///! # 合规检查系统
///!
///! Compliance Checking System
///! 提供KYC/AML和合规验证功能
///!
///! **版本**: v1.0
///! **模块**: charter-std/sovereignty/compliance.ch

use utils::crypto::sha3_384_hash;

// ============================================================================
// 合规级别枚举
// ============================================================================

/// KYC级别
pub enum KYCLevel {
    /// 未验证
    None,
    
    /// 基础验证（姓名、邮箱）
    Basic,
    
    /// 中级验证（身份证件）
    Intermediate,
    
    /// 高级验证（生物识别）
    Advanced,
    
    /// 机构验证
    Institutional
}

/// AML风险级别
pub enum AMLRiskLevel {
    /// 低风险
    Low,
    
    /// 中风险
    Medium,
    
    /// 高风险
    High,
    
    /// 禁止
    Prohibited
}

/// 合规状态
pub enum ComplianceStatus {
    /// 未检查
    Unchecked,
    
    /// 检查中
    Checking,
    
    /// 通过
    Passed,
    
    /// 失败
    Failed,
    
    /// 需要更新
    NeedsUpdate
}

// ============================================================================
// 合规信息结构
// ============================================================================

/// KYC信息
struct KYCInfo {
    /// 用户地址
    user: Address,
    
    /// KYC级别
    level: KYCLevel,
    
    /// 验证时间
    verified_at: Timestamp,
    
    /// 过期时间
    expires_at: Timestamp,
    
    /// 验证机构
    verifier: Address,
    
    /// 文档哈希
    document_hash: Hash,
    
    /// 国家代码（ISO 3166-1）
    country_code: String,
    
    /// 是否被制裁
    is_sanctioned: bool
}

/// AML检查记录
struct AMLCheckRecord {
    /// 检查ID
    check_id: Hash,
    
    /// 用户地址
    user: Address,
    
    /// 风险级别
    risk_level: AMLRiskLevel,
    
    /// 检查时间
    checked_at: Timestamp,
    
    /// 检查机构
    checker: Address,
    
    /// 风险评分（0-100）
    risk_score: u8,
    
    /// 风险因素
    risk_factors: Vec<String>,
    
    /// 报告哈希
    report_hash: Hash
}

/// 白名单记录
struct WhitelistRecord {
    /// 地址
    address: Address,
    
    /// 添加时间
    added_at: Timestamp,
    
    /// 添加者
    added_by: Address,
    
    /// 原因
    reason: String,
    
    /// 过期时间（可选）
    expires_at: Option<Timestamp>
}

/// 黑名单记录
struct BlacklistRecord {
    /// 地址
    address: Address,
    
    /// 添加时间
    added_at: Timestamp,
    
    /// 添加者
    added_by: Address,
    
    /// 原因
    reason: String,
    
    /// 是否永久
    is_permanent: bool
}

/// 地域限制
struct GeoRestriction {
    /// 国家代码
    country_code: String,
    
    /// 是否允许
    is_allowed: bool,
    
    /// 原因
    reason: String
}

// ============================================================================
// 合规事件
// ============================================================================

/// KYC验证事件
event KYCVerified {
    user: Address,
    level: KYCLevel,
    verifier: Address,
    timestamp: Timestamp
}

/// AML检查事件
event AMLChecked {
    check_id: Hash,
    user: Address,
    risk_level: AMLRiskLevel,
    risk_score: u8,
    timestamp: Timestamp
}

/// 白名单添加事件
event WhitelistAdded {
    address: Address,
    added_by: Address,
    reason: String,
    timestamp: Timestamp
}

/// 黑名单添加事件
event BlacklistAdded {
    address: Address,
    added_by: Address,
    reason: String,
    timestamp: Timestamp
}

/// 合规检查失败事件
event ComplianceFailed {
    user: Address,
    reason: String,
    timestamp: Timestamp
}

