Contract Address Details

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
import "./AdminZamik.sol";

interface IKYCWhitelistV2 {
    function isWhitelisted(address account) external view returns (bool);
}

interface IUORSRegistryV2 {
    function authorizedUORS(address operater) external view returns (bool);
}

/// @notice Kar zeton bere z RWA Marketplace v2.
interface ITrgV2 {
    function usdc() external view returns (address);
    function feeRecipient() external view returns (address);
    function placanaProvizija(address zeton) external view returns (uint256);
}

/**
 * @notice Nastavitve novega zetona v2 v eni strukturi (glej RWAToken: "stack too deep").
 */
struct NastavitveZetonaV2 {
    string  ime;
    string  simbol;
    string  metapodatkiCID;
    uint256 vrednostUSD;
    address zkVerifier;
    address entropyOracle;
    address trg;            // RWA Marketplace v2 — edina pot za obicajno prodajo
    address kyc;            // 0x0 = brez omejitve, a mora biti napisano izrecno
    address lastnik;
    address uors;
    address overitelj;
}

/**
 * @title RWATokenV2
 * @notice Delez realnega sredstva. Razlike proti RWAToken:
 *
 *  1. PROVIZIJE SAMO V USDC. Zeton nima provizije v enotah — ne ob kovanju ne ob
 *     prenosu. Platforma tako nikoli ni solastnica sredstva. Provizija za izdajo
 *     (0,5 % cenitve) je zapisana v USDC in jo RWA Marketplace v2 zadrzi od
 *     kupnine prvih prodaj prvotnega lastnika, dokler ni poravnana.
 *
 *  2. PRENOS SAMO PREK TRGA. Obicajen prenos gre samo v hrambo trga ali iz nje.
 *     Prenos mimo trga (dedovanje, darilo, sodna odlocba) izvede overitelj z
 *     odtisom listine, skozi javno napoved in zamik.
 *
 *  3. RAZDRUZITEV. Imetnik vsaj 90 % enot lahko zahteva, da se sredstvo sprosti
 *     iz zetona. Manjsina dobi USDC po ceni, ki ni nizja od nove neodvisne
 *     cenitve; ima pravico do ugovora in druge cenitve. Potek je opisan pri
 *     funkcijah spodaj.
 *
 * @dev ZDRUZLJIVOST Z ZKVerifierjem: obstojeci ZKVerifier skuje `amount - 0,5 %`
 *      prejemniku in nato poklice `mintFee(feeRecipient(), 0,5 %)`. Ta zeton vrne
 *      kot `feeRecipient()` prvotnega lastnika, zato lastnik dobi VSE enote,
 *      ZKVerifierja pa ni treba menjati. Dogodek `MintFeeCollected` v ZKVerifierju
 *      pri tem zetonu pomeni "drugi del kovanja lastniku", ne provizije.
 */
contract RWATokenV2 is ERC20, Ownable, ReentrancyGuard, AdminZamik {
    using SafeERC20 for IERC20;

    // ── Sredstvo ──────────────────────────────────────────────────────────────
    string  public assetMetadataCID;          // nespremenljiv (glej RWAToken)
    uint256 public assetValueUSD;             // 18 decimalk
    address public immutable zkVerifier;
    address public immutable entropyOracle;
    address public immutable trg;
    address public immutable uors;
    address public immutable overitelj;
    uint256 public immutable aktivenOd;
    address public kyc;
    address public prvotniLastnik;
    bool    public zamrznjen;
    mapping(bytes32 => bool) public usedProofs;

    bool    private provizijaOdprta;
    uint256 private skovanoLastniku;
    bool    private prenosOdobren;

    // ── Provizija za izdajo (USDC, 6 decimalk) ─────────────────────────────────
    uint256 public constant PROVIZIJA_IZDAJE_BPS = 50;   // 0,5 % cenitve ob kovanju
    /// @notice Celotna provizija za izdajo v USDC; zapise se ob kovanju in se ne spreminja.
    uint256 public provizijaIzdaje;

    // ── Razdruzitev ───────────────────────────────────────────────────────────
    uint256 public constant PRAG_BPS          = 9_000;   // 90 % vseh enot
    uint256 public constant PRAG_UGOVORA_BPS  = 500;     // druga cenitev vsaj 5 % visja
    uint256 public constant POLOG_UGOVORA     = 500e6;   // 500 USDC
    uint256 public constant DNI_CENITEV       = 30;      // overitelj vpise cenitev
    uint256 public constant DNI_POLOG         = 14;      // sprozitelj polozi USDC
    uint256 public constant DNI_UGOVOR        = 30;      // rok za ugovor / za drugo cenitev
    uint256 public constant DNI_DOPLACILO     = 14;      // sprozitelj doplaca po uspesnem ugovoru
    uint256 public constant DNI_POTRDITEV     = 30;      // overitelj potrdi; sicer preklic
    uint256 public constant DNI_PAVZA         = 30;      // po preklicu do nove zahteve

    enum Faza { Ni, Zahtevano, Ocenjeno, Polozeno, Ugovor, Doplacilo, Razdruzeno }

    Faza    public faza;
    uint256 public krog;                 // zaporedna stevilka postopka
    address public sprozitelj;
    address public placilniZeton;        // USDC, zapisan ob zahtevi
    uint256 public rok;                  // rok trenutne faze (unix cas)
    uint256 public cenitevRazdruzitve;   // nova cenitev, 18 decimalk
    uint256 public drugaCenitev;         // cenitev po ugovoru, 18 decimalk (0 = je ni)
    uint256 public trznaCena;            // USDC za enoto (6 decimalk), 0 = ni prodaj
    uint256 public cenaNaEnoto;          // USDC za 1e18 enote — po tej se odkupi
    bytes32 public odtisCenitve;
    bytes32 public odtisDrugeCenitve;
    bytes32 public odtisListine;
    uint256 public enotSprozitelja;      // zapisano ob pologu
    uint256 public enotManjsine;         // zapisano ob pologu
    uint256 public polozeno;             // USDC v hrambi za manjsino (+ provizija pred potrditvijo)
    uint256 public provizijaVPologu;     // neporavnana provizija za izdajo, zajeta v pologu
    /// @notice Pred tem casom nove zahteve ni. Brez pavze bi lahko vecinski imetnik
    ///         z zaporednimi zahtevami in preklici trgovanje zamrznil za nedolocen cas.
    uint256 public naslednjaZahtevaOd;

