Merge pull request #1 from tokenstation/v0.2

V0.2

contracts/Factories/ERC20Factory/ERC20Factory.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+// @title Interface for obtaining token info from contracts
+// @author tokenstation.dev
+
+pragma solidity 0.8.13;
+

contracts/Factories/ERC20Factory/util/LPToken.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+// @title Interface for obtaining token info from contracts
+// @author tokenstation.dev
+
+pragma solidity 0.8.13;
+
+import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+contract LPTokenERC20 {
+
+}

contracts/Factories/WeightedFactory/WeightedPoolFactory.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+// @title Interface for obtaining token info from contracts
+// @author tokenstation.dev
+
+pragma solidity 0.8.13;
+
+import { IFactory } from "../interfaces/IFactory.sol";
+import { WeightedPool } from "../../SwapContracts/WeightedPool/WeightedPool.sol";
+import { IWeightedVault } from "../../Vaults/WeightedPool/interfaces/IWeightedVault.sol";
+
+// TODO: add functions for setting weightedVault
+
+
+contract WeightedPoolFactory is IFactory {
+
+    uint256 constant public MAX_TOKENS = 20;
+
+    IWeightedVault public weightedVault;
+
+    event PoolCreated(
+        address indexed poolAddress,
+        address[] tokens,
+        uint256[] weights,
+        uint256 swapFee,
+        uint256 depositFee,
+        uint256 indexed poolId
+    );
+
+    string constant public version = "v1";
+    string constant public basePoolsName = "WeightedPool";
+    uint256 constant internal ONE = 1e18;
+
+    address[] public pools;
+    mapping(address => bool) public knownPools;
+    /**
+      Initial cost of writing non-zero value is 22100 gas
+      When we restore previously written value to 0 (if storage slot previously had 0 value) 
+      we pay 2200 get 19900 gas refund, so final cost is:
+      cost = 22100 + 2200 - 19900 = 4400 gas per token
+      usually there are 2-5 tokens, so cost of uniqueness check is ~8k-20k
+
+      Also, mappings can only be created as state variables (as of solc 0.8.13)
+     */
+    mapping(address => bool) internal uniqueTokens;
+
+    function crearePool(
+        address[] memory tokens_,
+        uint256[] memory weights_,
+        uint256 swapFee_,
+        uint256 depositFee_,
+        string memory lpName,
+        string memory lpSymbol
+    )
+        external
+        returns (address poolAddress)
+    {
+        require(
+            tokens_.length == weights_.length,
+            "Invalid array length"
+        );
+        require(
+            tokens_.length >= 2,
+            "Cannot create pool with 0 or 1 token"
+        );
+        require(
+            tokens_.length <= MAX_TOKENS,
+            "Cannot create pool with more than 20 tokens"
+        );
+
+        uint256 weightSum = 0;
+        for (uint256 tokenId = 0; tokenId < tokens_.length; tokenId++) {
+            require(
+                tokens_[tokenId] != address(0),
+                "Zero-address tokens are forbidden"
+            );
+            require(
+                !uniqueTokens[tokens_[tokenId]],
+                "Token duplication detected. Pool can only have unique tokens."
+            );
+            require(
+                weights_[tokenId] >= 0, // TODO: add real value
+                "Weight cannot be lower than {value}"
+            );
+
+            uniqueTokens[tokens_[tokenId]] = true;
+            weightSum += weights_[tokenId];
+        }
+
+        require(
+            weightSum == ONE,
+            "Sum of all weights is not equal to ONE (1e18)"
+        );
+
+        // Free storage to get gas refund
+        for (uint256 tokenId = 0; tokenId < tokens_.length; tokenId++) {
+            delete uniqueTokens[tokens_[tokenId]];
+        }
+
+        poolAddress = address(
+            new WeightedPool(
+                msg.sender,
+                tokens_,
+                weights_,
+                swapFee_,
+                depositFee_,
+                lpName,
+                lpSymbol
+            )
+        );
+
+        require(
+            weightedVault.registerPool(
+                poolAddress,
+                tokens_
+            ),
+            "Cannot register pool in vault, aborting pool creation"
+        );
+
+        emit PoolCreated(poolAddress, tokens_, weights_, swapFee_, depositFee_, pools.length);
+        pools.push(poolAddress);
+        knownPools[poolAddress] = true;
+    }
+
+    function getPoolById(
+        uint256 poolId
+    )
+        external
+        view
+        override
+        returns (address)
+    {
+        return pools[poolId];
+    }
+
+    function checkPoolAddress(
+        address poolAddress
+    ) 
+        external 
+        view 
+        override
+        returns (bool knownPool)
+    {
+        return knownPools[poolAddress];
+    }
+}

contracts/Factories/interfaces/IFactory.sol

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+// SPDX-License-Identifier: GPL-3.0-or-later
+// @title Interface for obtaining token info from contracts
+// @author tokenstation.dev
+
+pragma solidity 0.8.13;
+
+interface IFactory {
+    function getPoolById(uint256 poolId) external view returns(address poolAddress);
+    function checkPoolAddress(address poolAddress) external view returns(bool poolExists);
+}