Contract Source Code (Vyper language format)

IDE

• Blockscan IDE
• 🤖 Code ReaderBeta
• Remix IDE

More Options

• Similar
• Submit Audit
• Compare

# @version 0.3.3
"""
@title YFI Buyer
@license MIT
@author banteg
@notice
    Buy YFI for DAI at the current Chainlink price.

    New in v0.2.0
    - Accept and release a LlamaPay stream on buy
"""
from vyper.interfaces import ERC20

YFI: constant(address) = 0x0bc529c00C6401aEF6D220BE8C6Ea1667F6Ad93e
DAI: constant(address) = 0x6B175474E89094C44Da98b954EedeAC495271d0F
YFI_USD: constant(address) = 0xA027702dbb89fbd58938e4324ac03B58d812b0E1
LLAMAPAY: constant(address) = 0x60c7B0c5B3a4Dc8C690b074727a17fF7aA287Ff2

STALE_AFTER: constant(uint256) = 3600

admin: public(address)
treasury: public(address)
rate: public(uint216)

struct ChainlinkRound:
    roundId: uint80
    answer: int256
    startedAt: uint256
    updatedAt: uint256
    answeredInRound: uint80

interface Chainlink:
    def latestRoundData() -> ChainlinkRound: view

struct Withdrawable:
    amount: uint256
    last_update: uint256
    owed: uint256

interface LlamaPay:
    def withdraw(source: address, target: address, rate: uint216): nonpayable
    def withdrawable(source: address, target: address, rate: uint216) -> Withdrawable: view

event Buyback:
    buyer: indexed(address)
    yfi: uint256
    dai: uint256

event UpdateAdmin:
    admin: indexed(address)

event UpdateTreasury:
    treasury: indexed(address)

event UpdateRate:
    rate: indexed(uint216)


@external
def __init__():
    self.admin = msg.sender
    self.treasury = msg.sender
    
    log UpdateAdmin(msg.sender)
    log UpdateTreasury(msg.sender)


@view
@internal
def withdrawable() -> uint256:
    if self.rate != 0:
        return LlamaPay(LLAMAPAY).withdrawable(self.admin, self, self.rate).amount
    return 0


@external
def buy_dai(yfi_amount: uint256):
    oracle: ChainlinkRound = Chainlink(YFI_USD).latestRoundData()
    assert oracle.updatedAt + STALE_AFTER > block.timestamp  # dev: stale oracle

    if self.rate != 0:
        LlamaPay(LLAMAPAY).withdraw(self.admin, self, self.rate)

    dai_amount: uint256 = convert(oracle.answer, uint256) * yfi_amount / 10 ** 8

    assert ERC20(YFI).transferFrom(msg.sender, self.treasury, yfi_amount)  # dev: no allowance
    assert ERC20(DAI).transfer(msg.sender, dai_amount)  # dev: not enough dai

    log Buyback(msg.sender, yfi_amount, dai_amount)


@view
@external
def price() -> uint256:
    oracle: ChainlinkRound = Chainlink(YFI_USD).latestRoundData()
    return convert(oracle.answer, uint256) * 10 ** 10


@view
@external
def total_dai() -> uint256:
    return ERC20(DAI).balanceOf(self) + self.withdrawable()


@view
@external
def max_amount() -> uint256:
    oracle: ChainlinkRound = Chainlink(YFI_USD).latestRoundData()
    amount: uint256 = ERC20(DAI).balanceOf(self) + self.withdrawable()
    return amount / convert(oracle.answer, uint256) * 10 ** 8


@external
def sweep(token: address, amount: uint256 = MAX_UINT256):
    assert msg.sender == self.admin
    value: uint256 = amount
    if value == MAX_UINT256:
        value = ERC20(token).balanceOf(self)
    
    assert ERC20(token).transfer(self.admin, value)


@external
def set_admin(proposed_admin: address):
    assert msg.sender == self.admin
    self.admin = proposed_admin

    log UpdateAdmin(proposed_admin)


@external
def set_treasury(new_treasury: address):
    assert msg.sender == self.admin
    self.treasury = new_treasury

    log UpdateTreasury(new_treasury)


@external
def set_rate(new_rate: uint216):
    assert msg.sender == self.admin
    self.rate = new_rate

    log UpdateRate(new_rate)

• No Contract Security Audit Submitted- Submit Audit Here

[{"name":"Buyback","inputs":[{"name":"buyer","type":"address","indexed":true},{"name":"yfi","type":"uint256","indexed":false},{"name":"dai","type":"uint256","indexed":false}],"anonymous":false,"type":"event"},{"name":"UpdateAdmin","inputs":[{"name":"admin","type":"address","indexed":true}],"anonymous":false,"type":"event"},{"name":"UpdateTreasury","inputs":[{"name":"treasury","type":"address","indexed":true}],"anonymous":false,"type":"event"},{"name":"UpdateRate","inputs":[{"name":"rate","type":"uint216","indexed":true}],"anonymous":false,"type":"event"},{"stateMutability":"nonpayable","type":"constructor","inputs":[],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"buy_dai","inputs":[{"name":"yfi_amount","type":"uint256"}],"outputs":[]},{"stateMutability":"view","type":"function","name":"price","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"total_dai","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"max_amount","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"sweep","inputs":[{"name":"token","type":"address"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"sweep","inputs":[{"name":"token","type":"address"},{"name":"amount","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_admin","inputs":[{"name":"proposed_admin","type":"address"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_treasury","inputs":[{"name":"new_treasury","type":"address"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_rate","inputs":[{"name":"new_rate","type":"uint216"}],"outputs":[]},{"stateMutability":"view","type":"function","name":"admin","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"treasury","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"rate","inputs":[],"outputs":[{"name":"","type":"uint216"}]}]

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