.

.editorconfig

+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
\ No newline at end of file

.eslintrc

+{
+  "env": {
+    "node": true,
+    "browser": true,
+    "es6": true,
+    "mocha": true
+  },
+  "extends": ["eslint:recommended", "plugin:prettier/recommended", "prettier"],
+  "globals": {
+    "Atomics": "readonly",
+    "SharedArrayBuffer": "readonly"
+  },
+  "parser": "babel-eslint",
+  "parserOptions": {
+    "ecmaVersion": 2018
+  },
+  "rules": {
+    "indent": ["error", 2],
+    "linebreak-style": ["error", "unix"],
+    "quotes": ["error", "single"],
+    "semi": ["error", "never"],
+    "object-curly-spacing": ["error", "always"],
+    "comma-dangle": ["error", "always-multiline"],
+    "require-await": "error",
+    "prettier/prettier": ["error", { "printWidth": 110 }]
+  }
+}

.gitattributes

+*.sol linguist-language=Solidity
\ No newline at end of file

.gitignore

+build
+.vscode
+/index.js
+
+# Created by .ignore support plugin (hsz.mobi)
+### Node template
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# TypeScript v1 declaration files
+typings/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+.env.test
+.env.Goerli
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+
+# next.js build output
+.next
+
+# nuxt.js build output
+.nuxt
+
+# vuepress build output
+.vuepress/dist
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+coverage.json
+package-lock.json
+yarn.lock
+XFTanon_flat.sol
+yarn.lock
+shifters.ts
+artifacts

.nvmrc

+v19.4.0

.prettierignore

+.vscode
+build
+circuits
+contracts/Verifier.sol
+scripts/ganacheHelper.js
+cli.js
+index.js
+coverage
+coverage.json

.prettierrc

+{
+  "singleQuote": true,
+  "trailingComma": "all",
+  "bracketSpacing": true,
+  "semi": false,
+  "printWidth": 110,
+  "overrides": [
+    {
+      "files": "*.sol",
+      "options": {
+        "singleQuote": false,
+        "printWidth": 130
+      }
+    }
+  ]
+}

.solhint.json

+{
+  "extends": "solhint:recommended",
+  "rules": {
+    "prettier/prettier": [
+      "error",
+      {
+        "printWidth": 110
+      }
+    ],
+    "quotes": ["error", "double"]
+  },
+  "plugins": ["prettier"]
+}

README.md

-# offshift-contracts-public
+# Offshift Anon 
+## Initial Setup
+This repository requires [NodeJS](https://nodejs.org/) 16.15 or higher. [Node Version Manager](https://github.com/nvm-sh/nvm) is recommended for easy installation and version management. Once NodeJS is running, install dependencies
+```
+npm install
+```
+## Proving Circuit Setup
+To load the proving/verification keys
+```
+npm run download
+```
+This will create the `build/circuits` folder and copy the files `withdraw_proving_key.bin`, `withdraw_proving_key.json`, `withdraw_verification_key.json`, `withdraw.json`, and `Verifier.sol` into it.
 
+To build the circuit and proving key from source
+```
+npm run build
+```
+You will need the files `withdraw_proving_key.json` and `withdraw_verification_key.json` inside the `build/circuits` folder
+
+## Migrations and Testing
+To run an Ethereum mainnet fork (in a separate terminal window)
+```
+npm run fork
+```
+(Note: You will need a mainnet RPC endpoint to fork, a list of providers can be found here: https://www.alchemy.com/list-of/rpc-node-providers-on-ethereum)
+
+To run a contract migration
+```
+npm run migrate:dev
+```
+To run unit tests. (Note: for note encryption testing, NodeJS version 19 is required. Run `nvm install 19` if not already installed.)
+```
+nvm use 19
+npm run test
+```
+
+## Audit
+Smart contract audit by Paladin Blockchain Security: https://paladinsec.co/projects/offshift/
\ No newline at end of file

