escrow_goods.sol

/* A contract to store goods with escrowed funds. */

/* Deployment:
Owner: seller
Last address: dynamic
Lib ABI: [{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"}],"name":"buy","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"}],"name":"getFees","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"yes","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"cancel","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"},{"name":"recipient","type":"address"},{"name":"amount","type":"uint256"}],"name":"reject","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"}],"name":"accept","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"who","type":"address"},{"name":"payment","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"arbYes","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"}],"name":"getMoney","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"}],"name":"unbuy","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"}],"name":"kill","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"data","type":"EscrowLib.Context storage"},{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"no","outputs":[],"type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"message","type":"string"}],"name":"log_event","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"lockid","type":"uint256"},{"indexed":false,"name":"datainfo","type":"string"},{"indexed":true,"name":"version","type":"uint256"},{"indexed":false,"name":"datatype","type":"uint256"},{"indexed":true,"name":"sender","type":"address"},{"indexed":false,"name":"count","type":"uint256"},{"indexed":false,"name":"payment","type":"uint256"}],"name":"content","type":"event"}]
ABI: [{"constant":false,"inputs":[{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"cancel","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"}],"name":"buy","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"}],"name":"getMoney","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"no","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"},{"name":"recipient","type":"address"},{"name":"amount","type":"uint256"}],"name":"reject","outputs":[],"type":"function"},{"constant":false,"inputs":[],"name":"kill","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"who","type":"address"},{"name":"payment","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"arbYes","outputs":[],"type":"function"},{"constant":true,"inputs":[],"name":"data","outputs":[{"name":"seller","type":"address"},{"name":"arbiter","type":"address"},{"name":"freezePeriod","type":"uint256"},{"name":"feePromille","type":"uint256"},{"name":"rewardPromille","type":"uint256"},{"name":"activityTime","type":"uint256"},{"name":"feeFunds","type":"uint256"},{"name":"totalEscrows","type":"uint256"},{"name":"status","type":"uint16"},{"name":"count","type":"uint16"},{"name":"price","type":"uint256"},{"name":"availableCount","type":"uint16"},{"name":"pendingCount","type":"uint16"},{"name":"atomicLock","type":"uint16"}],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"}],"name":"yes","outputs":[],"type":"function"},{"constant":false,"inputs":[{"name":"id","type":"uint256"},{"name":"datainfo","type":"string"},{"name":"_version","type":"uint256"},{"name":"_count","type":"uint16"}],"name":"accept","outputs":[],"type":"function"},{"constant":false,"inputs":[],"name":"unbuy","outputs":[],"type":"function"},{"constant":false,"inputs":[],"name":"getFees","outputs":[],"type":"function"},{"inputs":[{"name":"_arbiter","type":"address"},{"name":"_freezePeriod","type":"uint256"},{"name":"_feePromille","type":"uint256"},{"name":"_rewardPromille","type":"uint256"},{"name":"_count","type":"uint16"},{"name":"_price","type":"uint256"}],"type":"constructor"}]
Optimized: yes
Solidity version: v0.3.6-2016-08-12-9e03bda
*/

library EscrowLib {

    struct EscrowInfo {

        address buyer;
        uint lockedFunds;
        uint frozenTime;
        uint frozenFunds;
        uint buyerNo;
        uint sellerNo;
    }

    uint constant arbitragePeriod = 30 days;
    uint constant stalePeriod = 180 days;
    uint constant safeGas = 25000;

    struct Context {

          //seller/owner of the goods
          address seller;

          //escrow related

          address arbiter;

          uint freezePeriod;
          //each lock fee in promilles.
          uint feePromille;
          //reward in promilles. promille = percent * 10, eg 1,5% reward = 15 rewardPromille
          uint rewardPromille;

          uint activityTime;
          uint feeFunds;
          uint totalEscrows;

          mapping (uint => EscrowInfo) escrows;

