Crypto-ERC20-DevToken-RewardCalculations-V1.0

     /**
      * @notice
      * calculateStakeReward is used to calculate how much a user should be rewarded for their stakes
      * and the duration the stake has been active
     */
      function calculateStakeReward(Stake memory _stake) internal view returns(uint256){
          // First calculate how long the stake has been active
          // Use current seconds since epoch - the seconds since epoch the stake was made
          // The output will be duration in SECONDS ,
          // We will reward the user 0.1% per Hour So thats 0.1% per 3600 seconds
          // the alghoritm is  seconds = block.timestamp - stake seconds (block.timestap - _stake.since)
          // hours = Seconds / 3600 (seconds /3600) 3600 is an variable in Solidity names hours
          // we then multiply each token by the hours staked , then divide by the rewardPerHour rate 
          return (((block.timestamp - _stake.since) / 1 hours) * _stake.amount) / rewardPerHour;
      }

      /**
      * @notice 
      * calculateTotalAvailableRewards will iterate all stakes made by a account
      * and summerize the total unclaimed rewards
      * 
       */
       function calculateTotalAvailableRewards(address _staker) public view returns(uint256){
           uint256 total_reward;
            // Itterate all stakes from the address and calculate their reward for each stake
           Stake[] memory user_stakes = stakes[_staker];

           for(uint256 i = 0; i<user_stakes.length; i++) {
               // Skip any stake that is actually stopped or empty
               if(user_stakes[i].amount == 0 || user_stakes[i].until != 0){
                   continue;
               }

               total_reward = total_reward + calculateStakeReward(user_stakes[i]);
           }

           return total_reward;
       }