pragma solidity ^0.5.2;


library SafeMath {
    
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        
        
        
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b);

        return c;
    }

    
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        
        require(b > 0);
        uint256 c = a / b;
        

        return c;
    }

    
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a);
        uint256 c = a - b;

        return c;
    }

    
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a);

        return c;
    }

    
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0);
        return a % b;
    }
}

interface ERC165Interface {
    
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

contract ERC721Interface is ERC165Interface {
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    function balanceOf(address owner) public view returns (uint256 balance);
    function ownerOf(uint256 tokenId) public view returns (address owner);
    function approve(address to, uint256 tokenId) public;
    function getApproved(uint256 tokenId) public view returns (address operator);
    function setApprovalForAll(address operator, bool _approved) public;
    function isApprovedForAll(address owner, address operator) public view returns (bool);
    function transferFrom(address from, address to, uint256 tokenId) public;
    function safeTransferFrom(address from, address to, uint256 tokenId) public;
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
}

contract ERC721MetadataInterface is ERC721Interface {
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

contract ERC721EnumerableInterface is ERC721Interface {
    function totalSupply() public view returns (uint256);
    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);
    function tokenByIndex(uint256 index) public view returns (uint256);
}

contract ERC165 is ERC165Interface {
    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
    

    
    mapping(bytes4 => bool) private _supportedInterfaces;

    
    constructor () internal {
        _registerInterface(_INTERFACE_ID_ERC165);
    }

    
    function supportsInterface(bytes4 interfaceId) external view returns (bool) {
        return _supportedInterfaces[interfaceId];
    }

    
    function _registerInterface(bytes4 interfaceId) internal {
        require(interfaceId != 0xffffffff);
        _supportedInterfaces[interfaceId] = true;
    }
}

contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    
    function owner() public view returns (address) {
        return _owner;
    }

    
    modifier onlyOwner() {
        require(isOwner());
        _;
    }

    
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    
    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
    }

    
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0));
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

contract ERC721ReceiverInterface {
    
    function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
    public returns (bytes4);
}

contract ERC721Extended is ERC721Interface, ERC721MetadataInterface, ERC721EnumerableInterface, ERC165, Ownable {
    using SafeMath for uint256;

    
    mapping(uint256 => address) private _tokenOwner;

    
    mapping(uint256 => address) private _tokenApprovals;

    
    mapping(address => uint256) private _ownedTokensCount;

    
    mapping(address => mapping (address => bool)) private _operatorApprovals;

    
    string private _name;

    
    string private _symbol;

    
    mapping(uint256 => string) private _tokenURIs;

    
    mapping(address => uint256[]) private _ownedTokens;

    
    mapping(uint256 => uint256) private _ownedTokensIndex;

    
    uint256[] private _allTokens;

    
    mapping(uint256 => uint256) private _allTokensIndex;

    
    bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;

    
    bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;

    
    bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;

    
    bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;

    
    constructor(string memory name, string memory symbol) public {
        _name = name;
        _symbol = symbol;
        _registerInterface(_INTERFACE_ID_ERC721);
        _registerInterface(_INTERFACE_ID_ERC721_METADATA);
        _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
    }

    
    function balanceOf(address owner) public view returns (uint256) {
        require(owner != address(0));
        return _current(owner);
    }

    
    function ownerOf(uint256 tokenId) public view returns (address) {
        address owner = _tokenOwner[tokenId];
        require(owner != address(0));
        return owner;
    }

    
    function approve(address to, uint256 tokenId) public {
        address owner = ownerOf(tokenId);
        require(to != owner);
        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));

