/**
 * Source Code first verified at https://etherscan.io on Tuesday, April 16, 2019
 (UTC) */

// File: contracts/evmscript/ScriptHelpers.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library ScriptHelpers {
    function getSpecId(bytes _script) internal pure returns (uint32) {
        return uint32At(_script, 0);
    }

    function uint256At(bytes _data, uint256 _location) internal pure returns (uint256 result) {
        assembly {
            result := mload(add(_data, add(0x20, _location)))
        }
    }

    function addressAt(bytes _data, uint256 _location) internal pure returns (address result) {
        uint256 word = uint256At(_data, _location);

        assembly {
            result := div(and(word, 0xffffffffffffffffffffffffffffffffffffffff000000000000000000000000),
            0x1000000000000000000000000)
        }
    }

    function uint32At(bytes _data, uint256 _location) internal pure returns (uint32 result) {
        uint256 word = uint256At(_data, _location);

        assembly {
            result := div(and(word, 0xffffffff00000000000000000000000000000000000000000000000000000000),
            0x100000000000000000000000000000000000000000000000000000000)
        }
    }

    function locationOf(bytes _data, uint256 _location) internal pure returns (uint256 result) {
        assembly {
            result := add(_data, add(0x20, _location))
        }
    }

    function toBytes(bytes4 _sig) internal pure returns (bytes) {
        bytes memory payload = new bytes(4);
        assembly { mstore(add(payload, 0x20), _sig) }
        return payload;
    }
}

// File: contracts/common/Uint256Helpers.sol

pragma solidity ^0.4.24;


library Uint256Helpers {
    uint256 private constant MAX_UINT64 = uint64(-1);

    string private constant ERROR_NUMBER_TOO_BIG = "UINT64_NUMBER_TOO_BIG";

    function toUint64(uint256 a) internal pure returns (uint64) {
        require(a <= MAX_UINT64, ERROR_NUMBER_TOO_BIG);
        return uint64(a);
    }
}

// File: contracts/common/TimeHelpers.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract TimeHelpers {
    using Uint256Helpers for uint256;

    /**
    * @dev Returns the current block number.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber() internal view returns (uint256) {
        return block.number;
    }

    /**
    * @dev Returns the current block number, converted to uint64.
    *      Using a function rather than `block.number` allows us to easily mock the block number in
    *      tests.
    */
    function getBlockNumber64() internal view returns (uint64) {
        return getBlockNumber().toUint64();
    }

    /**
    * @dev Returns the current timestamp.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp() internal view returns (uint256) {
        return block.timestamp; // solium-disable-line security/no-block-members
    }

    /**
    * @dev Returns the current timestamp, converted to uint64.
    *      Using a function rather than `block.timestamp` allows us to easily mock it in
    *      tests.
    */
    function getTimestamp64() internal view returns (uint64) {
        return getTimestamp().toUint64();
    }
}

// File: contracts/common/UnstructuredStorage.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


library UnstructuredStorage {
    function getStorageBool(bytes32 position) internal view returns (bool data) {
        assembly { data := sload(position) }
    }

    function getStorageAddress(bytes32 position) internal view returns (address data) {
        assembly { data := sload(position) }
    }

    function getStorageBytes32(bytes32 position) internal view returns (bytes32 data) {
        assembly { data := sload(position) }
    }

    function getStorageUint256(bytes32 position) internal view returns (uint256 data) {
        assembly { data := sload(position) }
    }

    function setStorageBool(bytes32 position, bool data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageAddress(bytes32 position, address data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageBytes32(bytes32 position, bytes32 data) internal {
        assembly { sstore(position, data) }
    }

    function setStorageUint256(bytes32 position, uint256 data) internal {
        assembly { sstore(position, data) }
    }
}

// File: contracts/common/Initializable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract Initializable is TimeHelpers {
    using UnstructuredStorage for bytes32;

    // keccak256("aragonOS.initializable.initializationBlock")
    bytes32 internal constant INITIALIZATION_BLOCK_POSITION = 0xebb05b386a8d34882b8711d156f463690983dc47815980fb82aeeff1aa43579e;

    string private constant ERROR_ALREADY_INITIALIZED = "INIT_ALREADY_INITIALIZED";
    string private constant ERROR_NOT_INITIALIZED = "INIT_NOT_INITIALIZED";

    modifier onlyInit {
        require(getInitializationBlock() == 0, ERROR_ALREADY_INITIALIZED);
        _;
    }

    modifier isInitialized {
        require(hasInitialized(), ERROR_NOT_INITIALIZED);
        _;
    }

    /**
    * @return Block number in which the contract was initialized
    */
    function getInitializationBlock() public view returns (uint256) {
        return INITIALIZATION_BLOCK_POSITION.getStorageUint256();
    }

    /**
    * @return Whether the contract has been initialized by the time of the current block
    */
    function hasInitialized() public view returns (bool) {
        uint256 initializationBlock = getInitializationBlock();
        return initializationBlock != 0 && getBlockNumber() >= initializationBlock;
    }

    /**
    * @dev Function to be called by top level contract after initialization has finished.
    */
    function initialized() internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(getBlockNumber());
    }

    /**
    * @dev Function to be called by top level contract after initialization to enable the contract
    *      at a future block number rather than immediately.
    */
    function initializedAt(uint256 _blockNumber) internal onlyInit {
        INITIALIZATION_BLOCK_POSITION.setStorageUint256(_blockNumber);
    }
}

