-        symbol			= Account.supported( name )
-    except ValueError as exc:
-        log.info( f"Failed to identify currency {name!r} as a supported Cryptocurrency: {exc}" )
-        raise
-    return TokenInfo(
-        name		= Account.CRYPTO_SYMBOLS[symbol],
-        symbol		= symbol,
-        decimals	= 24 if decimals is None else decimals,
-        icon		= next( ( Path( __file__ ).resolve().parent / "Cryptos" ).glob( symbol + '*.*' ), None ),
-    )
+    return tokenknown( name, decimals=decimals )
 
 
 class Invoice:
@@ -323,19 +303,31 @@ def __init__(
         # and an Ethereum account provided, the buyer can pay in BTC to the Bitcoin account, or in
         # ETH or WBTC to the Ethereum account.  This will add the symbols for all Crypto proxies to
         # currencies_account.
-        currencies_proxy	= {}
+        currencies_alias	= {}  # eg. { "WBTC": TokenInfo( "BTC", ... ), ... }
+        currencies_proxy	= {}  # eg. { "BTC": TokenInfo( "WBTC", ... ), ... }
         for c in currencies:
             try:
-                currencies_proxy[c] = tokeninfo( c, w3_url=w3_url, use_provider=use_provider )
+                currencies_proxy[c] = alias = tokeninfo( c, w3_url=w3_url, use_provider=use_provider )
             except Exception as exc:
-                log.info( f"Failed to find proxy for Invoice currency {c}: {exc}" )
+                # May fail later, if no conversions provided for this currency
+                log.warning( f"Failed to find proxy for Invoice currency {c}: {exc}" )
             else:
-                # Yup; a proxy for a Crypto Eg. BTC -> WBTC was found, or a native ERC-20 eg. USDC
+                # Yup; a proxy for a Crypto eg. BTC -> WBTC was found, or a native ERC-20 eg. USDC
                 # was found; associate it with any ETH account provided.
                 if eth := currencies_account.get( 'ETH' ):
                     currencies_account[currencies_proxy[c].symbol] = eth
+                try:
+                    known	= tokenknown( c )
+                except Exception:
+                    pass
+                else:
+                    # Aliases; of course, the native symbol is included in known aliases
+                    currencies_alias[alias.symbol] = known
+                    currencies_alias[known.symbol] = known
+                    log.info( f"Currency {c}'s Proxy Symbol {alias.symbol} is an alias for {known.symbol}" )
         log.info( f"Found {len( currencies_proxy )} Invoice currency proxies: {commas( ( f'{c}: {p.symbol}' for c,p in currencies_proxy.items() ), final='and')}" )
         log.info( f"Added {len( set( currencies_account ) - currencies )} proxies: {commas( set( currencies_account ) - currencies, final='and' )}" )
+        log.info( f"Alias {len( currencies_alias )} symbols to their native Crytocurrencies: {commas( ( f'{a}: {c.symbol}' for a,c in currencies_alias.items() ), final='and')}" )
         currencies		= set( currencies_account )
 
         # Find all LineItem.currency -> Invoice.currencies conversions required.  This establishes
@@ -406,7 +398,8 @@ def __init__(
 
         self.currencies		= currencies		# { "USDC", "BTC", ... }
         self.currencies_account	= currencies_account    # { "USDC": "0xaBc...12D", "BTC": "bc1...", ... }
-        self.currencies_proxy	= currencies_proxy      # { "BTC": TokenInfo( ... ), ... }
+        self.currencies_proxy	= currencies_proxy      # { "BTC": TokenInfo( "WBTC", ... ), ... }
+        self.currencies_alias	= currencies_alias      # { "WBTC": TokenInfo( "BTC", ... ), ... }
         self.conversions	= conversions		# { ("BTC","ETH"): 14.3914, ... }
 
