// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract PureBi { 
    
    // --- 0. BRANDING ---
    string public constant name = "PureBilingualVersation Research Registry";
    string public constant symbol = "PURE BI-VERSATION"; 

    // --- 1. IDENTITY & REPUTATION (PER DIALECT) ---
    mapping(address => bool) public isRegistered;
    // user -> dialect -> xp
    mapping(address => mapping(string => uint256)) public userXP;
    // user -> dialect -> role
    mapping(address => mapping(string => string)) public userRole;
    // Global admin checking
    mapping(address => bool) public isAdmin;
    
    address public labAdmin; // The Gasless Relayer (Python Backend)

    // --- 2. REGISTRY & LICENSING ---
    struct DialectEntry {
        uint256 id;
        string phrase;      
        string dialect;     
        string ipfsCid;     
        address contributor;
        string licenseType; 
        uint256 verificationCount;
        uint256 rejectionCount;
        bool isVerified;
        bool isBurned;
    }

    uint256 public entryCounter;
    mapping(uint256 => DialectEntry) public entries;

    // Consensus Tracking (entry_id -> user -> bool)
    mapping(uint256 => mapping(address => bool)) public hasVoted;

    // The Burn Ward Tracking
    mapping(uint256 => string) public burnReasons;
    mapping(uint256 => address[]) public rejectorsList;
    mapping(uint256 => uint256) public appealCount;
    mapping(uint256 => mapping(address => bool)) public hasAppealed;

    // --- 3. BACKUP SYSTEM ---
    struct DataSnapshot {
        uint256 timestamp;
        string dataType;    
        string ipfsCid;     
        string description; 
    }

    mapping(string => DataSnapshot[]) public backups; 

    // --- 4. EVENTS ---
    event EntryProposed(uint256 indexed id, string phrase, address indexed proposer);
    event EntryVerified(uint256 indexed id, address indexed verifier);
    event EntryRejected(uint256 indexed id, address indexed rejector, string reason);
    event EntryBurned(uint256 indexed id, address indexed contributor, string reason);
    event EntryAppealed(uint256 indexed id, address indexed appealer, bool success);
    event ReputationMinted(address indexed researcher, string dialect, uint256 amount);
    event RankUpgraded(address indexed researcher, string dialect, string newRole); 
    event BackupCreated(string indexed dataKey, string ipfsCid, uint256 timestamp);

    constructor() {
        labAdmin = msg.sender; // The Python Backend Wallet
        isAdmin[msg.sender] = true;
    }

    // --- MODIFIERS ---
    modifier onlyRelayer() {
        require(msg.sender == labAdmin, "Only the Python Relayer can execute transactions");
        _;
    }

    // --- CORE FUNCTIONS ---
    function proposeEntry(string memory _phrase, string memory _dialect, string memory _ipfsCid, string memory _license, address _contributor) public onlyRelayer returns (uint256) {
        entryCounter++;
        
        entries[entryCounter] = DialectEntry(entryCounter, _phrase, _dialect, _ipfsCid, _contributor, _license, 0, 0, false, false);
        emit EntryProposed(entryCounter, _phrase, _contributor);
        
        if (!isRegistered[_contributor]) {
            isRegistered[_contributor] = true;
        }
        
        // Auto-register brand new React users as Initiates in this dialect if they have no role
        if (bytes(userRole[_contributor][_dialect]).length == 0 && !isAdmin[_contributor]) {
            userRole[_contributor][_dialect] = "Initiate";
        }
        
        return entryCounter;
    }

    function verifyEntry(uint256 _id, address _verifier) public onlyRelayer {
        DialectEntry storage entry = entries[_id];
        require(!entry.isVerified && !entry.isBurned, "Entry already resolved");
        require(entry.contributor != _verifier, "Cannot verify own entry");
        require(!hasVoted[_id][_verifier], "User already voted");

        string memory role = userRole[_verifier][entry.dialect];
        bool isGod = isAdmin[_verifier];
        bool isOracle = keccak256(bytes(role)) == keccak256(bytes("Oracle"));

        require(isGod || isOracle, "Only Admins or Oracles can verify");

        hasVoted[_id][_verifier] = true;
        _mintReputation(_verifier, entry.dialect, 10); // +10 XP for doing the audit

        if (isGod) {
            _applyVerification(_id);
        } else {
            entry.verificationCount++;
            if (entry.verificationCount >= 2) {
                _applyVerification(_id);
            }
        }
    }

    function _applyVerification(uint256 _id) internal {
        entries[_id].isVerified = true;
        _mintReputation(entries[_id].contributor, entries[_id].dialect, 50); // +50 XP to the original submitter
        emit EntryVerified(_id, msg.sender);
    }

    function rejectEntry(uint256 _id, address _rejector, string memory _reason) public onlyRelayer {
        DialectEntry storage entry = entries[_id];
        require(!entry.isVerified && !entry.isBurned, "Entry already resolved");
        require(entry.contributor != _rejector, "Cannot reject own entry");
        require(!hasVoted[_id][_rejector], "User already voted");