    /// @dev Izid ugovora po krogu. `vracilo`: 0 = se odprto, 1 = polno, 2 = strosek deljen.
    struct Ugovor { uint256 stevilo; uint8 vracilo; bool ugovorOpravljen; }
    mapping(uint256 => Ugovor) public ugovori;
    mapping(uint256 => mapping(address => bool)) public ugovarjal;

    // ── Dogodki ───────────────────────────────────────────────────────────────
    event Zamrznjeno(address indexed kdo);
    event Odmrznjeno(address indexed kdo);
    event AssetValueUpdated(uint256 newValueUSD);
    event TokensMinted(address indexed to, uint256 amount, bytes32 proofHash);
    event PrvotniLastnikZapisan(address indexed lastnik);
    event KycUpdated(address indexed newKyc);
    event PrenosZOdobritvijo(address indexed od, address indexed komu, uint256 kolicina, bytes32 odtisListine);

    event RazdruzitevZahtevana(uint256 indexed krog, address indexed sprozitelj, uint256 enot);
    event CenitevVpisana(uint256 indexed krog, uint256 cenitevUSD, uint256 trznaCena, uint256 cenaNaEnoto, bytes32 odtis);
    event Polozeno(uint256 indexed krog, uint256 znesek, uint256 enotManjsine);
    event UgovorVlozen(uint256 indexed krog, address indexed kdo);
    event DrugaCenitevVpisana(uint256 indexed krog, uint256 cenitevUSD, bool uspel, uint256 cenaNaEnoto, bytes32 odtis);
    event Doplacano(uint256 indexed krog, uint256 znesek);
    event RazdruzitevPreklicana(uint256 indexed krog, address indexed kdo);
    event Razdruzeno(uint256 indexed krog, bytes32 odtisListine);
    event Dvignjeno(address indexed kdo, uint256 enot, uint256 usdc);
    event PologUgovoraVrnjen(uint256 indexed krog, address indexed kdo, uint256 znesek);

    constructor(NastavitveZetonaV2 memory n)
        ERC20(n.ime, n.simbol)
        Ownable(n.lastnik)
    {
        require(n.zkVerifier != address(0), "ZKVerifier je nujen");
        require(n.trg        != address(0), "Trg je nujen");
        require(n.lastnik    != address(0), "Lastnik je nujen");
        require(n.uors       != address(0), "UORSRegistry je nujen");
        assetMetadataCID = n.metapodatkiCID;
        assetValueUSD    = n.vrednostUSD;
        zkVerifier       = n.zkVerifier;
        entropyOracle    = n.entropyOracle;
        trg              = n.trg;
        kyc              = n.kyc;
        uors             = n.uors;
        overitelj        = n.overitelj;
        aktivenOd        = block.timestamp + Omrezja.zamik();
    }

    // ── Dovoljenja ────────────────────────────────────────────────────────────
    modifier samoUORS() {
        require(IUORSRegistryV2(uors).authorizedUORS(msg.sender), "Samo UORS operater");
        _;
    }

    modifier samoOveritelj() {
        require(overitelj != address(0), "Sredstvo nima zapisanega overitelja");
        require(msg.sender == overitelj, "Samo overitelj tega sredstva");
        require(IUORSRegistryV2(uors).authorizedUORS(msg.sender), "Overitelj ni vec pooblascen");
        _;
    }

    /// @dev Rok v dneh. Na testnih verigah (Omrezja.jeTestno) je en "dan" ena minuta,
    ///      da je postopek mogoce pokazati v eni seji — enako nacelo kot `zamik()`.
    function _dni(uint256 d) internal view returns (uint256) {
        return Omrezja.jeTestno(block.chainid) ? d * 1 minutes : d * 1 days;
    }

    /// @notice Dolzina enega "dneva" v rokih razdruzitve na tej verigi (sekunde).
    function dan() external view returns (uint256) { return _dni(1); }

    function zaporaPrenosa() external view returns (uint256) { return Omrezja.zamik(); }

    function jePrenosMogoc() external view returns (bool mogoc, uint256 odKdaj, bool zamrznjeno) {
        return (block.timestamp >= aktivenOd && !zamrznjen && faza == Faza.Ni, aktivenOd, zamrznjen);
    }

    /// @notice Ali razdruzitev tece (ali je koncana) — trg takrat ne sprejema poslov.
    function razdruzitevVTeku() external view returns (bool) { return faza != Faza.Ni; }

    function zamrzni() external samoUORS { zamrznjen = true;  emit Zamrznjeno(msg.sender); }
    function odmrzni() external samoUORS { zamrznjen = false; emit Odmrznjeno(msg.sender); }

    // ── Kovanje ───────────────────────────────────────────────────────────────

    function mintWithProof(address to, uint256 amount, bytes32 proofHash) external {
        require(msg.sender == zkVerifier, "Only ZK verifier");
        require(!usedProofs[proofHash], "Proof already used");
        require(prvotniLastnik == address(0), "Sredstvo je ze skovano");
        usedProofs[proofHash] = true;
        prvotniLastnik  = to;
        provizijaOdprta = true;
        skovanoLastniku = amount;
        // 18 decimalk USD → 6 decimalk USDC
        provizijaIzdaje = assetValueUSD * PROVIZIJA_IZDAJE_BPS / 10_000 / 1e12;
        _mint(to, amount);
        emit TokensMinted(to, amount, proofHash);
        emit PrvotniLastnikZapisan(to);
    }

    /**
     * @notice Drugi del kovanja (glej opombo o zdruzljivosti zgoraj). Enote gredo
     *         prvotnemu lastniku, ne platformi.
     */
    function mintFee(address to, uint256 amount) external {
        require(msg.sender == zkVerifier, "Only ZK verifier");
        require(provizijaOdprta, "Provizija brez kovanja");
        require(to == prvotniLastnik, "Enote gredo samo prvotnemu lastniku");
        require(amount * 199 <= skovanoLastniku, "Provizija previsoka");
        provizijaOdprta = false;
        _mint(to, amount);
    }

