assignment 4

Lesson3/assignment/yours.sol

@@ -1 +1,94 @@
 /*作业请提交在这个目录下*/
+pragma solidity ^0.4.14;
+
+contract Payroll {
+    struct Employee {
+        address id;
+        uint salary;
+        uint lastPayday;
+    }
+
+    uint constant payDuration = 10 seconds;
+    uint totalSalary = 0;
+
+    address owner;
+    mapping (address => Employee) private employees;
+
+    modifier onlyOwner() {
+        require(owner == msg.sender);
+        _;
+    }
+
+    modifier onlySelf(address employeeId) {
+        require(employeeId == msg.sender);
+        _;
+    }
+
+    function Payroll() public{
+        owner = msg.sender;
+    }
+
+    function _partialPaid(Employee employee) private {
+      uint amount = (now - employee.lastPayday) / payDuration * employee.salary;
+      employee.id.transfer(amount);
+    }
+
+    function addEmployee(address employeeId, uint salary) public onlyOwner {
+      var employee = employees[employeeId];
+      assert(employee.id == 0x0);
+      employees[employeeId] = Employee(employeeId, salary, now);
+      totalSalary += salary * 1 ether;
+    }
+
+    function removeEmployee(address employeeId) public onlyOwner {
+      var employee = employees[employeeId];
+      assert(employee.id != 0x0);
+      _partialPaid(employees[employeeId]);
+      delete employees[employeeId];
+      totalSalary -= employees[employeeId].salary * 1 ether;
+    }
+
+    function updateEmployee(address employeeId, uint salary) public onlyOwner {
+      var employee = employees[employeeId];
+      assert(employee.id != 0x0);
+      _partialPaid(employee);
+      totalSalary -= employees[employeeId].salary;
+      employees[employeeId].salary = salary * 1 ether;
+      employees[employeeId].lastPayday = now;
+      totalSalary += salary * 1 ether;
+    }
+
+    function addFund() payable public returns (uint) {
+      return this.balance;
+    }
+
+    function calculateRunway() public view returns (uint) {
+        assert(totalSalary > 0);
+        return this.balance / totalSalary;
+    }
+
+    function hasEnoughFund() public view returns (bool) {
+      return calculateRunway() > 0;
+    }
+
+    function checkEmployee(address employeeId) public view returns (uint salary, uint lastPayday) {
+        var employee = employees[employeeId];
+        salary = employee.salary;
+        lastPayday = lastPayday;
+    }
+
+    function getPaid() public {
+      var employee = employees[msg.sender];
+      assert(employee.id != 0x0);
+      uint nextPayday = employees[msg.sender].lastPayday + payDuration;
+      assert(nextPayday < now);
+      employees[msg.sender].lastPayday = nextPayday;
+      employee.id.transfer(employees[msg.sender].salary);
+    }
+
+    function changePaymentAddress(address EmployeeId, address newAddress) public onlySelf(EmployeeId){
+      var employee = employees[msg.sender];
+      assert(employee.id != 0x0);
+      employees[msg.sender].id = newAddress;
+    }
+}