circuits/merkleTree.circom

+include "../node_modules/circomlib/circuits/mimcsponge.circom";
+
+// Computes MiMC([left, right])
+template HashLeftRight() {
+    signal input left;
+    signal input right;
+    signal output hash;
+
+    component hasher = MiMCSponge(2, 1);
+    hasher.ins[0] <== left;
+    hasher.ins[1] <== right;
+    hasher.k <== 0;
+    hash <== hasher.outs[0];
+}
+
+// if s == 0 returns [in[0], in[1]]
+// if s == 1 returns [in[1], in[0]]
+template DualMux() {
+    signal input in[2];
+    signal input s;
+    signal output out[2];
+
+    s * (1 - s) === 0
+    out[0] <== (in[1] - in[0])*s + in[0];
+    out[1] <== (in[0] - in[1])*s + in[1];
+}
+
+// Verifies that merkle proof is correct for given merkle root and a leaf
+// pathIndices input is an array of 0/1 selectors telling whether given pathElement is on the left or right side of merkle path
+template MerkleTreeChecker(levels) {
+    signal input leaf;
+    signal input root;
+    signal input pathElements[levels];
+    signal input pathIndices[levels];
+
+    component selectors[levels];
+    component hashers[levels];
+
+    for (var i = 0; i < levels; i++) {
+        selectors[i] = DualMux();
+        selectors[i].in[0] <== i == 0 ? leaf : hashers[i - 1].hash;
+        selectors[i].in[1] <== pathElements[i];
+        selectors[i].s <== pathIndices[i];
+
+        hashers[i] = HashLeftRight();
+        hashers[i].left <== selectors[i].out[0];
+        hashers[i].right <== selectors[i].out[1];
+    }
+
+    root === hashers[levels - 1].hash;
+}

circuits/withdraw.circom

+include "../node_modules/circomlib/circuits/bitify.circom";
+include "../node_modules/circomlib/circuits/pedersen.circom";
+include "merkleTree.circom";
+
+// computes Pedersen(nullifier + secret)
+template CommitmentHasher() {
+    signal input nullifier;
+    signal input secret;
+    signal output commitment;
+    signal output nullifierHash;
+
+    component commitmentHasher = Pedersen(496);
+    component nullifierHasher = Pedersen(248);
+    component nullifierBits = Num2Bits(248);
+    component secretBits = Num2Bits(248);
+    nullifierBits.in <== nullifier;
+    secretBits.in <== secret;
+    for (var i = 0; i < 248; i++) {
+        nullifierHasher.in[i] <== nullifierBits.out[i];
+        commitmentHasher.in[i] <== nullifierBits.out[i];
+        commitmentHasher.in[i + 248] <== secretBits.out[i];
+    }
+
+    commitment <== commitmentHasher.out[0];
+    nullifierHash <== nullifierHasher.out[0];
+}
+
+// Verifies that commitment that corresponds to given secret and nullifier is included in the merkle tree of deposits
+template Withdraw(levels) {
+    signal input root;
+    signal input nullifierHash;
+    signal input recipient; // not taking part in any computations
+    signal input relayer;  // not taking part in any computations
+    signal input fee;      // not taking part in any computations
+    signal input refund;   // not taking part in any computations
+    signal private input nullifier;
+    signal private input secret;
+    signal private input pathElements[levels];
+    signal private input pathIndices[levels];
+
+    component hasher = CommitmentHasher();
+    hasher.nullifier <== nullifier;
+    hasher.secret <== secret;
+    hasher.nullifierHash === nullifierHash;
+
+    component tree = MerkleTreeChecker(levels);
+    tree.leaf <== hasher.commitment;
+    tree.root <== root;
+    for (var i = 0; i < levels; i++) {
+        tree.pathElements[i] <== pathElements[i];
+        tree.pathIndices[i] <== pathIndices[i];
+    }
+
+    // Add hidden signals to make sure that tampering with recipient or fee will invalidate the snark proof
+    // Most likely it is not required, but it's better to stay on the safe side and it only takes 2 constraints
+    // Squares are used to prevent optimizer from removing those constraints
+    signal recipientSquare;
+    signal feeSquare;
+    signal relayerSquare;
+    signal refundSquare;
+    recipientSquare <== recipient * recipient;
+    feeSquare <== fee * fee;
+    relayerSquare <== relayer * relayer;
+    refundSquare <== refund * refund;
+}
+
+component main = Withdraw(20);

