GoFundMe

ABI

[{"constant":true,"inputs":[],"name":"getTotalApprovalRequests","outputs":[{"name":"total","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"index","type":"uint256"}],"name":"getNumberOfSpendings","outputs":[{"name":"numSpendings","type":"uint256"},{"name":"numSpendingsOpen","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"index","type":"uint256"},{"name":"to","type":"address"},{"name":"amount","type":"uint256"},{"name":"receipt","type":"string"},{"name":"isOpen","type":"bool"}],"name":"spendDonations","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"index","type":"uint256"}],"name":"getCampaign","outputs":[{"name":"campaignName","type":"string"},{"name":"owner","type":"address"},{"name":"supportingDocuments","type":"string"},{"name":"totalDonations","type":"uint256[4]"},{"name":"times","type":"uint256[2]"},{"name":"campaignType","type":"string"},{"name":"requiredDonation","type":"uint256"},{"name":"donors","type":"address[]"},{"name":"donorsOpen","type":"address[]"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"index","type":"uint256"},{"name":"amount","type":"uint256"},{"name":"isOpen","type":"bool"}],"name":"donateTokens","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"index","type":"uint256"}],"name":"getPendingShareBack","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_donationTime","type":"uint256"},{"name":"_spendTime","type":"uint256"},{"name":"_requiredDonation","type":"uint256"},{"name":"_supportingDocuments","type":"string"},{"name":"_campaignType","type":"string"},{"name":"_campaignName","type":"string"}],"name":"startCampaign","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getMyCampaigns","outputs":[{"name":"indices","type":"uint256[]"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"id","type":"uint256"}],"name":"getApprovalReqeustDetail","outputs":[{"name":"amount","type":"uint256"},{"name":"approved","type":"bool"},{"name":"spendReceipt","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"campaignIndex","type":"uint256"},{"name":"spendingIndex","type":"uint256"},{"name":"isOpen","type":"bool"}],"name":"getSpendingDetail","outputs":[{"name":"amount","type":"uint256"},{"name":"to","type":"address"},{"name":"receipt","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"apporvalRequestId","type":"uint256"}],"name":"approveExpense","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"index","type":"uint256"},{"name":"donor","type":"address"}],"name":"getDonation","outputs":[{"name":"amount","type":"uint256"},{"name":"amountOpen","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"index","type":"uint256"}],"name":"endCampaign","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"erc20Address","type":"address"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":false,"name":"creator","type":"address"},{"indexed":false,"name":"campaignName","type":"string"},{"indexed":false,"name":"index","type":"uint256"},{"indexed":false,"name":"requiredDonation","type":"uint256"}],"name":"CampaignCreated","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"index","type":"uint256"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"donor","type":"address"}],"name":"TokensDonated","type":"event"}]

GoFundMeContract.sol

/**
 *Submitted for verification at Etherscan.io on 2020-02-14
*/

pragma solidity >=0.4.22 <0.6.0;

interface ERC20 {
    function balanceOf(address _owner) view external returns (uint balance);
    function transferFrom(address _from, address _to, uint _value) external returns (bool success);
    function approve(address _spender, uint _value) external returns (bool success);
    function allowance(address _owner, address _spender) external view returns (uint remaining);
    function decimals() external view returns(uint digits);
    function transfer(address recipient, uint256 amount) external returns (bool);
}

contract GoFundMe {
    
    address contractOwner;
    uint256 totalCampaigns;
    
