contract PendingManager is Object, PendingManagerEmitter, PendingManagerInterface {

    uint constant NO_RECORDS_WERE_FOUND = 4;
    uint constant PENDING_MANAGER_SCOPE = 4000;
    uint constant PENDING_MANAGER_INVALID_INVOCATION = PENDING_MANAGER_SCOPE + 1;
    uint constant PENDING_MANAGER_HASNT_VOTED = PENDING_MANAGER_SCOPE + 2;
    uint constant PENDING_DUPLICATE_TX = PENDING_MANAGER_SCOPE + 3;
    uint constant PENDING_MANAGER_CONFIRMED = PENDING_MANAGER_SCOPE + 4;
    uint constant PENDING_MANAGER_REJECTED = PENDING_MANAGER_SCOPE + 5;
    uint constant PENDING_MANAGER_IN_PROCESS = PENDING_MANAGER_SCOPE + 6;
    uint constant PENDING_MANAGER_TX_DOESNT_EXIST = PENDING_MANAGER_SCOPE + 7;
    uint constant PENDING_MANAGER_TX_WAS_DECLINED = PENDING_MANAGER_SCOPE + 8;
    uint constant PENDING_MANAGER_TX_WAS_NOT_CONFIRMED = PENDING_MANAGER_SCOPE + 9;
    uint constant PENDING_MANAGER_INSUFFICIENT_GAS = PENDING_MANAGER_SCOPE + 10;
    uint constant PENDING_MANAGER_POLICY_NOT_FOUND = PENDING_MANAGER_SCOPE + 11;

    using SafeMath for uint;

    enum GuardState {
        Decline, Confirmed, InProcess
    }

    struct Requirements {
        bytes32 groupName;
        uint acceptLimit;
        uint declineLimit;
    }

    struct Policy {
        uint groupsCount;
        mapping(uint => Requirements) participatedGroups; // index => globalGroupIndex
        mapping(bytes32 => uint) groupName2index; // groupName => localIndex
        
        uint totalAcceptedLimit;
        uint totalDeclinedLimit;

        uint securesCount;
        mapping(uint => uint) index2txIndex;
        mapping(uint => uint) txIndex2index;
    }

    struct Vote {
        bytes32 groupName;
        bool accepted;
    }

    struct Guard {
        GuardState state;
        uint basePolicyIndex;

        uint alreadyAccepted;
        uint alreadyDeclined;
        
        mapping(address => Vote) votes; // member address => vote
        mapping(bytes32 => uint) acceptedCount; // groupName => how many from group has already accepted
        mapping(bytes32 => uint) declinedCount; // groupName => how many from group has already declined
    }

    address public accessManager;

    mapping(address => bool) public authorized;

    uint public policiesCount;
    mapping(uint => bytes32) index2PolicyId; // index => policy hash
    mapping(bytes32 => uint) policyId2Index; // policy hash => index
    mapping(bytes32 => Policy) policyId2policy; // policy hash => policy struct

    uint public txCount;
    mapping(uint => bytes32) index2txKey;
    mapping(bytes32 => uint) txKey2index; // tx key => index
    mapping(bytes32 => Guard) txKey2guard;

    /// @dev Execution is allowed only by authorized contract
    modifier onlyAuthorized {
        if (authorized[msg.sender] || address(this) == msg.sender) {
            _;
        }
    }

    /// @dev Pending Manager's constructor
    ///
    /// @param _accessManager access manager's address
    function PendingManager(address _accessManager) public {
        require(_accessManager != 0x0);
        accessManager = _accessManager;
    }

    function() payable public {
        revert();
    }

    /// @notice Update access manager address
    ///
    /// @param _accessManager access manager's address
    function setAccessManager(address _accessManager) external onlyContractOwner returns (uint) {
        require(_accessManager != 0x0);
        accessManager = _accessManager;
        return OK;
    }

    /// @notice Sign in contract
    ///
    /// @param _contract contract's address
    function signIn(address _contract) external onlyContractOwner returns (uint) {
        require(_contract != 0x0);
        authorized[_contract] = true;
        return OK;
    }

    /// @notice Sign out contract
    ///
    /// @param _contract contract's address
    function signOut(address _contract) external onlyContractOwner returns (uint) {
        require(_contract != 0x0);
        delete authorized[_contract];
        return OK;
    }