config.json

+{
+    "MERKLE_TREE_HEIGHT": 20,
+    "ETH_AMOUNT": "100000000000000000",
+    "weth9": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
+    "oracle": "0xA09FdE92b5FBb1d96da0108466bEBfd9E52CE901",
+    "dry": true,
+    "old": {
+        "owner": "0x7f3B46E1E7d0E60fE496C41e8f0D21d7e962D37d",
+        "pool": "0xefc73f21bb4645ea4cb1f1b5a674985c590c4070",
+        "token": "0xabe580e7ee158da464b51ee1a83ac0289622e6be"
+    },
+    "tokenStyle": {
+        "anonUSD": {
+            "name": "anonUSD",
+            "symbol": "anonUSD",
+            "icon": "assets/images/zkUSD.svg",
+            "color": "#D1C1FE",
+            "pool": "0x0000000000000000000000000000000000000000",
+            "chainlink": "0x5f4ec3df9cbd43714fe2740f5e3616155c5b8419",
+            "threshold": "975000000000000000",
+            "address": "",
+            "denoms": ["500"],
+            "price": "",
+            "mint": "10000000000000000000000"
+        },
+        "anonBTC": {
+            "name": "anonBTC",
+            "symbol": "anonBTC",
+            "icon": "assets/images/zkBTC.svg",
+            "color": "#5800B0",
+            "pool": "0x0000000000000000000000000000000000000000",
+            "chainlink": "0xdeb288F737066589598e9214E782fa5A8eD689e8",
+            "threshold": "975000000000000000",
+            "address": "",
+            "denoms": ["1"],
+            "price": "",
+            "mint": "10000000000000000000"
+        },
+        "anonETH": {
+            "name": "anonETH",
+            "symbol": "anonETH",
+            "icon": "assets/images/zkETH.svg",
+            "color": "#6B39FA",
+            "pool": "0x0000000000000000000000000000000000000000",
+            "chainlink": "0x0000000000000000000000000000000000000000",
+            "threshold": "975000000000000000",
+            "address": "",
+            "denoms": ["1"],
+            "price": 1,
+            "mint": "100000000000000000000"
+        },
+        "XFT": {
+            "name": "XFT",
+            "symbol": "XFT",
+            "icon": "assets/images/XFT-light.svg",
+            "color": "#FFFFFF",
+            "pool": "0x701b319aff36311f720f0a1ebd6636dd84bb3e8b",
+            "chainlink": "0x0000000000000000000000000000000000000000",
+            "threshold": "975000000000000000",
+            "address": "0x76bc677d444f1e9d57daf5187ee2b7dc852745ae"
+        }
+    },
+    "ethDenomination": "50000000000000000",
+    "xftToken": "",
+    "HASHER": "",
+    "VERIFIER": "",
+    "STORAGE": "",
+    "TOKEN_POOL": "",
+    "XFT_POOL": "",
+    "FAUCET": "",
+    "INTERVAL_SHORT": 180,
+    "INTERVAL_LONG": 1800,
+    "TOKEN_AMOUNT": "10000000000000000000000",
+    "ERC20_TOKEN": "",
+    "AUSD_TOKEN": "",
+    "FEE_AMOUNT": "",
+    "FAUCET_SEND": "true",
+    "uniswap": {
+        "xftUniPool": "0x701b319aff36311f720f0a1ebd6636dd84bb3e8b",
+        "NonfungiblePositionManager": "0xC36442b4a4522E871399CD717aBDD847Ab11FE88",
+        "UniswapV3Factory": "0x1F98431c8aD98523631AE4a59f267346ea31F984",
+        "SwapRouter": "0xE592427A0AEce92De3Edee1F18E0157C05861564",
+        "UniswapV3Staker": "0xe34139463bA50bD61336E0c446Bd8C0867c6fE65",
+        "nftID": 449412
+    }
+}
\ No newline at end of file

contracts/Interfaces/AggregatorV3Interface.sol

+// SPDX-License-Identifier: MIT
+pragma solidity ^0.7.0;
+
+interface AggregatorV3Interface {
+  function decimals() external view returns (uint8);
+
+  function description() external view returns (string memory);
+
+  function version() external view returns (uint256);
+
+  // getRoundData and latestRoundData should both raise "No data present"
+  // if they do not have data to report, instead of returning unset values
+  // which could be misinterpreted as actual reported values.
+  function getRoundData(uint80 _roundId)
+    external
+    view
+    returns (
+      uint80 roundId,
+      int256 answer,
+      uint256 startedAt,
+      uint256 updatedAt,
+      uint80 answeredInRound
+    );
+
+  function latestRoundData()
+    external
+    view
+    returns (
+      uint80 roundId,
+      int256 answer,
+      uint256 startedAt,
+      uint256 updatedAt,
+      uint80 answeredInRound
+    );
+}