    ERC20 erc20;
    uint256 decimal;
    
    struct SpendData {
        uint256 amount;
        string spendReceipt;
        address to;
        bool approved;
    }
    
    struct SpendingApprovals {
        uint256 campaignId;
        uint256 expenditureId;
        bool isOpen;
    }
    
    mapping(address => SpendingApprovals[]) recipientsToApprovals;
    
    struct Campaign {
        string campaignName;
        address owner;
        string supportingDocuments;
        uint256 donationEndTime;
        uint256 spendingEndTime;
        string campaignType;
        uint256 requiredDonation;
        
        uint256 totalDonation;
        uint256 totalDonationOpen;
        mapping(address => uint256) donations;
        mapping(address => uint256) donationsOpen;
        mapping(address => uint256) percentageDonation;
        mapping(address => uint256) percentageDonationsOpen;
        address[] donors;
        address[] donorsOpen;
    
        bool campaignEnded;
        bool moneyReturned;
        
        uint256 totalSpent;
        mapping(uint256 => SpendData) expenditures;
        uint256 numberOfSpendings;
        
        uint256 totalSpentOpen;
        mapping(uint256 => SpendData) expendituresOpen;
        uint256 numberOfSpendingsOpen;
    }
    
    Campaign[] campaigns;
    mapping(address => uint256[]) addressToCampaignIndices;
    
    event CampaignCreated(address creator, string campaignName, uint256 index, uint256 requiredDonation);
    event TokensDonated(uint256 index, uint256 amount, address donor);
    
    constructor(address erc20Address) public {
        contractOwner = msg.sender;
        totalCampaigns = 0;
        erc20 = ERC20(erc20Address);
        decimal = 2;
    }

    function startCampaign(uint256 _donationTime, uint256 _spendTime, uint256 _requiredDonation, string memory _supportingDocuments, string memory _campaignType, string memory _campaignName) public{
        uint256 currentIndex = totalCampaigns++;
        Campaign memory campaign;
        campaign.owner = msg.sender;
        campaign.campaignName = _campaignName;
        campaign.campaignType = _campaignType;
        campaign.donationEndTime = now + _donationTime;
        campaign.spendingEndTime = now + _spendTime;
        campaign.requiredDonation = _requiredDonation;
        campaign.supportingDocuments = _supportingDocuments;
        campaign.campaignEnded = false;
        campaign.moneyReturned = false;
        campaign.numberOfSpendings = 0;
        campaign.totalSpent = 0;
        
        campaign.numberOfSpendingsOpen = 0;
        campaign.totalSpentOpen = 0;
        
        campaigns.push(campaign);
        
        addressToCampaignIndices[msg.sender].push(currentIndex);
        
        emit CampaignCreated(msg.sender, _campaignName, currentIndex, _requiredDonation);
    } 
    
    function getCampaign(uint256 index) public view returns(
        string memory campaignName, 
        address owner, 
        string memory supportingDocuments,
        uint256[4] totalDonations,
        uint256[2] memory times,
        string memory campaignType, 
        uint256 requiredDonation,
        address[] memory donors,
        address[] memory donorsOpen
        ){
            Campaign memory currentCampaign = campaigns[index];
            campaignName = currentCampaign.campaignName;
            owner = currentCampaign.owner;
            supportingDocuments = currentCampaign.supportingDocuments;
            totalDonations[0] = currentCampaign.totalDonation;
            totalDonations[1] = currentCampaign.totalDonationOpen;
            totalDonations[2] = currentCampaign.totalSpent;
            totalDonations[3] = currentCampaign.totalSpentOpen;
            times[0] = currentCampaign.donationEndTime;
            times[1] = currentCampaign.spendingEndTime;
            campaignType = currentCampaign.campaignType;
            requiredDonation = currentCampaign.requiredDonation;
            donors = currentCampaign.donors;
            donorsOpen = currentCampaign.donorsOpen;
        }
        
    function donateTokens(uint256 index, uint256 amount, bool isOpen) public {
        Campaign storage currentCampaign = campaigns[index];
        require(now <= currentCampaign.donationEndTime, "This campaign is not accepting donations now");
        
        safeTransfer(msg.sender, address(this), amount);
        