    /// @notice Register new policy rule
    /// Can be called only by contract owner
    ///
    /// @param _sig target method signature
    /// @param _contract target contract address
    /// @param _groupName group's name
    /// @param _acceptLimit accepted vote limit
    /// @param _declineLimit decline vote limit
    ///
    /// @return code
    function addPolicyRule(
        bytes4 _sig,
        address _contract,
        bytes32 _groupName,
        uint _acceptLimit,
        uint _declineLimit
    )
    onlyContractOwner
    external
    returns (uint)
    {
        require(_sig != 0x0);
        require(_contract != 0x0);
        require(GroupsAccessManager(accessManager).isGroupExists(_groupName));
        require(_acceptLimit != 0);
        require(_declineLimit != 0);

        bytes32 _policyHash = keccak256(_sig, _contract);
        
        if (policyId2Index[_policyHash] == 0) {
            uint _policiesCount = policiesCount.add(1);
            index2PolicyId[_policiesCount] = _policyHash;
            policyId2Index[_policyHash] = _policiesCount;
            policiesCount = _policiesCount;
        }

        Policy storage _policy = policyId2policy[_policyHash];
        uint _policyGroupsCount = _policy.groupsCount;

        if (_policy.groupName2index[_groupName] == 0) {
            _policyGroupsCount += 1;
            _policy.groupName2index[_groupName] = _policyGroupsCount;
            _policy.participatedGroups[_policyGroupsCount].groupName = _groupName;
            _policy.groupsCount = _policyGroupsCount;
        }

        uint _previousAcceptLimit = _policy.participatedGroups[_policyGroupsCount].acceptLimit;
        uint _previousDeclineLimit = _policy.participatedGroups[_policyGroupsCount].declineLimit;
        _policy.participatedGroups[_policyGroupsCount].acceptLimit = _acceptLimit;
        _policy.participatedGroups[_policyGroupsCount].declineLimit = _declineLimit;
        _policy.totalAcceptedLimit = _policy.totalAcceptedLimit.sub(_previousAcceptLimit).add(_acceptLimit);
        _policy.totalDeclinedLimit = _policy.totalDeclinedLimit.sub(_previousDeclineLimit).add(_declineLimit);

        PolicyRuleAdded(_sig, _contract, _policyHash, _groupName, _acceptLimit, _declineLimit);
        return OK;
    }

    /// @notice Remove policy rule
    /// Can be called only by contract owner
    ///
    /// @param _groupName group's name
    ///
    /// @return code
    function removePolicyRule(
        bytes4 _sig,
        address _contract,
        bytes32 _groupName
    ) 
    onlyContractOwner 
    external 
    returns (uint) 
    {
        require(_sig != bytes4(0));
        require(_contract != 0x0);
        require(GroupsAccessManager(accessManager).isGroupExists(_groupName));

        bytes32 _policyHash = keccak256(_sig, _contract);
        Policy storage _policy = policyId2policy[_policyHash];
        uint _policyGroupNameIndex = _policy.groupName2index[_groupName];

        if (_policyGroupNameIndex == 0) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        uint _policyGroupsCount = _policy.groupsCount;
        if (_policyGroupNameIndex != _policyGroupsCount) {
            Requirements storage _requirements = _policy.participatedGroups[_policyGroupsCount];
            _policy.participatedGroups[_policyGroupNameIndex] = _requirements;
            _policy.groupName2index[_requirements.groupName] = _policyGroupNameIndex;
        }

        _policy.totalAcceptedLimit = _policy.totalAcceptedLimit.sub(_policy.participatedGroups[_policyGroupsCount].acceptLimit);
        _policy.totalDeclinedLimit = _policy.totalDeclinedLimit.sub(_policy.participatedGroups[_policyGroupsCount].declineLimit);

        delete _policy.groupName2index[_groupName];
        delete _policy.participatedGroups[_policyGroupsCount];
        _policy.groupsCount = _policyGroupsCount.sub(1);

        PolicyRuleRemoved(_sig, _contract, _policyHash, _groupName);
        return OK;
    }