     def headers( self ):
@@ -597,12 +590,17 @@ def can( c ):
             # {Sub}total for payment cryptocurrrencies are rounded to the individual
             # Cryptocurrency's designated decimals // 3.  For typical ERC-20 tokens, this is
             # eg. USDC: 6 // 3 == 2, WBTC: 18 // 3 == 6.  For known Cryptocurrencies, eg. BTC: 24 //
-            # 3 == 8.  TODO: There should be a more sensible / less brittle way to do this.
+            # 3 == 8.
+            #
+            # If a symbol is a "proxy" token for some upstream known cryptocurrency, then the
+            # upstream native cryptocurrency's decimals should be used, so that all lines match.  We
+            # keep track of each cryptocurrency_alias[<proxy-symbol>] -> <original-symbol>
+            #
+            # TODO: There should be a more sensible / less brittle way to do this.
             def deci( c ):
-                try:
-                    return cryptocurrency_known( c ).decimals // 3
-                except Exception:
-                    return self.currencies_proxy[c].decimals // 3
+                if c in self.currencies_alias:
+                    return self.currencies_alias[c].decimals // 3
+                return self.currencies_proxy[c].decimals // 3
 
             def toti( c ):
                 return headers_can.index( can( f'_Total {c}' ))
diff --git a/slip39/invoice/artifact_test.py b/slip39/invoice/artifact_test.py
@@ -258,20 +258,20 @@ def test_tabulate( tmp_path ):
 | Account                                    | Crypto   | Currency      |       Taxes |      Subtotal |
 |--------------------------------------------+----------+---------------+-------------+---------------|
 | bc1qk0a9hr7wjfxeenz9nwenw9flhq0tmsf6vsgnn2 | BTC      | Bitcoin       |  0.00088444 |      0.567269 |
-| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | ETH      | Ethereum      |  0.0132667  |      8.50904  |
+| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | ETH      | Ethereum      |  0.013267   |      8.50904  |
 | 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | USDC     | USD Coin      | 19.9        | 12,763.6      |
-| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WBTC     | Wrapped BTC   |  0          |      0.57     |
+| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WBTC     | Wrapped BTC   |  0.00088444 |      0.567269 |
 | 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WETH     | Wrapped Ether |  0.013267   |      8.50904  |
-| rUPzi4ZwoYxi7peKCqUkzqEuSrzSRyLguV         | XRP      | Ripple        | 53.0667     | 34,036.2      |
+| rUPzi4ZwoYxi7peKCqUkzqEuSrzSRyLguV         | XRP      | Ripple        | 53.07       | 34,036.2      |
 
 | Account                                    | Crypto   | Currency      |       Taxes |         Total |
 |--------------------------------------------+----------+---------------+-------------+---------------|
 | bc1qk0a9hr7wjfxeenz9nwenw9flhq0tmsf6vsgnn2 | BTC      | Bitcoin       |  0.00088444 |      0.567269 |
-| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | ETH      | Ethereum      |  0.0132667  |      8.50904  |
+| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | ETH      | Ethereum      |  0.013267   |      8.50904  |
 | 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | USDC     | USD Coin      | 19.9        | 12,763.6      |
-| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WBTC     | Wrapped BTC   |  0          |      0.57     |
+| 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WBTC     | Wrapped BTC   |  0.00088444 |      0.567269 |
 | 0xfc2077CA7F403cBECA41B1B0F62D91B5EA631B5E | WETH     | Wrapped Ether |  0.013267   |      8.50904  |
-| rUPzi4ZwoYxi7peKCqUkzqEuSrzSRyLguV         | XRP      | Ripple        | 53.0667     | 34,036.2      |"""  # noqa: E501
+| rUPzi4ZwoYxi7peKCqUkzqEuSrzSRyLguV         | XRP      | Ripple        | 53.07       | 34,036.2      |"""  # noqa: E501
 
     this			= Path( __file__ ).resolve()
     test			= this.with_suffix( '' )
diff --git a/slip39/invoice/ethereum.py b/slip39/invoice/ethereum.py
@@ -40,6 +40,7 @@
 from web3		import Web3
 from web3.middleware	import construct_sign_and_send_raw_middleware
 
