PandExchange

Technical documentation of the PandExchange V1 contract

Contract name: PandExchange

Code source: Public soon

Data structure

UserDCAData

struct UserDCAData {
    uint256 periodDays;
    uint256 totalOccurrences;
    uint256 currentOccurrence;
    uint256 amountPerOccurrence;
    address tokenIn;
    address tokenOut;
    uint256 tokenInLockedAmount;
    address[] swapPath;
    uint256 fee5Decimals;
    address exchangeRouterAddress;
    uint256 slippageTolerance5Decimals;
}

The data structure holding all the information for a single DCAO of a user. The user address is not present in the structure as each UserDCAData object is linked to the user address by a mapping in the MapDCA public variable.

Name	Type	Description
periodDays	uint256	The minimum time between each occurrences, in days. A value of 2 means that the DCAO will be executed every two days
totalOccurrences	uint256	The total number of occurrences in the DCAO
currentOccurrence	uint256	The current number of exchanged that has taken place for this DCAO. A value equal to totalOccurrences means that the DCAO is over
amountPerOccurrence	uint256	The amount of tokenIn that will be exchanged at each occurrence. This amount includes the fee for the transaction executor
tokenIn	address	The address of the input token of this DCAO
tokenOut	addres	The address of the output token of this DCAO
tokenInLockedAmount	uint256	The remaining amount of tokenIn to be exchanged in this DCAO
swapPath	address[]	The path used to swap tokenIn for tokenOut
fee5Decimals	uint256	The fee set by the user for the transactions executors, with 5 decimals. Meaning a value of 100 000 means a fee of 100%, a value of 1 000 means a fee of 1%
exchangeRouterAddress	address	The address of the router where the swap will occur
slippageTolerance5Decimals	uint256	The slippage tolerance set by the user for this DCAO. It describes the maximum difference the user agree to risk between the announced exchanged amount and the real exchanged amount.

Public variables

MapDCA

mapping(address => mapping(uint256 => UserDCAData)) public mapDCA;

The mapping responsible for stocking all the DCAO of every users. Each user address is mapped to another mapping which link an ID to the corresponding UserDCAData object. To get the DCAO of user, you need his address and the ID of the specific DCAO you are looking for. The ID is the block.timestamp of the time the DCAO has been created. It ensures unicity for the IDs for each user.

Read functions

GetOwner

function getOwner() public view returns (address)

This function return the address of the contract's owner. The owner address is used to send the fee taken at each DCAO creation on the contract

Write functions

addNewDCAToUser

function addNewDCAToUser(
        UserDCAData memory _userDCAData,
        uint256 _amountOutMinFirstTransaction
    ) external payable notPaused returns (uint256)

This function allows an user to create a new DCAO for himself. It cannot be called if the contract is paused.

Event: Emits AddedNewDCA

Parameters:

Name	Type	Description
_userDCAData	UserDCAData	The data structure containing all the information about the DCAO. See the data structure part for details. Note: currentOccurrence value must be 0 when calling this function
_amountOutMinFirstTransaction	uint256	The minimum exchanged amount for the first occurrence of the DCAO. Used to avoid slippage

Return value(s):

Name	Type	Description
timestamp	uint256	The ID of the newly created DCAO

Note: As the first occurrence is executed at the creation of a DCAO, the executeSingleUserDCA function is also called. Find its description below.

executeSingleUserDCA

function executeSingleUserDCA(
        address _userAddress,
        uint256 _DCAStartDate,
        uint256 _amountOutMin
    ) public notPaused

This function execute an occurrence of a DCAO for any user. This does two things: Updating the state of the concerned DCAO in the contract, and performing the swap. It cannot be used while the contract is paused.

Events: Emit OccurrenceExecuted

Parameters:

Name	Type	Description
_userAddress	address	The address of the user owning the desired DCAO
_DCAStartDate	address	The ID of the desired DCAO of the user above
_amountOutMin	uint256	The minimum acceptable amount of output token obtained in the swap. It should be calculated beforehand using the DCAO slippage tolerance value

deleteUserDCA

function deleteUserDCA(uint256 _startDate) external

This function delete the DCAO of an user. Doing so transfer back to the user all unused input token. This function can be used even if the contract is paused, so that it is not possible to block any users' funds

Events: Emit DeletedDCA

Parameters:

Name	Type	Description
_startDate	uint256	The ID of the user's DCAO

modifyDCAFee

function modifyDCAFee(uint256 _newFee5Decimals, uint256 _DCAStartDate)
        public
        notPaused

This function allows an user to modify the executor's fee for one of its DCAO. This function cannot be used when the contract is paused.

Events: Emit FeeUpdated

Parameters:

Name	Type	Description
_newFee5Decimals	uint256	The new fee to be applied for the next occurrences' execution of this specific DCAO. Written with 5 decimals
_DCAStartDate	uint256	The ID of the DCAO the user want to modify

modifySlippageTolerance

function modifySlippageTolerance(uint256 _DCAStartDate, uint256 _newSlippage)
        public
        notPaused

This function allows an user to update the slippage tolerance for each swap of a specific DCAO. This function cannot be used when the contract is paused.

