88 lines
2.8 KiB
Nim
88 lines
2.8 KiB
Nim
import std/macros
|
|
import pkg/chronos
|
|
import pkg/contractabi
|
|
import ./basics
|
|
import ./provider
|
|
|
|
export basics
|
|
export provider
|
|
|
|
type
|
|
Contract* = ref object of RootObj
|
|
provider: Provider
|
|
address: Address
|
|
ContractError* = object of IOError
|
|
|
|
template raiseContractError(message: string) =
|
|
raise newException(ContractError, message)
|
|
|
|
proc createTxData(function: string, parameters: tuple): seq[byte] =
|
|
let selector = selector(function, typeof parameters).toArray
|
|
return @selector & AbiEncoder.encode(parameters)
|
|
|
|
proc createTx(contract: Contract,
|
|
function: string,
|
|
parameters: tuple): Transaction =
|
|
Transaction(to: contract.address, data: createTxData(function, parameters))
|
|
|
|
proc decodeResponse(T: type, bytes: seq[byte]): T =
|
|
without decoded =? AbiDecoder.decode(bytes, T):
|
|
raiseContractError "unable to decode return value as " & $T
|
|
return decoded
|
|
|
|
proc call[ContractType: Contract, ResultType](
|
|
contract: ContractType,
|
|
function: string,
|
|
parameters: tuple):Future[ResultType] {.async.} =
|
|
let transaction = createTx(contract, function, parameters)
|
|
let response = await contract.provider.call(transaction)
|
|
return decodeResponse(ResultType, response)
|
|
|
|
func getParameterTuple(procedure: var NimNode): NimNode =
|
|
let parameters = procedure[3]
|
|
var tupl = newNimNode(nnkTupleConstr, parameters)
|
|
for parameter in parameters[2..^1]:
|
|
for name in parameter[0..^3]:
|
|
tupl.add name
|
|
return tupl
|
|
|
|
func addContractCall(procedure: var NimNode) =
|
|
let name = procedure[0]
|
|
let function = if name.kind == nnkPostfix: $name[1] else: $name
|
|
let parameters = procedure[3]
|
|
let contract = parameters[1][0]
|
|
let contracttype = parameters[1][1]
|
|
let resulttype = parameters[0]
|
|
let tupl = getParameterTuple(procedure)
|
|
procedure[6] = quote do:
|
|
return await call[`contracttype`,`resulttype`](`contract`, `function`, `tupl`)
|
|
|
|
func addFuture(procedure: var NimNode) =
|
|
let returntype = procedure[3][0]
|
|
if returntype.kind == nnkEmpty:
|
|
procedure[3][0] = quote do: Future[void]
|
|
else:
|
|
procedure[3][0] = quote do: Future[`returntype`]
|
|
|
|
func addAsyncPragma(procedure: var NimNode) =
|
|
let pragmas = procedure[4]
|
|
if pragmas.kind == nnkEmpty:
|
|
procedure[4] = newNimNode(nnkPragma)
|
|
procedure[4].add ident("async")
|
|
|
|
func new*(ContractType: type Contract,
|
|
address: Address,
|
|
provider: Provider): ContractType =
|
|
ContractType(provider: provider, address: address)
|
|
|
|
macro contract*(procedure: untyped{nkProcDef|nkMethodDef}): untyped =
|
|
let parameters = procedure[3]
|
|
let body = procedure[6]
|
|
parameters.expectMinLen(2)
|
|
body.expectKind(nnkEmpty)
|
|
var contractcall = copyNimTree(procedure)
|
|
contractcall.addContractCall()
|
|
contractcall.addFuture()
|
|
contractcall.addAsyncPragma()
|
|
contractcall
|