Y12 Safe Remote Purchase 1

ysrp1.sol

// Solidity by Example — Solidity 0.2.0 documentation  http://solidity.readthedocs.org/en/latest/solidity-by-example.html
// Ethereum以太坊智能合約環境說明 https://gist.github.com/y12studio/f142cd9789c7d396d8f7
//
// 1.賣家建立合約並放入價值商品2倍ETH當押金。 
// 2.買家確認賣家合約押金無誤，confirmPurchase()轉入與賣家等值押金。 
// 3.買家收到貨物後確認，confirmReceived()賣家收回押金加價金，買家收回押金減去價金。
//
// Testnet Address : 0x4378717cb207EB27BF2f58d8Bb2C2deA66B1BF43
// JSON Interface
// [ { "constant": true, "inputs": [], "name": "seller", "outputs": [ { "name": "", "type": "address", "value": "0x13a9684203635a4f03e9cb30befdc3e0f69e8163", "displayName": "" } ], "type": "function", "displayName": "seller" }, { "constant": false, "inputs": [], "name": "abort", "outputs": [], "type": "function", "displayName": "abort" }, { "constant": true, "inputs": [], "name": "value", "outputs": [ { "name": "", "type": "uint256", "value": "5000000000000000", "displayName": "" } ], "type": "function", "displayName": "value" }, { "constant": true, "inputs": [], "name": "buyer", "outputs": [ { "name": "", "type": "address", "value": "0xdb271e79b114348915b0d7fca557f5e42cc90da8", "displayName": "" } ], "type": "function", "displayName": "buyer" }, { "constant": false, "inputs": [], "name": "confirmReceived", "outputs": [], "type": "function", "displayName": "confirm Received" }, { "constant": true, "inputs": [], "name": "state", "outputs": [ { "name": "", "type": "uint8", "value": "2", "displayName": "" } ], "type": "function", "displayName": "state" }, { "constant": false, "inputs": [], "name": "confirmPurchase", "outputs": [], "type": "function", "displayName": "confirm Purchase" }, { "inputs": [], "type": "constructor" }, { "anonymous": false, "inputs": [], "name": "aborted", "type": "event" }, { "anonymous": false, "inputs": [], "name": "purchaseConfirmed", "type": "event" }, { "anonymous": false, "inputs": [], "name": "itemReceived", "type": "event" } ]
// 
contract YsrPurchase
{
    uint public value;
    address public seller;
    address public buyer;
    enum State { Created, Locked, Inactive }
    State public state;
    function YsrPurchase()
    {
        if(msg.value == 0 ) throw;
        seller = msg.sender;
        value = msg.value / 2;
        if (2 * value != msg.value) throw;
    }
   
    modifier onlyBuyer()
    {
        if (msg.sender != buyer) throw;
        _
    }
    modifier onlySeller()
    {
        if (msg.sender != seller) throw;
        _
    }
   
    event aborted();
    event purchaseConfirmed();
    event itemReceived();

    /// Abort the purchase and reclaim the ether.
    /// Can only be called by the seller before
    /// the contract is locked.
    function abort()
        onlySeller
    {
        if(state != State.Created) throw;
        aborted();
        seller.send(this.balance);
        state = State.Inactive;
    }
    /// Confirm the purchase as buyer.
    /// Transaction has to include `2 * value` ether.
    /// The ether will be locked until confirmReceived
    /// is called.
    function confirmPurchase()
    {
        if(state != State.Created) throw;
        if(msg.value != 2 * value) throw;
        purchaseConfirmed();
        buyer = msg.sender;
        state = State.Locked;
    }
    /// Confirm that you (the buyer) received the item.
    /// This will release the locked ether.
    function confirmReceived()
        onlyBuyer
    {
        if (state != State.Locked) throw;
        if (msg.value > 0) throw;
        itemReceived();
        buyer.send(value); // We ignore the return value on purpose
        seller.send(this.balance);
        state = State.Inactive;
    }
    function() { throw; }
}