// Vulnerability label: LE_RENT
pragma solidity ^0.4.24;

/**
 * @title Owned
 * @dev Basic contract to define an owner.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract Owned {

    // The owner
    address public owner;

    event OwnerChanged(address indexed _newOwner);

    /**
     * @dev Throws if the sender is not the owner.
     */
    modifier onlyOwner {
        require(msg.sender == owner, "Must be owner");
        _;
    }

    constructor() public {
        owner = msg.sender;
    }

    /**
     * @dev Lets the owner transfer ownership of the contract to a new owner.
     * @param _newOwner The new owner.
     */
    function changeOwner(address _newOwner) external onlyOwner {
        require(_newOwner != address(0), "Address must not be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }
}

/**
 * @title Managed
 * @dev Basic contract that defines a set of managers. Only the owner can add/remove managers.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract Managed is Owned {

    // The managers
    mapping (address => bool) public managers;

    /**
     * @dev Throws if the sender is not a manager.
     */
    modifier onlyManager {
        require(managers[msg.sender] == true, "M: Must be manager");
        _;
    }

    event ManagerAdded(address indexed _manager);
    event ManagerRevoked(address indexed _manager);

    /**
    * @dev Adds a manager. 
    * @param _manager The address of the manager.
    */
    function addManager(address _manager) external onlyOwner {
        require(_manager != address(0), "M: Address must not be null");
        if(managers[_manager] == false) {
            managers[_manager] = true;
            emit ManagerAdded(_manager);
        }        
    }

    /**
    * @dev Revokes a manager.
    * @param _manager The address of the manager.
    */
    function revokeManager(address _manager) external onlyOwner {
        require(managers[_manager] == true, "M: Target must be an existing manager");
        delete managers[_manager];
        emit ManagerRevoked(_manager);
    }
}

/**
 * ENS Registry interface.
 */
contract ENSRegistry {
    function owner(bytes32 _node) public view returns (address);
    function resolver(bytes32 _node) public view returns (address);
    function ttl(bytes32 _node) public view returns (uint64);
    function setOwner(bytes32 _node, address _owner) public;
    function setSubnodeOwner(bytes32 _node, bytes32 _label, address _owner) public;
    function setResolver(bytes32 _node, address _resolver) public;
    function setTTL(bytes32 _node, uint64 _ttl) public;
}

/**
 * ENS Resolver interface.
 */
contract ENSResolver {
    function addr(bytes32 _node) public view returns (address);
    function setAddr(bytes32 _node, address _addr) public;
    function name(bytes32 _node) public view returns (string);
    function setName(bytes32 _node, string _name) public;
}

/**
 * ENS Reverse Registrar interface.
 */
contract ENSReverseRegistrar {
    function claim(address _owner) public returns (bytes32 _node);
    function claimWithResolver(address _owner, address _resolver) public returns (bytes32);
    function setName(string _name) public returns (bytes32);
    function node(address _addr) public view returns (bytes32);
}

/*
 * @title String & slice utility library for Solidity contracts.
 * @author Nick Johnson <arachnid@notdot.net>
 *
 * @dev Functionality in this library is largely implemented using an
 *      abstraction called a 'slice'. A slice represents a part of a string -
 *      anything from the entire string to a single character, or even no
 *      characters at all (a 0-length slice). Since a slice only has to specify
 *      an offset and a length, copying and manipulating slices is a lot less
 *      expensive than copying and manipulating the strings they reference.
 *
 *      To further reduce gas costs, most functions on slice that need to return
 *      a slice modify the original one instead of allocating a new one; for
 *      instance, `s.split(".")` will return the text up to the first '.',
 *      modifying s to only contain the remainder of the string after the '.'.
 *      In situations where you do not want to modify the original slice, you
 *      can make a copy first with `.copy()`, for example:
 *      `s.copy().split(".")`. Try and avoid using this idiom in loops; since
 *      Solidity has no memory management, it will result in allocating many
 *      short-lived slices that are later discarded.
 *
 *      Functions that return two slices come in two versions: a non-allocating
 *      version that takes the second slice as an argument, modifying it in
 *      place, and an allocating version that allocates and returns the second
 *      slice; see `nextRune` for example.
 *
 *      Functions that have to copy string data will return strings rather than
 *      slices; these can be cast back to slices for further processing if
 *      required.
 *
 *      For convenience, some functions are provided with non-modifying
 *      variants that create a new slice and return both; for instance,
 *      `s.splitNew('.')` leaves s unmodified, and returns two values
 *      corresponding to the left and right parts of the string.
 */
/* solium-disable */
library strings {
    struct slice {
        uint _len;
        uint _ptr;
    }

    function memcpy(uint dest, uint src, uint len) private pure {
        // Copy word-length chunks while possible
        for(; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
    }

    /*
     * @dev Returns a slice containing the entire string.
     * @param self The string to make a slice from.
     * @return A newly allocated slice containing the entire string.
     */
    function toSlice(string memory self) internal pure returns (slice memory) {
        uint ptr;
        assembly {
            ptr := add(self, 0x20)
        }
        return slice(bytes(self).length, ptr);
    }

