pragma solidity 0.5.17;

import "@daostack/infra/contracts/votingMachines/IntVoteInterface.sol";
import "@daostack/infra/contracts/votingMachines/VotingMachineCallbacksInterface.sol";
import "./UniversalScheme.sol";
import "../votingMachines/VotingMachineCallbacks.sol";


/**
 * @title A registrar for Schemes for organizations
 * @dev The SchemeRegistrar is used for registering and unregistering schemes at organizations
 */

contract SchemeRegistrar is UniversalScheme, VotingMachineCallbacks, ProposalExecuteInterface {
    event NewSchemeProposal(
        address indexed _avatar,
        bytes32 indexed _proposalId,
        address indexed _intVoteInterface,
        address _scheme,
        bytes32 _parametersHash,
        bytes4 _permissions,
        string _descriptionHash
    );

    event RemoveSchemeProposal(address indexed _avatar,
        bytes32 indexed _proposalId,
        address indexed _intVoteInterface,
        address _scheme,
        string _descriptionHash
    );

    event ProposalExecuted(address indexed _avatar, bytes32 indexed _proposalId, int256 _param);
    event ProposalDeleted(address indexed _avatar, bytes32 indexed _proposalId);

    // a SchemeProposal is a  proposal to add or remove a scheme to/from the an organization
    struct SchemeProposal {
        address scheme; //
        bool addScheme; // true: add a scheme, false: remove a scheme.
        bytes32 parametersHash;
        bytes4 permissions;
    }

    // A mapping from the organization (Avatar) address to the saved data of the organization:
    mapping(address=>mapping(bytes32=>SchemeProposal)) public organizationsProposals;

    // A mapping from hashes to parameters (use to store a particular configuration on the controller)
    struct Parameters {
        bytes32 voteRegisterParams;
        bytes32 voteRemoveParams;
        IntVoteInterface intVote;
    }

    mapping(bytes32=>Parameters) public parameters;

    /**
    * @dev execution of proposals, can only be called by the voting machine in which the vote is held.
    * @param _proposalId the ID of the voting in the voting machine
    * @param _param a parameter of the voting result, 1 yes and 2 is no.
    */
    function executeProposal(bytes32 _proposalId, int256 _param) external onlyVotingMachine(_proposalId) returns(bool) {
        Avatar avatar = proposalsInfo[msg.sender][_proposalId].avatar;
        SchemeProposal memory proposal = organizationsProposals[address(avatar)][_proposalId];
        require(proposal.scheme != address(0));
        delete organizationsProposals[address(avatar)][_proposalId];
        emit ProposalDeleted(address(avatar), _proposalId);
        if (_param == 1) {

          // Define controller and get the params:
            Controller controller = Controller(avatar.owner());

          // Add a scheme:
            if (proposal.addScheme) {
                require(controller.registerScheme(
                        proposal.scheme,
                        proposal.parametersHash,
                        proposal.permissions,
                        address(avatar))
                );
            }
          // Remove a scheme:
            if (!proposal.addScheme) {
                require(controller.unregisterScheme(proposal.scheme, address(avatar)));
            }
        }
        emit ProposalExecuted(address(avatar), _proposalId, _param);
        return true;
    }

    /**
    * @dev hash the parameters, save them if necessary, and return the hash value
    */
    function setParameters(
        bytes32 _voteRegisterParams,
        bytes32 _voteRemoveParams,
        IntVoteInterface _intVote
    ) public returns(bytes32)
    {
        bytes32 paramsHash = getParametersHash(_voteRegisterParams, _voteRemoveParams, _intVote);
        parameters[paramsHash].voteRegisterParams = _voteRegisterParams;
        parameters[paramsHash].voteRemoveParams = _voteRemoveParams;
        parameters[paramsHash].intVote = _intVote;
        return paramsHash;
    }

    /**
    * @dev create a proposal to register a scheme
    * @param _avatar the address of the organization the scheme will be registered for
    * @param _scheme the address of the scheme to be registered
    * @param _parametersHash a hash of the configuration of the _scheme
    * @param _permissions the permission of the scheme to be registered
    * @param _descriptionHash proposal's description hash
    * @return a proposal Id
    * @dev NB: not only proposes the vote, but also votes for it
    */
    function proposeScheme(
        Avatar _avatar,
        address _scheme,
        bytes32 _parametersHash,
        bytes4 _permissions,
        string memory _descriptionHash
    )
    public
    returns(bytes32)
    {
        // propose
        require(_scheme != address(0), "scheme cannot be zero");
        Parameters memory controllerParams = parameters[getParametersFromController(_avatar)];

        bytes32 proposalId = controllerParams.intVote.propose(
            2,
            controllerParams.voteRegisterParams,
            msg.sender,
            address(_avatar)
        );

        SchemeProposal memory proposal = SchemeProposal({
            scheme: _scheme,
            parametersHash: _parametersHash,
            addScheme: true,
            permissions: _permissions
        });
        emit NewSchemeProposal(
            address(_avatar),
            proposalId,
            address(controllerParams.intVote),
            _scheme, _parametersHash,
            _permissions,
            _descriptionHash
        );
        organizationsProposals[address(_avatar)][proposalId] = proposal;
        proposalsInfo[address(controllerParams.intVote)][proposalId] = ProposalInfo({
            blockNumber:block.number,
            avatar:_avatar
        });
        return proposalId;
    }

    /**
    * @dev propose to remove a scheme for a controller
    * @param _avatar the address of the controller from which we want to remove a scheme
    * @param _scheme the address of the scheme we want to remove
    * @param _descriptionHash proposal description hash
    * NB: not only registers the proposal, but also votes for it
    */
    function proposeToRemoveScheme(Avatar _avatar, address _scheme, string memory _descriptionHash)
    public
    returns(bytes32)
    {
        require(_scheme != address(0), "scheme cannot be zero");
        bytes32 paramsHash = getParametersFromController(_avatar);
        Parameters memory params = parameters[paramsHash];

        IntVoteInterface intVote = params.intVote;
        bytes32 proposalId = intVote.propose(2, params.voteRemoveParams, msg.sender, address(_avatar));
        organizationsProposals[address(_avatar)][proposalId].scheme = _scheme;
        emit RemoveSchemeProposal(address(_avatar), proposalId, address(intVote), _scheme, _descriptionHash);
        proposalsInfo[address(params.intVote)][proposalId] = ProposalInfo({
            blockNumber:block.number,
            avatar:_avatar
        });
        return proposalId;
    }

    function getParametersHash(
        bytes32 _voteRegisterParams,
        bytes32 _voteRemoveParams,
        IntVoteInterface _intVote
    ) public pure returns(bytes32)
    {
        return keccak256(abi.encodePacked(_voteRegisterParams, _voteRemoveParams, _intVote));
    }
}