contracts/Interfaces/ElasticIERC20.sol

+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.6.0 <0.8.0;
+
+/**
+ * @dev Interface of the ERC20 standard as defined in the EIP.
+ */
+interface ElasticIERC20 {
+    /**
+     * @dev Returns the amount of tokens in existence.
+     */
+    function totalSupply() external view returns (uint256);
+
+    /**
+     * @dev Returns the amount of tokens owned by `account`.
+     */
+    function balanceOf(address account) external view returns (uint256);
+
+    /**
+     * @dev Moves `amount` tokens from the caller's account to `recipient`.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transfer(address recipient, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Returns the remaining number of tokens that `spender` will be
+     * allowed to spend on behalf of `owner` through {transferFrom}. This is
+     * zero by default.
+     *
+     * This value changes when {approve} or {transferFrom} are called.
+     */
+    function allowance(address owner, address spender) external view returns (uint256);
+
+    /**
+     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * IMPORTANT: Beware that changing an allowance with this method brings the risk
+     * that someone may use both the old and the new allowance by unfortunate
+     * transaction ordering. One possible solution to mitigate this race
+     * condition is to first reduce the spender's allowance to 0 and set the
+     * desired value afterwards:
+     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
+     *
+     * Emits an {Approval} event.
+     */
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Moves `amount` tokens from `sender` to `recipient` using the
+     * allowance mechanism. `amount` is then deducted from the caller's
+     * allowance.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
+
+    // Additional mint and burn functions
+    function burn(address account, uint256 amount) external;
+    function mint(address account, uint256 amount) external;
+
+    /**
+     * @dev Emitted when `value` tokens are moved from one account (`from`) to
+     * another (`to`).
+     *
+     * Note that `value` may be zero.
+     */
+    event Transfer(address indexed from, address indexed to, uint256 value);
+
+    /**
+     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
+     * a call to {approve}. `value` is the new allowance.
+     */
+    event Approval(address indexed owner, address indexed spender, uint256 value);
+}

contracts/Interfaces/IERC20.sol

+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.6.0 <0.8.0;
+
+/**
+ * @dev Interface of the ERC20 standard as defined in the EIP.
+ */
+interface IERC20 {
+    /**
+     * @dev Returns the amount of tokens in existence.
+     */
+    function totalSupply() external view returns (uint256);
+
+    /**
+     * @dev Returns the amount of tokens owned by `account`.
+     */
+    function balanceOf(address account) external view returns (uint256);
+
+    /**
+     * @dev Moves `amount` tokens from the caller's account to `recipient`.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transfer(address recipient, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Returns the remaining number of tokens that `spender` will be
+     * allowed to spend on behalf of `owner` through {transferFrom}. This is
+     * zero by default.
+     *
+     * This value changes when {approve} or {transferFrom} are called.
+     */
+    function allowance(address owner, address spender) external view returns (uint256);
+
+    /**
+     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * IMPORTANT: Beware that changing an allowance with this method brings the risk
+     * that someone may use both the old and the new allowance by unfortunate
+     * transaction ordering. One possible solution to mitigate this race
+     * condition is to first reduce the spender's allowance to 0 and set the
+     * desired value afterwards:
+     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
+     *
+     * Emits an {Approval} event.
+     */
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Moves `amount` tokens from `sender` to `recipient` using the
+     * allowance mechanism. `amount` is then deducted from the caller's
+     * allowance.
+     *
+     * Returns a boolean value indicating whether the operation succeeded.
+     *
+     * Emits a {Transfer} event.
+     */
+    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
+
+    /**
+     * @dev Emitted when `value` tokens are moved from one account (`from`) to
+     * another (`to`).
+     *
+     * Note that `value` may be zero.
+     */
+    event Transfer(address indexed from, address indexed to, uint256 value);
+
+    /**
+     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
+     * a call to {approve}. `value` is the new allowance.
+     */
+    event Approval(address indexed owner, address indexed spender, uint256 value);
+}

