index.rsh

'reach 0.1';

export const main = Reach.App(() => {
  const Creator = Participant('Creator', {
    getSale: Fun([], Object({
        nftId: Token,
        minBid: UInt,
        lenInBlocks: UInt,
    })),
    auctionReady: Fun([], Null),
    seeBid: Fun([Address, UInt], Null),
    showOutcome: Fun([Address, UInt], Null),
    });
  const Bidder = API('Bidder', {
    bid: Fun([UInt], Tuple(Address, UInt)),
  });
  const V = View({
    min: UInt,
    nft: Token,
    currBid: UInt,
  });
  init();

  Creator.only(() => {
    const {nftId, minBid, lenInBlocks} = declassify(interact.getSale());
  });
  Creator.publish(nftId, minBid, lenInBlocks);
  const amt = 1;
  commit();
  Creator.pay([[amt, nftId]]);
  Creator.interact.auctionReady();
  V.nft.set(nftId);
  V.min.set(minBid);
  assert(balance(nftId) == amt, "balance of NFT is wrong");
  const end = lastConsensusTime() + lenInBlocks;
  const [highestBidder ,lastPrice, isFirstBid] = 
    parallelReduce([Creator, minBid, true])
    .define(() => {
      V.currBid.set(lastPrice);
    })
    .invariant(balance(nftId) == amt)
    .invariant(balance() == (isFirstBid ? 0 : lastPrice))
    .while(lastConsensusTime() <= end)
    .api_(Bidder.bid, (bid) => {
      check(bid > lastPrice, "bid is too low");
      return [ bid, (notify) => {
        notify([highestBidder, lastPrice]);
        if ( ! isFirstBid ) {
          transfer(lastPrice).to(highestBidder);
        }
        const who = this;
        Creator.interact.seeBid(who, bid);
        return [who, bid, false];
      }];
    })
    .timeout(absoluteTime(end), () => {
      Creator.publish();
      return [highestBidder, lastPrice, isFirstBid];
    });

  transfer(amt, nftId).to(highestBidder);
  if ( ! isFirstBid ) { transfer(lastPrice).to(Creator); }
  Creator.interact.showOutcome(highestBidder, lastPrice);
  commit();
  exit();
});