update validator smart contract

contracts/validator/contract/TomoValidator.sol

@@ -10,12 +10,17 @@ contract TomoValidator is IValidator {
         bool isValidator;
         bool isCandidate;
         uint256 cap;
+        mapping(address => uint256) voters;
     }
 
     mapping(address => ValidatorState) validatorsState;
+    address[] public validators;
+    address[] public candidates;
     uint256 threshold = 1000 * 10** 18; // 1000 TOMO
 
     function TomoValidator(address[] _validators, uint256[] _caps) public {
+        validators = _validators;
+        candidates = _validators;
         
         for (uint256 i = 0; i < _validators.length; i++) {
             validatorsState[_validators[i]] = ValidatorState({
@@ -30,6 +35,9 @@ contract TomoValidator is IValidator {
     function propose(address _candidate) external payable {
         // only validator can propose a candidate
         require(validatorsState[msg.sender].isValidator);
+        if (!validatorsState[_candidate].isCandidate) {
+            candidates.push(_candidate);
+        }
         validatorsState[_candidate] = ValidatorState({
             isValidator: false,
             isCandidate: true,
@@ -43,7 +51,46 @@ contract TomoValidator is IValidator {
         require(validatorsState[_candidate].isCandidate);
         validatorsState[_candidate].cap = validatorsState[_candidate].cap.add(msg.value);
         if (validatorsState[_candidate].cap >= threshold) {
-            validatorsState[_candidate].isValidator = true;
+            if (!validatorsState[_candidate].isValidator) {
+                validators.push(_candidate);
             }
+            validatorsState[_candidate].isValidator = true;
+            validatorsState[_candidate].voters[msg.sender] = validatorsState[_candidate].voters[msg.sender].add(msg.value);
+        }
+    }
+
+    function getValidators() public view returns(address[]) {
+       return validators;
+    }
+
+    function getCandidates() public view returns(address[]) {
+       return candidates;
+    }
+
+    function getCandidateCap(address _candidate) public view returns(uint256) {
+        return validatorsState[_candidate].cap;
+    }
+
+    function getVoterCap(address _candidate, address _voter) public view returns(uint256) {
+        return validatorsState[_candidate].voters[_voter];
+    }
+
+    function isValidator(address _candidate) public view returns(bool) {
+       return validatorsState[_candidate].isValidator;
+    }
+
+    function isCandidate(address _candidate) public view returns(bool) {
+       return validatorsState[_candidate].isCandidate;
+    }
+
+    function unvote(address _candidate, uint256 _cap) public {
+        // only unvote for candidate who does not become validator yet
+        require(!validatorsState[_candidate].isValidator);
+        require(validatorsState[_candidate].isCandidate);
+        require(validatorsState[_candidate].voters[msg.sender] >= _cap);
+        validatorsState[_candidate].cap = validatorsState[_candidate].cap.sub(_cap);
+        validatorsState[_candidate].voters[msg.sender] = validatorsState[_candidate].voters[msg.sender].sub(_cap);
+        // refunding to user after unvoting
+        msg.sender.transfer(_cap);
     }
 }