contracts/Interfaces/IERC20Minimal.sol

+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity >=0.5.0;
+
+/// @title Minimal ERC20 interface for Uniswap
+/// @notice Contains a subset of the full ERC20 interface that is used in Uniswap V3
+interface IERC20Minimal {
+    /// @notice Returns the balance of a token
+    /// @param account The account for which to look up the number of tokens it has, i.e. its balance
+    /// @return The number of tokens held by the account
+    function balanceOf(address account) external view returns (uint256);
+
+    /// @notice Transfers the amount of token from the `msg.sender` to the recipient
+    /// @param recipient The account that will receive the amount transferred
+    /// @param amount The number of tokens to send from the sender to the recipient
+    /// @return Returns true for a successful transfer, false for an unsuccessful transfer
+    function transfer(address recipient, uint256 amount) external returns (bool);
+
+    /// @notice Returns the current allowance given to a spender by an owner
+    /// @param owner The account of the token owner
+    /// @param spender The account of the token spender
+    /// @return The current allowance granted by `owner` to `spender`
+    function allowance(address owner, address spender) external view returns (uint256);
+
+    /// @notice Sets the allowance of a spender from the `msg.sender` to the value `amount`
+    /// @param spender The account which will be allowed to spend a given amount of the owners tokens
+    /// @param amount The amount of tokens allowed to be used by `spender`
+    /// @return Returns true for a successful approval, false for unsuccessful
+    function approve(address spender, uint256 amount) external returns (bool);
+
+    /// @notice Transfers `amount` tokens from `sender` to `recipient` up to the allowance given to the `msg.sender`
+    /// @param sender The account from which the transfer will be initiated
+    /// @param recipient The recipient of the transfer
+    /// @param amount The amount of the transfer
+    /// @return Returns true for a successful transfer, false for unsuccessful
+    function transferFrom(
+        address sender,
+        address recipient,
+        uint256 amount
+    ) external returns (bool);
+
+    /// @notice Event emitted when tokens are transferred from one address to another, either via `#transfer` or `#transferFrom`.
+    /// @param from The account from which the tokens were sent, i.e. the balance decreased
+    /// @param to The account to which the tokens were sent, i.e. the balance increased
+    /// @param value The amount of tokens that were transferred
+    event Transfer(address indexed from, address indexed to, uint256 value);
+
+    /// @notice Event emitted when the approval amount for the spender of a given owner's tokens changes.
+    /// @param owner The account that approved spending of its tokens
+    /// @param spender The account for which the spending allowance was modified
+    /// @param value The new allowance from the owner to the spender
+    event Approval(address indexed owner, address indexed spender, uint256 value);
+}