    /*
     * @dev Returns the length of a null-terminated bytes32 string.
     * @param self The value to find the length of.
     * @return The length of the string, from 0 to 32.
     */
    function len(bytes32 self) internal pure returns (uint) {
        uint ret;
        if (self == 0)
            return 0;
        if (self & 0xffffffffffffffffffffffffffffffff == 0) {
            ret += 16;
            self = bytes32(uint(self) / 0x100000000000000000000000000000000);
        }
        if (self & 0xffffffffffffffff == 0) {
            ret += 8;
            self = bytes32(uint(self) / 0x10000000000000000);
        }
        if (self & 0xffffffff == 0) {
            ret += 4;
            self = bytes32(uint(self) / 0x100000000);
        }
        if (self & 0xffff == 0) {
            ret += 2;
            self = bytes32(uint(self) / 0x10000);
        }
        if (self & 0xff == 0) {
            ret += 1;
        }
        return 32 - ret;
    }

    /*
     * @dev Returns a slice containing the entire bytes32, interpreted as a
     *      null-terminated utf-8 string.
     * @param self The bytes32 value to convert to a slice.
     * @return A new slice containing the value of the input argument up to the
     *         first null.
     */
    function toSliceB32(bytes32 self) internal pure returns (slice memory ret) {
        // Allocate space for `self` in memory, copy it there, and point ret at it
        assembly {
            let ptr := mload(0x40)
            mstore(0x40, add(ptr, 0x20))
            mstore(ptr, self)
            mstore(add(ret, 0x20), ptr)
        }
        ret._len = len(self);
    }

    /*
     * @dev Returns a new slice containing the same data as the current slice.
     * @param self The slice to copy.
     * @return A new slice containing the same data as `self`.
     */
    function copy(slice memory self) internal pure returns (slice memory) {
        return slice(self._len, self._ptr);
    }

    /*
     * @dev Copies a slice to a new string.
     * @param self The slice to copy.
     * @return A newly allocated string containing the slice's text.
     */
    function toString(slice memory self) internal pure returns (string memory) {
        string memory ret = new string(self._len);
        uint retptr;
        assembly { retptr := add(ret, 32) }

        memcpy(retptr, self._ptr, self._len);
        return ret;
    }

    /*
     * @dev Returns the length in runes of the slice. Note that this operation
     *      takes time proportional to the length of the slice; avoid using it
     *      in loops, and call `slice.empty()` if you only need to know whether
     *      the slice is empty or not.
     * @param self The slice to operate on.
     * @return The length of the slice in runes.
     */
    function len(slice memory self) internal pure returns (uint l) {
        // Starting at ptr-31 means the LSB will be the byte we care about
        uint ptr = self._ptr - 31;
        uint end = ptr + self._len;
        for (l = 0; ptr < end; l++) {
            uint8 b;
            assembly { b := and(mload(ptr), 0xFF) }
            if (b < 0x80) {
                ptr += 1;
            } else if(b < 0xE0) {
                ptr += 2;
            } else if(b < 0xF0) {
                ptr += 3;
            } else if(b < 0xF8) {
                ptr += 4;
            } else if(b < 0xFC) {
                ptr += 5;
            } else {
                ptr += 6;
            }
        }
    }

    /*
     * @dev Returns true if the slice is empty (has a length of 0).
     * @param self The slice to operate on.
     * @return True if the slice is empty, False otherwise.
     */
    function empty(slice memory self) internal pure returns (bool) {
        return self._len == 0;
    }

    /*
     * @dev Returns a positive number if `other` comes lexicographically after
     *      `self`, a negative number if it comes before, or zero if the
     *      contents of the two slices are equal. Comparison is done per-rune,
     *      on unicode codepoints.
     * @param self The first slice to compare.
     * @param other The second slice to compare.
     * @return The result of the comparison.
     */
    function compare(slice memory self, slice memory other) internal pure returns (int) {
        uint shortest = self._len;
        if (other._len < self._len)
            shortest = other._len;

        uint selfptr = self._ptr;
        uint otherptr = other._ptr;
        for (uint idx = 0; idx < shortest; idx += 32) {
            uint a;
            uint b;
            assembly {
                a := mload(selfptr)
                b := mload(otherptr)
            }
            if (a != b) {
                // Mask out irrelevant bytes and check again
                uint256 mask = uint256(-1); // 0xffff...
                if(shortest < 32) {
                  mask = ~(2 ** (8 * (32 - shortest + idx)) - 1);
                }
                uint256 diff = (a & mask) - (b & mask);
                if (diff != 0)
                    return int(diff);
            }
            selfptr += 32;
            otherptr += 32;
        }
        return int(self._len) - int(other._len);
    }

    /*
     * @dev Returns true if the two slices contain the same text.
     * @param self The first slice to compare.
     * @param self The second slice to compare.
     * @return True if the slices are equal, false otherwise.
     */
    function equals(slice memory self, slice memory other) internal pure returns (bool) {
        return compare(self, other) == 0;
    }