          //goods related

          //status of the goods: Available, Pending, Sold, Canceled
          uint16 status;
          //how many for sale
          uint16 count;
          //price per item
          uint price;

          uint16 availableCount;
          uint16 pendingCount;

          mapping (address => uint) buyers;

          uint16 atomicLock;
    }

    event log_event(string message);
    event content(uint indexed lockid, string datainfo, uint indexed version, uint datatype, address indexed sender, uint count, uint payment);
    modifier onlyowner(Context storage data) { if (msg.sender == data.seller) _ }

    function kill(Context storage data) {

        //do not allow killing contract with active escrows
        if(data.totalEscrows > 0) {
            log_event("totalEscrows > 0");
            return;
        }
        //do not allow killing contract with unclaimed escrow fees
        if(data.feeFunds > 0) {
            log_event("feeFunds > 0");
            return;
        }
        //only allow the seller to kill contract
        if(msg.sender != data.seller) {
            log_event("msg.sender != data.seller");
            return;
        }
        suicide(msg.sender);
    }

    function safeSend(Context storage data, address addr, uint value) internal returns (bool) {

        if(data.atomicLock > 0) throw;
        data.atomicLock = 1;
        if (!(addr.call.gas(safeGas).value(value)())) {
            data.atomicLock = 0;
            return false;
        }
        data.atomicLock = 0;
        return true;
    }

    //escrow API

    //vote YES - immediately sends funds to the peer
    function yes(Context storage data, uint id, string datainfo, uint _version) {

        EscrowInfo info = data.escrows[id];

        if(info.lockedFunds == 0) {
            log_event("info.lockedFunds == 0");
            return;
        }
        if(msg.sender != info.buyer && msg.sender != data.seller) {
            log_event("msg.sender != info.buyer && msg.sender != data.seller");
            return;
        }

        uint payment = info.lockedFunds;
        if(payment > this.balance) {
            //HACK: should not get here - funds cannot be unlocked in this case
            log_event("payment > this.balance");
            return;
        }

        if(msg.sender == info.buyer) {
            //send funds to seller
            if(!safeSend(data, data.seller, payment)) {
                log_event("!safeSend(data, data.seller, payment)");
                return;
            }
        } else if(msg.sender == data.seller) {
            //send funds to buyer
            if(!safeSend(data, info.buyer, payment)) {
                log_event("!safeSend(data, info.buyer, payment)");
                return;
            }
        } else {
            //HACK: should not get here
            log_event("unknown msg.sender");
            return;
        }

        //remove record from escrows
        if(data.totalEscrows > 0) data.totalEscrows -= 1;
        info.lockedFunds = 0;

        content(id, datainfo, _version, 11, msg.sender, 0, payment);
    }

    //vote NO - freeze funds for arbitrage
    function no(Context storage data, uint id, string datainfo, uint _version) {

        EscrowInfo info = data.escrows[id];

        if(info.lockedFunds == 0) {
            log_event("info.lockedFunds == 0");
            return;
        }
        if(msg.sender != info.buyer && msg.sender != data.seller) {
            log_event("msg.sender != info.buyer && msg.sender != data.seller");
            return;
        }

        //freeze funds
        //only allow one time freeze
        if(info.frozenFunds == 0) {
            info.frozenFunds = info.lockedFunds;
            info.frozenTime = now;
        }

        if(msg.sender == info.buyer) {
            info.buyerNo = 1;
        }
        else if(msg.sender == data.seller) {
            info.sellerNo = 1;
        } else {
            //HACK: should not get here
            log_event("unknown msg.sender");
            return;
        }

        content(id, datainfo, _version, 12, msg.sender, 0, info.lockedFunds);
    }

    //arbiter's decision on the case.
    //arbiter can only decide when both buyer and seller voted NO
    //arbiter decides on his own reward but not bigger than announced percentage (rewardPromille)
    function arbYes(Context storage data, uint id, address who, uint payment, string datainfo, uint _version) {
        
        if(msg.sender != data.arbiter) return;

        EscrowInfo info = data.escrows[id];

        if(info.lockedFunds == 0) {
            log_event("info.lockedFunds == 0");
            return;
        }
        if(info.frozenFunds == 0) {
            log_event("info.frozenFunds == 0");
            return;
        }

        if(who != data.seller && who != info.buyer) {
            log_event("who != data.seller && who != info.buyer");
            return;
        }
        //requires both NO to arbitrage
        if(info.buyerNo == 0 || info.sellerNo == 0) {
            log_event("info.buyerNo == 0 || info.sellerNo == 0");
            return;
        }

        if(payment > info.lockedFunds) {
            log_event("payment > info.lockedFunds");
            return;
        }
        if(payment > this.balance) {
            //HACK: should not get here - funds cannot be unlocked in this case
            log_event("payment > this.balance");
            return;
        }

