Merge pull request #507 from input-output-hk/paweljakubas/469/add-est…

…imate-fee-endpoint

Add estimate fee endpoint

lib/cli/src/Cardano/CLI.hs

@@ -94,11 +94,13 @@ import Cardano.Wallet.Api.Server
 import Cardano.Wallet.Api.Types
     ( AddressAmount
     , ApiAddress
+    , ApiFee
     , ApiMnemonicT (..)
     , ApiT (..)
     , ApiTransaction
     , ApiWallet
     , PostTransactionData (..)
+    , PostTransactionFeeData (..)
     , WalletPostData (..)
     , WalletPutData (..)
     )
@@ -695,6 +697,10 @@ data WalletClient t = WalletClient
         :: ApiT WalletId
         -> PostTransactionData t
         -> ClientM (ApiTransaction t)
+    , postTransactionFee
+        :: ApiT WalletId
+        -> PostTransactionFeeData t
+        -> ClientM ApiFee
     }
 
 walletClient :: forall t. (DecodeAddress t, EncodeAddress t) => WalletClient t
@@ -714,8 +720,9 @@ walletClient =
             :<|> _ -- Put Wallet Passphrase
             = wallets
 
-        _postTransaction =
-            transactions
+        _postTransaction
+            :<|> _postTransactionFee
+            = transactions
     in
         WalletClient
             { listAddresses = _listAddresses
@@ -725,6 +732,7 @@ walletClient =
             , postWallet = _postWallet
             , putWallet = _putWallet
             , postTransaction = _postTransaction
+            , postTransactionFee = _postTransactionFee
             }
 
 runClient

lib/core/src/Cardano/Wallet.hs

@@ -23,6 +23,7 @@ module Cardano.Wallet
 
     -- * Errors
     , ErrCreateUnsignedTx (..)
+    , ErrEstimateTxFee (..)
     , ErrNoSuchWallet (..)
     , ErrSignTx (..)
     , ErrSubmitTx (..)
@@ -78,6 +79,7 @@ import Cardano.Wallet.Primitive.CoinSelection
     )
 import Cardano.Wallet.Primitive.Fee
     ( ErrAdjustForFee (..)
+    , Fee (..)
     , FeeOptions (..)
     , FeePolicy
     , adjustForFee
@@ -243,6 +245,15 @@ data WalletLayer s t = WalletLayer
         -- coin selection for the given outputs. In order to construct (and
         -- sign) an actual transaction, have a look at 'signTx'.
 
+    , estimateTxFee
+        :: (DefineTx t)
+        => WalletId
+        -> CoinSelectionOptions
+        -> NonEmpty TxOut
+        -> ExceptT ErrEstimateTxFee IO Fee
+        -- ^ Estimate a transaction fee by automatically selecting inputs from the
+        -- wallet to cover the requested outputs.
+
     , signTx
         :: (Show s, NFData s, IsOwned s, GenChange s)
         => WalletId
@@ -278,6 +289,12 @@ data ErrCreateUnsignedTx
     | ErrCreateUnsignedTxFee ErrAdjustForFee
     deriving (Show, Eq)
 
+-- | Errors occuring when estimating transaction fee
+data ErrEstimateTxFee
+    = ErrEstimateTxFeeNoSuchWallet ErrNoSuchWallet
+    | ErrEstimateTxFeeCoinSelection ErrCoinSelection
+    deriving (Show, Eq)
+
 -- | Errors occuring when signing a transaction
 data ErrSignTx
     = ErrSignTx ErrMkStdTx
@@ -361,6 +378,7 @@ newWalletLayer tracer block0 feePolicy db nw tl = do
         , restoreWallet = _restoreWallet registry
         , listAddresses = _listAddresses
         , createUnsignedTx = _createUnsignedTx
+        , estimateTxFee = _estimateTxFee
         , signTx = _signTx
         , submitTx = _submitTx
         , attachPrivateKey = _attachPrivateKey
@@ -607,6 +625,21 @@ newWalletLayer tracer block0 feePolicy db nw tl = do
                     }
             debug "Coins after fee adjustment" =<< adjustForFee feeOpts utxo' sel
 