    /*
     * @dev Extracts the first rune in the slice into `rune`, advancing the
     *      slice to point to the next rune and returning `self`.
     * @param self The slice to operate on.
     * @param rune The slice that will contain the first rune.
     * @return `rune`.
     */
    function nextRune(slice memory self, slice memory rune) internal pure returns (slice memory) {
        rune._ptr = self._ptr;

        if (self._len == 0) {
            rune._len = 0;
            return rune;
        }

        uint l;
        uint b;
        // Load the first byte of the rune into the LSBs of b
        assembly { b := and(mload(sub(mload(add(self, 32)), 31)), 0xFF) }
        if (b < 0x80) {
            l = 1;
        } else if(b < 0xE0) {
            l = 2;
        } else if(b < 0xF0) {
            l = 3;
        } else {
            l = 4;
        }

        // Check for truncated codepoints
        if (l > self._len) {
            rune._len = self._len;
            self._ptr += self._len;
            self._len = 0;
            return rune;
        }

        self._ptr += l;
        self._len -= l;
        rune._len = l;
        return rune;
    }

    /*
     * @dev Returns the first rune in the slice, advancing the slice to point
     *      to the next rune.
     * @param self The slice to operate on.
     * @return A slice containing only the first rune from `self`.
     */
    function nextRune(slice memory self) internal pure returns (slice memory ret) {
        nextRune(self, ret);
    }

    /*
     * @dev Returns the number of the first codepoint in the slice.
     * @param self The slice to operate on.
     * @return The number of the first codepoint in the slice.
     */
    function ord(slice memory self) internal pure returns (uint ret) {
        if (self._len == 0) {
            return 0;
        }

        uint word;
        uint length;
        uint divisor = 2 ** 248;

        // Load the rune into the MSBs of b
        assembly { word:= mload(mload(add(self, 32))) }
        uint b = word / divisor;
        if (b < 0x80) {
            ret = b;
            length = 1;
        } else if(b < 0xE0) {
            ret = b & 0x1F;
            length = 2;
        } else if(b < 0xF0) {
            ret = b & 0x0F;
            length = 3;
        } else {
            ret = b & 0x07;
            length = 4;
        }

        // Check for truncated codepoints
        if (length > self._len) {
            return 0;
        }

        for (uint i = 1; i < length; i++) {
            divisor = divisor / 256;
            b = (word / divisor) & 0xFF;
            if (b & 0xC0 != 0x80) {
                // Invalid UTF-8 sequence
                return 0;
            }
            ret = (ret * 64) | (b & 0x3F);
        }

        return ret;
    }

    /*
     * @dev Returns the keccak-256 hash of the slice.
     * @param self The slice to hash.
     * @return The hash of the slice.
     */
    function keccak(slice memory self) internal pure returns (bytes32 ret) {
        assembly {
            ret := keccak256(mload(add(self, 32)), mload(self))
        }
    }

    /*
     * @dev Returns true if `self` starts with `needle`.
     * @param self The slice to operate on.
     * @param needle The slice to search for.
     * @return True if the slice starts with the provided text, false otherwise.
     */
    function startsWith(slice memory self, slice memory needle) internal pure returns (bool) {
        if (self._len < needle._len) {
            return false;
        }

        if (self._ptr == needle._ptr) {
            return true;
        }

        bool equal;
        assembly {
            let length := mload(needle)
            let selfptr := mload(add(self, 0x20))
            let needleptr := mload(add(needle, 0x20))
            equal := eq(keccak256(selfptr, length), keccak256(needleptr, length))
        }
        return equal;
    }

    /*
     * @dev If `self` starts with `needle`, `needle` is removed from the
     *      beginning of `self`. Otherwise, `self` is unmodified.
     * @param self The slice to operate on.
     * @param needle The slice to search for.
     * @return `self`
     */
    function beyond(slice memory self, slice memory needle) internal pure returns (slice memory) {
        if (self._len < needle._len) {
            return self;
        }

        bool equal = true;
        if (self._ptr != needle._ptr) {
            assembly {
                let length := mload(needle)
                let selfptr := mload(add(self, 0x20))
                let needleptr := mload(add(needle, 0x20))
                equal := eq(keccak256(selfptr, length), keccak256(needleptr, length))
            }
        }

        if (equal) {
            self._len -= needle._len;
            self._ptr += needle._len;
        }

        return self;
    }

    /*
     * @dev Returns true if the slice ends with `needle`.
     * @param self The slice to operate on.
     * @param needle The slice to search for.
     * @return True if the slice starts with the provided text, false otherwise.
     */
    function endsWith(slice memory self, slice memory needle) internal pure returns (bool) {
        if (self._len < needle._len) {
            return false;
        }

        uint selfptr = self._ptr + self._len - needle._len;

        if (selfptr == needle._ptr) {
            return true;
        }

        bool equal;
        assembly {
            let length := mload(needle)
            let needleptr := mload(add(needle, 0x20))
            equal := eq(keccak256(selfptr, length), keccak256(needleptr, length))
        }

        return equal;
    }

    /*
     * @dev If `self` ends with `needle`, `needle` is removed from the
     *      end of `self`. Otherwise, `self` is unmodified.
     * @param self The slice to operate on.
     * @param needle The slice to search for.
     * @return `self`
     */
    function until(slice memory self, slice memory needle) internal pure returns (slice memory) {
        if (self._len < needle._len) {
            return self;
        }