// ============================================================================
// 合规检查系统
// ============================================================================

/// 合规检查系统
certificate ComplianceChecker {
    /// KYC信息存储 (user => kyc_info)
    let _kyc_info: Map<Address, KYCInfo>;
    
    /// AML检查记录 (user => check_records)
    let _aml_records: Map<Address, Vec<AMLCheckRecord>>;
    
    /// 白名单
    let _whitelist: Map<Address, WhitelistRecord>;
    
    /// 黑名单
    let _blacklist: Map<Address, BlacklistRecord>;
    
    /// 地域限制 (country_code => restriction)
    let _geo_restrictions: Map<String, GeoRestriction>;
    
    /// 管理员地址
    let _admin: Address;
    
    /// KYC验证机构集合
    let _kyc_verifiers: Set<Address>;
    
    /// AML检查机构集合
    let _aml_checkers: Set<Address>;
    
    /// 最低KYC级别要求
    let _min_kyc_level: KYCLevel;
    
    /// 最高AML风险级别允许
    let _max_aml_risk: AMLRiskLevel;
    
    // ========== 构造函数 ==========
    
    constructor() {
        self._admin = msg.sender;
        self._kyc_verifiers.insert(msg.sender);
        self._aml_checkers.insert(msg.sender);
        self._min_kyc_level = KYCLevel::Basic;
        self._max_aml_risk = AMLRiskLevel::Medium;
    }
    
    // ========== KYC管理 ==========
    
    /// 设置KYC信息
    ///
    /// # 参数
    /// - `user`: 用户地址
    /// - `level`: KYC级别
    /// - `expires_at`: 过期时间
    /// - `document_hash`: 文档哈希
    /// - `country_code`: 国家代码
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn set_kyc(
        user: Address,
        level: KYCLevel,
        expires_at: Timestamp,
        document_hash: Hash,
        country_code: String
    ) -> bool {
        require(self._kyc_verifiers.contains(msg.sender), "Not a KYC verifier");
        require(!user.is_zero(), "Invalid user");
        require(expires_at > block.timestamp, "Invalid expiry time");
        require(!country_code.is_empty(), "Country code required");
        
        // 检查地域限制
        if let Some(restriction) = self._geo_restrictions.get(country_code.clone()) {
            require(restriction.is_allowed, "Country not allowed");
        }
        
        let kyc_info = KYCInfo {
            user: user,
            level: level,
            verified_at: block.timestamp,
            expires_at: expires_at,
            verifier: msg.sender,
            document_hash: document_hash,
            country_code: country_code,
            is_sanctioned: false
        };
        
        self._kyc_info[user] = kyc_info;
        
        emit KYCVerified {
            user: user,
            level: level,
            verifier: msg.sender,
            timestamp: block.timestamp
        };
        
        return true;
    }
    
    /// 获取KYC信息
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `Option<KYCInfo>`: KYC信息
    pub fn get_kyc(user: Address) -> Option<KYCInfo> {
        return self._kyc_info.get(user);
    }
    
    /// 检查KYC是否有效
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `bool`: 是否有效
    pub fn is_kyc_valid(user: Address) -> bool {
        if let Some(kyc) = self._kyc_info.get(user) {
            return block.timestamp < kyc.expires_at && !kyc.is_sanctioned;
        }
        return false;
    }
    
    /// 检查KYC级别是否满足要求
    ///
    /// # 参数
    /// - `user`: 用户地址
    /// - `required_level`: 要求的级别
    ///
    /// # 返回
    /// - `bool`: 是否满足
    pub fn check_kyc_level(user: Address, required_level: KYCLevel) -> bool {
        if let Some(kyc) = self._kyc_info.get(user) {
            if !self.is_kyc_valid(user) {
                return false;
            }
            return self._compare_kyc_level(kyc.level, required_level);
        }
        return false;
    }
    