+from ..api		import Account
 from ..util		import memoize, retry, commas, into_bytes, timer
 from ..defaults		import (
     ETHERSCAN_MEMO_MAXAGE, ETHERSCAN_MEMO_MAXSIZE,
@@ -1256,8 +1257,8 @@ def w3_provider( w3_url, use_provider ):
 @dataclass( eq=True, frozen=True )      # Makes it hashable
 class TokenInfo:
     """Represents a Crypto-currency or on-chain Token (eg. ERC-20)"""
-    name: str
     symbol: str
+    name: str
     decimals: int
     contract: Optional[str] = None      # If not an ERC-20 token contract, no contract address
     icon: Optional[Union[str,Path]] = None
@@ -1368,6 +1369,27 @@ def aliasinfo( info ):
 tokeninfo.ERC20s		= {}  # noqa: E305; { <chain>: {'contract': <info>, 'name': <info>, 'symbol': info, ... }}
 
 
+def tokenknown( name, decimals=None ):
+    """If name is a recognized core supported Cryptocurrency, return a TokenInfo useful for formatting.
+
+    Since Bitcoin (and other similar cryptocurrencies) are typically assumed to have 8 decimal
+    places (a Sat(oshi) is 1/10^8 of a Bitcoin), we'll make the default decimals//3 precision work
+    out to 8).
+
+    """
+    try:
+        symbol			= Account.supported( name )
+    except ValueError as exc:
+        log.info( f"Failed to identify currency {name!r} as a supported Cryptocurrency: {exc}" )
+        raise
+    return TokenInfo(
+        symbol		= symbol,
+        name		= Account.CRYPTO_SYMBOLS[symbol],
+        decimals	= Account.CRYPTO_DECIMALS[symbol] if decimals is None else decimals,
+        icon		= next( ( Path( __file__ ).resolve().parent / "Cryptos" ).glob( symbol + '*.*' ), None ),
+    )
+
+
 @memoize( maxage=TOKPRICES_MEMO_MAXAGE, maxsize=TOKPRICES_MEMO_MAXSIZE, log_at=logging.INFO )
 def tokenprice( w3_url, chain, token, base, use_wrappers=None, use_provider=None ):
     """Return memoized token address prices, in terms of a base token address.  The resultant Fraction
diff --git a/slip39/util.py b/slip39/util.py
@@ -97,6 +97,20 @@ def log_level( adjust ):
     ]
 
 
+def log_apis( func ):
+    """Decorator for logging function args, kwds, and results"""
+    @wraps( func )
+    def wrapper( *args, **kwds ):
+        try:
+            result = func(*args, **kwds)
+        except Exception as exc:
+            log.warning( f"{func.__name__}( {args!r} {kwds!r} ): {exc}" )
+        else:
+            log.info( f"{func.__name__}( {args!r} {kwds!r} ) == {result}" )
+        return result
+    return wrapper
+
+
 #
 # util.is_...		-- Test for various object capabilities
 #

Original file line number	Diff line number	Diff line change
`@@ -97,6 +97,20 @@ def log_level( adjust ):`
`97`	`97`	`]`
`98`	`98`
`99`	`99`
	`100`	`+def log_apis( func ):`
	`101`	`+ """Decorator for logging function args, kwds, and results"""`
	`102`	`+ @wraps( func )`
	`103`	`+ def wrapper( args, *kwds ):`
	`104`	`+ try:`
	`105`	`+ result = func(args, *kwds)`
	`106`	`+ except Exception as exc:`
	`107`	`+ log.warning( f"{func.__name__}( {args!r} {kwds!r} ): {exc}" )`
	`108`	`+ else:`
	`109`	`+ log.info( f"{func.__name__}( {args!r} {kwds!r} ) == {result}" )`
	`110`	`+ return result`
	`111`	`+ return wrapper`
	`112`	`+`
	`113`	`+`
`100`	`114`	`#`
`101`	`115`	`# util.is_... -- Test for various object capabilities`
`102`	`116`	`#`