        uint selfptr = self._ptr + self._len - needle._len;
        bool equal = true;
        if (selfptr != needle._ptr) {
            assembly {
                let length := mload(needle)
                let needleptr := mload(add(needle, 0x20))
                equal := eq(keccak256(selfptr, length), keccak256(needleptr, length))
            }
        }

        if (equal) {
            self._len -= needle._len;
        }

        return self;
    }

    // Returns the memory address of the first byte of the first occurrence of
    // `needle` in `self`, or the first byte after `self` if not found.
    function findPtr(uint selflen, uint selfptr, uint needlelen, uint needleptr) private pure returns (uint) {
        uint ptr = selfptr;
        uint idx;

        if (needlelen <= selflen) {
            if (needlelen <= 32) {
                bytes32 mask = bytes32(~(2 ** (8 * (32 - needlelen)) - 1));

                bytes32 needledata;
                assembly { needledata := and(mload(needleptr), mask) }

                uint end = selfptr + selflen - needlelen;
                bytes32 ptrdata;
                assembly { ptrdata := and(mload(ptr), mask) }

                while (ptrdata != needledata) {
                    if (ptr >= end)
                        return selfptr + selflen;
                    ptr++;
                    assembly { ptrdata := and(mload(ptr), mask) }
                }
                return ptr;
            } else {
                // For long needles, use hashing
                bytes32 hash;
                assembly { hash := keccak256(needleptr, needlelen) }

                for (idx = 0; idx <= selflen - needlelen; idx++) {
                    bytes32 testHash;
                    assembly { testHash := keccak256(ptr, needlelen) }
                    if (hash == testHash)
                        return ptr;
                    ptr += 1;
                }
            }
        }
        return selfptr + selflen;
    }

    // Returns the memory address of the first byte after the last occurrence of
    // `needle` in `self`, or the address of `self` if not found.
    function rfindPtr(uint selflen, uint selfptr, uint needlelen, uint needleptr) private pure returns (uint) {
        uint ptr;

        if (needlelen <= selflen) {
            if (needlelen <= 32) {
                bytes32 mask = bytes32(~(2 ** (8 * (32 - needlelen)) - 1));

                bytes32 needledata;
                assembly { needledata := and(mload(needleptr), mask) }

                ptr = selfptr + selflen - needlelen;
                bytes32 ptrdata;
                assembly { ptrdata := and(mload(ptr), mask) }

                while (ptrdata != needledata) {
                    if (ptr <= selfptr)
                        return selfptr;
                    ptr--;
                    assembly { ptrdata := and(mload(ptr), mask) }
                }
                return ptr + needlelen;
            } else {
                // For long needles, use hashing
                bytes32 hash;
                assembly { hash := keccak256(needleptr, needlelen) }
                ptr = selfptr + (selflen - needlelen);
                while (ptr >= selfptr) {
                    bytes32 testHash;
                    assembly { testHash := keccak256(ptr, needlelen) }
                    if (hash == testHash)
                        return ptr + needlelen;
                    ptr -= 1;
                }
            }
        }
        return selfptr;
    }

    /*
     * @dev Modifies `self` to contain everything from the first occurrence of
     *      `needle` to the end of the slice. `self` is set to the empty slice
     *      if `needle` is not found.
     * @param self The slice to search and modify.
     * @param needle The text to search for.
     * @return `self`.
     */
    function find(slice memory self, slice memory needle) internal pure returns (slice memory) {
        uint ptr = findPtr(self._len, self._ptr, needle._len, needle._ptr);
        self._len -= ptr - self._ptr;
        self._ptr = ptr;
        return self;
    }

    /*
     * @dev Modifies `self` to contain the part of the string from the start of
     *      `self` to the end of the first occurrence of `needle`. If `needle`
     *      is not found, `self` is set to the empty slice.
     * @param self The slice to search and modify.
     * @param needle The text to search for.
     * @return `self`.
     */
    function rfind(slice memory self, slice memory needle) internal pure returns (slice memory) {
        uint ptr = rfindPtr(self._len, self._ptr, needle._len, needle._ptr);
        self._len = ptr - self._ptr;
        return self;
    }

    /*
     * @dev Splits the slice, setting `self` to everything after the first
     *      occurrence of `needle`, and `token` to everything before it. If
     *      `needle` does not occur in `self`, `self` is set to the empty slice,
     *      and `token` is set to the entirety of `self`.
     * @param self The slice to split.
     * @param needle The text to search for in `self`.
     * @param token An output parameter to which the first token is written.
     * @return `token`.
     */
    function split(slice memory self, slice memory needle, slice memory token) internal pure returns (slice memory) {
        uint ptr = findPtr(self._len, self._ptr, needle._len, needle._ptr);
        token._ptr = self._ptr;
        token._len = ptr - self._ptr;
        if (ptr == self._ptr + self._len) {
            // Not found
            self._len = 0;
        } else {
            self._len -= token._len + needle._len;
            self._ptr = ptr + needle._len;
        }
        return token;
    }

    /*
     * @dev Splits the slice, setting `self` to everything after the first
     *      occurrence of `needle`, and returning everything before it. If
     *      `needle` does not occur in `self`, `self` is set to the empty slice,
     *      and the entirety of `self` is returned.
     * @param self The slice to split.
     * @param needle The text to search for in `self`.
     * @return The part of `self` up to the first occurrence of `delim`.
     */
    function split(slice memory self, slice memory needle) internal pure returns (slice memory token) {
        split(self, needle, token);
    }