        //limit payment
        uint reward = (info.lockedFunds * data.rewardPromille) / 1000;
        if(reward > (info.lockedFunds - payment)) {
            log_event("reward > (info.lockedFunds - payment)");
            return;
        }

        //send funds to the winner
        if(!safeSend(data, who, payment)) {
            log_event("!safeSend(data, who, payment)");
            return;
        }

        //send the rest as reward
        info.lockedFunds -= payment;
        data.feeFunds += info.lockedFunds;
        info.lockedFunds = 0;

        content(id, datainfo, _version, 13, msg.sender, 0, payment);
    }

    //allow arbiter to get his collected fees
    function getFees(Context storage data) {

        if(msg.sender != data.arbiter) {
            log_event("msg.sender != data.arbiter");
            return;
        }
        if(data.feeFunds > this.balance) {
            //HACK: should not get here - funds cannot be unlocked in this case
            log_event("data.feeFunds > this.balance");
            return;
        }
        
        if(!safeSend(data, data.arbiter, data.feeFunds)) {
            log_event("!safeSend(data, data.arbiter, data.feeFunds)");
            return;
        }

        data.feeFunds = 0;
    }

    //allow buyer or seller take timeouted funds.
    //buyer can get funds if seller is silent and seller can get funds if buyer is silent (after freezePeriod)
    //buyer can get back funds under arbitrage if arbiter is silent (after arbitragePeriod)
    function getMoney(Context storage data, uint id) {

        EscrowInfo info = data.escrows[id];

        if(info.lockedFunds == 0) {
            log_event("info.lockedFunds == 0");
            return;
        }
        //HACK: this check is necessary since frozenTime == 0 at escrow creation
        if(info.frozenFunds == 0) {
            log_event("info.frozenFunds == 0");
            return;
        }

        //timout for voting not over yet
        if(now < (info.frozenTime + data.freezePeriod)) {
            log_event("now < (info.frozenTime + data.freezePeriod)");
            return;
        }

        uint payment = info.lockedFunds;
        if(payment > this.balance) {
            //HACK: should not get here - funds cannot be unlocked in this case
            log_event("payment > this.balance");
            return;
        }

        //both has voted - money is under arbitrage
        if(info.buyerNo != 0 && info.sellerNo != 0) {

            //arbitrage timeout is not over yet
            if(now < (info.frozenTime + data.freezePeriod + arbitragePeriod)) {
                log_event("now < (info.frozenTime + data.freezePeriod + arbitragePeriod)");
                return;
            }

            //arbiter was silent so redeem the funds to the buyer
            if(!safeSend(data, info.buyer, payment)) {
                log_event("!safeSend(data, info.buyer, payment)");
                return;
            }
            info.lockedFunds = 0;
            return;
        }

        if(info.buyerNo != 0) {

            if(!safeSend(data, info.buyer, payment)) {
                log_event("!safeSend(data, info.buyer, payment)");
                return;
            }
            info.lockedFunds = 0;
            return;
        }
        if(info.sellerNo != 0) {

            if(!safeSend(data, data.seller, payment)) {
                log_event("!safeSend(data, data.seller, payment)");
                return;
            }
            info.lockedFunds = 0;
            return;
        }
    }

    //goods API

    //buy with escrow. id - escrow info id
    function buy(Context storage data, uint id, string datainfo, uint _version, uint16 _count) {

        //reject money transfers for bad item status

        if(data.status != 1) throw;
        if(msg.value < (data.price * _count)) throw;
        if(_count > data.availableCount) throw;
        if(data.feePromille > 1000) throw;
        if(data.rewardPromille > 1000) throw;
        if((data.feePromille + data.rewardPromille) > 1000) throw;

        //create default EscrowInfo struct or access existing
        EscrowInfo info = data.escrows[id];

        //lock only once for a given id
        if(info.lockedFunds > 0) throw;

