swapable
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Swapable: Automated Liquidity Pools
187 lines (186 loc) • 9.63 kB
JavaScript
"use strict";
/**
* This file is part of Swapable shared under AGPL-3.0
* Copyright (C) 2021 Using Blockchain Ltd, Reg No.: 12658136, United Kingdom
*
* @package Swapable
* @author Grégory Saive for Using Blockchain Ltd <greg@ubc.digital>
* @license AGPL-3.0
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.AddLiquidity = void 0;
const symbol_sdk_1 = require("symbol-sdk");
// internal dependencies
const index_1 = require("../../index");
const Executable_1 = require("./Executable");
//XXX remove this, used only for type-discovery in command options below.
const Symbol_Testnet_SWP = new index_1.AssetIdentifier('00000001', new symbol_sdk_1.PublicAccount());
const Symbol_Testnet_XYM = new index_1.AssetIdentifier('00000002', new symbol_sdk_1.PublicAccount());
/**
* @class Swapable.AddLiquidity
* @package Swapable
* @subpackage Commands
* @since v1.0.0
* @description Class that describes a command for adding assets
* in automated liquidity pools (i.e. "deposit").
* @summary
* This automated pool command accepts the following arguments:
*
* | Argument | Description | Example |
* | --- | --- | --- |
* | provider | Liquidity provider | `new PublicAccount(...)` |
* | input_x | Amount and asset identifier of `x` (first in pair) | `new AssetAmount(...)` |
* | input_y | Amount and asset identifier of `y` (second in pair) | `new AssetAmount(...)` |
*
* The execution of this command results in the creation of
* the following list of transactions with their respective
* *signer* and a description:
*
* | Sequence | Type | Signer | Description |
* | --- | --- | --- | --- |
* | 01 | MosaicSupplyChangeTransaction | Target Account | Creates an amount of automated pool shares that is proportional to the amount of liquidity added in the pool. These shares represent the contribution made to the pool by the liquidity provider. |
* | 02 | TransferTransaction | Target Account | Transfers the added automated pool shares to the liquidity provider. |
* | 03 | TransferTransaction | Provider Account | Transfers the **added liquidity** of `x` and `y` to the target account. |
* | 04 | TransferTransaction | Provider Account | Adds an execution proof message sent to the **target** account. |
*
*/
class AddLiquidity extends Executable_1.Executable {
constructor() {
super(...arguments);
/**
* @access public
* @description The list of **required** arguments to execute
* *this* automated pool command.
*/
this.arguments = [
'provider',
'input_x',
'input_y',
];
// end-region abstract methods
}
/**
* Verifies **allowance** of \a actor to execute a command
* with arguments \a argv. This method returns true if all
* required arguments are present.
*
* This method asserts the presence of mandatory arguments.
*
* @access public
* @param {PublicAccount} actor The actor is whom executes the command.
* @param {Array<CommandOption>} argv The command options (arguments).
* @return {AllowanceResult} Returns whether an actor is authorized to execute this command.
* @throws {FailureMissingArgument} On missing mandatory argument(s).
**/
canExecute(actor, argv) {
// - Asserts the presence of mandatory inputs
super.assertHasMandatoryArguments(argv, this.arguments);
// - Allows anyone to add liquidity to automated pools
// given a connected command execution (read-only).
return new index_1.AllowanceResult(!!this.reserveInfo && !!this.mosaicInfo);
}
// region abstract methods
/**
* This method returns the automated pool command name,
* e.g. "CreatePool" or "AddLiquidity", etc.
*
* @access public
* @return {string}
**/
get name() {
return 'AddLiquidity';
}
/**
* This method MUST return a unique automated pool command
* descriptor which includes:
*
* - the open standard descriptor (e.g.: "Swapable") ;
* - the open standard *revision* (e.g.: 1) ;
* - the kebab-case command name (e.g.: "create-pool") ;
* - and the automated pool shares asset identifier.
*
* Items are joined with the `:` operator and attached to a
* so-called execution proof transaction.
*
* @access public
* @return {string}
**/
get descriptor() {
return 'Swapable(v' + this.context.revision + ')' + ':add-liquidity:' + this.identifier.id;
}
/**
* This method returns a list of unsigned transactions in a
* sequencial order of execution. The resulting transaction
* array is later wrapped inside a digital contract that is
* executed atomically such that either all transactions do
* succeed or all transactions are cancelled.
