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contracts...Marketplace.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;

contract ItemTransaction {
    address public owner;

    struct Buyer {
      uint depositAmount;
      bool isReported;
      bool exists;
    }
    mapping(address => Buyer) public buyers;
    address payable[] public buyersList;
    
    enum Status {
        UNPAID,
        ACTIVE,
        SOLD,
        REPORTED
    }
    Status public status;
    
    string public identifier;
    uint askingPrice;
    
    /* Seller methods */

    constructor(string memory _identifier, uint _askingPrice) payable {
      owner = msg.sender;
      status = Status.UNPAID;
      identifier = identifier;
      askingPrice = _askingPrice;
    }
  
    function listItemForSale() public payable {
      require(msg.sender == owner);
      require(status == Status.UNPAID);
      require(msg.value >= getSellerDepositCost());
      
      status = Status.ACTIVE;
    }
    
    function getSellerDepositCost() public view returns(uint){
        return askingPrice / 10;
    }
    
    function yieldBuyerDeposits() private {
        require(msg.sender == owner);
        
        for (uint i = 0; i < buyersList.length; i++) {
            address payable buyerAddress = buyersList[i];
            if (!buyers[buyerAddress].isReported) {
                buyerAddress.transfer(buyers[buyerAddress].depositAmount);
            }
        }
        status = Status.SOLD;
    }

    function confirmTransaction(address buyer) public {
        require(msg.sender == owner);
        require(status != Status.REPORTED);

        yieldBuyerDeposits();
        status = Status.SOLD;
    }
    
    function destroy() payable public {
        require(msg.sender == owner);
        require(status == Status.ACTIVE);
        
        yieldBuyerDeposits();
        selfdestruct(payable(owner));
    }
    
    function reportBuyer(address offendingBuyer) public {
        require(msg.sender == owner);
        
        buyers[offendingBuyer].isReported = true;
    }

    /* Buyer methods */
    
    function contactSellerToTransact() public payable {
        require(msg.sender != owner);
        require(status != Status.REPORTED && status != Status.SOLD);
        require(buyers[msg.sender].depositAmount >= getBuyerDepositCost() || msg.value >= getBuyerDepositCost());
        
        buyersList.push(payable(msg.sender));
        buyers[msg.sender] = Buyer({
            depositAmount: msg.value,
            isReported: false,
            exists: true
        });
    }
    
    function getBuyerDepositCost() public view returns(uint){
       return askingPrice / 100;
    }
    
    function confirmSuccessfulTransaction() public {
        require(msg.sender != owner);
        require(buyers[msg.sender].exists);

        yieldSellerDeposit();
    }
    
    function yieldSellerDeposit() private {
        require(status != Status.REPORTED);
        
        address payable sellerAddress = payable(owner);
        sellerAddress.transfer(getSellerDepositCost());
    }

    function reportSeller() public {
        require(msg.sender != owner);
        require(status == Status.ACTIVE);
        
        status = Status.REPORTED;
    }
}