///! ACC-20 Enhanced - GNACS增强版可替代资产协议
///!
///! 这是NAC原生的ACC-20增强版，集成了GNACS编码、主权管理和合规检查。
///! 
///! 与标准ACC-20的区别：
///! - 集成GNACS 48位编码系统
///! - 支持7种主权类型（A0-G5）
///! - 内置KYC/AML合规检查
///! - 支持资产冻结和估值管理
///! - 完整的审计追踪

module acc20_enhanced;

use asset::gnacs::{GNACSCode, AssetCategory, Jurisdiction, ComplianceLevel, RiskLevel};
use sovereignty::types::{SovereigntyType};
use sovereignty::rules::{SovereigntyRules, TransferRules};
use utils::crypto::{Hash, sha3_384_hash};

/// ACC-20增强版资产
contract ACC20Enhanced {
    // ========== 基础信息 ==========
    
    /// 资产名称
    name: string;
    
    /// 资产符号
    symbol: string;
    
    /// 小数位数
    decimals: u8;
    
    /// 总供应量
    total_supply: u128;
    
    // ========== GNACS集成 ==========
    
    /// GNACS编码（48位数字基因）
    gnacs_code: GNACSCode;
    
    // ========== 主权管理 ==========
    
    /// 主权类型
    sovereignty_type: SovereigntyType;
    
    /// 主权规则
    sovereignty_rules: SovereigntyRules;
    
    // ========== 持有量管理 ==========
    
    /// 持有量映射（使用Holdings而不是balance）
    holdings: map<Address, u128>;
    
    /// 授权映射
    allowances: map<Address, map<Address, u128>>;
    
    // ========== 合规管理 ==========
    
    /// KYC级别映射
    kyc_levels: map<Address, KYCLevel>;
    
    /// AML状态映射
    aml_status: map<Address, AMLStatus>;
    
    /// 合规状态
    compliance_status: ComplianceStatus;
    
    /// 白名单
    whitelist: map<Address, bool>;
    
    /// 黑名单
    blacklist: map<Address, bool>;
    
    // ========== 冻结管理 ==========
    
    /// 全局冻结标志
    globally_frozen: bool;
    
    /// 账户冻结映射
    frozen_accounts: map<Address, bool>;
    
    // ========== RWA扩展 ==========
    
    /// 估值信息
    valuation: AssetValuation;
    
    /// 审计追踪
    audit_trail: vec<AuditEntry>;
    
    /// 碎片化支持
    fragmentable: bool;
    
    /// 跨链支持
    cross_chain_enabled: bool;
    
    // ========== 贸易金融扩展 ==========
    
    /// 信用证集成
    letter_of_credit: Option<LetterOfCredit>;
    
    /// 保函支持
    bank_guarantee: Option<BankGuarantee>;
    
    /// 应收账款
    accounts_receivable: Option<AccountsReceivable>;
    
    // ========== 管理员 ==========
    
    /// 所有者
    owner: Address;
    
    /// 合规官
    compliance_officer: Address;
    
    /// 估值师
    valuator: Address;
    
    // ========== 构造函数 ==========
    
    public fn new(
        name: string,
        symbol: string,
        decimals: u8,
        gnacs_code: GNACSCode,
        sovereignty_type: SovereigntyType,
    ) -> Result<Self, Error> {
        // 验证GNACS编码
        if !gnacs_code.is_valid() {
            return Err(Error::InvalidGNACS);
        }
        
        // 创建默认主权规则
        let sovereignty_rules = SovereigntyRules::default_for_type(sovereignty_type);
        
        return Ok(Self {
            name,
            symbol,
            decimals,
            total_supply: 0,
            gnacs_code,
            sovereignty_type,
            sovereignty_rules,
            holdings: map::new(),
            allowances: map::new(),
            kyc_levels: map::new(),
            aml_status: map::new(),
            compliance_status: ComplianceStatus::Pending,
            whitelist: map::new(),
            blacklist: map::new(),
            globally_frozen: false,
            frozen_accounts: map::new(),
            valuation: AssetValuation::new(),
            audit_trail: vec::new(),
            fragmentable: false,
            cross_chain_enabled: false,
            letter_of_credit: None,
            bank_guarantee: None,
            accounts_receivable: None,
            owner: msg::sender(),
            compliance_officer: msg::sender(),
            valuator: msg::sender(),
        });
    }
    
    // ========== 查询函数 ==========
    
    /// 获取资产名称
    public fn get_name() -> string {
        return self.name;
    }
    
    /// 获取资产符号
    public fn get_symbol() -> string {
        return self.symbol;
    }
    
    /// 获取小数位数
    public fn get_decimals() -> u8 {
        return self.decimals;
    }
    
    /// 获取总供应量
    public fn get_total_supply() -> u128 {
        return self.total_supply;
    }
    
