pragma solidity ^0.6.0;


// This file has been flattened from
// https://github.com/OpenZeppelin/openzeppelin-sdk/blob/solc-0.6/packages/lib/contracts/upgradeability/AdminUpgradeabilityProxy.sol
// Due to the lack of 0.6.0 version
// File: @openzeppelin/upgrades/contracts/upgradeability/Proxy.sol
// dHEDGE DAO - https://dhedge.org
//
// MIT License
// ===========
//
// Copyright (c) 2020 dHEDGE DAO
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//
/**
 * @title Proxy
 * @dev Implements delegation of calls to other contracts, with proper
 * forwarding of return values and bubbling of failures.
 * It defines a fallback function that delegates all calls to the address
 * returned by the abstract _implementation() internal function.
 */
abstract contract Proxy {
    /**
     * @dev Fallback function.
     * Implemented entirely in `_fallback`.
     */
    fallback() external payable {
        _fallback();
    }

    receive() external payable {
        _fallback();
    }

    /**
     * @return The Address of the implementation.
     */
    function _implementation() internal virtual view returns (address);

    /**
     * @dev Delegates execution to an implementation contract.
     * This is a low level function that doesn't return to its internal call site.
     * It will return to the external caller whatever the implementation returns.
     * @param implementation Address to delegate.
     */
    function _delegate(address implementation) internal {
        assembly {
            // Copy msg.data. We take full control of memory in this inline assembly
            // block because it will not return to Solidity code. We overwrite the
            // Solidity scratch pad at memory position 0.
            calldatacopy(0, 0, calldatasize())

            // Call the implementation.
            // out and outsize are 0 because we don't know the size yet.
            let result := delegatecall(
                gas(),
                implementation,
                0,
                calldatasize(),
                0,
                0
            )

            // Copy the returned data.
            returndatacopy(0, 0, returndatasize())

            switch result
                // delegatecall returns 0 on error.
                case 0 {
                    revert(0, returndatasize())
                }
                default {
                    return(0, returndatasize())
                }
        }
    }

    /**
     * @dev Function that is run as the first thing in the fallback function.
     * Can be redefined in derived contracts to add functionality.
     * Redefinitions must call super._willFallback().
     */
    function _willFallback() internal virtual {}

    /**
     * @dev fallback implementation.
     * Extracted to enable manual triggering.
     */
    function _fallback() internal {
        _willFallback();
        _delegate(_implementation());
    }
}

// File: @openzeppelin/upgrades/contracts/utils/Address.sol
/**
 * Utility library of inline functions on addresses
 *
 * Source https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-solidity/v2.1.3/contracts/utils/Address.sol
 * This contract is copied here and renamed from the original to avoid clashes in the compiled artifacts
 * when the user imports a zos-lib contract (that transitively causes this contract to be compiled and added to the
 * build/artifacts folder) as well as the vanilla Address implementation from an openzeppelin version.
 */
library OpenZeppelinUpgradesAddress {
    /**
     * Returns whether the target address is a contract
     * @dev This function will return false if invoked during the constructor of a contract,
     * as the code is not actually created until after the constructor finishes.
     * @param account address of the account to check
     * @return whether the target address is a contract
     */
    function isContract(address account) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }
}

// File: @openzeppelin/upgrades/contracts/upgradeability/BaseUpgradeabilityProxy.sol
/**
 * @title BaseUpgradeabilityProxy
 * @dev This contract implements a proxy that allows to change the
 * implementation address to which it will delegate.
 * Such a change is called an implementation upgrade.
 */
contract BaseUpgradeabilityProxy is Proxy {
    /**
     * @dev Emitted when the implementation is upgraded.
     * @param implementation Address of the new implementation.
     */
    event Upgraded(address indexed implementation);

    /**
     * @dev Storage slot with the address of the current implementation.
     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
     * validated in the constructor.
     */
    bytes32
        internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Returns the current implementation.
     * @return impl Address of the current implementation
     */
    function _implementation() internal override view returns (address impl) {
        bytes32 slot = IMPLEMENTATION_SLOT;
        assembly {
            impl := sload(slot)
        }
    }

    /**
     * @dev Upgrades the proxy to a new implementation.
     * @param newImplementation Address of the new implementation.
     */
    function _upgradeTo(address newImplementation) internal {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Sets the implementation address of the proxy.
     * @param newImplementation Address of the new implementation.
     */
    function _setImplementation(address newImplementation) internal {
        require(
            OpenZeppelinUpgradesAddress.isContract(newImplementation),
            "Cannot set a proxy implementation to a non-contract address"
        );

        bytes32 slot = IMPLEMENTATION_SLOT;

        assembly {
            sstore(slot, newImplementation)
        }
    }
}

// File: @openzeppelin/upgrades/contracts/upgradeability/UpgradeabilityProxy.sol
/**
 * @title UpgradeabilityProxy
 * @dev Extends BaseUpgradeabilityProxy with a constructor for initializing
 * implementation and init data.
 */
contract UpgradeabilityProxy is BaseUpgradeabilityProxy {
    /**
     * @dev Contract constructor.
     * @param _logic Address of the initial implementation.
     * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
     * It should include the signature and the parameters of the function to be called, as described in
     * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
     * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
     */
    constructor(address _logic, bytes memory _data) public payable {
        assert(
            IMPLEMENTATION_SLOT ==
                bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1)
        );
        _setImplementation(_logic);
        if (_data.length > 0) {
            (bool success, ) = _logic.delegatecall(_data);
            require(success);
        }
    }
}

