Add functionality for transaction creation

CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.6.1.1]
 
+### Added
+
+- Type for transaction creation errors
+- Types for Sapling circuit parameters
+- Function to create transaction
+
 ### Changed
 
 - Add `Read` instance for `Rseed`

librustzcash-wrapper/src/lib.rs

@@ -1809,9 +1809,53 @@ pub extern "C" fn rust_wrapper_create_transaction(
             let h = Hhex {bytes: out_bytes};
             marshall_to_haskell_var(&h, out, out_len, RW);
         },
-        Err(_e) => {
+        Err(e) => {
-            let x = Hhex {bytes: vec![0]};
+            match e {
-            marshall_to_haskell_var(&x, out, out_len, RW);
+                Error::InsufficientFunds(_y) => {
+                    let x = Hhex {bytes: vec![0]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::ChangeRequired(_y1) => {
+                    let x = Hhex {bytes: vec![1]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::Fee(_y2) => {
+                    let x = Hhex {bytes: vec![2]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::Balance(x) => {
+                    let x = Hhex {bytes: vec![3]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::TransparentBuild(x) => {
+                    let x = Hhex {bytes: vec![4]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::SaplingBuild(x) => {
+                    let x = Hhex {bytes: vec![5]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::OrchardBuild(x) => {
+                    let x = Hhex {bytes: vec![6]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::OrchardSpend(x) => {
+                    let x = Hhex {bytes: vec![7]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::OrchardRecipient(x) => {
+                    let x = Hhex {bytes: vec![8]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::SaplingBuilderNotAvailable => {
+                    let x = Hhex {bytes: vec![9]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                },
+                Error::OrchardBuilderNotAvailable => {
+                    let x = Hhex {bytes: vec![10]};
+                    marshall_to_haskell_var(&x, out, out_len, RW);
+                }
+            }
         }
     }
 }

src/ZcashHaskell/Types.hs

@@ -692,6 +692,29 @@ data OutgoingNote = OutGoingNote
     deriving anyclass (Data.Structured.Show)
     deriving (BorshSize, ToBorsh, FromBorsh) via AsStruct OutgoingNote
 
+newtype SaplingSpendParams = SaplingSpendParams
+  { sapSParams :: BS.ByteString
+  } deriving newtype (Eq, Prelude.Show, Read)
+
+newtype SaplingOutputParams = SaplingOutputParams
+  { sapOParams :: BS.ByteString
+  } deriving newtype (Eq, Prelude.Show, Read)
+
+data TxError
+  = InsufficientFunds
+  | ChangeRequired
+  | Fee
+  | Balance
+  | TransparentBuild
+  | SaplingBuild
+  | OrchardBuild
+  | OrchardSpend
+  | OrchardRecipient
+  | SaplingBuilderNotAvailable
+  | OrchardBuilderNotAvailable
+  | ZHError
+  deriving (Eq, Prelude.Show, Read)
+
 -- * Classes
 -- | Class to represent types with a bytestring representation
 class ToBytes a where

src/ZcashHaskell/Utils.hs

@@ -19,8 +19,9 @@ module ZcashHaskell.Utils where
 
 import C.Zcash
   ( rustWrapperBech32Decode
-  , rustWrapperBech32mEncode
   , rustWrapperBech32Encode
+  , rustWrapperBech32mEncode
+  , rustWrapperCreateTx
   , rustWrapperF4Jumble
   , rustWrapperF4UnJumble
   , rustWrapperTxRead
@@ -31,7 +32,7 @@ import Data.Aeson
 import Data.Binary.Get
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Lazy as LBS
-import Data.HexString (HexString(..))
+import Data.HexString (HexString(..), toBytes)
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as E
 import Foreign.Rust.Marshall.Variable
@@ -121,3 +122,49 @@ readZebraTransaction hex =
   where
     rawTx = (withPureBorshVarBuffer . rustWrapperTxRead) $ hexBytes hex
 
+createTransaction ::
+     Maybe SaplingWitness -- ^ to obtain the Sapling anchor
+  -> Maybe OrchardWitness -- ^ to obtain the Orchard anchor
+  -> [TransparentTxSpend] -- ^ the list of transparent notes to spend
+  -> [SaplingTxSpend] -- ^ the list of Sapling notes to spend
+  -> [OrchardTxSpend] -- ^ the list of Orchard notes to spend
+  -> [OutgoingNote] -- ^ the list of outgoing notes, including change notes
+  -> SaplingSpendParams -- ^ the Sapling circuit spending parameters
+  -> SaplingOutputParams -- ^ the Sapling circuit output parameters
+  -> ZcashNet -- ^ the network to be used
+  -> Int -- ^ target block height
+  -> Either TxError HexString
+createTransaction sapAnchor orchAnchor tSpend sSpend oSpend outgoing sParams oParams znet bh =
+  if BS.length (hexBytes txResult) > 1
+    then Right txResult
+    else case head (BS.unpack $ hexBytes txResult) of
+           0 -> Left InsufficientFunds
+           1 -> Left ChangeRequired
+           2 -> Left Fee
+           3 -> Left Balance
+           4 -> Left TransparentBuild
+           5 -> Left SaplingBuild
+           6 -> Left OrchardBuild
+           7 -> Left OrchardSpend
+           8 -> Left OrchardRecipient
+           9 -> Left SaplingBuilderNotAvailable
+           10 -> Left OrchardBuilderNotAvailable
+           _ -> Left ZHError
+  where
+    txResult =
+      withPureBorshVarBuffer $
+      rustWrapperCreateTx
+        (case sapAnchor of
+           Nothing -> "0"
+           Just sA -> toBytes $ sapWit sA)
+        (case orchAnchor of
+           Nothing -> "0"
+           Just oA -> toBytes $ orchWit oA)
+        tSpend
+        sSpend
+        oSpend
+        outgoing
+        (sapSParams sParams)
+        (sapOParams oParams)
+        (znet == MainNet)
+        (fromIntegral bh)