Contract Source Code:

# @version 0.3.9

"""
@title Curve DCA Bot
@license Apache 2.0
@author Volume.finance
"""

struct Deposit:
    depositor: address
    route: address[9]
    swap_params: uint256[3][4]
    pools: address[4]
    input_amount: uint256
    number_trades: uint256
    interval: uint256
    remaining_counts: uint256
    starting_time: uint256

interface WrappedEth:
    def deposit(): payable

interface CurveSwapRouter:
    def exchange_multiple(
        _route: address[9],
        _swap_params: uint256[3][4],
        _amount: uint256,
        _expected: uint256,
        _pools: address[4]=[ZERO_ADDRESS, ZERO_ADDRESS, ZERO_ADDRESS, ZERO_ADDRESS],
        _receiver: address=msg.sender
    ) -> uint256: payable

interface ERC20:
    def balanceOf(_owner: address) -> uint256: view

VETH: constant(address) = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE # Virtual ETH
ROUTER: immutable(address)
MAX_SIZE: constant(uint256) = 8
compass_evm: public(address)
admin: public(address)
deposit_list: HashMap[uint256, Deposit]
next_deposit: public(uint256)
refund_wallet: public(address)
fee: public(uint256)
paloma: public(bytes32)
service_fee_collector: public(address)

event Deposited:
    deposit_id: uint256
    token0: address
    token1: address
    input_amount: uint256
    number_trades: uint256
    interval: uint256
    starting_time: uint256
    depositor: address

event Swapped:
    deposit_id: uint256
    remaining_counts: uint256
    amount: uint256
    out_amount: uint256

event Canceled:
    deposit_id: uint256

event UpdateCompass:
    old_compass: address
    new_compass: address

event UpdateRefundWallet:
    old_refund_wallet: address
    new_refund_wallet: address

event UpdateFee:
    old_fee: uint256
    new_fee: uint256

event SetPaloma:
    paloma: bytes32

event UpdateServiceFeeCollector:
    old_service_fee_collector: address
    new_service_fee_collector: address

@external
def __init__(_compass_evm: address, router: address, _refund_wallet: address, _fee: uint256, _service_fee_collector: address):
    self.compass_evm = _compass_evm
    ROUTER = router
    self.refund_wallet = _refund_wallet
    self.fee = _fee
    self.service_fee_collector = _service_fee_collector
    log UpdateCompass(empty(address), _compass_evm)
    log UpdateRefundWallet(empty(address), _refund_wallet)
    log UpdateFee(0, _fee)
    log UpdateServiceFeeCollector(empty(address), _service_fee_collector)

@internal
def _safe_transfer_from(_token: address, _from: address, _to: address, _value: uint256):
    _response: Bytes[32] = raw_call(
        _token,
        _abi_encode(_from, _to, _value, method_id=method_id("transferFrom(address,address,uint256)")),
        max_outsize=32
    )  # dev: failed transferFrom
    if len(_response) > 0:
        assert convert(_response, bool), "failed transferFrom"  # dev: failed transferFrom

@external
@payable
@nonreentrant('lock')
def deposit(route: address[9], swap_params: uint256[3][4], amount: uint256, pools: address[4], number_trades: uint256, interval: uint256, starting_time: uint256):
    _value: uint256 = msg.value
    _fee: uint256 = self.fee
    _fee = _fee * number_trades
    assert _value >= _fee, "Insufficient fee"
    send(self.refund_wallet, _fee)
    _value = unsafe_sub(_value, _fee)
    last_index: uint256 = 0
    for i in range(4):
        last_index = 8 - i * 2
        if route[last_index] != empty(address):
            break
    token1: address = route[last_index]
    if route[0] == VETH:
        assert _value >= amount, "Insufficient deposit"
        if _value > amount:
            send(msg.sender, unsafe_sub(_value, amount))
    else:
        send(msg.sender, _value)
        self._safe_transfer_from(route[0], msg.sender, self, amount)
    _next_deposit: uint256 = self.next_deposit
    _starting_time: uint256 = starting_time
    if starting_time <= block.timestamp:
        _starting_time = block.timestamp
    assert number_trades > 0, "Wrong trade count"
    self.deposit_list[_next_deposit] = Deposit({
        depositor: msg.sender,
        route: route,
        swap_params: swap_params,
        pools: pools,
        input_amount: amount,
        number_trades: number_trades,
        interval: interval,
        remaining_counts: number_trades,
        starting_time: _starting_time
    })
    log Deposited(_next_deposit, route[0], route[last_index], amount, number_trades, interval, _starting_time, msg.sender)
    _next_deposit += 1
    self.next_deposit = _next_deposit

@internal
def _safe_approve(_token: address, _to: address, _value: uint256):
    _response: Bytes[32] = raw_call(
        _token,
        _abi_encode(_to, _value, method_id=method_id("approve(address,uint256)")),
        max_outsize=32
    )  # dev: failed approve
    if len(_response) > 0:
        assert convert(_response, bool), "failed approve"  # dev: failed approve

@internal
def _safe_transfer(_token: address, _to: address, _value: uint256):
    _response: Bytes[32] = raw_call(
        _token,
        _abi_encode(_to, _value, method_id=method_id("transfer(address,uint256)")),
        max_outsize=32
    )  # dev: failed transfer
    if len(_response) > 0:
        assert convert(_response, bool) # dev: failed transfer