    /// @notice Za ZKVerifier: kam gre drugi del kovanja. Pri tem zetonu je to lastnik.
    function feeRecipient() external view returns (address) { return prvotniLastnik; }

    // ── Prenos ────────────────────────────────────────────────────────────────

    function _update(address from, address to, uint256 amount) internal override {
        bool isMint = (from == address(0));
        bool isBurn = (to == address(0));

        // Unicenje (dvig po razdruzitvi) je izvzeto iz KYC namerno: imetnik,
        // ki mu je bil KYC odvzet, mora se vedno priti do svojega USDC.
        if (kyc != address(0) && !isBurn) {
            require(IKYCWhitelistV2(kyc).isWhitelisted(to), "Prejemnik ni KYC preverjen");
            if (!isMint) require(IKYCWhitelistV2(kyc).isWhitelisted(from), "Posiljatelj ni KYC preverjen");
        }

        if (!isMint) {
            require(!zamrznjen, "Sredstvo je zamrznjeno");
            require(block.timestamp >= aktivenOd, "Sredstvo se ni aktivno za prenos");
            if (!isBurn) {
                if (faza != Faza.Ni) {
                    // Med razdruzitvijo se enote ne premikajo. Izjema je vracilo iz
                    // hrambe trga (preklic oglasa), da lahko prodajalec dvigne USDC.
                    require(from == trg, "Razdruzitev v teku: prenos ni mogoc");
                } else {
                    require(from == trg || to == trg || prenosOdobren,
                            "Prenos samo prek RWA Marketplace");
                }
            }
        }

        super._update(from, to, amount);
    }

    /**
     * @notice Prenos mimo trga (dedovanje, darilo, sodna odlocba) — 1. korak: javna napoved.
     * @dev Overitelj s tem premakne tuje enote, zato gre skozi napoved in zamik: imetnik
     *      vidi, kaj prihaja, skrbnik pa lahko napoved prekliče (`prekliciSpremembo`).
     */
    function napoviPrenesiZOdobritvijo(address od, address komu, uint256 kolicina, bytes32 odtis)
        external samoOveritelj
    {
        require(odtis != bytes32(0), "Odtis listine je nujen");
        _napovej(keccak256(abi.encode("prenos", od, komu, kolicina, odtis)), "RWATokenV2.prenos");
    }

    /// @notice 2. korak: izvedba po zamiku. Velja samo za napovedane podatke.
    function prenesiZOdobritvijo(address od, address komu, uint256 kolicina, bytes32 odtis)
        external samoOveritelj
    {
        require(faza == Faza.Ni, "Razdruzitev v teku");
        _porabi(keccak256(abi.encode("prenos", od, komu, kolicina, odtis)), "RWATokenV2.prenos");
        prenosOdobren = true;
        _transfer(od, komu, kolicina);
        prenosOdobren = false;
        emit PrenosZOdobritvijo(od, komu, kolicina, odtis);
    }

    // ── Razdruzitev ───────────────────────────────────────────────────────────

    /**
     * @notice 1. Imetnik vsaj 90 % vseh enot zahteva razdruzitev. Trgovanje se zamrzne.
     * @dev Kdorkoli, ne samo prvotni lastnik: enote so lastnistvo.
     */
    function zahtevajRazdruzitev() external {
        require(faza == Faza.Ni, "Razdruzitev ze tece");
        require(prvotniLastnik != address(0), "Sredstvo se ni skovano");
        require(!zamrznjen, "Sredstvo je zamrznjeno");
        require(block.timestamp >= naslednjaZahtevaOd, "Po preklicu nova zahteva se ni mogoca");
        uint256 enot = balanceOf(msg.sender);
        require(enot * 10_000 >= totalSupply() * PRAG_BPS, "Potrebnih je vsaj 90 % enot");

        krog++;
        faza               = Faza.Zahtevano;
        sprozitelj         = msg.sender;
        placilniZeton      = ITrgV2(trg).usdc();
        rok                = block.timestamp + _dni(DNI_CENITEV);
        cenitevRazdruzitve = 0;
        drugaCenitev       = 0;
        trznaCena          = 0;
        cenaNaEnoto        = 0;
        odtisCenitve       = bytes32(0);
        odtisDrugeCenitve  = bytes32(0);
        enotSprozitelja    = 0;
        enotManjsine       = 0;
        polozeno           = 0;
        provizijaVPologu   = 0;
        emit RazdruzitevZahtevana(krog, msg.sender, enot);
    }

    /// @dev cena = najvecja od (cenitev na enoto; povprecje cenitve in trzne cene).
    function _cena(uint256 cenitevUSD, uint256 trzna) internal view returns (uint256) {
        uint256 naEnoto = cenitevUSD * 1e6 / totalSupply();
        if (trzna == 0) return naEnoto;
        uint256 povp = (naEnoto + trzna) / 2;
        return povp > naEnoto ? povp : naEnoto;
    }

    /**
     * @notice 2. Overitelj vpise NOVO neodvisno cenitev, trzno ceno in odtis porocila.
     * @param cenitevUSD  cenitev celotnega sredstva, 18 decimalk
     * @param trznaNaEnoto povprecna cena prodaj na RWA Marketplace v zadnjih 90 dneh,
     *        utezena s kolicino, v USDC za enoto (6 decimalk); 0 = prodaj ni bilo.
     *        Izracun iz javnih dogodkov trga lahko preveri vsak.
     */
    function vpisiCenitev(uint256 cenitevUSD, uint256 trznaNaEnoto, bytes32 odtis) external samoOveritelj {
        require(faza == Faza.Zahtevano, "Ni zahteve za razdruzitev");
        require(cenitevUSD > 0, "Cenitev je nujna");
        require(odtis != bytes32(0), "Odtis porocila je nujen");
        cenitevRazdruzitve = cenitevUSD;
        trznaCena          = trznaNaEnoto;
        odtisCenitve       = odtis;
        cenaNaEnoto        = _cena(cenitevUSD, trznaNaEnoto);
        faza               = Faza.Ocenjeno;
        rok                = block.timestamp + _dni(DNI_POLOG);
        emit CenitevVpisana(krog, cenitevUSD, trznaNaEnoto, cenaNaEnoto, odtis);
    }