    /// @notice Add transaction
    ///
    /// @param _key transaction id
    ///
    /// @return code
    function addTx(bytes32 _key, bytes4 _sig, address _contract) external onlyAuthorized returns (uint) {
        require(_key != bytes32(0));
        require(_sig != bytes4(0));
        require(_contract != 0x0);

        bytes32 _policyHash = keccak256(_sig, _contract);
        require(isPolicyExist(_policyHash));

        if (isTxExist(_key)) {
            return _emitError(PENDING_DUPLICATE_TX);
        }

        if (_policyHash == bytes32(0)) {
            return _emitError(PENDING_MANAGER_POLICY_NOT_FOUND);
        }

        uint _index = txCount.add(1);
        txCount = _index;
        index2txKey[_index] = _key;
        txKey2index[_key] = _index;

        Guard storage _guard = txKey2guard[_key];
        _guard.basePolicyIndex = policyId2Index[_policyHash];
        _guard.state = GuardState.InProcess;

        Policy storage _policy = policyId2policy[_policyHash];
        uint _counter = _policy.securesCount.add(1);
        _policy.securesCount = _counter;
        _policy.index2txIndex[_counter] = _index;
        _policy.txIndex2index[_index] = _counter;

        ProtectionTxAdded(_key, _policyHash, block.number);
        return OK;
    }

    /// @notice Delete transaction
    /// @param _key transaction id
    /// @return code
    function deleteTx(bytes32 _key) external onlyContractOwner returns (uint) {
        require(_key != bytes32(0));

        if (!isTxExist(_key)) {
            return _emitError(PENDING_MANAGER_TX_DOESNT_EXIST);
        }

        uint _txsCount = txCount;
        uint _txIndex = txKey2index[_key];
        if (_txIndex != _txsCount) {
            bytes32 _last = index2txKey[txCount];
            index2txKey[_txIndex] = _last;
            txKey2index[_last] = _txIndex;
        }

        delete txKey2index[_key];
        delete index2txKey[_txsCount];
        txCount = _txsCount.sub(1);

        uint _basePolicyIndex = txKey2guard[_key].basePolicyIndex;
        Policy storage _policy = policyId2policy[index2PolicyId[_basePolicyIndex]];
        uint _counter = _policy.securesCount;
        uint _policyTxIndex = _policy.txIndex2index[_txIndex];
        if (_policyTxIndex != _counter) {
            uint _movedTxIndex = _policy.index2txIndex[_counter];
            _policy.index2txIndex[_policyTxIndex] = _movedTxIndex;
            _policy.txIndex2index[_movedTxIndex] = _policyTxIndex;
        }

        delete _policy.index2txIndex[_counter];
        delete _policy.txIndex2index[_txIndex];
        _policy.securesCount = _counter.sub(1);

        TxDeleted(_key);
        return OK;
    }

    /// @notice Accept transaction
    /// Can be called only by registered user in GroupsAccessManager
    ///
    /// @param _key transaction id
    ///
    /// @return code
    function accept(bytes32 _key, bytes32 _votingGroupName) external returns (uint) {
        if (!isTxExist(_key)) {
            return _emitError(PENDING_MANAGER_TX_DOESNT_EXIST);
        }

        if (!GroupsAccessManager(accessManager).isUserInGroup(_votingGroupName, msg.sender)) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        Guard storage _guard = txKey2guard[_key];
        if (_guard.state != GuardState.InProcess) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        if (_guard.votes[msg.sender].groupName != bytes32(0) && _guard.votes[msg.sender].accepted) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        Policy storage _policy = policyId2policy[index2PolicyId[_guard.basePolicyIndex]];
        uint _policyGroupIndex = _policy.groupName2index[_votingGroupName];
        uint _groupAcceptedVotesCount = _guard.acceptedCount[_votingGroupName];
        if (_groupAcceptedVotesCount == _policy.participatedGroups[_policyGroupIndex].acceptLimit) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        _guard.votes[msg.sender] = Vote(_votingGroupName, true);
        _guard.acceptedCount[_votingGroupName] = _groupAcceptedVotesCount + 1;
        uint _alreadyAcceptedCount = _guard.alreadyAccepted + 1;
        _guard.alreadyAccepted = _alreadyAcceptedCount;