    /*
     * @dev Splits the slice, setting `self` to everything before the last
     *      occurrence of `needle`, and `token` to everything after it. If
     *      `needle` does not occur in `self`, `self` is set to the empty slice,
     *      and `token` is set to the entirety of `self`.
     * @param self The slice to split.
     * @param needle The text to search for in `self`.
     * @param token An output parameter to which the first token is written.
     * @return `token`.
     */
    function rsplit(slice memory self, slice memory needle, slice memory token) internal pure returns (slice memory) {
        uint ptr = rfindPtr(self._len, self._ptr, needle._len, needle._ptr);
        token._ptr = ptr;
        token._len = self._len - (ptr - self._ptr);
        if (ptr == self._ptr) {
            // Not found
            self._len = 0;
        } else {
            self._len -= token._len + needle._len;
        }
        return token;
    }

    /*
     * @dev Splits the slice, setting `self` to everything before the last
     *      occurrence of `needle`, and returning everything after it. If
     *      `needle` does not occur in `self`, `self` is set to the empty slice,
     *      and the entirety of `self` is returned.
     * @param self The slice to split.
     * @param needle The text to search for in `self`.
     * @return The part of `self` after the last occurrence of `delim`.
     */
    function rsplit(slice memory self, slice memory needle) internal pure returns (slice memory token) {
        rsplit(self, needle, token);
    }

    /*
     * @dev Counts the number of nonoverlapping occurrences of `needle` in `self`.
     * @param self The slice to search.
     * @param needle The text to search for in `self`.
     * @return The number of occurrences of `needle` found in `self`.
     */
    function count(slice memory self, slice memory needle) internal pure returns (uint cnt) {
        uint ptr = findPtr(self._len, self._ptr, needle._len, needle._ptr) + needle._len;
        while (ptr <= self._ptr + self._len) {
            cnt++;
            ptr = findPtr(self._len - (ptr - self._ptr), ptr, needle._len, needle._ptr) + needle._len;
        }
    }

    /*
     * @dev Returns True if `self` contains `needle`.
     * @param self The slice to search.
     * @param needle The text to search for in `self`.
     * @return True if `needle` is found in `self`, false otherwise.
     */
    function contains(slice memory self, slice memory needle) internal pure returns (bool) {
        return rfindPtr(self._len, self._ptr, needle._len, needle._ptr) != self._ptr;
    }

    /*
     * @dev Returns a newly allocated string containing the concatenation of
     *      `self` and `other`.
     * @param self The first slice to concatenate.
     * @param other The second slice to concatenate.
     * @return The concatenation of the two strings.
     */
    function concat(slice memory self, slice memory other) internal pure returns (string memory) {
        string memory ret = new string(self._len + other._len);
        uint retptr;
        assembly { retptr := add(ret, 32) }
        memcpy(retptr, self._ptr, self._len);
        memcpy(retptr + self._len, other._ptr, other._len);
        return ret;
    }

    /*
     * @dev Joins an array of slices, using `self` as a delimiter, returning a
     *      newly allocated string.
     * @param self The delimiter to use.
     * @param parts A list of slices to join.
     * @return A newly allocated string containing all the slices in `parts`,
     *         joined with `self`.
     */
    function join(slice memory self, slice[] memory parts) internal pure returns (string memory) {
        if (parts.length == 0)
            return "";

        uint length = self._len * (parts.length - 1);
        for(uint i = 0; i < parts.length; i++)
            length += parts[i]._len;

        string memory ret = new string(length);
        uint retptr;
        assembly { retptr := add(ret, 32) }

        for(i = 0; i < parts.length; i++) {
            memcpy(retptr, parts[i]._ptr, parts[i]._len);
            retptr += parts[i]._len;
            if (i < parts.length - 1) {
                memcpy(retptr, self._ptr, self._len);
                retptr += self._len;
            }
        }

        return ret;
    }
}

/**
 * @title ENSConsumer
 * @dev Helper contract to resolve ENS names.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract ENSConsumer {

    using strings for *;

    // namehash('addr.reverse')
    bytes32 constant public ADDR_REVERSE_NODE = 0x91d1777781884d03a6757a803996e38de2a42967fb37eeaca72729271025a9e2;

    // the address of the ENS registry
    address ensRegistry;

    /**
    * @dev No address should be provided when deploying on Mainnet to avoid storage cost. The 
    * contract will use the hardcoded value.
    */
    constructor(address _ensRegistry) public {
        ensRegistry = _ensRegistry;
    }

    /**
    * @dev Resolves an ENS name to an address.
    * @param _node The namehash of the ENS name. 
    */
    function resolveEns(bytes32 _node) public view returns (address) {
        address resolver = getENSRegistry().resolver(_node);
        return ENSResolver(resolver).addr(_node);
    }

    /**
    * @dev Gets the official ENS registry.
    */
    function getENSRegistry() public view returns (ENSRegistry) {
        return ENSRegistry(ensRegistry);
    }