// File: @openzeppelin/upgrades/contracts/upgradeability/BaseAdminUpgradeabilityProxy.sol
/**
 * @title BaseAdminUpgradeabilityProxy
 * @dev This contract combines an upgradeability proxy with an authorization
 * mechanism for administrative tasks.
 * All external functions in this contract must be guarded by the
 * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
 * feature proposal that would enable this to be done automatically.
 */
contract BaseAdminUpgradeabilityProxy is BaseUpgradeabilityProxy {
    /**
     * @dev Emitted when the administration has been transferred.
     * @param previousAdmin Address of the previous admin.
     * @param newAdmin Address of the new admin.
     */
    event AdminChanged(address previousAdmin, address newAdmin);

    /**
     * @dev Storage slot with the admin of the contract.
     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
     * validated in the constructor.
     */

    bytes32
        internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /**
     * @dev Modifier to check whether the `msg.sender` is the admin.
     * If it is, it will run the function. Otherwise, it will delegate the call
     * to the implementation.
     */
    modifier ifAdmin() {
        if (msg.sender == _admin()) {
            _;
        } else {
            _fallback();
        }
    }

    /**
     * @return The address of the proxy admin.
     */
    function admin() external ifAdmin returns (address) {
        return _admin();
    }

    /**
     * @return The address of the implementation.
     */
    function implementation() external ifAdmin returns (address) {
        return _implementation();
    }

    /**
     * @dev Changes the admin of the proxy.
     * Only the current admin can call this function.
     * @param newAdmin Address to transfer proxy administration to.
     */
    function changeAdmin(address newAdmin) external ifAdmin {
        require(
            newAdmin != address(0),
            "Cannot change the admin of a proxy to the zero address"
        );
        emit AdminChanged(_admin(), newAdmin);
        _setAdmin(newAdmin);
    }

    /**
     * @dev Upgrade the backing implementation of the proxy.
     * Only the admin can call this function.
     * @param newImplementation Address of the new implementation.
     */
    function upgradeTo(address newImplementation) external ifAdmin {
        _upgradeTo(newImplementation);
    }

    /**
     * @dev Upgrade the backing implementation of the proxy and call a function
     * on the new implementation.
     * This is useful to initialize the proxied contract.
     * @param newImplementation Address of the new implementation.
     * @param data Data to send as msg.data in the low level call.
     * It should include the signature and the parameters of the function to be called, as described in
     * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
     */
    function upgradeToAndCall(address newImplementation, bytes calldata data)
        external
        payable
        ifAdmin
    {
        _upgradeTo(newImplementation);
        (bool success, ) = newImplementation.delegatecall(data);
        require(success);
    }

    /**
     * @return adm The admin slot.
     */
    function _admin() internal view returns (address adm) {
        bytes32 slot = ADMIN_SLOT;
        assembly {
            adm := sload(slot)
        }
    }

    /**
     * @dev Sets the address of the proxy admin.
     * @param newAdmin Address of the new proxy admin.
     */
    function _setAdmin(address newAdmin) internal {
        bytes32 slot = ADMIN_SLOT;

        assembly {
            sstore(slot, newAdmin)
        }
    }

    /**
     * @dev Only fall back when the sender is not the admin.
     */
    function _willFallback() internal virtual override {
        require(
            msg.sender != _admin(),
            "Cannot call fallback function from the proxy admin"
        );
        super._willFallback();
    }
}

// File: @openzeppelin/upgrades/contracts/upgradeability/AdminUpgradeabilityProxy.sol
/**
 * @title AdminUpgradeabilityProxy
 * @dev Extends from BaseAdminUpgradeabilityProxy with a constructor for
 * initializing the implementation, admin, and init data.
 */
contract AdminUpgradeabilityProxy is
    BaseAdminUpgradeabilityProxy,
    UpgradeabilityProxy
{
    /**
     * Contract constructor.
     * @param _logic address of the initial implementation.
     * @param _admin Address of the proxy administrator.
     * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
     * It should include the signature and the parameters of the function to be called, as described in
     * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
     * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
     */
    constructor(
        address _logic,
        address _admin,
        bytes memory _data
    ) public payable UpgradeabilityProxy(_logic, _data) {
        assert(
            ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1)
        );
        _setAdmin(_admin);
    }

    function _willFallback()
        internal
        override(BaseAdminUpgradeabilityProxy, Proxy)
    {
        super._willFallback();
    }
}

// dHEDGE DAO - https://dhedge.org
//
// MIT License
// ===========
//
// Copyright (c) 2020 dHEDGE DAO
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//
// ---------------------------------------------------------------------
// dHedge DAO Token Proxy
//
// Notes          : This contract is a proxy to the dHedge DAO Token.
//                  It allows upgradeability using CALLDELEGATE pattern (code courtesy of https://openzeppelin.org/).
//                  This address should be accessed with the ABI of the current token delegate contract.
//
// ---------------------------------------------------------------------
contract DHedgeTokenProxy is AdminUpgradeabilityProxy {
    constructor(address _implementation, bytes memory _data)
        public
        payable
        AdminUpgradeabilityProxy(_implementation, msg.sender, _data)
    {}
}