added a crowd funding project

Author: dev-sumukha

CrowdFunding.sol

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >0.5.0 <= 0.9.0;
+
+contract CrowdFunding{
+    mapping(address => uint) contributors;
+    address public manager;
+    uint public minimumContribution;
+    uint public deadline;
+    uint public target;
+    uint public raisedAmount;
+    uint public noOfContributors;
+
+    struct Request{
+        string description;
+        address payable recipient;
+        uint value;
+        bool completed; // to check the transaction is completed or not
+        uint noOfVoters; // how many people voted towards it
+        mapping(address => bool)voters; // this is like voter list remember festival example for this
+    }       
+    mapping(uint => Request) requests;
+    uint public numRequest;
+
+    constructor(uint _target,uint _deadline)public{
+        target = _target;
+        manager = msg.sender;
+        deadline = block.timestamp + _deadline;
+        minimumContribution = 100 wei;
+    }
+
+    // users will transfer the ether to contract
+
+    function transferEth() payable public{
+        require(block.timestamp <= deadline,"You have already crossed deadline");
+        require(msg.value > minimumContribution,"Invalid Funds");
+
+        if(contributors[msg.sender] == 0){
+            noOfContributors++; // checking the user is donating for 1st time
+        }
+
+        raisedAmount = raisedAmount + msg.value;
+        contributors[msg.sender] = contributors[msg.sender] + msg.value;
+    }
+
+    function getBalance() public view returns(uint){
+        return address(this).balance;
+    }
+
+    function refund() public{
+        require(block.timestamp > deadline && raisedAmount < target,"You cannot get refund");
+        require(contributors[msg.sender] > 0,"You have not contributed");
+
+        address payable user = payable(msg.sender);
+        user.transfer(contributors[msg.sender]); // transferring the money
+
+        contributors[msg.sender] = 0; // resetting the amount to 0
+    }
+
+    modifier onlyManager(){
+        require(msg.sender == manager,"you are not authorised person");
+        _;
+    }
+
+    // creating the request OR generating the request
+    function createRequest(string memory _description,address payable _recipient,uint _value) public onlyManager{
+        Request storage newRequest = requests[numRequest];
+
+        numRequest++;
+
+        newRequest.description = _description;
+        newRequest.recipient = _recipient;
+        newRequest.value = _value;
+        newRequest.completed = false;
+        newRequest.noOfVoters = 0;
+    }  
+
+    function voteRequest(uint _requestNo) public{
+        require(contributors[msg.sender] > 0,"You have not contributed the money");
+        Request storage currRequest = requests[_requestNo];
+
+        // checking the voter is not voting twice
+        currRequest.voters[msg.sender] = true;
+        currRequest.noOfVoters++;
+    }
+
+    function makePayment(uint _requestNo) public onlyManager{
+        Request storage currRequest = requests[_requestNo];
+
+        require(currRequest.completed == false,"Payment has been done already");
+
+        // calculating the majority
+
+        require(currRequest.noOfVoters > (noOfContributors / 2),"No majority");
+        currRequest.recipient.transfer(currRequest.value);
+        
+    }
+}