    /// 标记为制裁对象
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn mark_sanctioned(user: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        require(self._kyc_info.contains_key(user), "KYC not found");
        
        let mut kyc = self._kyc_info[user];
        kyc.is_sanctioned = true;
        self._kyc_info[user] = kyc;
        
        return true;
    }
    
    // ========== AML检查 ==========
    
    /// 执行AML检查
    ///
    /// # 参数
    /// - `user`: 用户地址
    /// - `risk_level`: 风险级别
    /// - `risk_score`: 风险评分
    /// - `risk_factors`: 风险因素
    /// - `report_hash`: 报告哈希
    ///
    /// # 返回
    /// - `Hash`: 检查ID
    pub fn perform_aml_check(
        user: Address,
        risk_level: AMLRiskLevel,
        risk_score: u8,
        risk_factors: Vec<String>,
        report_hash: Hash
    ) -> Hash {
        require(self._aml_checkers.contains(msg.sender), "Not an AML checker");
        require(!user.is_zero(), "Invalid user");
        require(risk_score <= 100, "Invalid risk score");
        
        // 生成检查ID
        let check_id = self._generate_check_id(user);
        
        let record = AMLCheckRecord {
            check_id: check_id,
            user: user,
            risk_level: risk_level,
            checked_at: block.timestamp,
            checker: msg.sender,
            risk_score: risk_score,
            risk_factors: risk_factors,
            report_hash: report_hash
        };
        
        // 存储记录
        if !self._aml_records.contains_key(user) {
            self._aml_records[user] = Vec::new();
        }
        self._aml_records[user].push(record);
        
        emit AMLChecked {
            check_id: check_id,
            user: user,
            risk_level: risk_level,
            risk_score: risk_score,
            timestamp: block.timestamp
        };
        
        return check_id;
    }
    
    /// 获取最新的AML检查记录
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `Option<AMLCheckRecord>`: AML检查记录
    pub fn get_latest_aml_check(user: Address) -> Option<AMLCheckRecord> {
        if let Some(records) = self._aml_records.get(user) {
            if records.len() > 0 {
                return Some(records[records.len() - 1]);
            }
        }
        return None;
    }
    
    /// 获取所有AML检查记录
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `Vec<AMLCheckRecord>`: AML检查记录列表
    pub fn get_aml_history(user: Address) -> Vec<AMLCheckRecord> {
        return self._aml_records.get(user).unwrap_or(Vec::new());
    }
    
    /// 检查AML风险是否可接受
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `bool`: 是否可接受
    pub fn is_aml_acceptable(user: Address) -> bool {
        if let Some(record) = self.get_latest_aml_check(user) {
            return self._compare_aml_risk(record.risk_level, self._max_aml_risk);
        }
        return false;
    }
    
    // ========== 白名单管理 ==========
    
    /// 添加到白名单
    ///
    /// # 参数
    /// - `address`: 地址
    /// - `reason`: 原因
    /// - `expires_at`: 过期时间（可选）
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn add_to_whitelist(
        address: Address,
        reason: String,
        expires_at: Option<Timestamp>
    ) -> bool {
        require(msg.sender == self._admin, "Only admin");
        require(!address.is_zero(), "Invalid address");
        
        if let Some(expiry) = expires_at {
            require(expiry > block.timestamp, "Invalid expiry time");
        }
        
        let record = WhitelistRecord {
            address: address,
            added_at: block.timestamp,
            added_by: msg.sender,
            reason: reason.clone(),
            expires_at: expires_at
        };
        
        self._whitelist[address] = record;
        
        emit WhitelistAdded {
            address: address,
            added_by: msg.sender,
            reason: reason,
            timestamp: block.timestamp
        };
        
        return true;
    }
    
    /// 从白名单移除
    ///
    /// # 参数
    /// - `address`: 地址
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn remove_from_whitelist(address: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        
        self._whitelist.remove(address);
        
        return true;
    }
    
    /// 检查是否在白名单
    ///
    /// # 参数
    /// - `address`: 地址
    ///
    /// # 返回
    /// - `bool`: 是否在白名单
    pub fn is_whitelisted(address: Address) -> bool {
        if let Some(record) = self._whitelist.get(address) {
            // 检查是否过期
            if let Some(expiry) = record.expires_at {
                return block.timestamp < expiry;
            }
            return true;
        }
        return false;
    }
    