contracts/Interfaces/INonfungiblePositionManager.sol

+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity >=0.7.5;
+pragma abicoder v2;
+
+import '@openzeppelin/contracts/token/ERC721/IERC721Metadata.sol';
+import '@openzeppelin/contracts/token/ERC721/IERC721Enumerable.sol';
+
+import '@uniswap/v3-periphery/contracts/interfaces/IPoolInitializer.sol';
+import '@uniswap/v3-periphery/contracts/interfaces/IERC721Permit.sol';
+import '@uniswap/v3-periphery/contracts/interfaces/IPeripheryPayments.sol';
+import '@uniswap/v3-periphery/contracts/interfaces/IPeripheryImmutableState.sol';
+import '@uniswap/v3-periphery/contracts/libraries/PoolAddress.sol';
+
+/// @title Non-fungible token for positions
+/// @notice Wraps Uniswap V3 positions in a non-fungible token interface which allows for them to be transferred
+/// and authorized.
+interface INonfungiblePositionManager is
+    IPoolInitializer,
+    IPeripheryPayments,
+    IPeripheryImmutableState,
+    IERC721Metadata,
+    IERC721Enumerable,
+    IERC721Permit
+{
+    /// @notice Emitted when liquidity is increased for a position NFT
+    /// @dev Also emitted when a token is minted
+    /// @param tokenId The ID of the token for which liquidity was increased
+    /// @param liquidity The amount by which liquidity for the NFT position was increased
+    /// @param amount0 The amount of token0 that was paid for the increase in liquidity
+    /// @param amount1 The amount of token1 that was paid for the increase in liquidity
+    event IncreaseLiquidity(uint256 indexed tokenId, uint128 liquidity, uint256 amount0, uint256 amount1);
+    /// @notice Emitted when liquidity is decreased for a position NFT
+    /// @param tokenId The ID of the token for which liquidity was decreased
+    /// @param liquidity The amount by which liquidity for the NFT position was decreased
+    /// @param amount0 The amount of token0 that was accounted for the decrease in liquidity
+    /// @param amount1 The amount of token1 that was accounted for the decrease in liquidity
+    event DecreaseLiquidity(uint256 indexed tokenId, uint128 liquidity, uint256 amount0, uint256 amount1);
+    /// @notice Emitted when tokens are collected for a position NFT
+    /// @dev The amounts reported may not be exactly equivalent to the amounts transferred, due to rounding behavior
+    /// @param tokenId The ID of the token for which underlying tokens were collected
+    /// @param recipient The address of the account that received the collected tokens
+    /// @param amount0 The amount of token0 owed to the position that was collected
+    /// @param amount1 The amount of token1 owed to the position that was collected
+    event Collect(uint256 indexed tokenId, address recipient, uint256 amount0, uint256 amount1);
+
+    /// @notice Returns the position information associated with a given token ID.
+    /// @dev Throws if the token ID is not valid.
+    /// @param tokenId The ID of the token that represents the position
+    /// @return nonce The nonce for permits
+    /// @return operator The address that is approved for spending
+    /// @return token0 The address of the token0 for a specific pool
+    /// @return token1 The address of the token1 for a specific pool
+    /// @return fee The fee associated with the pool
+    /// @return tickLower The lower end of the tick range for the position
+    /// @return tickUpper The higher end of the tick range for the position
+    /// @return liquidity The liquidity of the position
+    /// @return feeGrowthInside0LastX128 The fee growth of token0 as of the last action on the individual position
+    /// @return feeGrowthInside1LastX128 The fee growth of token1 as of the last action on the individual position
+    /// @return tokensOwed0 The uncollected amount of token0 owed to the position as of the last computation
+    /// @return tokensOwed1 The uncollected amount of token1 owed to the position as of the last computation
+    function positions(uint256 tokenId)
+        external
+        view
+        returns (
+            uint96 nonce,
+            address operator,
+            address token0,
+            address token1,
+            uint24 fee,
+            int24 tickLower,
+            int24 tickUpper,
+            uint128 liquidity,
+            uint256 feeGrowthInside0LastX128,
+            uint256 feeGrowthInside1LastX128,
+            uint128 tokensOwed0,
+            uint128 tokensOwed1
+        );
+
+    struct MintParams {
+        address token0;
+        address token1;
+        uint24 fee;
+        int24 tickLower;
+        int24 tickUpper;
+        uint256 amount0Desired;
+        uint256 amount1Desired;
+        uint256 amount0Min;
+        uint256 amount1Min;
+        address recipient;
