Possible solution to the Challenge - Repricing Approach

.gitignore

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+node_modules
+.env
+coverage
+coverage.json
+typechain
+
+OldContracts
+
+#Hardhat files
+cache
+artifacts

README.md

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 # Smart Contract Challenge
+## Index
+
+The challenge
+- [Challenge Itself](#a-challenge)
+- [1) Setup a project and create a contract](#1-setup-a-project-and-create-a-contract) 
+- [2) Write tests](#2-write-tests) 
+- [3) Deploy your contract](#3-deploy-your-contract) 
+- [4) Interact with the contract](#4-interact-with-the-contract) 
+
+The solution
+- [Solution - Repricing Approach](#solution---repricing-approach)
+- [0) Ropsten Verified Contracts](#0-ropsten-verified-contracts)
+- [A) Solution Summary](#a-solution-summary)
+- [B) Mockup and Project Theorical Context](#b-mockup-and-project-theorical-context-click-on-image-to-enlarge)
+- [C) Contract Relationships Tree](#c-contract-relationships-tree-click-on-image-to-enlarge)
+- [D) Usage and Deployment Instructions](#d-usage-and-deployment-instructions)
+- [E) Security Measures Taken](#e-security-measures-taken)
+- [F) Tests Results and Gas Consumption](#f-tests-results-and-gas-consumption)
+- [G) Scripts](#g-scripts)
 
 ## A) Challenge
 
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 Create a script (or a Hardhat task) to query the total amount of ETH held in the contract.
 