        if(isOpen == true){
            currentCampaign.totalDonationOpen += amount;
            if(currentCampaign.donationsOpen[msg.sender] == 0){
                currentCampaign.donorsOpen.push(msg.sender);
            }
            currentCampaign.donationsOpen[msg.sender] += amount;    
        }else{
            currentCampaign.totalDonation += amount;
            if(currentCampaign.donations[msg.sender] == 0){
                currentCampaign.donors.push(msg.sender);
            }
            currentCampaign.donations[msg.sender] += amount;   
        }
        
        emit TokensDonated(index, amount, msg.sender);
    }
    
    function getMyCampaigns() public view returns(uint256[] indices){
        indices = addressToCampaignIndices[msg.sender];
    }
    
    function getDonation(uint256 index, address donor) public view returns(uint256 amount, uint256 amountOpen){
        Campaign storage currentCampaign = campaigns[index];
        amount = currentCampaign.donations[donor];
        amountOpen = currentCampaign.donationsOpen[donor];
    }
        
    function safeTransfer(address _from, address _to, uint256 _amount) private {
        require(erc20.balanceOf(_from) >= _amount, "Sender Does Not Hold Enough Tokens");
        require(erc20.allowance(_from, address(this)) >= _amount, "Sender Has Not Provided Enough Allowance to the Contract");
        erc20.transferFrom(_from, _to, _amount);
    }
    
    function endCampaign(uint256 index) public {
        Campaign storage currentCampaign = campaigns[index];
        require(now > currentCampaign.donationEndTime, "Campaign can not be closed yet");
        require(currentCampaign.owner == msg.sender, "Not the Owner of this campaign");
        calculatePercentage(index);
    }
    
    function calculatePercentage(uint256 index) private {
        Campaign storage currentCampaign = campaigns[index];
        require(currentCampaign.campaignEnded == false, "Campaign has already ended");
        address[] memory donors = currentCampaign.donors;
        uint256 totalDonation = currentCampaign.totalDonation;
        
        for(uint256 i = 0; i < donors.length; i++){
            currentCampaign.percentageDonation[donors[i]] = (totalDonation * 10 ** decimal) / currentCampaign.donations[donors[i]];
        }
        
        donors = currentCampaign.donorsOpen;
        totalDonation = currentCampaign.totalDonationOpen;
        
        for(i = 0; i < donors.length; i++){
            currentCampaign.percentageDonationsOpen[donors[i]] = (totalDonation * 10 ** decimal) / currentCampaign.donationsOpen[donors[i]];
        }
        
        currentCampaign.campaignEnded = true;
    }
    
    function spendDonations(uint256 index, address to, uint256 amount, string receipt, bool isOpen) public{
        Campaign storage currentCampaign = campaigns[index];
        require(now <= currentCampaign.spendingEndTime, "Spend Time is Closed");
        
        SpendData memory currentSpend;
        currentSpend.to = to;
        currentSpend.spendReceipt = receipt;
        currentSpend.amount = amount;
        currentSpend.approved = false;
        
        SpendingApprovals memory currentApproval;
        currentApproval.campaignId = index;
        
        uint256 expenditureId;
        
        if(isOpen == true){
            require(currentCampaign.totalSpentOpen + amount <= currentCampaign.totalDonationOpen, "You have used all your donation");    
            expenditureId = currentCampaign.numberOfSpendingsOpen++;
            currentCampaign.expendituresOpen[expenditureId] = currentSpend;
            currentCampaign.totalSpentOpen += amount;
            currentApproval.isOpen = true;
            currentApproval.expenditureId = expenditureId;
        }else{
            