+        uint256 deadline;
+    }
+
+    /// @notice Creates a new position wrapped in a NFT
+    /// @dev Call this when the pool does exist and is initialized. Note that if the pool is created but not initialized
+    /// a method does not exist, i.e. the pool is assumed to be initialized.
+    /// @param params The params necessary to mint a position, encoded as `MintParams` in calldata
+    /// @return tokenId The ID of the token that represents the minted position
+    /// @return liquidity The amount of liquidity for this position
+    /// @return amount0 The amount of token0
+    /// @return amount1 The amount of token1
+    function mint(MintParams calldata params)
+        external
+        payable
+        returns (
+            uint256 tokenId,
+            uint128 liquidity,
+            uint256 amount0,
+            uint256 amount1
+        );
+
+    struct IncreaseLiquidityParams {
+        uint256 tokenId;
+        uint256 amount0Desired;
+        uint256 amount1Desired;
+        uint256 amount0Min;
+        uint256 amount1Min;
+        uint256 deadline;
+    }
+
+    /// @notice Increases the amount of liquidity in a position, with tokens paid by the `msg.sender`
+    /// @param params tokenId The ID of the token for which liquidity is being increased,
+    /// amount0Desired The desired amount of token0 to be spent,
+    /// amount1Desired The desired amount of token1 to be spent,
+    /// amount0Min The minimum amount of token0 to spend, which serves as a slippage check,
+    /// amount1Min The minimum amount of token1 to spend, which serves as a slippage check,
+    /// deadline The time by which the transaction must be included to effect the change
+    /// @return liquidity The new liquidity amount as a result of the increase
+    /// @return amount0 The amount of token0 to acheive resulting liquidity
+    /// @return amount1 The amount of token1 to acheive resulting liquidity
+    function increaseLiquidity(IncreaseLiquidityParams calldata params)
+        external
+        payable
+        returns (
+            uint128 liquidity,
+            uint256 amount0,
+            uint256 amount1
+        );
+
+    struct DecreaseLiquidityParams {
+        uint256 tokenId;
+        uint128 liquidity;
+        uint256 amount0Min;
+        uint256 amount1Min;
+        uint256 deadline;
+    }
+
+    /// @notice Decreases the amount of liquidity in a position and accounts it to the position
+    /// @param params tokenId The ID of the token for which liquidity is being decreased,
+    /// amount The amount by which liquidity will be decreased,
+    /// amount0Min The minimum amount of token0 that should be accounted for the burned liquidity,
+    /// amount1Min The minimum amount of token1 that should be accounted for the burned liquidity,
+    /// deadline The time by which the transaction must be included to effect the change
+    /// @return amount0 The amount of token0 accounted to the position's tokens owed
+    /// @return amount1 The amount of token1 accounted to the position's tokens owed
+    function decreaseLiquidity(DecreaseLiquidityParams calldata params)
+        external
+        payable
+        returns (uint256 amount0, uint256 amount1);
+
+    struct CollectParams {
+        uint256 tokenId;
+        address recipient;
+        uint128 amount0Max;
+        uint128 amount1Max;
+    }
+
+    /// @notice Collects up to a maximum amount of fees owed to a specific position to the recipient
+    /// @param params tokenId The ID of the NFT for which tokens are being collected,
+    /// recipient The account that should receive the tokens,
+    /// amount0Max The maximum amount of token0 to collect,
+    /// amount1Max The maximum amount of token1 to collect
+    /// @return amount0 The amount of fees collected in token0
+    /// @return amount1 The amount of fees collected in token1
+    function collect(CollectParams calldata params) external payable returns (uint256 amount0, uint256 amount1);
+
+    /// @notice Burns a token ID, which deletes it from the NFT contract. The token must have 0 liquidity and all tokens
+    /// must be collected first.
+    /// @param tokenId The ID of the token that is being burned
+    function burn(uint256 tokenId) external payable;
+
+    
+    /// @notice Call multiple functions in the current contract and return the data from all of them if they all succeed
+    /// @dev The `msg.value` should not be trusted for any method callable from multicall.
+    /// @param data The encoded function data for each of the calls to make to this contract
+    /// @return results The results from each of the calls passed in via data
+    function multicall(bytes[] calldata data) external payable returns (bytes[] memory results);
+}

