pragma solidity ^0.6.0;
contract RoseRent {
address owner;
address admin;
struct ledger {
uint initTimestamp;
uint nextPaymentTimestamp;
uint currentWithdrawAllowance;
string reasonForUnemployement;
}
mapping (address => uint256) private studentRentPaid; // Mapping of students address => ammount the students paid for rent
mapping (address => ledger) private unemploymentAccounts; // Mapping of students address => their account (ledger struct)
address[] studentsAddresses; // Needed to loop over all the students
/*
* startUnemployment(): adds an account to the unemployment ledger so the owner can collect,
* and initializes all the relevant variables. Made for users to call and can only affect the address calling it.
* @arg _reasonForUnemployment - a string describing why.
* @returns nothing
*/
function startUnemployment (string memory _reasonForUnemployement) public {
require(unemploymentAccounts[msg.sender].initTimestamp == 0); // If they asked for it in the past, they can not again
studentsAddresses.push(msg.sender); // saves keys to look up in the future
unemploymentAccounts[msg.sender].initTimestamp = now;
unemploymentAccounts[msg.sender].nextPaymentTimestamp = 604800 + unemploymentAccounts[msg.sender].initTimestamp; //604800 is the number of seconds in a week.
unemploymentAccounts[msg.sender].currentWithdrawAllowance = 1000000000000000000; //1e18: Native value is in wei
unemploymentAccounts[msg.sender].reasonForUnemployement = _reasonForUnemployement;
}
/*
* claimUnemployment(): allows the account to collect unemployment.
* @arg _amountToWithdraw - value that the user wants to withdraw.
* @returns nothing
*/
function claimUnemployment (uint _amountToWithdraw) public {
// We are checking to make sure the amount withdrawn is positive and wont result in a negative balance.
require(unemploymentAccounts[msg.sender].currentWithdrawAllowance > 0);
require(unemploymentAccounts[msg.sender].currentWithdrawAllowance - _amountToWithdraw > 0);
unemploymentAccounts[msg.sender].currentWithdrawAllowance -= _amountToWithdraw;
msg.sender.transfer(_amountToWithdraw);
}
/*
* checkUnemploymentAllowance(): allows the account owner to check there account allowance.
* @returns uint256 - available allowance.
*/
function checkUnemploymentAllowence() public view returns (uint256){
return unemploymentAccounts[msg.sender].currentWithdrawAllowance;
}
/*
* getMoreAllowance(): allows the account to collect more unemployment after 1 week.
* @returns nothing
*/
function getMoreAllowance() public{
require(unemploymentAccounts[msg.sender].nextPaymentTimestamp < now);// Checks if 1 weeks has passed.
unemploymentAccounts[msg.sender].initTimestamp = now;
unemploymentAccounts[msg.sender].nextPaymentTimestamp = 604800 + unemploymentAccounts[msg.sender].initTimestamp; //604800 is the number of seconds in a week.
unemploymentAccounts[msg.sender].currentWithdrawAllowance += 1000000000000000000; // 1e18 Native value is in wei
}
/*
* depositRent(): allows the sender to pay rent conveniently here.
* @returns nothing
*/
function depositRent () public payable{ // realistically, we would reset the 'paid' status of students periodically, but won't here for simplicity.
studentRentPaid[msg.sender] += msg.value;
}
/*
* checkIfPaid(): allows for anyone to check if an address has paid rent.
* @arg _studentAddress - the address to check if they paid.
* @returns bool - true if they paid the minimum rent, false if they did not.
*/
function checkIfPaid (address _studentAddress) public view returns (bool){
if (studentRentPaid[_studentAddress] >= 4000000000000000000){ // 4 ETH Native value is in wei
return true;
}else{
return false;
}
}
//---------------------------Not part of the lab---------------------------
/*
* fundContract(): allows the additional funding of the smart contract easily. Anyone can call it.
* @returns nothing
*/
function fundContract() public payable{
}
/*
* initialize(): first function to be called by the managers.
* Sets the owner and admin and allows funding of the smart contract.
* @arg _owner - address of the owner (Professor).
* @arg _admin - address of the admin (TA).
* @returns nothing
*/
function initialize(address _owner, address _admin) public payable{
// address(0) means a address of all 0's (0x000000000000000000000) and that is the default address. Meaning they have not been set yet.
require ( (owner == address(0) && admin == address(0)) || msg.sender == admin || msg.sender == owner);
owner = _owner;
admin = _admin;
}
/*
* restartAllAccounts(): allows the restart of all users who have called "startUnemployment()". Used by admins to reset all students when it is needed.
* @returns nothing
*/
function restartAllAccounts() public payable{ //Will reset contract for everyone. Could send money here to add to the total balance
require(msg.sender == admin || msg.sender == owner);
for (uint i=0; i<studentsAddresses.length; i++) {
restartAccount(studentsAddresses[i]);
}
}
/*
* restartAccount(): allows the restart of a specific user given. As long a manager. Used by admins to reset a spesific students when it is needed.
* @arg _studentAddress - the students address which should be restarted.
* @returns nothing
*/
function restartAccount(address _studentAddress) public{ //Note: the keyword delete does not work on mapping or structs, so we must iterate over a know key list.
// since it has "_studentAddress" passed in, it does not rely on msg.sender. So the admins can reset any student, unlike startUnemployment which is caller restrictive.
require(msg.sender == admin || msg.sender == owner);
unemploymentAccounts[_studentAddress].initTimestamp = now;
unemploymentAccounts[_studentAddress].nextPaymentTimestamp = 604800 + unemploymentAccounts[_studentAddress].initTimestamp; //604800 is the number of seconds in a week.
unemploymentAccounts[_studentAddress].currentWithdrawAllowance = 1000000000000000000; //1e18 - Native value is in wei
studentRentPaid[_studentAddress] = 0;
}
}