IP leasing fee escrow

@Sebohe here is my very incomplete sketch of the IP leasing fee escrow contract

pragma solidity ^0.4.18;

import "../installed_contracts/zeppelin/contracts/math/SafeMath.sol";
import "../installed_contracts/tokens/contracts/eip20/EIP20Interface.sol";


contract RenewalFeeEscrow {
    using SafeMath for uint;
    EIP20Interface public token;

    mapping (address => uint) accountsReceivable;

    mapping (address => mapping (address => Bill)) billMapping;
    mapping (address => address[]) payersOfPayee;
    mapping (address => address[]) payeesOfPayer;

    bytes32 hashroot;

    struct Bill {
        uint account;
        uint perBlock;
        uint lastUpdated;
    }

    function addBill (address _payableTo) external {

    }

    function collectMyBills () internal {
        for (uint i = 0; i < payersOfPayee[msg.sender].length; i++) {
            address payer = payersOfPayee[msg.sender][i];

            Bill bill = billMapping[payer][msg.sender];
            uint blocksSinceUpdate = block.number.sub(bill.lastUpdated);
            uint amountOwed = blocksSinceUpdate.mul(bill.perBlock);

            bill.lastUpdated = block.number;

            // If they have enough to pay the bill in full
            if (amountOwed <= accounts[payer]) {
                // Debit their account and credit my account by amountOwed
                accounts[payer] = accounts[payer].sub(amountOwed);
                accounts[msg.sender] = accounts[msg.sender].add(amountOwed);
            } else {
                // Transfer remainder of their account to my account
                accounts[msg.sender] = accounts[msg.sender].add(accounts[payer]);
                accounts[payer] = 0;
            }
        }
    }

    function payMyBills () internal {
        for (uint i = 0; i < payeesOfPayer[msg.sender].length; i++) {
            address payee = payeesOfPayer[msg.sender][i];

            Bill bill = billMapping[msg.sender][payee];
            uint blocksSinceUpdate = block.number.sub(bill.lastUpdated);
            uint amountOwed = blocksSinceUpdate.mul(bill.perBlock);

            bill.lastUpdated = block.number;

            // If I have enough to pay the bill in full
            if (amountOwed <= accounts[msg.sender]) {
                // Debit my account and credit their account by amountOwed
                accounts[msg.sender] = accounts[msg.sender].sub(amountOwed);
                accounts[payee] = accounts[payee].add(amountOwed);
            } else {
                // Transfer remainder of my account to their account
                accounts[msg.sender] = 0;
                accounts[payee] = accounts[payee].add(accounts[msg.sender]);
            }
        }
    }
}


@Sebohe

  1. Make deposit into escrow for specific subnetDAO
  2. Make collectMyBills work
  3. Make withdrawing money from specific subnetDAO escrow work, with remainder of bill paid correctly before money comes out