Smart Escrow Implementation for Haggling System

// SPDX-License-Identifier: MIT pragma solidity ^0.8.17; /** * @title BayouBid HaggleEscrow * @notice Implements a trustless escrow for haggling on marketplace items * @dev This contract manages the full lifecycle of a haggle transaction */ contract HaggleEscrow { enum OfferStatus { Pending, Accepted, CounterOffered, Expired, Completed, Refunded } struct Offer { address buyer; address seller; uint256 itemId; uint256 offerAmount; uint256 counterOfferAmount; uint256 expiryTime; OfferStatus status; bool isEscrowFunded; } // Mapping from offerId to Offer mapping(uint256 => Offer) public offers; uint256 private nextOfferId = 1; // Platform fee percentage (0.5%) uint256 private constant PLATFORM_FEE_BPS = 50; // 50 basis points = 0.5% address private platformWallet; // Events event OfferSubmitted(uint256 indexed offerId, address indexed buyer, address indexed seller, uint256 itemId, uint256 amount, uint256 expiryTime); event OfferAccepted(uint256 indexed offerId, address indexed seller); event CounterOfferMade(uint256 indexed offerId, uint256 counterOfferAmount, uint256 newExpiryTime); event OfferCompleted(uint256 indexed offerId, uint256 finalAmount); event OfferRefunded(uint256 indexed offerId, string reason); event OfferExpired(uint256 indexed offerId); constructor(address _platformWallet) { platformWallet = _platformWallet; } /** * @notice Submit a new offer with funds in escrow * @param _seller The address of the item seller * @param _itemId The unique identifier of the item * @param _expiryTimeInHours Number of hours until the offer expires */ function submitOffer(address _seller, uint256 _itemId, uint256 _expiryTimeInHours) external payable returns (uint256) { require(_seller != address(0), "Invalid seller address"); require(_seller != msg.sender, "Cannot make offer on your own item"); require(msg.value > 0, "Offer amount must be greater than 0"); require(_expiryTimeInHours > 0, "Expiry time must be greater than 0"); uint256 expiryTime = block.timestamp + (_expiryTimeInHours * 1 hours); uint256 offerId = nextOfferId++; offers[offerId] = Offer({ buyer: msg.sender, seller: _seller, itemId: _itemId, offerAmount: msg.value, counterOfferAmount: 0, expiryTime: expiryTime, status: OfferStatus.Pending, isEscrowFunded: true }); emit OfferSubmitted(offerId, msg.sender, _seller, _itemId, msg.value, expiryTime); return offerId; } /** * @notice Accept an offer and release funds to the seller * @param _offerId The ID of the offer to accept */ function acceptOffer(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.seller, "Only seller can accept"); require(offer.status == OfferStatus.Pending, "Offer is not pending"); require(block.timestamp < offer.expiryTime, "Offer has expired"); require(offer.isEscrowFunded, "Escrow is not funded"); offer.status = OfferStatus.Accepted; // Calculate platform fee uint256 platformFee = (offer.offerAmount * PLATFORM_FEE_BPS) / 10000; uint256 sellerAmount = offer.offerAmount - platformFee; // Transfer funds (bool platformTransferSuccess, ) = platformWallet.call{value: platformFee}(""); require(platformTransferSuccess, "Platform fee transfer failed"); (bool sellerTransferSuccess, ) = offer.seller.call{value: sellerAmount}(""); require(sellerTransferSuccess, "Seller transfer failed"); offer.status = OfferStatus.Completed; offer.isEscrowFunded = false; emit OfferAccepted(_offerId, msg.sender); emit OfferCompleted(_offerId, offer.offerAmount); } /** * @notice Make a counter offer to the buyer * @param _offerId The ID of the offer to counter * @param _counterOfferAmount The counter offer amount * @param _additionalExpiryHours Additional hours to extend the expiry */ function makeCounterOffer( uint256 _offerId, uint256 _counterOfferAmount, uint256 _additionalExpiryHours ) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.seller, "Only seller can counter"); require(offer.status == OfferStatus.Pending, "Offer is not pending"); require(block.timestamp < offer.expiryTime, "Offer has expired"); require(_counterOfferAmount > offer.offerAmount, "Counter must be higher than offer"); offer.counterOfferAmount = _counterOfferAmount; offer.expiryTime = block.timestamp + (_additionalExpiryHours * 1 hours); offer.status = OfferStatus.CounterOffered; emit CounterOfferMade(_offerId, _counterOfferAmount, offer.expiryTime); } /** * @notice Accept a counter offer by paying the difference * @param _offerId The ID of the counter offer to accept */ function acceptCounterOffer(uint256 _offerId) external payable { Offer storage offer = offers[_offerId]; require(msg.sender == offer.buyer, "Only buyer can accept counter"); require(offer.status == OfferStatus.CounterOffered, "No counter offer exists"); require(block.timestamp < offer.expiryTime, "Counter offer has expired"); uint256 additionalAmount = offer.counterOfferAmount - offer.offerAmount; require(msg.value == additionalAmount, "Must pay exact difference amount"); // Update offer amount to the counter offer amount offer.offerAmount = offer.counterOfferAmount; offer.status = OfferStatus.Accepted; // Calculate platform fee uint256 platformFee = (offer.offerAmount * PLATFORM_FEE_BPS) / 10000; uint256 sellerAmount = offer.offerAmount - platformFee; // Transfer funds (bool platformTransferSuccess, ) = platformWallet.call{value: platformFee}(""); require(platformTransferSuccess, "Platform fee transfer failed"); (bool sellerTransferSuccess, ) = offer.seller.call{value: sellerAmount}(""); require(sellerTransferSuccess, "Seller transfer failed"); offer.status = OfferStatus.Completed; offer.isEscrowFunded = false; emit OfferCompleted(_offerId, offer.offerAmount); } /** * @notice Expire an offer and refund the buyer * @param _offerId The ID of the offer to expire */ function expireOffer(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(offer.status == OfferStatus.Pending || offer.status == OfferStatus.CounterOffered, "Offer must be pending or countered"); require(block.timestamp >= offer.expiryTime, "Offer has not expired yet"); require(offer.isEscrowFunded, "Escrow is not funded"); offer.status = OfferStatus.Expired; offer.isEscrowFunded = false; // Refund buyer (bool success, ) = offer.buyer.call{value: offer.offerAmount}(""); require(success, "Refund failed"); emit OfferExpired(_offerId); emit OfferRefunded(_offerId, "Offer expired"); } /** * @notice Cancel a pending offer (only buyer can cancel) * @param _offerId The ID of the offer to cancel */ function cancelOffer(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.buyer, "Only buyer can cancel"); require(offer.status == OfferStatus.Pending, "Offer must be pending"); require(offer.isEscrowFunded, "Escrow is not funded"); offer.status = OfferStatus.Refunded; offer.isEscrowFunded = false; // Refund buyer (bool success, ) = offer.buyer.call{value: offer.offerAmount}(""); require(success, "Refund failed"); emit OfferRefunded(_offerId, "Offer cancelled by buyer"); } /** * @notice Get offer details * @param _offerId The ID of the offer to query */ function getOfferDetails(uint256 _offerId) external view returns ( address buyer, address seller, uint256 itemId, uint256 offerAmount, uint256 counterOfferAmount, uint256 expiryTime, OfferStatus status, bool isEscrowFunded ) { Offer storage offer = offers[_offerId]; return ( offer.buyer, offer.seller, offer.itemId, offer.offerAmount, offer.counterOfferAmount, offer.expiryTime, offer.status, offer.isEscrowFunded ); } }

