Savings Account

Purpose
Savings account enables users to earn yield on their deposits from within the Sublime ecosystem. Users can tap into yield strategies - starting off with Aave, Compound and Yearn, allowing them to switch between protocols, as well as immediately supply capital to borrow pools or for credit lines.
Savings account interface is inspired from ERC20 and all the functions are designed to simulate ERC20 functionalities.
Functionality
Deposit Assets
Users can deposit any** ERC20 tokens and invest them into strategies
Function
function depositTo(
    uint256 amount,
    address asset,
    address strategy,
    address to
) returns (uint256)
Approvals
Restrictions
Arguments
APPROVE: Approve the tokens for the strategy if strategy != address(0) otherwise approve to savingsAccount
amount: The number of tokens deposited
asset: The address of the asset deposited. address(0) for Ether
strategy: Strategy into which the tokens should be deposited to.  If tokens shouldn't be deposited to any strategy but held in the savings account specify as address(0)
to: Address to which deposit is made
RETURN: Shares received after deposit to strategy
Note: (**) Inflationary/deflationary tokens are not supported.
Transfer
Users can transfer their tokens to others using
Function
function transfer(
    uint256 _amount,
    address _token,
    address _strategy,
    address _to
) returns (uint256)
Arguments
_amount: Number of tokens to transfer
_token: The token that is to be transferred. address(0) for Ether
_strategy: The strategy token is deposited in. If tokens which are held in the savings account are to be use, specify address(0)
_to: The address to which token is to be transferred
Withdraw
Users can withdraw the tokens they hold using
function withdraw(
    uint256 _amount,
    address _token,
    address _strategy,
    address payable _to,
    bool _withdrawShares
) returns (uint256)
Arguments
_amount: Number of tokens to withdraw
_token: The token that is to be withdrawn
_strategy: The strategy tokens are held in
_to: The address to which withdrawn tokens should be sent to
_withdrawShares: Flag that specifies if the shares have to be directly withdraw and sent to user or they are converted back to the tokens
​
RETURN: The number of tokens withdrawn
Approve
Users can approve tokens in savings account to be used by some other address
function approve(
    uint256 _amount,
    address _token,
    address _to
)
_amount: Allowance approved
_token: The token to be approved
_to: Address to which approval is done
Note: Approve like any other ERC20 suffers from the race condition when a new approval is made. So consider using Increase/Decrease allowance.
Increase Allowance
Users can increase the allowance of a token to a user using
function increaseAllowance(
    uint256 _amount,
    address _token,
    address _to
)
_amount: Amount by which allowance is increased
_token: The token to be approved
_to: Address to which approval is done
Decrease Allowance
Users can decrease the allowance of a token to a user using
function decreaseAllowance(
    uint256 _amount,
    address _token,
    address _to
)
_amount: Amount by which allowance is decreased
_token: The token to be approved
_to: Address to which approval is done
Transfer From
Users can transfer tokens from the allowance they have from someone using
Function
function transferFrom(
    uint256 _amount,
    address _token,
    address _strategy,
    address _from,
    address _to
)
Restrictions
APPROVE: There should be allowance in savingsAccount from _from to _to for the _token for atleast _amount
Arguments
_amount: Number of tokens to transfer
_token: The token that is transferred
_strategy: The strategy from which tokens is to be transferred
_from: The address which provided the allowance
_to: The address to which transfer is to be made
Withdraw From
Users can withdraw tokens from the allowance they have from someone using
function withdrawFrom(
    uint256 _amount,
    address _token,
    address _strategy,
    address _from,
    address payable _to,
    bool _withdrawShares
) returns (uint256 amountReceived)
Restrictions
APPROVE: There should be allowance from _from to _to for the _token for atleast _amount
Arguments
_amount: Number of tokens to transfer
_token: The token that is withdrawn
_strategy: The strategy from which tokens is to be transferred
_from: The address which provided the allowance
_to: The address to which withdrawal is to be made
_withdrawShares: Flag that specifies if the shares have to be directly withdraw and sent to user or they are converted back to the tokens
​
RETURN: The number of tokens withdrawn
Withdraw All
Users can use this function to withdraw an asset from all strategies
Function
function withdrawAll(address _token) returns (uint256)
Arguments
_token: Token that is to be withdrawn
​
RETURN: Total tokens received after withdrawal
Note: This function can cross gas limit to run if the number of strategies invested are large. Please use this function with care considering above.
Switch Strategy
Users can switch tokens from one strategy to another using
Function
function switchStrategy(
    uint256 _amount,
    address _token,
    address _currentStrategy,
    address _newStrategy
)
Arguments
_amount: Number of tokens to switch to _newStrategy
_token: Token to the switched strategies
_currentStrategy: Strategy in which the tokens are invested in
_newStrategy: Strategy to which tokens are to be switched
getTotalTokens
Number of tokens of a particular asset, a user holds in savingsAccount can be queried using
Function
function getTotalTokens(address _user, address _token) 
    external override returns (uint256 _totalTokens) {
Arguments
_user: Address for which asset is queried
_token: Token for which asset is queried
​
RETURN: Number of tokens of the asset that user holds