    /**
    * @dev Gets the official ENS reverse registrar. 
    */
    function getENSReverseRegistrar() public view returns (ENSReverseRegistrar) {
        return ENSReverseRegistrar(getENSRegistry().owner(ADDR_REVERSE_NODE));
    }
}

/**
 * @dev Interface for an ENS Mananger.
 */
interface IENSManager {
    function changeRootnodeOwner(address _newOwner) external;
    function register(string _label, address _owner) external;
    function isAvailable(bytes32 _subnode) external view returns(bool);
}

/**
 * @title Proxy
 * @dev Basic proxy that delegates all calls to a fixed implementing contract.
 * The implementing contract cannot be upgraded.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract Proxy {

    address implementation;

    event Received(uint indexed value, address indexed sender, bytes data);

    constructor(address _implementation) public {
        implementation = _implementation;
    }

    function() external payable {

        if(msg.data.length == 0 && msg.value > 0) { 
            emit Received(msg.value, msg.sender, msg.data); 
        }
        else {
            // solium-disable-next-line security/no-inline-assembly
            assembly {
                let target := sload(0)
                calldatacopy(0, 0, calldatasize())
                let result := delegatecall(gas, target, 0, calldatasize(), 0, 0)
                returndatacopy(0, 0, returndatasize())
                switch result 
                case 0 {revert(0, returndatasize())} 
                default {return (0, returndatasize())}
            }
        }
    }
}

/**
 * @title Module
 * @dev Interface for a module. 
 * A module MUST implement the addModule() method to ensure that a wallet with at least one module
 * can never end up in a "frozen" state.
 * @author Julien Niset - <julien@argent.xyz>
 */
interface Module {

    /**
     * @dev Inits a module for a wallet by e.g. setting some wallet specific parameters in storage.
     * @param _wallet The wallet.
     */
    function init(BaseWallet _wallet) external;

    /**
     * @dev Adds a module to a wallet.
     * @param _wallet The target wallet.
     * @param _module The modules to authorise.
     */
    function addModule(BaseWallet _wallet, Module _module) external;

    /**
    * @dev Utility method to recover any ERC20 token that was sent to the
    * module by mistake. 
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external;
}

/**
 * @title BaseWallet
 * @dev Simple modular wallet that authorises modules to call its invoke() method.
 * Based on https://gist.github.com/Arachnid/a619d31f6d32757a4328a428286da186 by 
 * @author Julien Niset - <julien@argent.xyz>
 */
contract BaseWallet {

    // The implementation of the proxy
    address public implementation;
    // The owner 
    address public owner;
    // The authorised modules
    mapping (address => bool) public authorised;
    // The enabled static calls
    mapping (bytes4 => address) public enabled;
    // The number of modules
    uint public modules;
    
    event AuthorisedModule(address indexed module, bool value);
    event EnabledStaticCall(address indexed module, bytes4 indexed method);
    event Invoked(address indexed module, address indexed target, uint indexed value, bytes data);
    event Received(uint indexed value, address indexed sender, bytes data);
    event OwnerChanged(address owner);
    
    /**
     * @dev Throws if the sender is not an authorised module.
     */
    modifier moduleOnly {
        require(authorised[msg.sender], "BW: msg.sender not an authorized module");
        _;
    }

    /**
     * @dev Inits the wallet by setting the owner and authorising a list of modules.
     * @param _owner The owner.
     * @param _modules The modules to authorise.
     */
    function init(address _owner, address[] _modules) external {
        require(owner == address(0) && modules == 0, "BW: wallet already initialised");
        require(_modules.length > 0, "BW: construction requires at least 1 module");
        owner = _owner;
        modules = _modules.length;
        for(uint256 i = 0; i < _modules.length; i++) {
            require(authorised[_modules[i]] == false, "BW: module is already added");
            authorised[_modules[i]] = true;
            Module(_modules[i]).init(this);
            emit AuthorisedModule(_modules[i], true);
        }
    }
    
    /**
     * @dev Enables/Disables a module.
     * @param _module The target module.
     * @param _value Set to true to authorise the module.
     */
    function authoriseModule(address _module, bool _value) external moduleOnly {
        if (authorised[_module] != _value) {
            if(_value == true) {
                modules += 1;
                authorised[_module] = true;
                Module(_module).init(this);
            }
            else {
                modules -= 1;
                require(modules > 0, "BW: wallet must have at least one module");
                delete authorised[_module];
            }
            emit AuthorisedModule(_module, _value);
        }
    }

    /**
    * @dev Enables a static method by specifying the target module to which the call
    * must be delegated.
    * @param _module The target module.
    * @param _method The static method signature.
    */
    function enableStaticCall(address _module, bytes4 _method) external moduleOnly {
        require(authorised[_module], "BW: must be an authorised module for static call");
        enabled[_method] = _module;
        emit EnabledStaticCall(_module, _method);
    }

    /**
     * @dev Sets a new owner for the wallet.
     * @param _newOwner The new owner.
     */
    function setOwner(address _newOwner) external moduleOnly {
        require(_newOwner != address(0), "BW: address cannot be null");
        owner = _newOwner;
        emit OwnerChanged(_newOwner);
    }
    