    /// @notice Neporavnani del provizije za izdajo (USDC).
    function neporavnanaProvizija() public view returns (uint256) {
        uint256 p = ITrgV2(trg).placanaProvizija(address(this));
        return p >= provizijaIzdaje ? 0 : provizijaIzdaje - p;
    }

    /// @notice Koliko USDC mora sprozitelj polozit zdaj.
    function potrebenPolog() public view returns (uint256) {
        uint256 manjsina = totalSupply() - balanceOf(sprozitelj);
        return manjsina * cenaNaEnoto / 1e18 + neporavnanaProvizija();
    }

    /**
     * @notice 3. Sprozitelj polozi ves USDC za enote manjsine in neporavnano provizijo.
     *         Zacne tece rok za ugovor.
     */
    function polozi() external nonReentrant {
        require(faza == Faza.Ocenjeno, "Ni casa za polog");
        require(msg.sender == sprozitelj, "Samo sprozitelj");
        require(block.timestamp <= rok, "Rok za polog je potekel");
        enotSprozitelja  = balanceOf(sprozitelj);
        enotManjsine     = totalSupply() - enotSprozitelja;
        provizijaVPologu = neporavnanaProvizija();
        uint256 znesek   = enotManjsine * cenaNaEnoto / 1e18 + provizijaVPologu;
        polozeno         = znesek;
        faza             = Faza.Polozeno;
        rok              = block.timestamp + _dni(DNI_UGOVOR);
        IERC20(placilniZeton).safeTransferFrom(msg.sender, address(this), znesek);
        emit Polozeno(krog, znesek, enotManjsine);
    }

    /**
     * @notice 4. Imetnik manjsinskih enot ugovarja ceni in polozi 500 USDC za drugo cenitev.
     * @dev En ugovor velja za vse. Kdor se pridruzi pred drugo cenitvijo, prav tako
     *      polozi 500 USDC; ob neuspehu si stroske ene cenitve delijo enako.
     */
    function ugovor() external nonReentrant {
        Ugovor storage u = ugovori[krog];
        if (faza == Faza.Polozeno) {
            require(!u.ugovorOpravljen, "Ugovor je ze bil obravnavan");
            require(block.timestamp < rok, "Rok za ugovor je potekel");
            faza = Faza.Ugovor;
            rok  = block.timestamp + _dni(DNI_UGOVOR);
        } else {
            require(faza == Faza.Ugovor, "Ni casa za ugovor");
        }
        require(msg.sender != sprozitelj, "Sprozitelj ne ugovarja");
        require(balanceOf(msg.sender) > 0, "Ugovarja lahko imetnik enot");
        require(!ugovarjal[krog][msg.sender], "Ze ugovarjal");
        ugovarjal[krog][msg.sender] = true;
        u.stevilo++;
        IERC20(placilniZeton).safeTransferFrom(msg.sender, address(this), POLOG_UGOVORA);
        emit UgovorVlozen(krog, msg.sender);
    }

    /**
     * @notice 5. Overitelj vpise drugo cenitev (drug cenilec).
     *         Vsaj 5 % visja → ugovor uspe: nova cena, sprozitelj doplaca razliko in
     *         strosek cenitve, ugovarjalci dobijo polog nazaj v celoti.
     *         Sicer ostane prva cena, 500 USDC dobi overitelj za cenilca.
     */
    function vpisiDrugoCenitev(uint256 cenitevUSD, bytes32 odtis) external samoOveritelj nonReentrant {
        require(faza == Faza.Ugovor, "Ni ugovora");
        require(cenitevUSD > 0, "Cenitev je nujna");
        require(odtis != bytes32(0), "Odtis porocila je nujen");
        Ugovor storage u = ugovori[krog];
        u.ugovorOpravljen = true;
        drugaCenitev      = cenitevUSD;
        odtisDrugeCenitve = odtis;

        bool uspel = cenitevUSD * 10_000 >= cenitevRazdruzitve * (10_000 + PRAG_UGOVORA_BPS);
        if (uspel) {
            uint256 nova = _cena(cenitevUSD, trznaCena);
            if (nova > cenaNaEnoto) cenaNaEnoto = nova;
            u.vracilo = 1;
            faza = Faza.Doplacilo;
            rok  = block.timestamp + _dni(DNI_DOPLACILO);
        } else {
            u.vracilo = 2;
            faza = Faza.Polozeno;
            rok  = block.timestamp;   // ugovor je bil, novega ni — potrditev je mogoca
            IERC20(placilniZeton).safeTransfer(overitelj, POLOG_UGOVORA);
        }
        emit DrugaCenitevVpisana(krog, cenitevUSD, uspel, cenaNaEnoto, odtis);
    }

    /// @notice Koliko mora sprozitelj doplacati po uspesnem ugovoru (razlika + cenitev).
    function potrebnoDoplacilo() public view returns (uint256) {
        if (faza != Faza.Doplacilo) return 0;
        uint256 manjsina = enotManjsine * cenaNaEnoto / 1e18 + provizijaVPologu;
        return manjsina - polozeno + POLOG_UGOVORA;
    }

    /// @notice 6. Doplacilo po uspesnem ugovoru.
    function doplacaj() external nonReentrant {
        require(faza == Faza.Doplacilo, "Doplacilo ni potrebno");
        require(msg.sender == sprozitelj, "Samo sprozitelj");
        require(block.timestamp <= rok, "Rok za doplacilo je potekel");
        uint256 znesek = potrebnoDoplacilo();
        polozeno += znesek - POLOG_UGOVORA;
        faza = Faza.Polozeno;
        rok  = block.timestamp;
        IERC20(placilniZeton).safeTransferFrom(msg.sender, address(this), znesek);
        IERC20(placilniZeton).safeTransfer(overitelj, POLOG_UGOVORA);
        emit Doplacano(krog, znesek);
    }

