# Market Liquidity Exercises This contract interacts with GMX market pools, allowing users to deposit and withdraw tokens. You'll complete 4 main tasks in the `GmLiquidity.sol` contract: 1. Implement a function to receive execution fee refunds from GMX 2. Complete the market token price calculation function 3. Implement deposit functionality for USDC into a BTC index, WBTC long, USDC short pool 4. Implement withdrawal functionality from the BTC/WBTC/USDC pool ## Task 1: Receive execution fee refund Implement a way for the contract to receive ETH refunds from GMX. ## Task 2: Get market token price ```solidity // Task 2 - Get market token price function getMarketTokenPriceUsd() public view returns (uint256) { // 1 USD = 1e8 uint256 btcPrice = oracle.getPrice(CHAINLINK_BTC_USD); } ``` Complete the `getMarketTokenPriceUsd` function to fetch and calculate the market token price of `GMX_TOKEN_BTC_WBTC_USDC` in USD. Market token price has 30 decimals (1e30 = 1 USD). - Call `reader.getMarketTokenPrices` to get market token price information > Hints: > > - Market is `GMX_TOKEN_BTC_WBTC_USDC` > - Index token is `GMX_BTC_WBTC_USDC_INDEX` > - Long token is `WBTC` > - Short token is `USDC` > - Set `indexTokenPrice` and `longTokenPrice` to +/- 1% of `btcPrice` > - Set `shortTokenPrice` to +/- 1% of USDC price. Assume 1 USDC = 1 USD > - The prices above must have decimals so that when multiplied by the token decimals, it will have 30 decimals. > - `WBTC` has 8 decimals > - Set `pnlFactorType` to `Keys.MAX_PNL_FACTOR_FOR_DEPOSITS` > - Set `maximized` to `true` - Return the price in the correct format (`uint256`) ## Task 3: Create deposit function ```solidity // Task 3 - Create an order to deposit USDC into GM_TOKEN_BTC_WBTC_USDC function createDeposit(uint256 usdcAmount) external payable returns (bytes32 key) { uint256 executionFee = 0.1 * 1e18; usdc.transferFrom(msg.sender, address(this), usdcAmount); // Task 3.1 - Send execution fee to the deposit vault // Task 3.2 - Send USDC to the deposit vault // Task 3.3 - Create an order to deposit USDC into GM_TOKEN_BTC_WBTC_USDC // Assume 1 USDC = 1 USD // USDC has 6 decimals // Market token has 18 decimals } ``` Complete the `createDeposit` function to: 1. Send execution fee to the deposit vault 2. Send USDC to the deposit vault 3. Create an order to deposit USDC into GM_TOKEN_BTC_WBTC_USDC pool - Calculate minimum expected market tokens based on price - Handle decimals correctly (USDC: 6 decimals, Market token: 18 decimals) ### Task 3.1 Send execution fee to the deposit vault Send the execution fee to `DEPOSIT_VAULT`. ### Task 3.2: Send USDC to the deposit vault Approve the `ROUTER` contract and send USDC to `DEPOSIT_VAULT`. ### Task 3.3: Create a deposit order Create an order to deposit liquidity into `GM_TOKEN_BTC_WBTC_USDC`. Return the order key. Optionally calculate `minMarketToken` based on the price of the market token (`getMarketTokenPriceUsd`). Market tokens have 18 decimals. ## Task 4: Create withdrawal function ```solidity // Task 4 - Create an order to withdraw liquidity from GM_TOKEN_BTC_WBTC_USDC function createWithdrawal() external payable returns (bytes32 key) { uint256 executionFee = 0.1 * 1e18; // Task 4.1 - Send execution fee to the withdrawal vault // Task 4.2 - Send GM_TOKEN_BTC_WBTC_USDC to the withdrawal vault // Task 4.3 - Create an order to withdraw WBTC and USDC from GM_TOKEN_BTC_WBTC_USDC // Assume 1 USD = 1 USDC } ``` Complete the `createWithdrawal` function to: 1. Send execution fee to the withdrawal vault 2. Send GM tokens to the withdrawal vault 3. Create an order to withdraw WBTC and USDC from the pool - Calculate minimum expected token amounts based on prices - Handle different token decimals correctly ### Task 4.1 Send execution fee to the withdrawal vault Send the execution fee to `WITHDRAWAL_VAULT`. ### Task 4.2: Send market token to the withdrawal vault Approve the `ROUTER` contract and send all of `GM_TOKEN_BTC_WBTC_USDC` owned by this contract to `WITHDRAWAL_VAULT`. ### Task 4.3: Create a withdrawal order Create an order to withdraw liquidity from `GM_TOKEN_BTC_WBTC_USDC`. Return the order key. Optionally calculate `minLongTokenAmount` and `minShortTokenAmount`. > Hints: > > - Get market token price by calling `getMarketTokenPriceUsd` > - Market token price has 30 decimals > - Half of the USD value of the market token owned by this contract will be paid out as BTC. The other half in USDC. > - Set `minLongTokenAmount` and `minShortTokenAmount` to less than 50% of the USD value of market tokens owned by this contract. > - Get BTC price by calling `oracle.getPrice(CHAINLINK_BTC_USD)` > - Assume 1 USDC = 1 USD > - WBTC has 8 decimals > - USDC has 6 decimals Market tokens have 18 decimals. ## Test ```shell forge test --fork-url $FORK_URL --fork-block-number $FORK_BLOCK_NUM --match-path test/GmLiquidity.test.sol -vvv ```