        ProtectionTxAccepted(_key, msg.sender, _votingGroupName);

        if (_alreadyAcceptedCount == _policy.totalAcceptedLimit) {
            _guard.state = GuardState.Confirmed;
            ProtectionTxDone(_key);
        }

        return OK;
    }

    /// @notice Decline transaction
    /// Can be called only by registered user in GroupsAccessManager
    ///
    /// @param _key transaction id
    ///
    /// @return code
    function decline(bytes32 _key, bytes32 _votingGroupName) external returns (uint) {
        if (!isTxExist(_key)) {
            return _emitError(PENDING_MANAGER_TX_DOESNT_EXIST);
        }

        if (!GroupsAccessManager(accessManager).isUserInGroup(_votingGroupName, msg.sender)) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        Guard storage _guard = txKey2guard[_key];
        if (_guard.state != GuardState.InProcess) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        if (_guard.votes[msg.sender].groupName != bytes32(0) && !_guard.votes[msg.sender].accepted) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        Policy storage _policy = policyId2policy[index2PolicyId[_guard.basePolicyIndex]];
        uint _policyGroupIndex = _policy.groupName2index[_votingGroupName];
        uint _groupDeclinedVotesCount = _guard.declinedCount[_votingGroupName];
        if (_groupDeclinedVotesCount == _policy.participatedGroups[_policyGroupIndex].declineLimit) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        _guard.votes[msg.sender] = Vote(_votingGroupName, false);
        _guard.declinedCount[_votingGroupName] = _groupDeclinedVotesCount + 1;
        uint _alreadyDeclinedCount = _guard.alreadyDeclined + 1;
        _guard.alreadyDeclined = _alreadyDeclinedCount;


        ProtectionTxDeclined(_key, msg.sender, _votingGroupName);

        if (_alreadyDeclinedCount == _policy.totalDeclinedLimit) {
            _guard.state = GuardState.Decline;
            ProtectionTxCancelled(_key);
        }

        return OK;
    }

    /// @notice Revoke user votes for transaction
    /// Can be called only by contract owner
    ///
    /// @param _key transaction id
    /// @param _user target user address
    ///
    /// @return code
    function forceRejectVotes(bytes32 _key, address _user) external onlyContractOwner returns (uint) {
        return _revoke(_key, _user);
    }

    /// @notice Revoke vote for transaction
    /// Can be called only by authorized user
    /// @param _key transaction id
    /// @return code
    function revoke(bytes32 _key) external returns (uint) {
        return _revoke(_key, msg.sender);
    }

    /// @notice Check transaction status
    /// @param _key transaction id
    /// @return code
    function hasConfirmedRecord(bytes32 _key) public view returns (uint) {
        require(_key != bytes32(0));

        if (!isTxExist(_key)) {
            return NO_RECORDS_WERE_FOUND;
        }

        Guard storage _guard = txKey2guard[_key];
        return _guard.state == GuardState.InProcess
        ? PENDING_MANAGER_IN_PROCESS
        : _guard.state == GuardState.Confirmed
        ? OK
        : PENDING_MANAGER_REJECTED;
    }


    /// @notice Check policy details
    ///
    /// @return _groupNames group names included in policies
    /// @return _acceptLimits accept limit for group
    /// @return _declineLimits decline limit for group
    function getPolicyDetails(bytes4 _sig, address _contract)
    public
    view
    returns (
        bytes32[] _groupNames,
        uint[] _acceptLimits,
        uint[] _declineLimits,
        uint _totalAcceptedLimit,
        uint _totalDeclinedLimit
    ) {
        require(_sig != bytes4(0));
        require(_contract != 0x0);
        
        bytes32 _policyHash = keccak256(_sig, _contract);
        uint _policyIdx = policyId2Index[_policyHash];
        if (_policyIdx == 0) {
            return;
        }

        Policy storage _policy = policyId2policy[_policyHash];
        uint _policyGroupsCount = _policy.groupsCount;
        _groupNames = new bytes32[](_policyGroupsCount);
        _acceptLimits = new uint[](_policyGroupsCount);
        _declineLimits = new uint[](_policyGroupsCount);

        for (uint _idx = 0; _idx < _policyGroupsCount; ++_idx) {
            Requirements storage _requirements = _policy.participatedGroups[_idx + 1];
            _groupNames[_idx] = _requirements.groupName;
            _acceptLimits[_idx] = _requirements.acceptLimit;
            _declineLimits[_idx] = _requirements.declineLimit;
        }

        (_totalAcceptedLimit, _totalDeclinedLimit) = (_policy.totalAcceptedLimit, _policy.totalDeclinedLimit);
    }