    /**
     * @notice 7. Overitelj potrdi razdruzitev z odtisom notarske listine. Enote
     *         sprozitelja se unicijo, provizija za izdajo gre platformi.
     */
    function potrdiRazdruzitev(bytes32 odtis) external samoOveritelj nonReentrant {
        require(faza == Faza.Polozeno, "Ni pripravljeno za potrditev");
        require(block.timestamp >= rok || enotManjsine == 0, "Rok za ugovor se tece");
        require(odtis != bytes32(0), "Odtis listine je nujen");
        faza         = Faza.Razdruzeno;
        odtisListine = odtis;
        _burn(sprozitelj, enotSprozitelja);
        uint256 p = provizijaVPologu;
        if (p > 0) {
            polozeno -= p;
            IERC20(placilniZeton).safeTransfer(ITrgV2(trg).feeRecipient(), p);
        }
        emit Razdruzeno(krog, odtis);
    }

    /// @notice 8. Imetnik po razdruzitvi dvigne USDC; njegove enote se unicijo.
    function dvigni() external nonReentrant {
        require(faza == Faza.Razdruzeno, "Sredstvo ni razdruzeno");
        uint256 enot = balanceOf(msg.sender);
        require(enot > 0, "Ni enot");
        uint256 znesek = enot * cenaNaEnoto / 1e18;
        _burn(msg.sender, enot);
        polozeno -= znesek;
        IERC20(placilniZeton).safeTransfer(msg.sender, znesek);
        emit Dvignjeno(msg.sender, enot, znesek);
    }

    /// @notice Ugovarjalec dvigne polog: v celoti, ce je ugovor uspel ali je bil postopek
    ///         preklican; sicer zmanjsan za svoj delez stroska ene cenitve.
    function dvigniPologUgovora(uint256 k) external nonReentrant {
        Ugovor storage u = ugovori[k];
        require(ugovarjal[k][msg.sender], "Ni ugovarjal ali je ze dvignil");
        require(u.vracilo != 0, "Ugovor se ni razresen");
        ugovarjal[k][msg.sender] = false;
        uint256 znesek = POLOG_UGOVORA;
        if (u.vracilo == 2) {
            uint256 delez = (POLOG_UGOVORA + u.stevilo - 1) / u.stevilo;   // zaokrozeno navzgor
            znesek -= delez;
        }
        if (znesek > 0) IERC20(placilniZeton).safeTransfer(msg.sender, znesek);
        emit PologUgovoraVrnjen(k, msg.sender, znesek);
    }

    /**
     * @notice Preklic razdruzitve. Trgovanje se odmrzne, sprozitelj dobi polog nazaj.
     * @dev Sprozitelj lahko preklice pred potrditvijo kadarkoli. Kdorkoli lahko
     *      preklice, ko je rok faze potekel in tisti, ki je na vrsti, ni ukrepal —
     *      tako nihce ne more zamrzniti trgovanja za nedolocen cas.
     *      Ob preklicu v fazi Doplacilo gre 500 USDC iz pologa overitelju za cenilca.
     */
    function preklici() external nonReentrant {
        Faza f = faza;
        require(f != Faza.Ni && f != Faza.Razdruzeno, "Ni postopka za preklic");
        if (msg.sender != sprozitelj) {
            uint256 meja = f == Faza.Polozeno ? rok + _dni(DNI_POTRDITEV) : rok;
            require(block.timestamp > meja, "Rok se ni potekel");
        }
        Ugovor storage u = ugovori[krog];
        uint256 vrni = polozeno;
        if (f == Faza.Doplacilo) {
            vrni -= POLOG_UGOVORA;
            IERC20(placilniZeton).safeTransfer(overitelj, POLOG_UGOVORA);
        }
        if (u.stevilo > 0 && u.vracilo == 0) u.vracilo = 1;
        address s = sprozitelj;
        uint256 k = krog;
        faza       = Faza.Ni;
        polozeno   = 0;
        naslednjaZahtevaOd = block.timestamp + _dni(DNI_PAVZA);
        sprozitelj = address(0);
        if (vrni > 0) IERC20(placilniZeton).safeTransfer(s, vrni);
        emit RazdruzitevPreklicana(k, msg.sender);
    }

    // ── Admin (skozi napoved in zamik) ────────────────────────────────────────

    function napoviSetKyc(address _kyc) external onlyOwner {
        _napovej(keccak256(abi.encode("setKyc", _kyc)), "RWATokenV2.setKyc");
    }

    function setKyc(address _kyc) external onlyOwner {
        _porabi(keccak256(abi.encode("setKyc", _kyc)), "RWATokenV2.setKyc");
        kyc = _kyc;
        emit KycUpdated(_kyc);
    }

    function napoviUpdateAssetValue(uint256 newValueUSD) external samoOveritelj {
        _napovej(keccak256(abi.encode("updateAssetValue", newValueUSD)), "RWATokenV2.updateAssetValue");
    }

    function updateAssetValue(uint256 newValueUSD) external samoOveritelj {
        _porabi(keccak256(abi.encode("updateAssetValue", newValueUSD)), "RWATokenV2.updateAssetValue");
        assetValueUSD = newValueUSD;
        emit AssetValueUpdated(newValueUSD);
    }

    function renounceOwnership() public pure override {
        revert("Renounce onemogocen");
    }
}
        

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity >=0.6.2;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.5.0) (utils/ReentrancyGuard.sol)

pragma solidity ^0.8.20;

import {StorageSlot} from "./StorageSlot.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If EIP-1153 (transient storage) is available on the chain you're deploying at,
 * consider using {ReentrancyGuardTransient} instead.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 *
 * IMPORTANT: Deprecated. This storage-based reentrancy guard will be removed and replaced
 * by the {ReentrancyGuardTransient} variant in v6.0.
 *
 * @custom:stateless
 */
abstract contract ReentrancyGuard {
    using StorageSlot for bytes32;

    // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.ReentrancyGuard")) - 1)) & ~bytes32(uint256(0xff))
    bytes32 private constant REENTRANCY_GUARD_STORAGE =
        0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00;

    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant NOT_ENTERED = 1;
    uint256 private constant ENTERED = 2;

    /**
     * @dev Unauthorized reentrant call.
     */
    error ReentrancyGuardReentrantCall();

    constructor() {
        _reentrancyGuardStorageSlot().getUint256Slot().value = NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    /**
     * @dev A `view` only version of {nonReentrant}. Use to block view functions
     * from being called, preventing reading from inconsistent contract state.
     *
     * CAUTION: This is a "view" modifier and does not change the reentrancy
     * status. Use it only on view functions. For payable or non-payable functions,
     * use the standard {nonReentrant} modifier instead.
     */
    modifier nonReentrantView() {
        _nonReentrantBeforeView();
        _;
    }

    function _nonReentrantBeforeView() private view {
        if (_reentrancyGuardEntered()) {
            revert ReentrancyGuardReentrantCall();
        }
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be NOT_ENTERED
        _nonReentrantBeforeView();

        // Any calls to nonReentrant after this point will fail
        _reentrancyGuardStorageSlot().getUint256Slot().value = ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _reentrancyGuardStorageSlot().getUint256Slot().value = NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _reentrancyGuardStorageSlot().getUint256Slot().value == ENTERED;
    }

    function _reentrancyGuardStorageSlot() internal pure virtual returns (bytes32) {
        return REENTRANCY_GUARD_STORAGE;
    }
}
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

/**
 * @title Omrezja
 * @notice Katere verige so TESTNE. Vse druge, tudi neznane, veljajo za produkcijske.
 *
 * Seznam je izrecen in kratek. Napaka je zato mogoca samo v varno smer: na
 * novem, se ne nastetem testnem omrezju dobi pogodba produkcijski (dolg) zamik,
 * nikoli obratno. Produkcijske verige ni treba nikjer nasteti, zato je ni mogoce
 * pozabiti — ista bajtna koda je na kateri koli EVM produkcijski verigi zascitena.
 */
library Omrezja {
    /// @notice true samo za nastete testne verige in lokalni razvojni vozel.
    function jeTestno(uint256 id) internal pure returns (bool) {
        return id == 943          // PulseChain Testnet v4
            || id == 11155111     // Ethereum Sepolia
            || id == 560048       // Ethereum Hoodi
            || id == 84532        // Base Sepolia
            || id == 421614       // Arbitrum Sepolia
            || id == 31337;       // lokalni razvojni vozel (Hardhat)
    }

    /// @notice Zamik za spremembe in zapore: produkcija 48 ur, testno 10 minut.
    function zamik() internal view returns (uint256) {
        return jeTestno(block.chainid) ? 10 minutes : 48 hours;
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.5.0) (interfaces/draft-IERC6093.sol)

pragma solidity >=0.8.4;

/**
 * @dev Standard ERC-20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a `spender` is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}

/**
 * @dev Standard ERC-721 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-721 tokens.
 */
interface IERC721Errors {
    /**
     * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in ERC-721.
     * Used in balance queries.
     * @param owner Address of the current owner of a token.
     */
    error ERC721InvalidOwner(address owner);

    /**
     * @dev Indicates a `tokenId` whose `owner` is the zero address.
     * @param tokenId Identifier number of a token.
     */
    error ERC721NonexistentToken(uint256 tokenId);

    /**
     * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param tokenId Identifier number of a token.
     * @param owner Address of the current owner of a token.
     */
    error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC721InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC721InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param tokenId Identifier number of a token.
     */
    error ERC721InsufficientApproval(address operator, uint256 tokenId);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC721InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC721InvalidOperator(address operator);
}

/**
 * @dev Standard ERC-1155 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-1155 tokens.
 */
interface IERC1155Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     * @param tokenId Identifier number of a token.
     */
    error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);

    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC1155InvalidSender(address sender);

    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC1155InvalidReceiver(address receiver);

    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param owner Address of the current owner of a token.
     */
    error ERC1155MissingApprovalForAll(address operator, address owner);

    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC1155InvalidApprover(address approver);

    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC1155InvalidOperator(address operator);

    /**
     * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
     * Used in batch transfers.
     * @param idsLength Length of the array of token identifiers
     * @param valuesLength Length of the array of token amounts
     */
    error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC165.sol)

pragma solidity >=0.4.16;

import {IERC165} from "../utils/introspection/IERC165.sol";
          

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "./Omrezja.sol";

import "@openzeppelin/contracts/access/Ownable.sol";

/**
 * @title AdminZamik
 * @notice Casovni zamik na nevarne admin spremembe.
 *
 * ZAKAJ TO OBSTAJA
 * ----------------
 * Owner kljuc na tej platformi NE more krasti: ne more kovati zetonov, ne more
 * premikati tujih zetonov in ne more v escrow. Kar PA lahko, je tiho zamenjati
 * nastavitve pod nogami uporabnikov — KYC listo, placilni token, prijavljeno
 * vrednost sredstva.
 *
 * Vsi trije so napadi, ki jih je mogoce VIDETI VNAPREJ. Zato jih ne branimo z
 * multisigom (ki varuje lastnika kljuca), ampak s casovnim zamikom (ki varuje
 * UPORABNIKA): sprememba se mora najprej javno napovedati, sele po zamiku jo je
 * mogoce izvesti. Uporabnik ima ves ta cas, da spremembo vidi in izstopi.
 *
 * Namenoma NI zunanje timelock pogodbe kot lastnika. Tak vzorec doda tveganje
 * nedosegljivosti: ce lastniku kdaj ne uspe sestaviti transakcije skozi tujo
 * pogodbo, so kontrakti zamrznjeni za vedno. Tu je zamik vgrajen, lastnik pa
 * ostane navadna denarnica.
 *
 * KAJ ZAMIK NE POKRIVA (namerno)
 * ------------------------------
 *   - pause()   — zasilna zavora mora biti takojsnja, sicer ni zavora
 *   - unpause() — vrnitev v obratovanje naj bo hitra
 *   - odvzem pravice zaustavljalca — ob razkritem kljucu ga moras vreci TAKOJ
 * Nevarnost caka, zasilna zavora ne.
 */
abstract contract AdminZamik is Ownable {
    /// @notice Rok, v katerem je napoved uporabna. Po njem potece.
    /// @dev Brez tega bi stara napoved lezala na verigi kot nabita puska:
    ///      napoves nekaj neopaznega danes, izvedes cez pol leta, ko nihce vec
    ///      ne gleda. Napoved, ki ni bila izvedena v roku, je treba ponoviti.
    uint256 public constant ROK = 7 days;

