From 671d42889a27deb953284dade363a5f2dda3545e Mon Sep 17 00:00:00 2001
From: Jackie <jackie_weiss@web.de>
Date: Tue, 12 Jul 2022 20:23:43 +0200
Subject: [PATCH] Add Wallet functionality

---
 ethers/wallet.nim | 127 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 ethers/wallet.nim

diff --git a/ethers/wallet.nim b/ethers/wallet.nim
new file mode 100644
index 0000000..4a58e85
--- /dev/null
+++ b/ethers/wallet.nim
@@ -0,0 +1,127 @@
+import eth/keys
+import eth/rlp
+import eth/common
+import eth/common/transaction as ct
+import stew/byteutils
+import ./providers/jsonrpc
+import ./transaction
+import ./signer
+
+export keys
+
+let rng = newRng()
+
+type SignableTransaction = common.Transaction
+
+type WalletError* = object of EthersError
+type Wallet* = ref object of Signer
+  privateKey*: PrivateKey
+  publicKey*: PublicKey
+  address*: Address
+  provider*: ?JsonRpcProvider
+
+proc new*(_: type Wallet, pk: string, provider: JsonRpcProvider): Wallet =
+  result = Wallet()
+  result.privateKey = PrivateKey.fromHex(pk).value
+  result.publicKey = result.privateKey.toPublicKey()
+  result.address = Address.init(result.publicKey.toCanonicalAddress())
+  result.provider = some provider
+proc new*(_: type Wallet, pk: string): Wallet =
+  result = Wallet()
+  result.privateKey = PrivateKey.fromHex(pk).value
+  result.publicKey = result.privateKey.toPublicKey()
+  result.address = Address.init(result.publicKey.toCanonicalAddress())
+proc connect*(wallet: Wallet, provider: JsonRpcProvider) =
+  wallet.provider = some provider
+proc createRandom*(_: type Wallet): Wallet =
+  result = Wallet()
+  result.privateKey = PrivateKey.random(rng[])
+  result.publicKey = result.privateKey.toPublicKey()
+  result.address = Address.init(result.publicKey.toCanonicalAddress())
+proc createRandom*(_: type Wallet, provider: JsonRpcProvider): Wallet =
+  result = Wallet()
+  result.privateKey = PrivateKey.random(rng[])
+  result.publicKey = result.privateKey.toPublicKey()
+  result.address = Address.init(result.publicKey.toCanonicalAddress())
+  result.provider = some provider
+
+method populateTransaction*(wallet: Wallet, tx: transaction.Transaction): Future[transaction.Transaction] {.async.} =
+  var populated = tx
+  if tx.nonce.isNone:
+    populated.nonce = some(await wallet.getTransactionCount(BlockTag.pending))
+  if tx.chainId.isNone:
+    populated.chainId = some(await wallet.getChainId())
+  if tx.gasLimit.isNone:
+    populated.gasLimit = some(await wallet.estimateGas(populated))
+  if tx.gasPrice.isNone and (tx.maxFee.isNone and tx.maxPriorityFee.isNone):
+    populated.gasPrice = some(await wallet.getGasPrice())
+  return populated
+
+func isPopulated(tx: transaction.Transaction) =
+  if tx.nonce.isNone or
+     tx.chainId.isNone or
+     tx.gasLimit.isNone or
+     (tx.gasPrice.isNone and (tx.maxFee.isNone or tx.maxPriorityFee.isNone)):
+    raise newException(WalletError, "Transaction is not properly populated")
+
+proc signTransaction(tr: var SignableTransaction, pk: PrivateKey) =
+  let h = tr.txHashNoSignature
+  let s = sign(pk, SkMessage(h.data))
+
+  let r = toRaw(s)
+  let v = r[64]
+
+  tr.R = fromBytesBe(UInt256, r.toOpenArray(0, 31))
+  tr.S = fromBytesBE(UInt256, r.toOpenArray(32, 63))
+
+  case tr.txType:
+  of TxLegacy:
+    #tr.V = int64(v) + int64(tr.chainId)*2 + 35  #TODO does not work, not sure why. Sending the tx results in error of too little funds. Maybe something wrong with signature and a wrong sender gets encoded?
+    tr.V = int64(v) + 27
+  of TxEip1559:
+    tr.V = int64(v)
+  else:
+    raise newException(WalletError, "Transaction type not supported")
+
+proc sendTransaction*(wallet: Wallet, tx: transaction.Transaction): Future[TransactionResponse] {.async.} =
+  if tx.sender.isSome:
+    doAssert tx.sender.get == wallet.address, "from Address mismatch"
+  isPopulated(tx)
+  var s: SignableTransaction
+  if tx.maxFee.isSome and tx.maxPriorityFee.isSome:
+    s.txType = TxEip1559
+    s.maxFee = GasInt(tx.maxFee.get.truncate(uint64))
+    s.maxPriorityFee = GasInt(tx.maxPriorityFee.get.truncate(uint64))
+  else:
+    s.txType = TxLegacy
+    s.gasPrice = GasInt(tx.gasPrice.get.truncate(uint64))
+  s.chainId = ChainId(tx.chainId.get.truncate(uint64))
+  s.gasLimit = GasInt(tx.gasLimit.get.truncate(uint64))
+  s.nonce = tx.nonce.get.truncate(uint64)
+  s.to = some EthAddress(tx.to)
+  s.payload = tx.data
+  signTransaction(s, wallet.privateKey)
+
+  let rawTX = "0x" & rlp.encode(s).toHex 
+  return await wallet.provider.get.sendRawTransaction(rawTX)
+
+proc signTransaction*(wallet: Wallet, tx: transaction.Transaction): Future[string] {.async.} =
+  if tx.sender.isSome:
+    doAssert tx.sender.get == wallet.address, "from Address mismatch"
+  isPopulated(tx)
+  var s: SignableTransaction
+  if tx.maxFee.isSome and tx.maxPriorityFee.isSome:
+    s.txType = TxEip1559
+    s.maxFee = GasInt(tx.maxFee.get.truncate(uint64))
+    s.maxPriorityFee = GasInt(tx.maxPriorityFee.get.truncate(uint64))
+  else:
+    s.txType = TxLegacy
+    s.gasPrice = GasInt(tx.gasPrice.get.truncate(uint64))
+  s.chainId = ChainId(tx.chainId.get.truncate(uint64))
+  s.gasLimit = GasInt(tx.gasLimit.get.truncate(uint64))
+  s.nonce = tx.nonce.get.truncate(uint64)
+  s.to = some EthAddress(tx.to)
+  s.payload = tx.data
+  signTransaction(s, wallet.privateKey)
+ 
+  return "0x" & rlp.encode(s).toHex
\ No newline at end of file