@internal
def _swap(deposit_id: uint256, remaining_count: uint256, amount_out_min: uint256) -> uint256:
    _deposit: Deposit = self.deposit_list[deposit_id]
    assert _deposit.remaining_counts > 0 and _deposit.remaining_counts == remaining_count, "wrong count"
    _amount: uint256 = _deposit.input_amount / _deposit.remaining_counts
    _deposit.input_amount -= _amount
    _deposit.remaining_counts -= 1
    self.deposit_list[deposit_id] = _deposit
    _out_amount: uint256 = 0
    last_index: uint256 = 0
    for i in range(4):
        last_index = 8 - i * 2
        if _deposit.route[last_index] != empty(address):
            break
    if _deposit.route[0] == VETH:
        _out_amount = CurveSwapRouter(ROUTER).exchange_multiple(_deposit.route, _deposit.swap_params, _amount, amount_out_min, _deposit.pools, self, value=_amount)
    else:
        self._safe_approve(_deposit.route[0], ROUTER, _amount)
        _out_amount = CurveSwapRouter(ROUTER).exchange_multiple(_deposit.route, _deposit.swap_params, _amount, amount_out_min, _deposit.pools, self)
    actual_amount: uint256 = 0
    if _deposit.route[last_index] == VETH:
        actual_amount = unsafe_div(_out_amount * 995, 1000)
        send(_deposit.depositor, actual_amount)
        send(self.service_fee_collector, unsafe_sub(_out_amount, actual_amount))
    else:
        actual_amount = unsafe_div(_out_amount * 995, 1000)
        self._safe_transfer(_deposit.route[last_index], _deposit.depositor, actual_amount)
        self._safe_transfer(_deposit.route[last_index], self.service_fee_collector, unsafe_sub(_out_amount, actual_amount))
    log Swapped(deposit_id, _deposit.remaining_counts, _amount, _out_amount)
    return _out_amount

@external
@nonreentrant('lock')
def multiple_swap(deposit_id: DynArray[uint256, MAX_SIZE], remaining_counts: DynArray[uint256, MAX_SIZE], amount_out_min: DynArray[uint256, MAX_SIZE]):
    assert msg.sender == self.compass_evm, "Unauthorized"
    _len: uint256 = len(deposit_id)
    assert _len == len(amount_out_min) and _len == len(remaining_counts), "Validation error"
    _len = unsafe_add(unsafe_mul(unsafe_add(_len, 2), 96), 36)
    assert len(msg.data) == _len, "invalid payload"
    assert self.paloma == convert(slice(msg.data, unsafe_sub(_len, 32), 32), bytes32), "invalid paloma"
    for i in range(MAX_SIZE):
        if i >= len(deposit_id):
            break
        self._swap(deposit_id[i], remaining_counts[i], amount_out_min[i])

@external
def multiple_swap_view(deposit_id: DynArray[uint256, MAX_SIZE], remaining_counts: DynArray[uint256, MAX_SIZE]) -> DynArray[uint256, MAX_SIZE]:
    assert msg.sender == empty(address) # only for view function
    _len: uint256 = len(deposit_id)
    res: DynArray[uint256, MAX_SIZE] = []
    for i in range(MAX_SIZE):
        if i >= len(deposit_id):
            break
        res.append(self._swap(deposit_id[i], remaining_counts[i], 1))
    return res

@external
@nonreentrant('lock')
def cancel(deposit_id: uint256):
    _deposit: Deposit = self.deposit_list[deposit_id]
    assert _deposit.depositor == msg.sender, "Unauthorized"
    assert _deposit.input_amount > 0, "all traded"
    if _deposit.route[0] == VETH:
        send(msg.sender, _deposit.input_amount)
    else:
        self._safe_transfer(_deposit.route[0], msg.sender, _deposit.input_amount)
    _deposit.input_amount = 0
    _deposit.remaining_counts = 0
    self.deposit_list[deposit_id] = _deposit
    log Canceled(deposit_id)

@external
def update_compass(new_compass: address):
    assert msg.sender == self.compass_evm and len(msg.data) == 68 and convert(slice(msg.data, 36, 32), bytes32) == self.paloma, "Unauthorized"
    self.compass_evm = new_compass
    log UpdateCompass(msg.sender, new_compass)

@external
def update_refund_wallet(new_refund_wallet: address):
    assert msg.sender == self.compass_evm and len(msg.data) == 68 and convert(slice(msg.data, 36, 32), bytes32) == self.paloma, "Unauthorized"
    old_refund_wallet: address = self.refund_wallet
    self.refund_wallet = new_refund_wallet
    log UpdateRefundWallet(old_refund_wallet, new_refund_wallet)

@external
def update_fee(new_fee: uint256):
    assert msg.sender == self.compass_evm and len(msg.data) == 68 and convert(slice(msg.data, 36, 32), bytes32) == self.paloma, "Unauthorized"
    old_fee: uint256 = self.fee
    self.fee = new_fee
    log UpdateFee(old_fee, new_fee)

@external
def set_paloma():
    assert msg.sender == self.compass_evm and self.paloma == empty(bytes32) and len(msg.data) == 36, "Invalid"
    _paloma: bytes32 = convert(slice(msg.data, 4, 32), bytes32)
    self.paloma = _paloma
    log SetPaloma(_paloma)

@external
def update_service_fee_collector(new_service_fee_collector: address):
    assert msg.sender == self.service_fee_collector, "Unauthorized"
    self.service_fee_collector = new_service_fee_collector
    log UpdateServiceFeeCollector(msg.sender, new_service_fee_collector)

@external
@payable
def __default__():
    assert msg.sender == ROUTER