资金使用的理想流程

graph LR
    subgraph 理想的善款使用流程
        A[捐赠者] -- 捐款 --> B(慈善组织)
        B -- 项目申报/预算 --> C(项目评审委员会)
        C -- 审批 --> D(资金分配)
        D -- 项目执行 --> E(受助者/项目成果)
        E -- 信息反馈 --> F(信息披露)
        F -- 公众监督/审计 --> A
    end

graph LR
    subgraph 基于区块链的善款使用系统
        A[捐赠者] -- 捐款 --> B(智能合约)
        B -- 项目申报 --> C(DAO/多签钱包)
        C -- 投票/审批 --> D(资金分配)
        D -- 项目执行 --> E(受助者/项目成果)
        E -- 信息反馈 --> F(链上数据)
        F -- 公众监督/审计 --> A
    end

    subgraph 区块链
        B
        C
        F
    end

pragma solidity ^0.8.0;

// 定义一个Token合约
interface IERC20 {
    function transfer(address recipient, uint256 amount) external returns (bool);
    function balanceOf(address account) external view returns (uint256);
     function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}

contract TransparentCharity {

    struct Project {
        string name;
        string description;
        uint targetAmount;
        uint raisedAmount;
        address payable beneficiary; // 项目受益人地址
        bool approved;
        bool completed;
    }

    mapping(uint => Project) public projects;
    uint public projectCounter;
    IERC20 public donationToken; // 使用ERC20 代币

    event ProjectCreated(uint indexed projectId, string name);
    event ProjectApproved(uint indexed projectId);
    event DonationReceived(address indexed donor, uint indexed projectId, uint amount);
    event FundsDisbursed(uint indexed projectId, address indexed beneficiary, uint amount);

    // DAO 地址或多签钱包地址
    address public daoOrMultisig;

    constructor(address _donationToken, address _daoOrMultisig) {
        donationToken = IERC20(_donationToken);
        daoOrMultisig = _daoOrMultisig;
        projectCounter = 0;
    }

    // 创建项目
    function createProject(string memory _name, string memory _description, uint _targetAmount, address payable _beneficiary) public {
        projectCounter++;
        projects[projectCounter] = Project(_name, _description, _targetAmount, 0, _beneficiary, false, false);
        emit ProjectCreated(projectCounter, _name);
    }

    // 项目审批 (由DAO或多签钱包调用)
    function approveProject(uint _projectId) public {
        require(msg.sender == daoOrMultisig, "Only DAO or Multisig can approve projects.");
        projects[_projectId].approved = true;
        emit ProjectApproved(_projectId);
    }

    // 捐款
       function donate(uint _projectId, uint _amount) public  {
        require(projects[_projectId].approved, "Project is not approved.");
        require(!projects[_projectId].completed, "Project is completed.");

        // 从捐赠者转移代币到合约
        require(donationToken.transferFrom(msg.sender, address(this), _amount), "Transfer failed.");

        projects[_projectId].raisedAmount += _amount;
        emit DonationReceived(msg.sender, _projectId, _amount);

        // (可选) 达到目标金额后自动标记项目完成
        if (projects[_projectId].raisedAmount >= projects[_projectId].targetAmount) {
            projects[_projectId].completed = true;
        }
    }

    // 资金拨付 (由DAO或多签钱包调用)
    function disburseFunds(uint _projectId) public {
        require(msg.sender == daoOrMultisig, "Only DAO or Multisig can disburse funds.");
        require(projects[_projectId].completed, "Project is not completed.");
        require(projects[_projectId].raisedAmount > 0, "No funds to disburse.");

        uint amountToDisburse = projects[_projectId].raisedAmount;
        projects[_projectId].raisedAmount = 0;

          // 从合约转移代币到受益人
        require(donationToken.transfer(projects[_projectId].beneficiary, amountToDisburse), "Transfer failed.");
        emit FundsDisbursed(_projectId, projects[_projectId].beneficiary, amountToDisburse);
    }

    // 获取项目信息
    function getProjectInfo(uint _projectId) public view returns (string memory, string memory, uint, uint, address, bool, bool) {
        Project storage p = projects[_projectId];
        return (p.name, p.description, p.targetAmount, p.raisedAmount, p.beneficiary, p.approved, p.completed);
    }
    
    //获取合约的token余额
      function getBalance() public view returns (uint) {
        return donationToken.balanceOf(address(this));
    }

    // ... 其他函数 ...
}