Create lending_protocol.sol

blockchain_integration/pi_network/defi/lending_protocol.sol

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+contract LendingProtocol is Ownable {
+    struct Loan {
+        address borrower;
+        uint256 amount;
+        uint256 interestRate; // in basis points
+        uint256 duration; // in seconds
+        uint256 startTime;
+        bool isActive;
+    }
+
+    mapping(address => Loan) public loans;
+    IERC20 public stablecoin;
+
+    event LoanRequested(address indexed borrower, uint256 amount, uint256 interestRate, uint256 duration);
+    event LoanRepaid(address indexed borrower, uint256 amount);
+
+    constructor(IERC20 _stablecoin) {
+        stablecoin = _stablecoin;
+    }
+
+    // Request a loan
+    function requestLoan(uint256 _amount, uint256 _interestRate, uint256 _duration) public {
+        require(loans[msg.sender].isActive == false, "Existing loan must be repaid first.");
+        require(stablecoin.balanceOf(address(this)) >= _amount, "Insufficient liquidity.");
+
+        loans[msg.sender] = Loan(msg.sender, _amount, _interestRate, _duration, block.timestamp, true);
+        stablecoin.transfer(msg.sender, _amount);
+        emit LoanRequested(msg.sender, _amount, _interestRate, _duration);
+    }
+
+    // Repay the loan
+    function repayLoan() public {
+        Loan storage loan = loans[msg.sender];
+        require(loan.isActive, "No active loan found.");
+
+        uint256 totalRepayment = loan.amount + (loan.amount * loan.interestRate / 10000);
+        require(stablecoin.balanceOf(msg.sender) >= totalRepayment, "Insufficient repayment amount.");
+
+        stablecoin.transferFrom(msg.sender, address(this), totalRepayment);
+        loan.isActive = false;
+        emit LoanRepaid(msg.sender, totalRepayment);
+    }
+
+    // Get loan details
+    function getLoanDetails(address _borrower) public view returns (uint256, uint256, uint256, uint256, bool) {
+        Loan storage loan = loans[_borrower];
+        return (loan.amount, loan.interestRate, loan.duration, loan.startTime, loan.isActive);
+    }
+}