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Config.sol

pragma solidity >=0.4.22 <0.7.0;

/**
 * @title Config
 * @dev Set and get settings
 */
contract Config {
    
    address private owner;
    
    modifier isOwner() {
        require(msg.sender == owner, "Caller is not owner");
        _;
    }
    
    struct Setting {
        string key;
        string value;
    }
    
    Setting[] settings;
    
    constructor() public {
        owner = msg.sender;
    }

    function set(string memory _key, string memory _value) public isOwner {
        //uint i = find(_key);
        //settings[i].value = _value;
        settings.push(Setting(_key, _value));
    }
    
    function unset(string memory _key) public isOwner {
        uint i = find(_key);
        if (i != 0) {
            delete settings[i];
        }
    }
    
    function get(string memory _key) public view returns (string memory, string memory) {
        uint i = find(_key);
        return (settings[i].key, settings[i].value);
    }
    
    function find(string memory _key) internal view returns (uint) {
        for(uint i = 0; i < settings.length; i++) {
            if (isEqual(settings[i].key, _key)) {
                return i;
            }
        }
        revert('key not found');
    }
    
    function isEqual(string memory a, string memory b) internal pure returns (bool) {
        if (bytes(a).length != bytes(b).length) {
            return false;
        } else {
            return keccak256(abi.encodePacked(a)) == keccak256(abi.encodePacked(b));
        }
    }

    /*function all() public view returns (Setting[] memory) {
        return settings;
    }*/

}