contracts/Interfaces/IOracle.sol

+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.6.0 <0.8.0;
+
+/**
+ * @dev Interface for Oracle.sol contract
+ */
+interface IOracle {
+    function getCost(
+        uint256 _amount,
+        address _chainlinkFeed,
+        address _xftPool
+    ) external view returns (uint256);
+
+    function getCostSimpleShift(
+        uint256 _amount,
+        address _chainlinkFeed,
+        address _xftPool,
+        address _tokenPool
+    ) external view returns (uint256);
+
+    function getTokensForAmount(
+        address _pool,
+        uint32 _interval,
+        address _chainlinkFeed,
+        uint256 _amount,
+        bool _ethLeftSide,
+        address _weth9
+    ) external view returns (uint256);
+
+    function ethLeftSide(address _chainlinkFeed) external view returns (bool);
+
+    function getTokensRaw(
+        address _xftPool,
+        address _tokenPool,
+        uint32 _interval,
+        uint256 _amount,
+        address _weth9
+    ) external view returns (uint256);
+
+    function isTokenBelowThreshold(
+        uint256 _threshold,
+        address _pool,
+        uint32 _interval,
+        address _chainlinkFeed,
+        bool _ethLeftSide,
+        address _weth9
+    ) external view returns (bool);
+}

contracts/Interfaces/IQuoterV2.sol

+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity >=0.7.5;
+pragma abicoder v2;
+
+/// @title QuoterV2 Interface
+/// @notice Supports quoting the calculated amounts from exact input or exact output swaps.
+/// @notice For each pool also tells you the number of initialized ticks crossed and the sqrt price of the pool after the swap.
+/// @dev These functions are not marked view because they rely on calling non-view functions and reverting
+/// to compute the result. They are also not gas efficient and should not be called on-chain.
+interface IQuoterV2 {
+    /// @notice Returns the amount out received for a given exact input swap without executing the swap
+    /// @param path The path of the swap, i.e. each token pair and the pool fee
+    /// @param amountIn The amount of the first token to swap
+    /// @return amountOut The amount of the last token that would be received
+    /// @return sqrtPriceX96AfterList List of the sqrt price after the swap for each pool in the path
+    /// @return initializedTicksCrossedList List of the initialized ticks that the swap crossed for each pool in the path
+    /// @return gasEstimate The estimate of the gas that the swap consumes
+    function quoteExactInput(bytes memory path, uint256 amountIn)
+        external
+        returns (
+            uint256 amountOut,
+            uint160[] memory sqrtPriceX96AfterList,
+            uint32[] memory initializedTicksCrossedList,
+            uint256 gasEstimate
+        );
+
+    struct QuoteExactInputSingleParams {
+        address tokenIn;
+        address tokenOut;
+        uint256 amountIn;
+        uint24 fee;
+        uint160 sqrtPriceLimitX96;
+    }
+
+    /// @notice Returns the amount out received for a given exact input but for a swap of a single pool
+    /// @param params The params for the quote, encoded as `QuoteExactInputSingleParams`
+    /// tokenIn The token being swapped in
+    /// tokenOut The token being swapped out
+    /// fee The fee of the token pool to consider for the pair
+    /// amountIn The desired input amount
+    /// sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
+    /// @return amountOut The amount of `tokenOut` that would be received
+    /// @return sqrtPriceX96After The sqrt price of the pool after the swap
+    /// @return initializedTicksCrossed The number of initialized ticks that the swap crossed
+    /// @return gasEstimate The estimate of the gas that the swap consumes
+    function quoteExactInputSingle(QuoteExactInputSingleParams memory params)
+        external
+        returns (
+            uint256 amountOut,
+            uint160 sqrtPriceX96After,
+            uint32 initializedTicksCrossed,
+            uint256 gasEstimate
+        );
+
+    /// @notice Returns the amount in required for a given exact output swap without executing the swap
+    /// @param path The path of the swap, i.e. each token pair and the pool fee. Path must be provided in reverse order
+    /// @param amountOut The amount of the last token to receive
+    /// @return amountIn The amount of first token required to be paid
+    /// @return sqrtPriceX96AfterList List of the sqrt price after the swap for each pool in the path
+    /// @return initializedTicksCrossedList List of the initialized ticks that the swap crossed for each pool in the path
+    /// @return gasEstimate The estimate of the gas that the swap consumes
+    function quoteExactOutput(bytes memory path, uint256 amountOut)
+        external
+        returns (
+            uint256 amountIn,
+            uint160[] memory sqrtPriceX96AfterList,
+            uint32[] memory initializedTicksCrossedList,
+            uint256 gasEstimate
+        );
+
+    struct QuoteExactOutputSingleParams {
+        address tokenIn;
+        address tokenOut;
+        uint256 amount;
+        uint24 fee;
+        uint160 sqrtPriceLimitX96;
+    }
+
+    /// @notice Returns the amount in required to receive the given exact output amount but for a swap of a single pool
+    /// @param params The params for the quote, encoded as `QuoteExactOutputSingleParams`
+    /// tokenIn The token being swapped in
+    /// tokenOut The token being swapped out
+    /// fee The fee of the token pool to consider for the pair
+    /// amountOut The desired output amount
+    /// sqrtPriceLimitX96 The price limit of the pool that cannot be exceeded by the swap
+    /// @return amountIn The amount required as the input for the swap in order to receive `amountOut`
+    /// @return sqrtPriceX96After The sqrt price of the pool after the swap
+    /// @return initializedTicksCrossed The number of initialized ticks that the swap crossed
+    /// @return gasEstimate The estimate of the gas that the swap consumes
+    function quoteExactOutputSingle(QuoteExactOutputSingleParams memory params)
+        external
+        returns (
+            uint256 amountIn,
+            uint160 sqrtPriceX96After,
+            uint32 initializedTicksCrossed,
+            uint256 gasEstimate
+        );
+}