    // ========== 黑名单管理 ==========
    
    /// 添加到黑名单
    ///
    /// # 参数
    /// - `address`: 地址
    /// - `reason`: 原因
    /// - `is_permanent`: 是否永久
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn add_to_blacklist(
        address: Address,
        reason: String,
        is_permanent: bool
    ) -> bool {
        require(msg.sender == self._admin, "Only admin");
        require(!address.is_zero(), "Invalid address");
        
        let record = BlacklistRecord {
            address: address,
            added_at: block.timestamp,
            added_by: msg.sender,
            reason: reason.clone(),
            is_permanent: is_permanent
        };
        
        self._blacklist[address] = record;
        
        emit BlacklistAdded {
            address: address,
            added_by: msg.sender,
            reason: reason,
            timestamp: block.timestamp
        };
        
        return true;
    }
    
    /// 从黑名单移除
    ///
    /// # 参数
    /// - `address`: 地址
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn remove_from_blacklist(address: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        
        if let Some(record) = self._blacklist.get(address) {
            require(!record.is_permanent, "Cannot remove permanent blacklist");
        }
        
        self._blacklist.remove(address);
        
        return true;
    }
    
    /// 检查是否在黑名单
    ///
    /// # 参数
    /// - `address`: 地址
    ///
    /// # 返回
    /// - `bool`: 是否在黑名单
    pub fn is_blacklisted(address: Address) -> bool {
        return self._blacklist.contains_key(address);
    }
    
    // ========== 地域限制 ==========
    
    /// 设置地域限制
    ///
    /// # 参数
    /// - `country_code`: 国家代码
    /// - `is_allowed`: 是否允许
    /// - `reason`: 原因
    ///
    /// # 返回
    /// - `bool`: 是否成功
    pub fn set_geo_restriction(
        country_code: String,
        is_allowed: bool,
        reason: String
    ) -> bool {
        require(msg.sender == self._admin, "Only admin");
        require(!country_code.is_empty(), "Country code required");
        
        let restriction = GeoRestriction {
            country_code: country_code.clone(),
            is_allowed: is_allowed,
            reason: reason
        };
        
        self._geo_restrictions[country_code] = restriction;
        
        return true;
    }
    
    /// 检查国家是否允许
    ///
    /// # 参数
    /// - `country_code`: 国家代码
    ///
    /// # 返回
    /// - `bool`: 是否允许
    pub fn is_country_allowed(country_code: String) -> bool {
        if let Some(restriction) = self._geo_restrictions.get(country_code) {
            return restriction.is_allowed;
        }
        // 默认允许
        return true;
    }
    
    // ========== 综合合规检查 ==========
    
    /// 执行完整的合规检查
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `ComplianceStatus`: 合规状态
    pub fn check_compliance(user: Address) -> ComplianceStatus {
        // 1. 检查黑名单
        if self.is_blacklisted(user) {
            emit ComplianceFailed {
                user: user,
                reason: "User is blacklisted",
                timestamp: block.timestamp
            };
            return ComplianceStatus::Failed;
        }
        
        // 2. 白名单用户直接通过
        if self.is_whitelisted(user) {
            return ComplianceStatus::Passed;
        }
        
        // 3. 检查KYC
        if !self.is_kyc_valid(user) {
            emit ComplianceFailed {
                user: user,
                reason: "KYC not valid",
                timestamp: block.timestamp
            };
            return ComplianceStatus::Failed;
        }
        
        if !self.check_kyc_level(user, self._min_kyc_level) {
            emit ComplianceFailed {
                user: user,
                reason: "KYC level insufficient",
                timestamp: block.timestamp
            };
            return ComplianceStatus::Failed;
        }
        