        string memory role = userRole[_rejector][entry.dialect];
        bool isGod = isAdmin[_rejector];
        bool isOracle = keccak256(bytes(role)) == keccak256(bytes("Oracle"));

        require(isGod || isOracle, "Only Admins or Oracles can reject");

        hasVoted[_id][_rejector] = true;
        rejectorsList[_id].push(_rejector); // Track for potential penalty
        _mintReputation(_rejector, entry.dialect, 10); // +10 XP for doing the audit
        
        emit EntryRejected(_id, _rejector, _reason);

        if (isGod) {
            _applyBurn(_id, _reason);
        } else {
            entry.rejectionCount++;
            if (entry.rejectionCount >= 3) {
                _applyBurn(_id, _reason);
            }
        }
    }

    function _applyBurn(uint256 _id, string memory _reason) internal {
        entries[_id].isBurned = true;
        burnReasons[_id] = _reason;
        
        address badActor = entries[_id].contributor;
        string memory dialect = entries[_id].dialect;
        
        // Burn -10 XP from the contributor
        if (userXP[badActor][dialect] >= 10) {
            userXP[badActor][dialect] -= 10;
        } else {
            userXP[badActor][dialect] = 0;
        }
        
        _updateRank(badActor, dialect);
        emit EntryBurned(_id, badActor, _reason);
    }

    function appealEntry(uint256 _id, address _appealer) public onlyRelayer {
        DialectEntry storage entry = entries[_id];
        require(entry.isBurned, "Entry is not burned");
        require(!hasAppealed[_id][_appealer], "User already appealed");
        
        string memory role = userRole[_appealer][entry.dialect];
        bool isGod = isAdmin[_appealer];
        bool isOracle = keccak256(bytes(role)) == keccak256(bytes("Oracle"));

        require(isGod || isOracle, "Only Admins or Oracles can appeal");

        hasAppealed[_id][_appealer] = true;
        appealCount[_id]++;
        
        // +10 XP for auditing the graveyard
        _mintReputation(_appealer, entry.dialect, 10); 
        
        if (isGod || appealCount[_id] >= 2) {
            // Overturn the rejection!
            entry.isBurned = false;
            entry.isVerified = true;
            
            // Restore submitter's 50 XP + 10 XP penalty refund
            _mintReputation(entry.contributor, entry.dialect, 60); 
            
            // Penalize the original rejectors -15 XP each
            address[] memory rejectors = rejectorsList[_id];
            for(uint i=0; i<rejectors.length; i++) {
                address r = rejectors[i];
                if (userXP[r][entry.dialect] >= 15) {
                    userXP[r][entry.dialect] -= 15;
                } else {
                    userXP[r][entry.dialect] = 0;
                }
                _updateRank(r, entry.dialect);
            }
            
            emit EntryAppealed(_id, _appealer, true);
        } else {
            emit EntryAppealed(_id, _appealer, false);
        }
    }

    function createBackup(string memory _dataKey, string memory _dataType, string memory _ipfsCid, string memory _description) public onlyRelayer {
        DataSnapshot memory newSnap = DataSnapshot(block.timestamp, _dataType, _ipfsCid, _description);
        backups[_dataKey].push(newSnap);
        emit BackupCreated(_dataKey, _ipfsCid, block.timestamp);
    }

    // --- INTERNAL REPUTATION & RANKING LOGIC ---
    function _mintReputation(address _user, string memory _dialect, uint256 _amount) internal {
        userXP[_user][_dialect] += _amount;
        emit ReputationMinted(_user, _dialect, _amount);
        _updateRank(_user, _dialect);
    }

    function _updateRank(address _user, string memory _dialect) internal {
        if (isAdmin[_user]) return;

        uint256 score = userXP[_user][_dialect];
        string memory newRole;

        if (score >= 1500) { newRole = "Oracle"; } 
        else if (score >= 800) { newRole = "Archivist"; } 
        else if (score >= 300) { newRole = "Linguist"; } 
        else if (score >= 100) { newRole = "Scout"; } 
        else { newRole = "Initiate"; }

        if (keccak256(abi.encodePacked(userRole[_user][_dialect])) != keccak256(abi.encodePacked(newRole))) {
            userRole[_user][_dialect] = newRole;
            emit RankUpgraded(_user, _dialect, newRole);
        }
    }

    // --- MIGRATION QUERIES ---
    function batchMigrateXP(address[] memory _users, string[] memory _dialects, uint256[] memory _xps) public onlyRelayer {
        require(_users.length == _dialects.length && _users.length == _xps.length, "Array lengths mismatch");
        for(uint i=0; i<_users.length; i++){
            userXP[_users[i]][_dialects[i]] += _xps[i];
            _updateRank(_users[i], _dialects[i]);
            emit ReputationMinted(_users[i], _dialects[i], _xps[i]);
        }
    }

    // --- HELPER QUERIES ---
    function getRole(address _user, string memory _dialect) public view returns (string memory) {
        if (isAdmin[_user]) return "Admin";
        if (bytes(userRole[_user][_dialect]).length == 0) return "Initiate";
        return userRole[_user][_dialect];
    }

    function getXP(address _user, string memory _dialect) public view returns (uint256) {
        return userXP[_user][_dialect];
    }
}