// File: contracts/common/Petrifiable.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract Petrifiable is Initializable {
    // Use block UINT256_MAX (which should be never) as the initializable date
    uint256 internal constant PETRIFIED_BLOCK = uint256(-1);

    function isPetrified() public view returns (bool) {
        return getInitializationBlock() == PETRIFIED_BLOCK;
    }

    /**
    * @dev Function to be called by top level contract to prevent being initialized.
    *      Useful for freezing base contracts when they're used behind proxies.
    */
    function petrify() internal onlyInit {
        initializedAt(PETRIFIED_BLOCK);
    }
}

// File: contracts/common/Autopetrified.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;



contract Autopetrified is Petrifiable {
    constructor() public {
        // Immediately petrify base (non-proxy) instances of inherited contracts on deploy.
        // This renders them uninitializable (and unusable without a proxy).
        petrify();
    }
}

// File: contracts/evmscript/IEVMScriptExecutor.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;


interface IEVMScriptExecutor {
    function execScript(bytes script, bytes input, address[] blacklist) external returns (bytes);
    function executorType() external pure returns (bytes32);
}

// File: contracts/evmscript/executors/BaseEVMScriptExecutor.sol

/*
 * SPDX-License-Identitifer:    MIT
 */

pragma solidity ^0.4.24;




contract BaseEVMScriptExecutor is IEVMScriptExecutor, Autopetrified {
    uint256 internal constant SCRIPT_START_LOCATION = 4;
}

// File: contracts/evmscript/executors/CallsScript.sol

pragma solidity 0.4.24;

// Inspired by https://github.com/reverendus/tx-manager




contract CallsScript is BaseEVMScriptExecutor {
    using ScriptHelpers for bytes;

    /* Hardcoded constants to save gas
    bytes32 internal constant EXECUTOR_TYPE = keccak256("CALLS_SCRIPT");
    */
    bytes32 internal constant EXECUTOR_TYPE = 0x2dc858a00f3e417be1394b87c07158e989ec681ce8cc68a9093680ac1a870302;

    string private constant ERROR_BLACKLISTED_CALL = "EVMCALLS_BLACKLISTED_CALL";
    string private constant ERROR_INVALID_LENGTH = "EVMCALLS_INVALID_LENGTH";

    /* This is manually crafted in assembly
    string private constant ERROR_CALL_REVERTED = "EVMCALLS_CALL_REVERTED";
    */

    event LogScriptCall(address indexed sender, address indexed src, address indexed dst);

    /**
    * @notice Executes a number of call scripts
    * @param _script [ specId (uint32) ] many calls with this structure ->
    *    [ to (address: 20 bytes) ] [ calldataLength (uint32: 4 bytes) ] [ calldata (calldataLength bytes) ]
    * @param _blacklist Addresses the script cannot call to, or will revert.
    * @return Always returns empty byte array
    */
    function execScript(bytes _script, bytes, address[] _blacklist) external isInitialized returns (bytes) {
        uint256 location = SCRIPT_START_LOCATION; // first 32 bits are spec id
        while (location < _script.length) {
            // Check there's at least address + calldataLength available
            require(_script.length - location >= 0x18, ERROR_INVALID_LENGTH);

            address contractAddress = _script.addressAt(location);
            // Check address being called is not blacklist
            for (uint256 i = 0; i < _blacklist.length; i++) {
                require(contractAddress != _blacklist[i], ERROR_BLACKLISTED_CALL);
            }

            // logged before execution to ensure event ordering in receipt
            // if failed entire execution is reverted regardless
            emit LogScriptCall(msg.sender, address(this), contractAddress);

            uint256 calldataLength = uint256(_script.uint32At(location + 0x14));
            uint256 startOffset = location + 0x14 + 0x04;
            uint256 calldataStart = _script.locationOf(startOffset);

            // compute end of script / next location
            location = startOffset + calldataLength;
            require(location <= _script.length, ERROR_INVALID_LENGTH);

            bool success;
            assembly {
                success := call(
                    sub(gas, 5000),       // forward gas left - 5000
                    contractAddress,      // address
                    0,                    // no value
                    calldataStart,        // calldata start
                    calldataLength,       // calldata length
                    0,                    // don't write output
                    0                     // don't write output
                )

                switch success
                case 0 {
                    let ptr := mload(0x40)

                    switch returndatasize
                    case 0 {
                        // No error data was returned, revert with "EVMCALLS_CALL_REVERTED"
                        // See remix: doing a `revert("EVMCALLS_CALL_REVERTED")` always results in
                        // this memory layout
                        mstore(ptr, 0x08c379a000000000000000000000000000000000000000000000000000000000)         // error identifier
                        mstore(add(ptr, 0x04), 0x0000000000000000000000000000000000000000000000000000000000000020) // starting offset
                        mstore(add(ptr, 0x24), 0x0000000000000000000000000000000000000000000000000000000000000016) // reason length
                        mstore(add(ptr, 0x44), 0x45564d43414c4c535f43414c4c5f524556455254454400000000000000000000) // reason

                        revert(ptr, 100) // 100 = 4 + 3 * 32 (error identifier + 3 words for the ABI encoded error)
                    }
                    default {
                        // Forward the full error data
                        returndatacopy(ptr, 0, returndatasize)
                        revert(ptr, returndatasize)
                    }
                }
                default { }
            }
        }
        // No need to allocate empty bytes for the return as this can only be called via an delegatecall
        // (due to the isInitialized modifier)
    }

    function executorType() external pure returns (bytes32) {
        return EXECUTOR_TYPE;
    }
}