todo.sol

todo.sol

pragma solidity ^0.4.20; 

contract TodoList { 
  
  struct Todo { 
    uint256 id; 
    bytes32 content; 
    address owner; 
    bool isCompleted; 
    uint256 timestamp; 
  } 
  
  uint256 public constant maxAmountOfTodos = 100;
  
  // Owner => todos 
  mapping(address => Todo[maxAmountOfTodos]) public todos; 
  
  // Owner => last todo id 
  mapping(address => uint256) public lastIds;
  
  
  // Add a todo to the list function 
  function addTodo(bytes32 _content) public { 
    Todo memory myNote = Todo(lastIds[msg.sender], _content, msg.sender, false, now); 
    todos[msg.sender][lastIds[msg.sender]] = myNote; 
    if(lastIds[msg.sender] >= maxAmountOfTodos) {
      lastIds[msg.sender] = 0; 
    } else {
    lastIds[msg.sender]++; 
    }
  } 
  
  // Mark a todo as completed 
  function markTodoAsCompleted(uint256 _todoId) public {
    require(_todoId < maxAmountOfTodos); 
    require(!todos[msg.sender][_todoId].isCompleted); 
    require(msg.sender == todos[msg.sender][_todoId].owner);
    todos[msg.sender][_todoId].isCompleted = true;
  }
}