    /// @notice id napovedi → cas, od katerega je izvedljiva (0 = ni napovedi)
    mapping(bytes32 => uint256) public izvedljivoOd;

    event SpremembaNapovedana(bytes32 indexed id, string kaj, uint256 izvedljivoOd, uint256 potece);
    event SpremembaIzvedena(bytes32 indexed id, string kaj);
    event SpremembaPreklicana(bytes32 indexed id, string kaj);

    /// @notice Koliko casa mora napovedana sprememba cakati, preden je izvedljiva.
    ///
    ///   produkcijske verige   48 ur      imetnik ima cas spremembo videti in izstopiti
    ///   testne verige         10 minut   razvojno okolje (seznam v Omrezja.sol)
    ///
    /// @dev Vrednost doloca `block.chainid`, ne nastavitev ob postavitvi. Ista
    ///      bajtna koda tako na vsaki produkcijski verigi vedno vrne 48 ur: testne
    ///      verige so nastete, vse druge (tudi neznane) so produkcijske.
    /// @dev `virtual` zato, da lahko posamezna testna pogodba vrednost povozi.
    function zamik() public view virtual returns (uint256) {
        return Omrezja.zamik();
    }

    // ── Notranje ────────────────────────────────────────────────────────────

    /// @dev id MORA vsebovati tocne parametre spremembe, sicer bi lahko
    ///      napovedal nedolzno vrednost in izvedel skodljivo.
    function _napovej(bytes32 id, string memory kaj) internal {
        require(izvedljivoOd[id] == 0, "Ze napovedano");
        uint256 od = block.timestamp + zamik();
        izvedljivoOd[id] = od;
        emit SpremembaNapovedana(id, kaj, od, od + ROK);
    }

    function _porabi(bytes32 id, string memory kaj) internal {
        uint256 od = izvedljivoOd[id];
        require(od != 0, "Ni napovedano");
        require(block.timestamp >= od, "Zamik se ni potekel");
        require(block.timestamp <= od + ROK, "Napoved je potekla");
        delete izvedljivoOd[id];
        emit SpremembaIzvedena(id, kaj);
    }

    // ── Javno ───────────────────────────────────────────────────────────────

    /// @notice Preklic napovedane spremembe. Takojsen — premisliti se mora biti
    ///         mogoce hitreje, kot se izvede.
    function prekliciSpremembo(bytes32 id, string calldata kaj) external onlyOwner {
        require(izvedljivoOd[id] != 0, "Ni napovedano");
        delete izvedljivoOd[id];
        emit SpremembaPreklicana(id, kaj);
    }

    /// @notice Stanje napovedi — da ga stran in nadzorni sistem lahko prikazeta.
    function stanjeNapovedi(bytes32 id)
        external
        view
        returns (bool napovedana, uint256 od, uint256 potece, bool izvedljivaZdaj)
    {
        uint256 t = izvedljivoOd[id];
        if (t == 0) return (false, 0, 0, false);
        return (true, t, t + ROK, block.timestamp >= t && block.timestamp <= t + ROK);
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.5.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;

    mapping(address account => mapping(address spender => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both values are immutable: they can only be set once during construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    /// @inheritdoc IERC20
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    /// @inheritdoc IERC20
    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }

    /// @inheritdoc IERC20
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }

    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }

    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }

    /**
     * @dev Sets `value` as the allowance of `spender` over the `owner`'s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }

    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation sets the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the `transferFrom` operation can force the flag to
     * true using the following override:
     *
     * ```solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }

    /**
     * @dev Updates `owner`'s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC20.sol)

pragma solidity >=0.4.16;

import {IERC20} from "../token/ERC20/IERC20.sol";
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/StorageSlot.sol)
// This file was procedurally generated from scripts/generate/templates/StorageSlot.js.

pragma solidity ^0.8.20;

/**
 * @dev Library for reading and writing primitive types to specific storage slots.
 *
 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
 * This library helps with reading and writing to such slots without the need for inline assembly.
 *
 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
 *
 * Example usage to set ERC-1967 implementation slot:
 * ```solidity
 * contract ERC1967 {
 *     // Define the slot. Alternatively, use the SlotDerivation library to derive the slot.
 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
 *
 *     function _getImplementation() internal view returns (address) {
 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
 *     }
 *
 *     function _setImplementation(address newImplementation) internal {
 *         require(newImplementation.code.length > 0);
 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
 *     }
 * }
 * ```
 *
 * TIP: Consider using this library along with {SlotDerivation}.
 */
library StorageSlot {
    struct AddressSlot {
        address value;
    }

    struct BooleanSlot {
        bool value;
    }

    struct Bytes32Slot {
        bytes32 value;
    }

    struct Uint256Slot {
        uint256 value;
    }

    struct Int256Slot {
        int256 value;
    }

    struct StringSlot {
        string value;
    }

    struct BytesSlot {
        bytes value;
    }

    /**
     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
     */
    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `BooleanSlot` with member `value` located at `slot`.
     */
    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `Bytes32Slot` with member `value` located at `slot`.
     */
    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `Uint256Slot` with member `value` located at `slot`.
     */
    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `Int256Slot` with member `value` located at `slot`.
     */
    function getInt256Slot(bytes32 slot) internal pure returns (Int256Slot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns a `StringSlot` with member `value` located at `slot`.
     */
    function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `StringSlot` representation of the string storage pointer `store`.
     */
    function getStringSlot(string storage store) internal pure returns (StringSlot storage r) {
        assembly ("memory-safe") {
            r.slot := store.slot
        }
    }