Event: Emit SlippageToleranceUpdated

Parameters:

_DCAStartDate	uint256	The ID of the DCAO the user want to modify
_newSlippage	uint256	The new slippage tolerance to be applied for the next occurrences' execution of this specific DCAO. Written with 5 decimals

setOwner

function setOwner(address _newOwner) public onlyOwner

This function allow the current contract's owner to change the owner address

Event: Emit NewOwner

Parameters:

_newOwner

address

The address of the new owner of the contract

pause

function pause() public onlyOwner

This function pause the contract preventing certain functions to be executed, such as addNewDCAToUser or executeSingleUserDCA. Only the owner can pause the contract

Event: None

Parameters: None

unPause

function unPause() public onlyOwner

This function unpause the contract allowing certain functions to be executed, such as addNewDCAToUser or executeSingleUserDCA. Only the owner can unpause the contract

Event: None

Parameters: None

Events

AddedNewDCA

event AddedNewDCA(
        uint256 indexed DCACreationTimestamp,
        address indexed userAddress,
        uint256 totalOccurrence,
        uint256 period,
        uint256 amountPerOccurrence,
        address tokenIn,
        address tokenOut,
        uint256 fee5Decimals,
        address exchangeRouterAddress,
        uint256 slippageTolerance5Decimals
    );

Emitted when a DCAO is created on the contract. It exposes the key information for this DCAO for anyone to keep track of it.

DCACreationTimestamp	uint256	The ID of the created DCAO
userAddress	address	The address of the user that created the DCAO
totalOccurrence	uint256	The total number of occurrences for this DCAO
period	uint256	The time between each occurrence execution, in days
amountPerOccurrence	uint256	The amount of tokenIn per occurrence, including the executor's fee
tokenIn	address	The input token address
tokenOut	address	The output token address
fee5Decimals	uint256	The executor's fee for every occurrence of this DCAO, with 5 decimals
exchangeRouterAddress	address	The address of the router used for the swap
slippageTolerance5Decimals	uint256	The slippage tolerance for this DCAO, with 5 decimals

OccurrenceExecuted

event OccurrenceExecuted(
        uint256 indexed DCACreationTimestamp,
        address indexed userAddress,
        uint256 totalOccurrence,
        uint256 currentOccurrence,
        uint256 nextOccurrenceTimestamp,
        uint256 estimatedMinimumAmountOut,
        address tokenIn,
        address tokenOut,
        uint256 tokenInAmount,
        uint256 fee5Decimals
    );

Emitted when an occurrence of a DCAO is executed.

DCACreationTimestamp	uint256	The ID of the executed DCAO
userAddress	address	The address of the owner of the executed DCAO
totalOccurrence	uint256	The total number of occurrences for this DCAO
currentOccurrence	uint256	The current number of executed occurrence of the executed DCAO
nextOccurrenceTimestamp	uint256	The time where the next occurrence of this DCAO will be able to be executed
estimatedMinimumAmountOut	uint256	The minimum amount of tokenOut that the owner of the DCAO was rewarded for this specific occurrence
tokenIn	address	The input token address
tokenOut	address	The output token address
tokenInAmount	uint256	The amount of exchanged tokenIn
fee5Decimals	uint256	The executor's fee for every occurrence of this DCAO, with 5 decimals

DeletedDCA

event DeletedDCA(
        uint256 indexed DCACreationTimestamp,
        address indexed userAddress
    );

Emitted when a DCA is deleted

DCACreationTimestamp	uint256	The ID of the deleted DCAO
userAddress	address	The address of the owner of the deleted DCAO

FeeUpdated

event FeeUpdated(
        address indexed owner,
        uint256 indexed DCACreationTimestamp,
        uint256 oldFee,
        uint256 newFee
    );

Emitted when the executor's fee of a DCAO is updated

DCACreationTimestamp	uint256	The ID of the DCAO
userAddress	address	The address of the owner of the DCAO
oldFee	uint256	The old executor's fee, with 5 decimals
newFee	uint256	The new executor's fee, with 5 decimals

SlippageToleranceUpdated

event SlippageTolerancegeUpdated(
        address indexed owner,
        uint256 indexed DCACreationTimestamp,
        uint256 oldSlippageTolerance,
        uint256 newSlippageTolerance
    );

Emitted when the slippage tolerance of a DCAO is updated

DCACreationTimestamp	uint256	The ID of the DCAO
userAddress	address	The address of the owner of the DCAO
oldSlippageTolerance	uint256	The old slippage tolerance, with 5 decimals
newSlippageTolerance	uint256	The new slippage tolerance, with 5 decimals

NewOwner

event NewOwner(address indexed oldOwner, address indexed newOwner);

Emitted when the contract's owner is changed

oldOwner	address	The address of the previous owner
newOwner	address	The address of the new owner