+
+    _estimateTxFee
+        :: DefineTx t
+        => WalletId
+        -> CoinSelectionOptions
+        -> NonEmpty TxOut
+        -> ExceptT ErrEstimateTxFee IO Fee
+    _estimateTxFee wid opts recipients = do
+        (w, _) <- withExceptT ErrEstimateTxFeeNoSuchWallet (_readWallet wid)
+        let utxo = availableUTxO @s @t w
+        (sel, _utxo') <- withExceptT ErrEstimateTxFeeCoinSelection $
+            CoinSelection.random opts recipients utxo
+        let estimateFee = computeFee feePolicy . estimateSize tl
+        pure $ estimateFee sel
+
     _signTx
         :: (Show s, NFData s, IsOwned s, GenChange s)
         => WalletId

lib/core/src/Cardano/Wallet/Api.hs

@@ -5,10 +5,12 @@ module Cardano.Wallet.Api where
 
 import Cardano.Wallet.Api.Types
     ( ApiAddress
+    , ApiFee
     , ApiT
     , ApiTransaction
     , ApiWallet
     , PostTransactionData
+    , PostTransactionFeeData
     , WalletPostData
     , WalletPutData
     , WalletPutPassphraseData
@@ -107,6 +109,7 @@ type PutWalletPassphrase = "wallets"
 
 type Transactions t =
     CreateTransaction t
+    :<|> PostTransactionFee t
 
 -- | https://input-output-hk.github.io/cardano-wallet/api/#operation/postTransaction
 type CreateTransaction t = "wallets"
@@ -115,6 +118,15 @@ type CreateTransaction t = "wallets"
     :> ReqBody '[JSON] (PostTransactionData t)
     :> PostAccepted '[JSON] (ApiTransaction t)
 
+
+-- | https://input-output-hk.github.io/cardano-wallet/api/#operation/postTransactionFee
+type PostTransactionFee t = "wallets"
+    :> Capture "walletId" (ApiT WalletId)
+    :> "transactions"
+    :> "fees"
+    :> ReqBody '[JSON] (PostTransactionFeeData t)
+    :> PostAccepted '[JSON] ApiFee
+
 {-------------------------------------------------------------------------------
                                    Internals
 -------------------------------------------------------------------------------}

lib/core/src/Cardano/Wallet/Api/Server.hs

@@ -29,6 +29,7 @@ import Cardano.Wallet
     ( ErrAdjustForFee (..)
     , ErrCoinSelection (..)
     , ErrCreateUnsignedTx (..)
+    , ErrEstimateTxFee (..)
     , ErrMkStdTx (..)
     , ErrNetworkUnreachable (..)
     , ErrNoSuchWallet (..)
@@ -47,10 +48,12 @@ import Cardano.Wallet.Api.Types
     ( AddressAmount (..)
     , ApiAddress (..)
     , ApiErrorCode (..)
+    , ApiFee (..)
     , ApiT (..)
     , ApiTransaction (..)
     , ApiWallet (..)
     , PostTransactionData
+    , PostTransactionFeeData
     , WalletBalance (..)
     , WalletPostData (..)
     , WalletPutData (..)
@@ -63,6 +66,8 @@ import Cardano.Wallet.Primitive.AddressDiscovery
     ( SeqState (..), defaultAddressPoolGap, mkSeqState )
 import Cardano.Wallet.Primitive.CoinSelection
     ( CoinSelectionOptions (..) )
+import Cardano.Wallet.Primitive.Fee
+    ( Fee (..) )
 import Cardano.Wallet.Primitive.Model
     ( availableBalance, getState, totalBalance )
 import Cardano.Wallet.Primitive.Types
@@ -367,7 +372,9 @@ transactions
     :: (DefineTx t, KeyToAddress t)
     => WalletLayer (SeqState t) t
     -> Server (Transactions t)
-transactions = createTransaction
+transactions w =
+    createTransaction w
+    :<|> postTransactionFee w
 
 createTransaction
     :: forall t. (DefineTx t, KeyToAddress t)
@@ -394,13 +401,30 @@ createTransaction w (ApiT wid) body = do
         , status = ApiT (meta ^. #status)
         }
   where
-    coerceCoin :: AddressAmount t -> TxOut
-    coerceCoin (AddressAmount (ApiT addr, _) (Quantity c)) =
-        TxOut addr (Coin $ fromIntegral c)
     coerceTxOut :: TxOut -> AddressAmount t
     coerceTxOut (TxOut addr (Coin c)) =
         AddressAmount (ApiT addr, Proxy @t) (Quantity $ fromIntegral c)
 