*
* :warning: This method creates at least one- or more than
* one - network-wide **account restriction**. Restrictions
* can potentially lock you out of your account, please use
* this only with caution and if you understand the risks.
*
* @see {execute()}
* @access public
* @return {Transaction[]} Given the execution of a command, returns a list of unsigned transactions.
**/
get transactions() {
var _a, _b, _c, _d, _e;
// - Reads the execution context
const reader = this.context.reader;
// - Reads external arguments
const provider = this.context.getInput('provider', new symbol_sdk_1.PublicAccount());
const input_x = this.context.getInput('input_x', new index_1.AssetAmount(Symbol_Testnet_SWP, 10));
const input_y = this.context.getInput('input_y', new index_1.AssetAmount(Symbol_Testnet_XYM, 10));
// - Reads shares and reserves information
const supply_lp = (_c = (_b = (_a = this.mosaicInfo) === null || _a === void 0 ? void 0 : _a.supply) === null || _b === void 0 ? void 0 : _b.compact()) !== null && _c !== void 0 ? _c : 0;
const reserve_x = this.reserveOf(input_x.identifier);
const reserve_y = this.reserveOf(input_y.identifier);
// MINT FEE principle (0.05 % of shares issued),
// https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2Pair.sol#L117
// if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
//XXX if (pool_exists)
//XXX rootK = Math.sqrt(reserve0 * reserve1)
//XXX rootKLast = Math.sqrt(kLast)
//XXX if (rootK > rootKLast)
//XXX numerator = totalSupply.mul(rootK.sub(rootKLast));
//XXX denominator = rootK.mul(5).add(rootKLast);
//XXX liquidity = numerator / denominator;
//XXX if (liquidity > 0) _mint(feeTo, liquidity);
//XXX else kLast = 0
// - Calculate liquidity proportions ("contribution of provider")
const liquidity = Math.min((input_x.amount * supply_lp) / reserve_x, (input_y.amount * supply_lp) / reserve_y);
// - Prepares the response
const transactions = [];
const signers = [];
// - Transaction 01: MosaicSupplyChangeTransaction
// :note: The canExecute() method verifies that `mosaicInfo` is set.
transactions.push(symbol_sdk_1.MosaicSupplyChangeTransaction.create(this.context.parameters.deadline, (_d = this.mosaicInfo) === null || _d === void 0 ? void 0 : _d.id, symbol_sdk_1.MosaicSupplyChangeAction.Increase, symbol_sdk_1.UInt64.fromUint(liquidity), reader.networkType, undefined));
// - Transaction 01 is issued by **target** account
signers.push(this.target);
// - Transaction 02: Transfers added automated pool shares to liquidity provider
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, provider.address, [
new symbol_sdk_1.Mosaic(this.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(liquidity))
], symbol_sdk_1.EmptyMessage, reader.networkType, undefined));
// - Transaction 02 is issued by **target** account
signers.push(this.target);
// - Transaction 03: Transfers initially added liquidity to target account
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, this.target.address, [
new symbol_sdk_1.Mosaic(input_x.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(input_x.amount)),
new symbol_sdk_1.Mosaic(input_y.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(input_y.amount))
], symbol_sdk_1.EmptyMessage, reader.networkType, undefined));
// - Transaction 03 is issued by **provider** account
signers.push(provider);
// - Transaction 04: Add execution proof transaction
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, this.target.address, [], // no mosaics
symbol_sdk_1.PlainMessage.create(this.descriptor
+ ':' + ((_e = this.mosaicInfo) === null || _e === void 0 ? void 0 : _e.id.toHex())
+ ':' + input_x.identifier.toMosaicId().toHex()
+ ':' + input_y.identifier.toMosaicId().toHex()), reader.networkType, undefined));
// - Transaction 04 is issued by **provider** account ("the actor")
signers.push(provider);
// - Assigns correct signer to each transaction
return transactions.map((transaction, i) => transaction.toAggregate(signers[i]));
}
}
exports.AddLiquidity = AddLiquidity;