// SPDX-License-Identifier: MIT

pragma solidity >=0.7.6 <0.8.0;

import {IWrappedERC20, ERC20Wrapper} from "@animoca/ethereum-contracts-core/contracts/utils/ERC20Wrapper.sol";
import {ManagedIdentity} from "@animoca/ethereum-contracts-core/contracts/metatx/ManagedIdentity.sol";
import {PolygonERC20PredicateBase} from "./PolygonERC20PredicateBase.sol";

/**
 * @title ERC20 Escrow Predicate (for Polygon).
 * Polygon bridging ERC20 escrowing predicate which works with a `Withdrawn(address account, uint256 value)` event.
 * @dev This contract should be deployed on the Root Chain (Ethereum).
 */
contract PolygonERC20EscrowPredicate is ManagedIdentity, PolygonERC20PredicateBase {
    using ERC20Wrapper for IWrappedERC20;

    // @inheritdoc PolygonERC20PredicateBase
    constructor(address rootChainManager_) PolygonERC20PredicateBase(rootChainManager_) {}

    //==================================================== TokenPredicate ===================================================//

    /**
     * Locks ERC20 tokens for deposit.
     * @dev Reverts if not called by the manager (RootChainManager).
     * @param depositor Address who wants to deposit tokens.
     * @param depositReceiver Address (address) who wants to receive tokens on child chain.
     * @param rootToken Token which gets deposited.
     * @param depositData ABI encoded amount.
     */
    function lockTokens(
        address depositor,
        address depositReceiver,
        address rootToken,
        bytes calldata depositData
    ) external override {
        _requireManagerRole(_msgSender());
        uint256 amount = abi.decode(depositData, (uint256));
        emit LockedERC20(depositor, depositReceiver, rootToken, amount);
        IWrappedERC20(rootToken).wrappedTransferFrom(depositor, address(this), amount);
    }

    /**
     * Validates the {Withdrawn} log signature, then sends the correct amount to withdrawer.
     * @dev Reverts if not called only by the manager (RootChainManager).
     * @param rootToken Token which gets withdrawn.
     * @param log Valid ERC20 burn log from child chain.
     */
    function exitTokens(
        address,
        address rootToken,
        bytes memory log
    ) public override {
        _requireManagerRole(_msgSender());
        (address withdrawer, uint256 amount) = _verifyWithdrawalLog(log);
        IWrappedERC20(rootToken).wrappedTransfer(withdrawer, amount);
    }
}