    /// 获取GNACS编码
    public fn get_gnacs_code() -> GNACSCode {
        return self.gnacs_code;
    }
    
    /// 获取主权类型
    public fn get_sovereignty_type() -> SovereigntyType {
        return self.sovereignty_type;
    }
    
    /// 获取持有量
    public fn holdings_of(owner: Address) -> u128 {
        return self.holdings.get(owner).unwrap_or(0);
    }
    
    /// 获取授权额度
    public fn allowance(owner: Address, spender: Address) -> u128 {
        return self.allowances
            .get(owner)
            .and_then(|inner| inner.get(spender))
            .unwrap_or(0);
    }
    
    /// 检查账户是否冻结
    public fn is_frozen(account: Address) -> bool {
        return self.globally_frozen || self.frozen_accounts.get(account).unwrap_or(false);
    }
    
    /// 获取合规状态
    public fn get_compliance_status() -> ComplianceStatus {
        return self.compliance_status;
    }
    
    /// 获取KYC级别
    public fn get_kyc_level(account: Address) -> KYCLevel {
        return self.kyc_levels.get(account).unwrap_or(KYCLevel::None);
    }
    
    /// 获取AML状态
    public fn get_aml_status(account: Address) -> AMLStatus {
        return self.aml_status.get(account).unwrap_or(AMLStatus::Unknown);
    }
    
    // ========== 转账函数 ==========
    
    /// 转账
    public fn transfer(to: Address, amount: u128) -> Result<bool, Error> {
        let from = msg::sender();
        return self._transfer(from, to, amount);
    }
    
    /// 从授权转账
    public fn transfer_from(from: Address, to: Address, amount: u128) -> Result<bool, Error> {
        let spender = msg::sender();
        
        // 检查授权额度
        let current_allowance = self.allowance(from, spender);
        if current_allowance < amount {
            return Err(Error::InsufficientAllowance);
        }
        
        // 执行转账
        self._transfer(from, to, amount)?;
        
        // 减少授权额度
        let new_allowance = current_allowance - amount;
        self.allowances.get_mut(from).unwrap().insert(spender, new_allowance);
        
        return Ok(true);
    }
    
    /// 内部转账函数
    fn _transfer(from: Address, to: Address, amount: u128) -> Result<bool, Error> {
        // 1. 基础检查
        if from == Address::zero() {
            return Err(Error::TransferFromZeroAddress);
        }
        if to == Address::zero() {
            return Err(Error::TransferToZeroAddress);
        }
        if amount == 0 {
            return Err(Error::ZeroAmount);
        }
        
        // 2. 冻结检查
        if self.is_frozen(from) {
            return Err(Error::AccountFrozen);
        }
        if self.is_frozen(to) {
            return Err(Error::AccountFrozen);
        }
        
        // 3. 合规检查
        self._check_compliance(from)?;
        self._check_compliance(to)?;
        
        // 4. 主权规则验证
        self._validate_sovereignty_transfer(from, to, amount)?;
        
        // 5. 余额检查
        let from_holdings = self.holdings_of(from);
        if from_holdings < amount {
            return Err(Error::InsufficientHoldings);
        }
        
        // 6. 执行转账
        let new_from_holdings = from_holdings - amount;
        let to_holdings = self.holdings_of(to);
        let new_to_holdings = to_holdings + amount;
        
        self.holdings.insert(from, new_from_holdings);
        self.holdings.insert(to, new_to_holdings);
        
        // 7. 记录审计追踪
        self._record_audit(
            AuditAction::Transfer,
            from,
            Some(to),
            amount,
            "Transfer executed".to_string(),
        );
        
        // 8. 触发事件
        emit Transfer(from, to, amount);
        
        return Ok(true);
    }
    
    // ========== 授权函数 ==========
    
    /// 授权
    public fn approve(spender: Address, amount: u128) -> Result<bool, Error> {
        let owner = msg::sender();
        
        if spender == Address::zero() {
            return Err(Error::ApproveToZeroAddress);
        }
        
        if !self.allowances.contains_key(owner) {
            self.allowances.insert(owner, map::new());
        }
        
        self.allowances.get_mut(owner).unwrap().insert(spender, amount);
        
        emit Approval(owner, spender, amount);
        
        return Ok(true);
    }
    
    /// 增加授权
    public fn increase_allowance(spender: Address, added_value: u128) -> Result<bool, Error> {
        let owner = msg::sender();
        let current_allowance = self.allowance(owner, spender);
        let new_allowance = current_allowance + added_value;
        
        return self.approve(spender, new_allowance);
    }
    
    /// 减少授权
    public fn decrease_allowance(spender: Address, subtracted_value: u128) -> Result<bool, Error> {
        let owner = msg::sender();
        let current_allowance = self.allowance(owner, spender);
        
        if current_allowance < subtracted_value {
            return Err(Error::AllowanceBelowZero);
        }
        
        let new_allowance = current_allowance - subtracted_value;
        return self.approve(spender, new_allowance);
    }
    
