open_auction2.vif

# Author: Haobin Ni, 2018
# Another simple open auction.
# Everyone can submit bids at any price.
# Everyone can end the auction after the end time.

beneficiary: IFL(address, beneficiary)
auction_start: IFL(timestamp, this)
auction_end: IFL(timestamp, this)
highest_bidder: IFL(address, this)
highest_bid: IFL(wei_value, this)
ended: IFL(bool, this)

@public
@IFL_beneficiary
def __init__(_beneficiary: address, _bidding_time: timedelta):
    self.beneficiary = _beneficiary
    self.auction_start = block.timestamp
    self.auction_end = self.auction_start + endorse(_bidding_time, beneficiary, this)

@public
@payable
@IFL_this
def bid():
    assert block.timestamp < self.auction_end
    assert msg.value > self.highest_bid
    if not self.highest_bid == 0:
        send(self.highest_bidder, self.highest_bid)
    self.highest_bidder = msg.sender
    self.highest_bid = msg.value


@public
@IFL_this
def end_auction():
    assert block.timestamp >= self.auction_end
    assert not self.ended
    self.ended = True
    send(endorse(self.beneficiary, beneficiary, this), self.highest_bid)