// SPDX-License-Identifier: MIT
pragma solidity ^0.8.21;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract NEscrow is Ownable {
    enum EscrowStatus { Created, Released, Refunded }

    struct Escrow {
        address sender;
        address recipient;
        uint256 amount;
        EscrowStatus status;
        uint256 refundTimestamp;
    }

    IERC20 public navisToken;
    mapping(bytes32 => Escrow) public escrows;

    event EscrowCreated(bytes32 indexed escrowId, address indexed sender, address indexed recipient, uint256 amount);
    event EscrowReleased(bytes32 indexed escrowId, address indexed sender, address indexed recipient, uint256 amount);
    event EscrowRefunded(bytes32 indexed escrowId, address indexed sender, address indexed recipient, uint256 amount);

    constructor(address _navisToken) {
        navisToken = IERC20(_navisToken);
    }

    modifier onlyParticipants(bytes32 escrowId) {
        Escrow storage escrow = escrows[escrowId];
        require(escrow.sender == msg.sender || escrow.recipient == msg.sender, "Not a participant");
        _;
    }

    modifier escrowNotReleased(bytes32 escrowId) {
        require(escrows[escrowId].status != EscrowStatus.Released, "Escrow already released");
        _;
    }

    modifier escrowNotRefunded(bytes32 escrowId) {
        require(escrows[escrowId].status != EscrowStatus.Refunded, "Escrow already refunded");
        _;
    }

    function createEscrow(bytes32 escrowId, address recipient, uint256 amount) external {
        require(recipient != address(0), "Invalid recipient address");
        require(amount > 0, "Amount must be greater than zero");

        Escrow storage escrow = escrows[escrowId];
        require(escrow.status == EscrowStatus.Created, "Escrow already exists");

        // Transfer NAVIS tokens to the escrow contract
        require(navisToken.transferFrom(msg.sender, address(this), amount), "Transfer failed");

        escrow.sender = msg.sender;
        escrow.recipient = recipient;
        escrow.amount = amount;
        escrow.status = EscrowStatus.Created;

        emit EscrowCreated(escrowId, msg.sender, recipient, amount);
    }

    function releaseEscrow(bytes32 escrowId) external onlyParticipants(escrowId) escrowNotReleased(escrowId) {
        Escrow storage escrow = escrows[escrowId];

        // Transfer NAVIS tokens to the recipient
        require(navisToken.transfer(escrow.recipient, escrow.amount), "Transfer failed");

        escrow.status = EscrowStatus.Released;

        emit EscrowReleased(escrowId, escrow.sender, escrow.recipient, escrow.amount);
    }

    function refundEscrow(bytes32 escrowId) external onlyParticipants(escrowId) escrowNotRefunded(escrowId) {
        Escrow storage escrow = escrows[escrowId];

        // Check if the refund timestamp has passed
        require(block.timestamp >= escrow.refundTimestamp, "Refund not allowed before the specified timestamp");

        // Transfer NAVIS tokens back to the sender
        require(navisToken.transfer(escrow.sender, escrow.amount), "Transfer failed");

        escrow.status = EscrowStatus.Refunded;

        emit EscrowRefunded(escrowId, escrow.sender, escrow.recipient, escrow.amount);
    }

    function setRefundTimestamp(bytes32 escrowId, uint256 newRefundTimestamp) external onlyOwner {
        Escrow storage escrow = escrows[escrowId];
        require(escrow.status == EscrowStatus.Created, "Refund timestamp can only be set for Created escrows");

        escrow.refundTimestamp = newRefundTimestamp;
    }

    function getEscrowDetails(bytes32 escrowId) external view returns (Escrow memory) {
        return escrows[escrowId];
    }
}