        //lock funds
        //refresh watchdog timer
        data.activityTime = now;

        uint fee = (msg.value * data.feePromille) / 1000;
        //limit fees
        if(fee > msg.value) throw;

        uint funds = (msg.value - fee);
        data.feeFunds += fee;
        data.totalEscrows += 1;

        info.buyer = msg.sender;
        info.lockedFunds = funds;
        info.frozenFunds = 0;
        info.buyerNo = 0;
        info.sellerNo = 0;

        data.pendingCount += _count;
        data.buyers[msg.sender] = 1;

        //Buy order to event log
        content(id, datainfo, _version, 1, msg.sender, _count, msg.value);
    }

    function accept(Context storage data, uint id, string datainfo, uint _version, uint16 _count) onlyowner(data) {
        
        if(_count > data.availableCount) {
            log_event("_count > availableCount");
            return;
        }
        if(_count > data.pendingCount) {
            log_event("_count > pendingCount");
            return;
        }

        data.pendingCount -= _count;
        data.availableCount -= _count;

        //Accept order to event log
        content(id, datainfo, _version, 2, msg.sender, _count, 0);
    }

    function reject(Context storage data, uint id, string datainfo, uint _version, uint16 _count, address recipient, uint amount) onlyowner(data) {
        
        if(_count > data.pendingCount) {
            log_event("_count > pendingCount");
            return;
        }

        data.pendingCount -= _count;

        //send money back
        yes(data, id, datainfo, _version);

        //Reject order to event log
        //HACK: "yes" call above may fail and this event will be non-relevant. Do not rely on it.
        content(id, datainfo, _version, 3, msg.sender, _count, amount);
    }

    function cancel(Context storage data, string datainfo, uint _version) onlyowner(data) {

        //Canceled data.status
        data.status = 2;

        //Cancel order to event log
        content(0, datainfo, _version, 4, msg.sender, data.availableCount, 0);
    }

    //remove buyer from the watchlist
    function unbuy(Context storage data) {

        data.buyers[msg.sender] = 0;
    }
}

contract escrow_goods {
    using EscrowLib for EscrowLib.Context;
    EscrowLib.Context public data;

    function escrow_goods(address _arbiter, uint _freezePeriod, uint _feePromille, uint _rewardPromille,
                          uint16 _count, uint _price) {

        data.seller = msg.sender;

        // all variables are always initialized to 0, save gas

        //escrow related
        data.arbiter = _arbiter;
        data.freezePeriod = _freezePeriod;
        data.feePromille = _feePromille;
        data.rewardPromille = _rewardPromille;

        data.activityTime = now;

        //goods related
        //status = Available
        data.status = 1;
        data.count = _count;
        data.price = _price;

        data.availableCount = data.count;
    }

    function kill() {
        data.kill();
    }

    //escrow API

    //vote YES - immediately sends funds to the peer
    function yes(uint id, string datainfo, uint _version) {
        data.yes(id, datainfo, _version);
    }

    //vote NO - freeze funds for arbitrage
    function no(uint id, string datainfo, uint _version) {
        data.no(id, datainfo, _version);
    }

    //arbiter's decision on the case.
    //arbiter can only decide when both buyer and seller voted NO
    //arbiter decides on his own reward but not bigger than announced percentage (rewardPromille)
    function arbYes(uint id, address who, uint payment, string datainfo, uint _version) {
      data.arbYes(id, who, payment, datainfo, _version);
    }

    //allow arbiter to get his collected fees
    function getFees() {
        data.getFees();
    }

    //allow buyer or seller take timeouted funds.
    //buyer can get funds if seller is silent and seller can get funds if buyer is silent (after freezePeriod)
    //buyer can get back funds under arbitrage if arbiter is silent (after arbitragePeriod)
    function getMoney(uint id) {
        data.getMoney(id);
    }

    //goods API

    //buy with escrow. id - escrow info id
    function buy(uint id, string datainfo, uint _version, uint16 _count) {
        data.buy(id, datainfo, _version, _count);
    }

    function accept(uint id, string datainfo, uint _version, uint16 _count) {
        data.accept(id, datainfo, _version, _count);
    }

    function reject(uint id, string datainfo, uint _version, uint16 _count, address recipient, uint amount) {
        data.reject(id, datainfo, _version, _count, recipient, amount);
    }

    function cancel(string datainfo, uint _version) {
        data.cancel(datainfo, _version);
    }

    //remove buyer from the watchlist
    function unbuy() {
        data.unbuy();
    }
}