    // ========== 管理函数 ==========
    
    /// 铸造
    public fn mint(to: Address, amount: u128) -> Result<bool, Error> {
        self._only_owner()?;
        
        if to == Address::zero() {
            return Err(Error::MintToZeroAddress);
        }
        
        // 检查合规状态
        if self.compliance_status != ComplianceStatus::Approved {
            return Err(Error::NotCompliant);
        }
        
        // 增加总供应量
        self.total_supply = self.total_supply + amount;
        
        // 增加持有量
        let current_holdings = self.holdings_of(to);
        self.holdings.insert(to, current_holdings + amount);
        
        // 记录审计
        self._record_audit(
            AuditAction::Mint,
            Address::zero(),
            Some(to),
            amount,
            "Minted new assets".to_string(),
        );
        
        emit Mint(to, amount);
        emit Transfer(Address::zero(), to, amount);
        
        return Ok(true);
    }
    
    /// 销毁
    public fn burn(amount: u128) -> Result<bool, Error> {
        let from = msg::sender();
        
        let current_holdings = self.holdings_of(from);
        if current_holdings < amount {
            return Err(Error::InsufficientHoldings);
        }
        
        // 减少总供应量
        self.total_supply = self.total_supply - amount;
        
        // 减少持有量
        self.holdings.insert(from, current_holdings - amount);
        
        // 记录审计
        self._record_audit(
            AuditAction::Burn,
            from,
            None,
            amount,
            "Burned assets".to_string(),
        );
        
        emit Burn(from, amount);
        emit Transfer(from, Address::zero(), amount);
        
        return Ok(true);
    }
    
    /// 冻结账户
    public fn freeze_account(account: Address) -> Result<bool, Error> {
        self._only_compliance_officer()?;
        
        self.frozen_accounts.insert(account, true);
        
        emit AccountFrozen(account);
        
        return Ok(true);
    }
    
    /// 解冻账户
    public fn unfreeze_account(account: Address) -> Result<bool, Error> {
        self._only_compliance_officer()?;
        
        self.frozen_accounts.insert(account, false);
        
        emit AccountUnfrozen(account);
        
        return Ok(true);
    }
    
    /// 全局冻结
    public fn global_freeze() -> Result<bool, Error> {
        self._only_owner()?;
        
        self.globally_frozen = true;
        
        emit GlobalFreeze();
        
        return Ok(true);
    }
    
    /// 全局解冻
    public fn global_unfreeze() -> Result<bool, Error> {
        self._only_owner()?;
        
        self.globally_frozen = false;
        
        emit GlobalUnfreeze();
        
        return Ok(true);
    }
    
    /// 设置KYC级别
    public fn set_kyc_level(account: Address, level: KYCLevel) -> Result<bool, Error> {
        self._only_compliance_officer()?;
        
        self.kyc_levels.insert(account, level);
        
        emit KYCLevelUpdated(account, level);
        
        return Ok(true);
    }
    
    /// 设置AML状态
    public fn set_aml_status(account: Address, status: AMLStatus) -> Result<bool, Error> {
        self._only_compliance_officer()?;
        
        self.aml_status.insert(account, status);
        
        emit AMLStatusUpdated(account, status);
        
        return Ok(true);
    }
    
    /// 更新估值
    public fn update_valuation(
        value_xtzh: u128,
        valuator: Address,
        report_hash: Hash,
    ) -> Result<bool, Error> {
        self._only_valuator()?;
        
        self.valuation.value_xtzh = value_xtzh;
        self.valuation.last_valuation_time = block::timestamp();
        self.valuation.valuator = valuator;
        self.valuation.valuation_report_hash = report_hash;
        
        emit ValuationUpdated(value_xtzh, valuator, report_hash);
        
        return Ok(true);
    }
    
    // ========== 内部辅助函数 ==========
    
    /// 检查合规性
    fn _check_compliance(account: Address) -> Result<(), Error> {
        // 检查黑名单
        if self.blacklist.get(account).unwrap_or(false) {
            return Err(Error::Blacklisted);
        }
        
        // 检查KYC
        let kyc_level = self.get_kyc_level(account);
        if kyc_level == KYCLevel::None {
            return Err(Error::KYCRequired);
        }
        
