vault deployment, query helper, bug fixes

src/QueryHelper.sol

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity =0.7.6;
+pragma abicoder v2;
+
+import "v3-core/contracts/interfaces/IUniswapV3Pool.sol";
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "./OrderLib.sol";
+import "./Vault.sol";
+import "./VaultDeployer.sol";
+import "./Factory.sol";
+
+contract QueryHelper {
+    uint8 constant public version = 1;
+    uint8 constant public UNKNOWN_DECIMALS = type(uint8).max;
+
+    function getBalances( address vault, address[] memory tokens ) public view
+    returns (
+        uint256[] memory balances,
+        uint256[] memory decimals
+    ) {
+        require(tokens.length < type(uint16).max);
+        balances = new uint256[](tokens.length);
+        decimals = new uint256[](tokens.length);
+        for( uint16 i=0; i < tokens.length; i++ ) {
+            try IERC20(tokens[i]).balanceOf(vault) returns (uint256 balance) {
+                balances[i] = balance;
+            }
+            catch {
+                balances[i] = 0;
+            }
+            try ERC20(tokens[i]).decimals() returns (uint8 dec) {
+                decimals[i] = dec;
+            }
+            catch {
+                decimals[i] = UNKNOWN_DECIMALS;
+            }
+        }
+    }
+
+    struct RoutesResult {
+        OrderLib.Exchange exchange;
+        uint24 fee;
+        address pool;
+    }
+
+    function getRoutes( address tokenA, address tokenB ) public view
+    returns(RoutesResult[] memory routes) {
+        // todo discover all supported pools
+        // here we find the highest liquidity pool for v2 and for v3
+        uint24[4] memory fees = [uint24(100),500,3000,10000];
+        uint24 uniswapV2Fee = 0;
+        uint128 uniswapV2Liquidity = 0;
+        address uniswapV2Pool = address(0);
+        uint24 uniswapV3Fee = 0;
+        uint128 uniswapV3Liquidity = 0;
+        address uniswapV3Pool = address(0);
+        for( uint8 f=0; f<4; f++ ) {
+            IUniswapV3Pool pool = IUniswapV3Pool(Constants.uniswapV3Factory.getPool(tokenA, tokenB, fees[f]));
+            try pool.liquidity() returns (uint128 liquidity) {
+                // todo v2
+                if( liquidity > uniswapV3Liquidity ) {
+                    uniswapV3Fee = fees[f];
+                    uniswapV3Liquidity = liquidity;
+                    uniswapV3Pool = address(pool);
+                }
+            }
+            catch {
+            }
+        }
+        uint8 routesCount = uniswapV3Fee > 0 ? 1 : 0 + uniswapV2Fee > 0 ? 1 : 0;
+        routes = new QueryHelper.RoutesResult[](routesCount);
+        uint8 i = 0;
+        // todo v2
+        if( uniswapV3Fee > 0 )
+            routes[i++] = QueryHelper.RoutesResult(OrderLib.Exchange.UniswapV3, uniswapV3Fee, uniswapV3Pool);
+    }
+
+    function poolStatus(IUniswapV3Pool pool) public view
+    returns (
+        int24 tick,
+        uint128 liquidity
+    ) {
+        (, tick,,,,,) = pool.slot0();
+        liquidity = pool.liquidity();
+    }
+}