        _tokenApprovals[tokenId] = to;
        emit Approval(owner, to, tokenId);
    }

    
    function getApproved(uint256 tokenId) public view returns (address) {
        require(_exists(tokenId));
        return _tokenApprovals[tokenId];
    }

    
    function setApprovalForAll(address to, bool approved) public {
        require(to != msg.sender);
        _operatorApprovals[msg.sender][to] = approved;
        emit ApprovalForAll(msg.sender, to, approved);
    }

    
    function isApprovedForAll(address owner, address operator) public view returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    
    function transferFrom(address from, address to, uint256 tokenId) public {
        require(_isApprovedOrOwner(msg.sender, tokenId));

        _transferFrom(from, to, tokenId);
    }

    
    function safeTransferFrom(address from, address to, uint256 tokenId) public {
        safeTransferFrom(from, to, tokenId, "");
    }

    
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
        transferFrom(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data));
    }

    
    function _exists(uint256 tokenId) internal view returns (bool) {
        address owner = _tokenOwner[tokenId];
        return owner != address(0);
    }

    
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
        require(_exists(tokenId));
        address owner = ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    
    function _mint(address to, uint256 tokenId) internal {
        require(to != address(0));
        require(!_exists(tokenId));

        _tokenOwner[tokenId] = to;
        _increment(to);

        _addTokenToOwnerEnumeration(to, tokenId);
        _addTokenToAllTokensEnumeration(tokenId);

        emit Transfer(address(0), to, tokenId);
    }

    
    function _burn(address owner, uint256 tokenId) internal {
        require(ownerOf(tokenId) == owner);

        _clearApproval(tokenId);

        _decrement(owner);
        _tokenOwner[tokenId] = address(0);

        
        if (bytes(_tokenURIs[tokenId]).length != 0) {
            delete _tokenURIs[tokenId];
        }

        _removeTokenFromOwnerEnumeration(owner, tokenId);
        
        _ownedTokensIndex[tokenId] = 0;
        _removeTokenFromAllTokensEnumeration(tokenId);

        emit Transfer(owner, address(0), tokenId);
    }

    
    function _burn(uint256 tokenId) internal {
        _burn(ownerOf(tokenId), tokenId);
    }

    
    function _transferFrom(address from, address to, uint256 tokenId) internal {
        require(ownerOf(tokenId) == from);
        require(to != address(0));

        _clearApproval(tokenId);

        _decrement(from);
        _increment(to);

        _tokenOwner[tokenId] = to;

        _removeTokenFromOwnerEnumeration(from, tokenId);
        _addTokenToOwnerEnumeration(to, tokenId);

        emit Transfer(from, to, tokenId);
    }

    
    function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
        internal returns (bool)
    {
        if (!_isContract(to)) {
            return true;
        }

        bytes4 retval = ERC721ReceiverInterface(to).onERC721Received(msg.sender, from, tokenId, _data);
        return (retval == _ERC721_RECEIVED);
    }

    
    function name() external view returns (string memory) {
        return _name;
    }

    
    function symbol() external view returns (string memory) {
        return _symbol;
    }

    
    function tokenURI(uint256 tokenId) external view returns (string memory) {
        require(_exists(tokenId));
        return _tokenURIs[tokenId];
    }

    
    function setTokenURI(uint256 tokenId, string calldata uri) external onlyOwner {
        _setTokenURI(tokenId, uri);
    }

    
    function _setTokenURI(uint256 tokenId, string memory uri) internal {
        require(_exists(tokenId));
        _tokenURIs[tokenId] = uri;
    }

    
    function totalSupply() public view returns (uint256) {
        return _allTokens.length;
    }

    
    function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
        require(index < balanceOf(owner));
        return _ownedTokens[owner][index];
    }

    
    function tokenByIndex(uint256 index) public view returns (uint256) {
        require(index < totalSupply());
        return _allTokens[index];
    }

    
    function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {
        return _ownedTokens[owner];
    }

    
    function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
        _ownedTokensIndex[tokenId] = _ownedTokens[to].length;
        _ownedTokens[to].push(tokenId);
    }

    
    function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
        _allTokensIndex[tokenId] = _allTokens.length;
        _allTokens.push(tokenId);
    }

    
    function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
        
        

        uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
        uint256 tokenIndex = _ownedTokensIndex[tokenId];

        
        if (tokenIndex != lastTokenIndex) {
            uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