    /**
     * @dev Performs a generic transaction.
     * @param _target The address for the transaction.
     * @param _value The value of the transaction.
     * @param _data The data of the transaction.
     */
    function invoke(address _target, uint _value, bytes _data) external moduleOnly {
        // solium-disable-next-line security/no-call-value
        require(_target.call.value(_value)(_data), "BW: call to target failed");
        emit Invoked(msg.sender, _target, _value, _data);
    }

    /**
     * @dev This method makes it possible for the wallet to comply to interfaces expecting the wallet to
     * implement specific static methods. It delegates the static call to a target contract if the data corresponds 
     * to an enabled method, or logs the call otherwise.
     */
    function() public payable {
        if(msg.data.length > 0) { 
            address module = enabled[msg.sig];
            if(module == address(0)) {
                emit Received(msg.value, msg.sender, msg.data);
            } 
            else {
                require(authorised[module], "BW: must be an authorised module for static call");
                // solium-disable-next-line security/no-inline-assembly
                assembly {
                    calldatacopy(0, 0, calldatasize())
                    let result := staticcall(gas, module, 0, calldatasize(), 0, 0)
                    returndatacopy(0, 0, returndatasize())
                    switch result 
                    case 0 {revert(0, returndatasize())} 
                    default {return (0, returndatasize())}
                }
            }
        }
    }
}

/**
 * ERC20 contract interface.
 */
contract ERC20 {
    function totalSupply() public view returns (uint);
    function decimals() public view returns (uint);
    function balanceOf(address tokenOwner) public view returns (uint balance);
    function allowance(address tokenOwner, address spender) public view returns (uint remaining);
    function transfer(address to, uint tokens) public returns (bool success);
    function approve(address spender, uint tokens) public returns (bool success);
    function transferFrom(address from, address to, uint tokens) public returns (bool success);
}

/**
 * @title ModuleRegistry
 * @dev Registry of authorised modules. 
 * Modules must be registered before they can be authorised on a wallet.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract ModuleRegistry is Owned {

    mapping (address => Info) internal modules;
    mapping (address => Info) internal upgraders;

    event ModuleRegistered(address indexed module, bytes32 name);
    event ModuleDeRegistered(address module);
    event UpgraderRegistered(address indexed upgrader, bytes32 name);
    event UpgraderDeRegistered(address upgrader);

    struct Info {
        bool exists;
        bytes32 name;
    }

    /**
     * @dev Registers a module.
     * @param _module The module.
     * @param _name The unique name of the module.
     */
    function registerModule(address _module, bytes32 _name) external onlyOwner {
        require(!modules[_module].exists, "MR: module already exists");
        modules[_module] = Info({exists: true, name: _name});
        emit ModuleRegistered(_module, _name);
    }

    /**
     * @dev Deregisters a module.
     * @param _module The module.
     */
    function deregisterModule(address _module) external onlyOwner {
        require(modules[_module].exists, "MR: module does not exists");
        delete modules[_module];
        emit ModuleDeRegistered(_module);
    }

        /**
     * @dev Registers an upgrader.
     * @param _upgrader The upgrader.
     * @param _name The unique name of the upgrader.
     */
    function registerUpgrader(address _upgrader, bytes32 _name) external onlyOwner {
        require(!upgraders[_upgrader].exists, "MR: upgrader already exists");
        upgraders[_upgrader] = Info({exists: true, name: _name});
        emit UpgraderRegistered(_upgrader, _name);
    }

    /**
     * @dev Deregisters an upgrader.
     * @param _upgrader The _upgrader.
     */
    function deregisterUpgrader(address _upgrader) external onlyOwner {
        require(upgraders[_upgrader].exists, "MR: upgrader does not exists");
        delete upgraders[_upgrader];
        emit UpgraderDeRegistered(_upgrader);
    }

    /**
    * @dev Utility method enbaling the owner of the registry to claim any ERC20 token that was sent to the
    * registry.
    * @param _token The token to recover.
    */
    function recoverToken(address _token) external onlyOwner {
        uint total = ERC20(_token).balanceOf(address(this));
        ERC20(_token).transfer(msg.sender, total);
    } 

    /**
     * @dev Gets the name of a module from its address.
     * @param _module The module address.
     * @return the name.
     */
    function moduleInfo(address _module) external view returns (bytes32) {
        return modules[_module].name;
    }

    /**
     * @dev Gets the name of an upgrader from its address.
     * @param _upgrader The upgrader address.
     * @return the name.
     */
    function upgraderInfo(address _upgrader) external view returns (bytes32) {
        return upgraders[_upgrader].name;
    }

    /**
     * @dev Checks if a module is registered.
     * @param _module The module address.
     * @return true if the module is registered.
     */
    function isRegisteredModule(address _module) external view returns (bool) {
        return modules[_module].exists;
    }

    /**
     * @dev Checks if a list of modules are registered.
     * @param _modules The list of modules address.
     * @return true if all the modules are registered.
     */
    function isRegisteredModule(address[] _modules) external view returns (bool) {
        for(uint i = 0; i < _modules.length; i++) {
            if (!modules[_modules[i]].exists) {
                return false;
            }
        }
        return true;
    }  

    /**
     * @dev Checks if an upgrader is registered.
     * @param _upgrader The upgrader address.
     * @return true if the upgrader is registered.
     */
    function isRegisteredUpgrader(address _upgrader) external view returns (bool) {
        return upgraders[_upgrader].exists;
    } 