            //TODO Write a check for KYC
            
            require(currentCampaign.totalSpent + amount <= currentCampaign.totalDonation, "You have used all your donation");    
            expenditureId = currentCampaign.numberOfSpendingsOpen++;
            currentCampaign.expenditures[expenditureId] = currentSpend;
            currentCampaign.totalSpent += amount;
            currentApproval.isOpen = false;
            currentApproval.expenditureId = expenditureId;
        }
        
        recipientsToApprovals[to].push(currentApproval);
    }
    
    function approveExpense(uint256 apporvalRequestId) public{
        SpendingApprovals storage currentApproval = recipientsToApprovals[msg.sender][apporvalRequestId];
        Campaign storage currentCampaign = campaigns[currentApproval.campaignId];
            
        if(currentApproval.isOpen){
            SpendData storage currentSpend = currentCampaign.expendituresOpen[currentApproval.expenditureId];
        } else{
            currentSpend = currentCampaign.expenditures[currentApproval.expenditureId];
        }
        
        require(currentSpend.approved == false, "Expense Already Approved");
        require(currentSpend.to == msg.sender, "Sender is not recipient of this Expense");
        
        currentSpend.approved = true;
        
        erc20.transfer(currentSpend.to, currentSpend.amount);
        
    }
    
    function getTotalApprovalRequests() public view returns(uint256 total){
        total = recipientsToApprovals[msg.sender].length;
    }
    
    function getApprovalReqeustDetail(uint256 id) public view returns(uint256 amount, bool approved, string spendReceipt){
        SpendingApprovals storage currentApproval = recipientsToApprovals[msg.sender][id];
        Campaign storage currentCampaign = campaigns[currentApproval.campaignId];
        SpendData storage currentSpend;
        if(currentApproval.isOpen == true){
            currentSpend = currentCampaign.expendituresOpen[currentApproval.expenditureId];
        }else{
            currentSpend = currentCampaign.expenditures[currentApproval.expenditureId];
        }
        
        amount = currentSpend.amount;
        approved = currentSpend.approved;
        spendReceipt = currentSpend.spendReceipt;
    }
    
    function getNumberOfSpendings(uint256 index) public view returns(uint256 numSpendings, uint256 numSpendingsOpen){
        Campaign storage currentCampaign = campaigns[index];
        numSpendings = currentCampaign.numberOfSpendings;
        numSpendingsOpen = currentCampaign.numberOfSpendingsOpen;
    }
    
    function getSpendingDetail(uint256 campaignIndex, uint256 spendingIndex, bool isOpen) public view returns(uint256 amount, address to, string receipt){
        Campaign storage currentCampaign = campaigns[campaignIndex];
        SpendData storage currentSpend = currentCampaign.expenditures[spendingIndex];
        
        if(isOpen == true){
             currentSpend = currentCampaign.expendituresOpen[spendingIndex];
        }
        
        amount = currentSpend.amount;
        to = currentSpend.to;
        receipt = currentSpend.spendReceipt;
    }
    
    function getPendingShareBack(uint256 index) public {
        Campaign storage currentCampaign = campaigns[index];
        require(now > currentCampaign.spendingEndTime, "The Campaign Owner is still spending money");
        require(currentCampaign.moneyReturned == false, "Share is already returned");
        
        uint256 leftAmount = currentCampaign.totalDonation - currentCampaign.totalSpent;
        address[] memory donors = currentCampaign.donors;
        
        for(uint256 i = 0; i < donors.length; i++){
            uint256 donorPercentage = getDonationPercentage(index, donors[i], false);
            uint256 toBeReturned = (leftAmount * 10 ** decimal) / donorPercentage;
            erc20.transfer(donors[i], toBeReturned);
        }
        
        leftAmount = currentCampaign.totalDonationOpen - currentCampaign.totalSpentOpen;
        donors = currentCampaign.donorsOpen;
        
        for(i = 0; i < donors.length; i++){
            donorPercentage = getDonationPercentage(index, donors[i], true);
            toBeReturned = (leftAmount * 10 ** decimal) / donorPercentage;
            erc20.transfer(donors[i], toBeReturned);
        }
        
        currentCampaign.moneyReturned = true;
    }
    
    function getDonationPercentage(uint256 index, address donor, bool isOpen) private view returns(uint256 percentage){
        if(isOpen == true){
            percentage = campaigns[index].percentageDonationsOpen[donor];
        }else{
            percentage = campaigns[index].percentageDonation[donor];    
        }
    }
}