    /// @notice Check policy include target group
    /// @param _policyHash policy hash (sig, contract address)
    /// @param _groupName group id
    /// @return bool
    function isGroupInPolicy(bytes32 _policyHash, bytes32 _groupName) public view returns (bool) {
        Policy storage _policy = policyId2policy[_policyHash];
        return _policy.groupName2index[_groupName] != 0;
    }

    /// @notice Check is policy exist
    /// @param _policyHash policy hash (sig, contract address)
    /// @return bool
    function isPolicyExist(bytes32 _policyHash) public view returns (bool) {
        return policyId2Index[_policyHash] != 0;
    }

    /// @notice Check is transaction exist
    /// @param _key transaction id
    /// @return bool
    function isTxExist(bytes32 _key) public view returns (bool){
        return txKey2index[_key] != 0;
    }

    function _updateTxState(Policy storage _policy, Guard storage _guard, uint confirmedAmount, uint declineAmount) private {
        if (declineAmount != 0 && _guard.state != GuardState.Decline) {
            _guard.state = GuardState.Decline;
        } else if (confirmedAmount >= _policy.groupsCount && _guard.state != GuardState.Confirmed) {
            _guard.state = GuardState.Confirmed;
        } else if (_guard.state != GuardState.InProcess) {
            _guard.state = GuardState.InProcess;
        }
    }

    function _revoke(bytes32 _key, address _user) private returns (uint) {
        require(_key != bytes32(0));
        require(_user != 0x0);

        if (!isTxExist(_key)) {
            return _emitError(PENDING_MANAGER_TX_DOESNT_EXIST);
        }

        Guard storage _guard = txKey2guard[_key];
        if (_guard.state != GuardState.InProcess) {
            return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
        }

        bytes32 _votedGroupName = _guard.votes[_user].groupName;
        if (_votedGroupName == bytes32(0)) {
            return _emitError(PENDING_MANAGER_HASNT_VOTED);
        }

        bool isAcceptedVote = _guard.votes[_user].accepted;
        if (isAcceptedVote) {
            _guard.acceptedCount[_votedGroupName] = _guard.acceptedCount[_votedGroupName].sub(1);
            _guard.alreadyAccepted = _guard.alreadyAccepted.sub(1);
        } else {
            _guard.declinedCount[_votedGroupName] = _guard.declinedCount[_votedGroupName].sub(1);
            _guard.alreadyDeclined = _guard.alreadyDeclined.sub(1);

        }

        delete _guard.votes[_user];

        ProtectionTxVoteRevoked(_key, _user, _votedGroupName);
        return OK;
    }
}
/// @title PendingManager
///
/// Base implementation
/// This contract serves as pending manager for transaction status
function accept(bytes32 _key, bytes32 _votingGroupName) external returns (uint) {
    if (!isTxExist(_key)) {
        return _emitError(PENDING_MANAGER_TX_DOESNT_EXIST);
    }

    if (!GroupsAccessManager(accessManager).isUserInGroup(_votingGroupName, msg.sender)) {
        return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
    }

    Guard storage _guard = txKey2guard[_key];
    if (_guard.state != GuardState.InProcess) {
        return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
    }

    if (_guard.votes[msg.sender].groupName != bytes32(0) && _guard.votes[msg.sender].accepted) {
        return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
    }

    Policy storage _policy = policyId2policy[index2PolicyId[_guard.basePolicyIndex]];
    uint _policyGroupIndex = _policy.groupName2index[_votingGroupName];
    uint _groupAcceptedVotesCount = _guard.acceptedCount[_votingGroupName];
    if (_groupAcceptedVotesCount == _policy.participatedGroups[_policyGroupIndex].acceptLimit) {
        return _emitError(PENDING_MANAGER_INVALID_INVOCATION);
    }

    _guard.votes[msg.sender] = Vote(_votingGroupName, true);
    _guard.acceptedCount[_votingGroupName] = _groupAcceptedVotesCount + 1;
    uint _alreadyAcceptedCount = _guard.alreadyAccepted + 1;
    _guard.alreadyAccepted = _alreadyAcceptedCount;

    ProtectionTxAccepted(_key, msg.sender, _votingGroupName);

    if (_alreadyAcceptedCount == _policy.totalAcceptedLimit) {
        _guard.state = GuardState.Confirmed;
        ProtectionTxDone(_key);
    }

    return OK;
}

/// @notice Accept transaction
/// Can be called only by registered user in GroupsAccessManager
///
/// @param _key transaction id
///
/// @return code