            _ownedTokens[from][tokenIndex] = lastTokenId; 
            _ownedTokensIndex[lastTokenId] = tokenIndex; 
        }

        
        _ownedTokens[from].length--;

        
        
    }

    
    function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
        
        

        uint256 lastTokenIndex = _allTokens.length.sub(1);
        uint256 tokenIndex = _allTokensIndex[tokenId];

        
        
        
        uint256 lastTokenId = _allTokens[lastTokenIndex];

        _allTokens[tokenIndex] = lastTokenId; 
        _allTokensIndex[lastTokenId] = tokenIndex; 

        
        _allTokens.length--;
        _allTokensIndex[tokenId] = 0;
    }

    
    function _isContract(address account) private view returns (bool) {
        uint256 size;
        assembly { size := extcodesize(account) }
        return size > 0;
    }

    
    function _current(address tokenAddress) private view returns (uint256) {
        return _ownedTokensCount[tokenAddress];
    }

    
    function _increment(address tokenAddress) private {
        _ownedTokensCount[tokenAddress] = _ownedTokensCount[tokenAddress].add(1);
    }

    
    function _decrement(address tokenAddress) private {
        _ownedTokensCount[tokenAddress] = _ownedTokensCount[tokenAddress].sub(1);
    }

    
    function _clearApproval(uint256 tokenId) private {
        if (_tokenApprovals[tokenId] != address(0)) {
            _tokenApprovals[tokenId] = address(0);
        }
    }
  }

contract RoleManager {

    mapping(address => bool) private admins;
    mapping(address => bool) private controllers;

    modifier onlyAdmins {
        require(admins[msg.sender], 'only admins');
        _;
    }

    modifier onlyControllers {
        require(controllers[msg.sender], 'only controllers');
        _;
    } 

    constructor() public {
        admins[msg.sender] = true;
        controllers[msg.sender] = true;
    }

    function addController(address _newController) external onlyAdmins{
        controllers[_newController] = true;
    } 

    function addAdmin(address _newAdmin) external onlyAdmins{
        admins[_newAdmin] = true;
    } 

    function removeController(address _controller) external onlyAdmins{
        controllers[_controller] = false;
    } 
    
    function removeAdmin(address _admin) external onlyAdmins{
        require(_admin != msg.sender, 'unexecutable operation'); 
        admins[_admin] = false;
    } 

    function isAdmin(address addr) external view returns (bool) {
        return (admins[addr]);
    }

    function isController(address addr) external view returns (bool) {
        return (controllers[addr]);
    }

}

contract AccessController {

    address public roleManagerAddr;

    modifier onlyAdmins {
        require(RoleManager(roleManagerAddr).isAdmin(msg.sender), 'only admins');
        _;
    }

    modifier onlyControllers {
        require(RoleManager(roleManagerAddr).isController(msg.sender), 'only controllers');
        _;
    }

    constructor (address _roleManagerAddr) public {
        require(_roleManagerAddr != address(0), '_roleManagerAddr: Invalid address (zero address)');
        roleManagerAddr = _roleManagerAddr;
    }

}

contract SpecialContentToken is ERC721Extended, AccessController {
  using SafeMath for uint256;

  uint256 public idCounter;

  constructor(address roleManagerAddr)
    public
    AccessController(roleManagerAddr)
    ERC721Extended("GeneA.I.dols Special Content", "GSC")
  {
  }

  function mint(address to, string calldata tokenURI) external onlyAdmins {
    idCounter = idCounter.add(1);
    _mint(to, idCounter);
    _setTokenURI(idCounter, tokenURI);
  }

  function setTokenURI(uint256 tokenId, string calldata tokenURI) external onlyAdmins {
    _setTokenURI(tokenId, tokenURI);
  }
}