/** * @notice Update the contract to include an inspection period */ enum DeliveryStatus { Pending, Shipped, Delivered, Accepted, Disputed } struct Delivery { DeliveryStatus status; uint256 deliveryTimestamp; uint256 inspectionEndTimestamp; string disputeReason; } // Add to Offer struct // Delivery delivery; function markAsDelivered(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.seller, "Only seller can mark as delivered"); require(offer.status == OfferStatus.Accepted, "Offer must be accepted"); offer.delivery.status = DeliveryStatus.Delivered; offer.delivery.deliveryTimestamp = block.timestamp; offer.delivery.inspectionEndTimestamp = block.timestamp + (48 hours); // 48 hour inspection period emit ItemDelivered(_offerId, block.timestamp, offer.delivery.inspectionEndTimestamp); } function acceptDelivery(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.buyer, "Only buyer can accept delivery"); require(offer.delivery.status == DeliveryStatus.Delivered, "Item must be marked as delivered"); require(block.timestamp <= offer.delivery.inspectionEndTimestamp, "Inspection period expired"); offer.delivery.status = DeliveryStatus.Accepted; // Release funds to seller (similar to acceptOffer logic) // ... emit DeliveryAccepted(_offerId); } function disputeDelivery(uint256 _offerId, string calldata _reason) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.buyer, "Only buyer can dispute"); require(offer.delivery.status == DeliveryStatus.Delivered, "Item must be marked as delivered"); require(block.timestamp <= offer.delivery.inspectionEndTimestamp, "Inspection period expired"); offer.delivery.status = DeliveryStatus.Disputed; offer.delivery.disputeReason = _reason; emit DeliveryDisputed(_offerId, _reason); // This would trigger the dispute resolution process // We'd need to implement arbitration logic }

// Add to the contract to handle regulatory requirements // ESCROW TIMELOCK PARAMETERS uint256 private constant MIN_INSPECTION_PERIOD = 24 hours; // Minimum by consumer law in most regions uint256 private constant MAX_DISPUTE_WINDOW = 14 days; // Maximum time after delivery for disputes // Additional metadata for regulatory compliance struct ComplianceData { string itemDescription; string itemCondition; bytes32 imageHash; // IPFS hash of the item image for verification bool hasWarranty; uint256 warrantyPeriod; } // Add function to validate disputes based on evidence function submitEvidence(uint256 _offerId, string calldata _evidenceDescription, bytes32 _evidenceHash) external { // Only allow during active disputes // Store evidence on-chain for transparency // This creates an immutable record for arbitration } // Required for certain jurisdictions to allow cancellation within cooling-off period function mandatoryCoolingOff(uint256 _offerId) external { Offer storage offer = offers[_offerId]; require(msg.sender == offer.buyer, "Only buyer can invoke cooling-off"); // Check if within cooling-off period (varies by jurisdiction, typically 14 days) require(block.timestamp <= offer.acceptanceTimestamp + (14 days), "Cooling-off period expired"); // Implement refund logic with potential restocking fee as allowed by law // ... } // Function to generate a legally-binding receipt function generateReceipt(uint256 _offerId) external view returns (string memory) { // Generate a detailed receipt with all transaction details // Include timestamps and all relevant metadata // This is crucial for tax and consumer protection purposes }