        // 4. 检查AML
        if !self.is_aml_acceptable(user) {
            emit ComplianceFailed {
                user: user,
                reason: "AML risk too high",
                timestamp: block.timestamp
            };
            return ComplianceStatus::Failed;
        }
        
        // 5. 检查地域限制
        if let Some(kyc) = self.get_kyc(user) {
            if !self.is_country_allowed(kyc.country_code) {
                emit ComplianceFailed {
                    user: user,
                    reason: "Country not allowed",
                    timestamp: block.timestamp
                };
                return ComplianceStatus::Failed;
            }
        }
        
        return ComplianceStatus::Passed;
    }
    
    /// 检查用户是否合规
    ///
    /// # 参数
    /// - `user`: 用户地址
    ///
    /// # 返回
    /// - `bool`: 是否合规
    pub fn is_compliant(user: Address) -> bool {
        return self.check_compliance(user) == ComplianceStatus::Passed;
    }
    
    // ========== 内部函数 ==========
    
    /// 生成检查ID
    fn _generate_check_id(user: Address) -> Hash {
        let mut data = Bytes::new();
        data.extend(user.as_bytes());
        data.extend(block.timestamp.to_bytes());
        data.extend(tx.hash.as_bytes());
        
        return sha3_384_hash(data);
    }
    
    /// 比较KYC级别
    fn _compare_kyc_level(level: KYCLevel, required: KYCLevel) -> bool {
        let level_value = match level {
            KYCLevel::None => 0,
            KYCLevel::Basic => 1,
            KYCLevel::Intermediate => 2,
            KYCLevel::Advanced => 3,
            KYCLevel::Institutional => 4
        };
        
        let required_value = match required {
            KYCLevel::None => 0,
            KYCLevel::Basic => 1,
            KYCLevel::Intermediate => 2,
            KYCLevel::Advanced => 3,
            KYCLevel::Institutional => 4
        };
        
        return level_value >= required_value;
    }
    
    /// 比较AML风险级别
    fn _compare_aml_risk(level: AMLRiskLevel, max_allowed: AMLRiskLevel) -> bool {
        let level_value = match level {
            AMLRiskLevel::Low => 1,
            AMLRiskLevel::Medium => 2,
            AMLRiskLevel::High => 3,
            AMLRiskLevel::Prohibited => 4
        };
        
        let max_value = match max_allowed {
            AMLRiskLevel::Low => 1,
            AMLRiskLevel::Medium => 2,
            AMLRiskLevel::High => 3,
            AMLRiskLevel::Prohibited => 4
        };
        
        return level_value <= max_value;
    }
    
    // ========== 管理函数 ==========
    
    /// 添加KYC验证机构
    pub fn add_kyc_verifier(verifier: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._kyc_verifiers.insert(verifier);
        return true;
    }
    
    /// 移除KYC验证机构
    pub fn remove_kyc_verifier(verifier: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._kyc_verifiers.remove(verifier);
        return true;
    }
    
    /// 添加AML检查机构
    pub fn add_aml_checker(checker: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._aml_checkers.insert(checker);
        return true;
    }
    
    /// 移除AML检查机构
    pub fn remove_aml_checker(checker: Address) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._aml_checkers.remove(checker);
        return true;
    }
    
    /// 设置最低KYC级别
    pub fn set_min_kyc_level(level: KYCLevel) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._min_kyc_level = level;
        return true;
    }
    
    /// 设置最高AML风险级别
    pub fn set_max_aml_risk(level: AMLRiskLevel) -> bool {
        require(msg.sender == self._admin, "Only admin");
        self._max_aml_risk = level;
        return true;
    }
}