}

/**
 * @title WalletFactory
 * @dev The WalletFactory contract creates and assigns wallets to accounts.
 * @author Julien Niset - <julien@argent.xyz>
 */
contract WalletFactory is Owned, Managed, ENSConsumer {

    // The address of the module registry
    address public moduleRegistry;
    // The address of the base wallet implementation
    address public walletImplementation;
    // The address of the ENS manager
    address public ensManager;
    // The address of the ENS resolver
    address public ensResolver;

    // *************** Events *************************** //

    event ModuleRegistryChanged(address addr);
    event WalletImplementationChanged(address addr);
    event ENSManagerChanged(address addr);
    event ENSResolverChanged(address addr);
    event WalletCreated(address indexed _wallet, address indexed _owner);

    // *************** Constructor ********************** //

    /**
     * @dev Default constructor.
     */
    constructor(
        address _ensRegistry, 
        address _moduleRegistry,
        address _walletImplementation, 
        address _ensManager, 
        address _ensResolver
    ) 
        ENSConsumer(_ensRegistry) 
        public 
    {
        moduleRegistry = _moduleRegistry;
        walletImplementation = _walletImplementation;
        ensManager = _ensManager;
        ensResolver = _ensResolver;
    }

    // *************** External Functions ********************* //

    /**
     * @dev Lets the manager create a wallet for an account. The wallet is initialised with a list of modules.
     * @param _owner The account address.
     * @param _modules The list of modules.
     * @param _label Optional ENS label of the new wallet (e.g. franck).
     */
    function createWallet(address _owner, address[] _modules, string _label) external onlyManager {
        require(_owner != address(0), "WF: owner cannot be null");
        require(_modules.length > 0, "WF: cannot assign with less than 1 module");
        require(ModuleRegistry(moduleRegistry).isRegisteredModule(_modules), "WF: one or more modules are not registered");
        // create the proxy
        Proxy proxy = new Proxy(walletImplementation);
        address wallet = address(proxy);
        // check for ENS
        bytes memory labelBytes = bytes(_label);
        if (labelBytes.length != 0) {
            // add the factory to the modules so it can claim the reverse ENS
            address[] memory extendedModules = new address[](_modules.length + 1);
            extendedModules[0] = address(this);
            for(uint i = 0; i < _modules.length; i++) {
                extendedModules[i + 1] = _modules[i];
            }
            // initialise the wallet with the owner and the extended modules
            BaseWallet(wallet).init(_owner, extendedModules);
            // register ENS
            registerWalletENS(wallet, _label);
            // remove the factory from the authorised modules
            BaseWallet(wallet).authoriseModule(address(this), false);
        } else {
            // initialise the wallet with the owner and the modules
            BaseWallet(wallet).init(_owner, _modules);
        }
        emit WalletCreated(wallet, _owner);
    }

    /**
     * @dev Lets the owner change the address of the module registry contract.
     * @param _moduleRegistry The address of the module registry contract.
     */
    function changeModuleRegistry(address _moduleRegistry) external onlyOwner {
        require(_moduleRegistry != address(0), "WF: address cannot be null");
        moduleRegistry = _moduleRegistry;
        emit ModuleRegistryChanged(_moduleRegistry);
    }

    /**
     * @dev Lets the owner change the address of the implementing contract.
     * @param _walletImplementation The address of the implementing contract.
     */
    function changeWalletImplementation(address _walletImplementation) external onlyOwner {
        require(_walletImplementation != address(0), "WF: address cannot be null");
        walletImplementation = _walletImplementation;
        emit WalletImplementationChanged(_walletImplementation);
    }

    /**
     * @dev Lets the owner change the address of the ENS manager contract.
     * @param _ensManager The address of the ENS manager contract.
     */
    function changeENSManager(address _ensManager) external onlyOwner {
        require(_ensManager != address(0), "WF: address cannot be null");
        ensManager = _ensManager;
        emit ENSManagerChanged(_ensManager);
    }

    /**
     * @dev Lets the owner change the address of the ENS resolver contract.
     * @param _ensResolver The address of the ENS resolver contract.
     */
    function changeENSResolver(address _ensResolver) external onlyOwner {
        require(_ensResolver != address(0), "WF: address cannot be null");
        ensResolver = _ensResolver;
        emit ENSResolverChanged(_ensResolver);
    }

    /**
     * @dev Register an ENS subname to a wallet.
     * @param _wallet The wallet address.
     * @param _label ENS label of the new wallet (e.g. franck).
     */
    function registerWalletENS(address _wallet, string _label) internal {
        // claim reverse
        bytes memory methodData = abi.encodeWithSignature("claimWithResolver(address,address)", ensManager, ensResolver);
        BaseWallet(_wallet).invoke(getENSReverseRegistrar(), 0, methodData);
        // register with ENS manager
        IENSManager(ensManager).register(_label, _wallet);
    }

    /**
     * @dev Inits the module for a wallet by logging an event.
     * The method can only be called by the wallet itself.
     * @param _wallet The wallet.
     */
    function init(BaseWallet _wallet) external pure {
        //do nothing
    }
}