    /**
     * @dev Returns a `BytesSlot` with member `value` located at `slot`.
     */
    function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r) {
        assembly ("memory-safe") {
            r.slot := slot
        }
    }

    /**
     * @dev Returns an `BytesSlot` representation of the bytes storage pointer `store`.
     */
    function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r) {
        assembly ("memory-safe") {
            r.slot := store.slot
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (interfaces/IERC1363.sol)

pragma solidity >=0.6.2;

import {IERC20} from "./IERC20.sol";
import {IERC165} from "./IERC165.sol";

/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.5.0) (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";
import {IERC1363} from "../../../interfaces/IERC1363.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    /**
     * @dev An operation with an ERC-20 token failed.
     */
    error SafeERC20FailedOperation(address token);

    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);

    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        if (!_safeTransfer(token, to, value, true)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        if (!_safeTransferFrom(token, from, to, value, true)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _safeTransfer(token, to, value, false);
    }

    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _safeTransferFrom(token, from, to, value, false);
    }

    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }

    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }

    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        if (!_safeApprove(token, spender, value, false)) {
            if (!_safeApprove(token, spender, 0, true)) revert SafeERC20FailedOperation(address(token));
            if (!_safeApprove(token, spender, value, true)) revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that relies on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that relies on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Oppositely, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }

    /**
     * @dev Imitates a Solidity `token.transfer(to, value)` call, relaxing the requirement on the return value: the
     * return value is optional (but if data is returned, it must not be false).
     *
     * @param token The token targeted by the call.
     * @param to The recipient of the tokens
     * @param value The amount of token to transfer
     * @param bubble Behavior switch if the transfer call reverts: bubble the revert reason or return a false boolean.
     */
    function _safeTransfer(IERC20 token, address to, uint256 value, bool bubble) private returns (bool success) {
        bytes4 selector = IERC20.transfer.selector;

        assembly ("memory-safe") {
            let fmp := mload(0x40)
            mstore(0x00, selector)
            mstore(0x04, and(to, shr(96, not(0))))
            mstore(0x24, value)
            success := call(gas(), token, 0, 0x00, 0x44, 0x00, 0x20)
            // if call success and return is true, all is good.
            // otherwise (not success or return is not true), we need to perform further checks
            if iszero(and(success, eq(mload(0x00), 1))) {
                // if the call was a failure and bubble is enabled, bubble the error
                if and(iszero(success), bubble) {
                    returndatacopy(fmp, 0x00, returndatasize())
                    revert(fmp, returndatasize())
                }
                // if the return value is not true, then the call is only successful if:
                // - the token address has code
                // - the returndata is empty
                success := and(success, and(iszero(returndatasize()), gt(extcodesize(token), 0)))
            }
            mstore(0x40, fmp)
        }
    }

    /**
     * @dev Imitates a Solidity `token.transferFrom(from, to, value)` call, relaxing the requirement on the return
     * value: the return value is optional (but if data is returned, it must not be false).
     *
     * @param token The token targeted by the call.
     * @param from The sender of the tokens
     * @param to The recipient of the tokens
     * @param value The amount of token to transfer
     * @param bubble Behavior switch if the transfer call reverts: bubble the revert reason or return a false boolean.
     */
    function _safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value,
        bool bubble
    ) private returns (bool success) {
        bytes4 selector = IERC20.transferFrom.selector;

        assembly ("memory-safe") {
            let fmp := mload(0x40)
            mstore(0x00, selector)
            mstore(0x04, and(from, shr(96, not(0))))
            mstore(0x24, and(to, shr(96, not(0))))
            mstore(0x44, value)
            success := call(gas(), token, 0, 0x00, 0x64, 0x00, 0x20)
            // if call success and return is true, all is good.
            // otherwise (not success or return is not true), we need to perform further checks
            if iszero(and(success, eq(mload(0x00), 1))) {
                // if the call was a failure and bubble is enabled, bubble the error
                if and(iszero(success), bubble) {
                    returndatacopy(fmp, 0x00, returndatasize())
                    revert(fmp, returndatasize())
                }
                // if the return value is not true, then the call is only successful if:
                // - the token address has code
                // - the returndata is empty
                success := and(success, and(iszero(returndatasize()), gt(extcodesize(token), 0)))
            }
            mstore(0x40, fmp)
            mstore(0x60, 0)
        }
    }

    /**
     * @dev Imitates a Solidity `token.approve(spender, value)` call, relaxing the requirement on the return value:
     * the return value is optional (but if data is returned, it must not be false).
     *
     * @param token The token targeted by the call.
     * @param spender The spender of the tokens
     * @param value The amount of token to transfer
     * @param bubble Behavior switch if the transfer call reverts: bubble the revert reason or return a false boolean.
     */
    function _safeApprove(IERC20 token, address spender, uint256 value, bool bubble) private returns (bool success) {
        bytes4 selector = IERC20.approve.selector;

        assembly ("memory-safe") {
            let fmp := mload(0x40)
            mstore(0x00, selector)
            mstore(0x04, and(spender, shr(96, not(0))))
            mstore(0x24, value)
            success := call(gas(), token, 0, 0x00, 0x44, 0x00, 0x20)
            // if call success and return is true, all is good.
            // otherwise (not success or return is not true), we need to perform further checks
            if iszero(and(success, eq(mload(0x00), 1))) {
                // if the call was a failure and bubble is enabled, bubble the error
                if and(iszero(success), bubble) {
                    returndatacopy(fmp, 0x00, returndatasize())
                    revert(fmp, returndatasize())
                }
                // if the return value is not true, then the call is only successful if:
                // - the token address has code
                // - the returndata is empty
                success := and(success, and(iszero(returndatasize()), gt(extcodesize(token), 0)))
            }
            mstore(0x40, fmp)
        }
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)

pragma solidity ^0.8.20;

import {Context} from "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);

    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (token/ERC20/IERC20.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)

pragma solidity ^0.8.20;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }

    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}
          

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.4.0) (utils/introspection/IERC165.sol)

pragma solidity >=0.4.16;

/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}