        // 检查AML
        let aml_status = self.get_aml_status(account);
        if aml_status == AMLStatus::HighRisk || aml_status == AMLStatus::Blocked {
            return Err(Error::AMLCheckFailed);
        }
        
        return Ok(());
    }
    
    /// 验证主权规则
    fn _validate_sovereignty_transfer(
        from: Address,
        to: Address,
        amount: u128,
    ) -> Result<(), Error> {
        // 使用主权规则验证器
        let result = self.sovereignty_rules.validate_transfer(
            from,
            to,
            amount,
            block::timestamp(),
        );
        
        if result.is_err() {
            return Err(Error::SovereigntyRuleViolation);
        }
        
        return Ok(());
    }
    
    /// 记录审计追踪
    fn _record_audit(
        action: AuditAction,
        from: Address,
        to: Option<Address>,
        amount: u128,
        note: string,
    ) {
        let entry = AuditEntry {
            timestamp: block::timestamp(),
            action,
            from,
            to,
            amount,
            note,
            tx_hash: tx::hash(),
        };
        
        self.audit_trail.push(entry);
    }
    
    /// 仅所有者
    fn _only_owner() -> Result<(), Error> {
        if msg::sender() != self.owner {
            return Err(Error::OnlyOwner);
        }
        return Ok(());
    }
    
    /// 仅合规官
    fn _only_compliance_officer() -> Result<(), Error> {
        if msg::sender() != self.compliance_officer {
            return Err(Error::OnlyComplianceOfficer);
        }
        return Ok(());
    }
    
    /// 仅估值师
    fn _only_valuator() -> Result<(), Error> {
        if msg::sender() != self.valuator {
            return Err(Error::OnlyValuator);
        }
        return Ok(());
    }
}

// ========== 辅助结构体 ==========

/// KYC级别
enum KYCLevel {
    None,           // 未验证
    Basic,          // 基础验证
    Intermediate,   // 中级验证
    Advanced,       // 高级验证
    Institutional,  // 机构验证
}

/// AML状态
enum AMLStatus {
    Unknown,        // 未知
    Clear,          // 清白
    LowRisk,        // 低风险
    MediumRisk,     // 中等风险
    HighRisk,       // 高风险
    Blocked,        // 已阻止
}

/// 合规状态
enum ComplianceStatus {
    Pending,        // 待审核
    Approved,       // 已批准
    Rejected,       // 已拒绝
    Suspended,      // 已暂停
    Revoked,        // 已撤销
}

/// 资产估值
struct AssetValuation {
    value_xtzh: u128,                   // XTZH计价
    last_valuation_time: Timestamp,     // 最后估值时间
    valuator: Address,                  // 估值师
    valuation_report_hash: Hash,        // 估值报告哈希
}

impl AssetValuation {
    fn new() -> Self {
        return Self {
            value_xtzh: 0,
            last_valuation_time: Timestamp::zero(),
            valuator: Address::zero(),
            valuation_report_hash: Hash::zero(),
        };
    }
}

/// 审计条目
struct AuditEntry {
    timestamp: Timestamp,
    action: AuditAction,
    from: Address,
    to: Option<Address>,
    amount: u128,
    note: string,
    tx_hash: Hash,
}

/// 审计动作
enum AuditAction {
    Transfer,
    Mint,
    Burn,
    Freeze,
    Unfreeze,
    Approve,
    KYCUpdate,
    AMLUpdate,
    ValuationUpdate,
}

/// 信用证
struct LetterOfCredit {
    issuing_bank: Address,
    beneficiary: Address,
    amount: u128,
    expiry_date: Timestamp,
    document_hash: Hash,
}

/// 保函
struct BankGuarantee {
    guarantor_bank: Address,
    beneficiary: Address,
    amount: u128,
    expiry_date: Timestamp,
    terms_hash: Hash,
}

/// 应收账款
struct AccountsReceivable {
    debtor: Address,
    amount: u128,
    due_date: Timestamp,
    invoice_hash: Hash,
}

// ========== 错误类型 ==========

enum Error {
    InvalidGNACS,
    TransferFromZeroAddress,
    TransferToZeroAddress,
    ZeroAmount,
    AccountFrozen,
    InsufficientHoldings,
    InsufficientAllowance,
    ApproveToZeroAddress,
    AllowanceBelowZero,
    MintToZeroAddress,
    NotCompliant,
    Blacklisted,
    KYCRequired,
    AMLCheckFailed,
    SovereigntyRuleViolation,
    OnlyOwner,
    OnlyComplianceOfficer,
    OnlyValuator,
}

// ========== 事件 ==========

event Transfer(from: Address, to: Address, amount: u128);
event Approval(owner: Address, spender: Address, amount: u128);
event Mint(to: Address, amount: u128);
event Burn(from: Address, amount: u128);
event AccountFrozen(account: Address);
event AccountUnfrozen(account: Address);
event GlobalFreeze();
event GlobalUnfreeze();
event KYCLevelUpdated(account: Address, level: KYCLevel);
event AMLStatusUpdated(account: Address, status: AMLStatus);
event ValuationUpdated(value_xtzh: u128, valuator: Address, report_hash: Hash);