+coerceCoin :: AddressAmount t -> TxOut
+coerceCoin (AddressAmount (ApiT addr, _) (Quantity c)) =
+    TxOut addr (Coin $ fromIntegral c)
+
+postTransactionFee
+    :: forall t. (DefineTx t)
+    => WalletLayer (SeqState t) t
+    -> ApiT WalletId
+    -> PostTransactionFeeData t
+    -> Handler ApiFee
+postTransactionFee w (ApiT wid) body = do
+    -- FIXME Compute the options based on the transaction's size / inputs
+    let opts = CoinSelectionOptions { maximumNumberOfInputs = 10 }
+    let outs = coerceCoin <$> (body ^. #payments)
+    (Fee fee) <- liftHandler $ W.estimateTxFee w wid opts outs
+    return ApiFee
+        { amount = Quantity (fromIntegral fee)
+        }
+
+
 {-------------------------------------------------------------------------------
                                 Error Handling
 -------------------------------------------------------------------------------}
@@ -507,6 +531,11 @@ instance LiftHandler ErrCreateUnsignedTx where
         ErrCreateUnsignedTxCoinSelection e -> handler e
         ErrCreateUnsignedTxFee e -> handler e
 
+instance LiftHandler ErrEstimateTxFee where
+    handler = \case
+        ErrEstimateTxFeeNoSuchWallet e -> handler e
+        ErrEstimateTxFeeCoinSelection e -> handler e
+
 instance LiftHandler ErrSignTx where
     handler = \case
         ErrSignTx (ErrKeyNotFoundForAddress addr) ->

lib/core/src/Cardano/Wallet/Api/Types.hs

@@ -36,8 +36,10 @@ module Cardano.Wallet.Api.Types
     , WalletPutData (..)
     , WalletPutPassphraseData (..)
     , PostTransactionData (..)
+    , PostTransactionFeeData (..)
     , ApiBlockData (..)
     , ApiTransaction (..)
+    , ApiFee (..)
     , AddressAmount (..)
     , ApiErrorCode (..)
 
@@ -163,6 +165,14 @@ data PostTransactionData t = PostTransactionData
     , passphrase :: !(ApiT (Passphrase "encryption"))
     } deriving (Eq, Generic, Show)
 
+newtype PostTransactionFeeData t = PostTransactionFeeData
+    { payments :: (NonEmpty (AddressAmount t))
+    } deriving (Eq, Generic, Show)
+
+newtype ApiFee = ApiFee
+    { amount :: (Quantity "lovelace" Natural)
+    } deriving (Eq, Generic, Show)
+
 data ApiTransaction t = ApiTransaction
     { id :: !(ApiT (Hash "Tx"))
     , amount :: !(Quantity "lovelace" Natural)
@@ -292,6 +302,11 @@ instance FromJSON WalletPutPassphraseData where
 instance ToJSON  WalletPutPassphraseData where
     toJSON = genericToJSON defaultRecordTypeOptions
 
+instance FromJSON ApiFee where
+    parseJSON = genericParseJSON defaultRecordTypeOptions
+instance ToJSON ApiFee where
+    toJSON = genericToJSON defaultRecordTypeOptions
+
 instance (PassphraseMaxLength purpose, PassphraseMinLength purpose)
     => FromJSON (ApiT (Passphrase purpose)) where
     parseJSON = parseJSON >=> eitherToParser . bimap ShowFmt ApiT . fromText
@@ -354,6 +369,11 @@ instance DecodeAddress t => FromJSON (PostTransactionData t) where
 instance EncodeAddress t => ToJSON (PostTransactionData t) where
     toJSON = genericToJSON defaultRecordTypeOptions
 
+instance DecodeAddress t => FromJSON (PostTransactionFeeData t) where
+    parseJSON = genericParseJSON defaultRecordTypeOptions
+instance EncodeAddress t => ToJSON (PostTransactionFeeData t) where
+    toJSON = genericToJSON defaultRecordTypeOptions
+
 instance FromJSON (ApiT SlotId) where
     parseJSON = fmap ApiT . genericParseJSON defaultRecordTypeOptions
 instance ToJSON (ApiT SlotId) where

lib/core/test/data/Cardano/Wallet/Api/ApiFee.json

@@ -0,0 +1,65 @@
+{
+    "seed": 1702885383116510579,
+    "samples": [
+        {
+            "amount": {
+                "quantity": 201,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 29,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 77,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 188,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 130,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 248,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 251,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 3,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 117,
+                "unit": "lovelace"
+            }
+        },
+        {
+            "amount": {
+                "quantity": 196,
+                "unit": "lovelace"
+            }
+        }
+    ]
+}