 _You can use any library you prefer: Ethers.js, Web3.js, Web3.py, eth-brownie_
+
+# Solution - Repricing Approach
+## 0) Ropsten Verified Contracts
+- DataStorage: https://ropsten.etherscan.io/address/0x5d8c2fd496A05bb68329Fe39E8A12B424D25E1b4
+- PoolBase: https://ropsten.etherscan.io/address/0x601a16CEBd0E607822995B2E8407891AE6BE4bAb
+- TokenBalances: https://ropsten.etherscan.io/address/0x169105b18148b45acb1d4e0354f48a17fe560629
+- rwEthToken: https://ropsten.etherscan.io/address/0x0Ddf2C71Ca974A6c40A0Fb83f670029AA7D678ea
+- PoolVault: https://ropsten.etherscan.io/address/0xeb69E5c8F8Bb00F683ffb9589466CD4D20325D60
+- PoolClient: https://ropsten.etherscan.io/address/0xdB0210D3FdAFCAA410811D9aa7034E64dde31DdF
+
+## A) Solution Summary
+The pool is works with a token repricing rewards system where each rewards injection modifies the supply ***equilibrium*** of both locked ether and rewards ether. 
+The Pool Contract Network is made of several contracts (modular) in order to preserve the integrity of the whole pool making it easier to interact, manage and    safeguard. The team will have to setup the pool variables on a separate contract from the one that will be used for proper staking and token-related transactions.
+The Pool Contract Network:
+- **DataStorage:** Storage for every mapping and state variable that needs to be tracked or modified of the pool. It can only be accesed through other pool contracts.
+- **PoolBase:** Environment to set every pool setting and functioning variable. Only for the team.
+- **TokenBalances:** Getter contract for variables of interest.
+- **rwETHToken:** ERC-20 compliant protocol for the rewards token as well as the calculations of exchange rates.
+- **PoolVault:** Sealed Vault where all the tokens are sent and stored. Anyone but other contracts from the pool can access it.
+- **PoolClient:** Interface between the stakers and the pool. From where every user can deposit and withdraw their funds.
+
+## B) Mockup and Project Theorical Context (click on image to enlarge)
+- The interest period can be modified just by injecting rewards in a different time-range.
+- The amount to inject is calculated with a contract function that takes as input the fixed interest rate for the current interest period. [Here](#tool-interest-calculator-for-a-period-of-time-takes-apy-as-input) is a simple tool to get a fast calculus of the interests.
+- At the beginning, a fee was meant to be charged for each transaction with the pool. That proposal is dismissed for the pool implementation. The fee can be implicit with the current interest rate of the pool. For example, if the market is offering an average of 5% yearly yield, while giving 4.9% p.y, you are implicitly charging a 0.1% yearly.
+
+![StakingPool](https://user-images.githubusercontent.com/97247251/161983422-de3255bb-6664-47e7-a9f8-a61e81b0a810.png)
+
+
+## C) Contract Relationships Tree (click on image to enlarge)
+- The displayed contracts within the mockup have been "exploded" into several modules of contracts for organization and operativeness.
+- The state variables and mappings are stored in a separate module **"DataStorage"**.
+- The user and the team will be only allowed to handle tokens via **"PoolClient"**.
+- The team will setup the pool settings on the **PoolBase** contract. <br/>
+
+![Staking Pool Contracts Tree drawio](https://user-images.githubusercontent.com/97247251/161981129-2f708754-9ec8-456c-bd96-d0e17aec2162.png)
+
+
+## D) Usage and Deployment Instructions
+### 1) Deployment order and constuctor parameters ()
+- `DataStorage(), TokenBalances(_dataStorageAddress), rwETHToken(_dataStorageAddress), PoolVault(_dataStorageAddress), PoolClient(_dataStorageAddress), PoolBase(_dataStorageAddress)`.
+
+### 2) Setting up the Pool
+- The Admin (deployer) can add local managers to assist with the task of managing de pool. The managers added will work only on the contract from where the `addPoolManager` function was called. This helps to constraint the range of application of the managers permissions. The `addPoolManager` is available on the `PoolBase` contract and all of their childs.
+- Once every pool contract is deployed, only the Admin (Storage guardian) should call dataStorage:  `setStorageLive()`.
+- The team or manager needs to call from PoolBase: `setPoolMaxSize`, `setRewardsInterval`, `setRewardsInterest`, `setContributionLimit`, `setMinContribution`. Those functions can only be called if the investing pool is closed (deposits and withdrawals are halted).
+- To set the pool as operational, the team or manager just needs to call `setPoolLive` from the PoolBase Contract.
+- It is advised to setup also managing roles for the management of the PoolClient Contract by calling the `addPoolManager` function from the mentioned contract. 
+
+### 2) Operating the Pool
+- While being live, the users can deposit ether and getting rwEther back by calling `deposit` from the `PoolClient` contract. The amount of rwEther that they get back depends on the current locked ether and rwEther supplies (repricing). 
+- Once the rewarding time has passed, the team needs to `setPoolLive` as false and call `calculateRewards` from the `PoolClient` contract. Once the rewards are calculated, they can be get by calling `getRewardsToInject` (please note that the output of this function will be a WEI value, 18 decimals).
+- Afterwards, the team needs to inject the exact same amount returned from before of ether in concept of rewards into the pool by calling `rewardsInjector` (remember that the role clearances of the `PoolBase` contract are not passed through the `PoolClient`; if it is desired to call this function by a team member, their role must be assigned within this contract). 
+- ***NOTE:*** When the team injects rewards the equilibrium between both ether and reward ether supplies is broken, this is when the repricing system starts to work.
+- After the team injected the rewards and set the pool as live, the users can leave their tokens staking or withdraw their funds by calling `withdraw(rewards to cash out)` from the `PoolClient` contract. 
+- **IMPORTANT:** Users need to approve the PoolClient contract with the amount of tokens to cash out before trying to withdraw their funds. This action can be performed directly from the rwETHToken contract or from the frontend of the pool (trigger approval request before calling withdraw method).  
+
+## E) Security Measures Taken
+- Pool contract calls can only be performed between contracts of the pool. To perform this action, the `onlyByPoolContract` modifier of the DataStorage contract, while deploying, checks that the transaction origin is the same as the one of the guardian (deployer of DataStorage). It is extremely important that the deployments are made directly by the Guardian (deployer a.k.a admin) instead of using third party contracts that may result on storing a malicious contract (tx.origin is checked). It is a key factor to setup the storage live once every contract is deployed thus not checking anymore the tx.origin as a condition. 
+- Reentrancy mutex modifier has been applied into relevant functions.
+- By using an ERC20 compliant model for the rwETH token, they can be transfered between accound freely. 
+- In addition to the latter, no internal mapping of "amount staked by user" is performed (allowing you to get some tokens by transfer and cashing out the rewards assigned to that amount of rwEther). It is checked the user balance of the reward tokens instead. 
+- The ether deposited as well as the rewards injected (more ether) are stored within a "vaulted contract" a.k.a PoolVault. No user or team member can access the funds of that contract directly. They can only be accesed by the PoolClient contract.
+- While withdrawing, both payable(to).call and reentrancy mutex are combined to prevent attacks. To keep the rwEth balance, the tokens are burned.
+- **IMPORTANT:** The withdrawer needs to provide allowance to the PoolClient contract for the amount of tokens to be withdrawn before calling `withdraw`. While having a frontend, that approval request can be triggered before calling the withdraw method.
+
+## F) Tests Results and Gas Consumption
+- All tests were performed using the Hardhat Localhost Node.
+
+
+![image](https://user-images.githubusercontent.com/97247251/162186241-d4c3dc5f-fb09-4122-8edd-98d8105c2c3d.png)
+
+
+![image](https://user-images.githubusercontent.com/97247251/162186177-76a0bc28-f122-4c34-addc-0cacec8697e1.png)
+
+
+
+## G) Scripts
+The project provides scripts to set quickly the pool variables and perform several actions. Also, it is provided a balance getter script that not only retrieves the pool balance but also checks that the balance is the same as the one stored in the contract mapping.
+
+## Tool: Interest Calculator for a Period of Time (takes APY as input)
+https://github.com/lior-abadi/challenge/blob/main/Theory%20and%20Initial%20Mockups/Interest%20Calculator.xlsm