//! 司法辖区定义和会计准则

use serde::{Deserialize, Serialize};
use std::collections::HashMap;

/// 司法辖区枚举
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum Jurisdiction {
    /// 美国辖区
    US,
    /// 欧盟辖区
    EU,
    /// 中国辖区
    CN,
    /// 香港辖区
    HK,
    /// 新加坡辖区
    SG,
    /// 英国辖区
    UK,
    /// 日本辖区
    JP,
    /// 中东辖区 (伊斯兰金融体系)
    ME,
}

/// 会计准则
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum AccountingStandard {
    /// 美国公认会计原则
    USGAAP,
    /// 国际财务报告准则
    IFRS,
    /// 中国企业会计准则
    CAS,
    /// 日本公认会计原则
    JGAAP,
    /// 伊斯兰金融机构会计与审计组织准则
    AAOIFI,
}

/// 法系类型
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum LegalSystem {
    /// 普通法系
    CommonLaw,
    /// 大陆法系
    CivilLaw,
    /// 社会主义法系
    SocialistLaw,
    /// 混合法系
    MixedLaw,
    /// 伊斯兰法系
    ShariaLaw,
}

/// 辖区详细信息
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct JurisdictionInfo {
    /// 辖区代码
    pub code: Jurisdiction,
    /// 法系类型
    pub legal_system: LegalSystem,
    /// 会计准则
    pub accounting_standard: AccountingStandard,
    /// 企业所得税率 (0-1)
    pub corporate_tax_rate: f64,
    /// 资本利得税率 (0-1)
    pub capital_gains_tax_rate: f64,
    /// 增值税率 (0-1)
    pub vat_rate: f64,
    /// 监管成本率 (0-1)
    pub regulatory_cost_rate: f64,
    /// 基础流动性折扣 (0-1)
    pub base_liquidity_discount: f64,
}

impl Jurisdiction {
    /// 获取辖区详细信息
    pub fn info(self) -> JurisdictionInfo {
        match self {
            Jurisdiction::US => JurisdictionInfo {
                code: Jurisdiction::US,
                legal_system: LegalSystem::CommonLaw,
                accounting_standard: AccountingStandard::USGAAP,
                corporate_tax_rate: 0.21,
                capital_gains_tax_rate: 0.20,
                vat_rate: 0.0,
                regulatory_cost_rate: 0.02,
                base_liquidity_discount: 0.075,
            },
            Jurisdiction::EU => JurisdictionInfo {
                code: Jurisdiction::EU,
                legal_system: LegalSystem::CivilLaw,
                accounting_standard: AccountingStandard::IFRS,
                corporate_tax_rate: 0.21,
                capital_gains_tax_rate: 0.25,
                vat_rate: 0.20,
                regulatory_cost_rate: 0.03,
                base_liquidity_discount: 0.125,
            },
            Jurisdiction::CN => JurisdictionInfo {
                code: Jurisdiction::CN,
                legal_system: LegalSystem::SocialistLaw,
                accounting_standard: AccountingStandard::CAS,
                corporate_tax_rate: 0.25,
                capital_gains_tax_rate: 0.20,
                vat_rate: 0.13,
                regulatory_cost_rate: 0.04,
                base_liquidity_discount: 0.20,
            },
            Jurisdiction::HK => JurisdictionInfo {
                code: Jurisdiction::HK,
                legal_system: LegalSystem::CommonLaw,
                accounting_standard: AccountingStandard::IFRS,
                corporate_tax_rate: 0.165,
                capital_gains_tax_rate: 0.0,
                vat_rate: 0.0,
                regulatory_cost_rate: 0.01,
                base_liquidity_discount: 0.075,
            },
            Jurisdiction::SG => JurisdictionInfo {
                code: Jurisdiction::SG,
                legal_system: LegalSystem::CommonLaw,
                accounting_standard: AccountingStandard::IFRS,
                corporate_tax_rate: 0.17,
                capital_gains_tax_rate: 0.0,
                vat_rate: 0.07,
                regulatory_cost_rate: 0.01,
                base_liquidity_discount: 0.075,
            },
            Jurisdiction::UK => JurisdictionInfo {
                code: Jurisdiction::UK,
                legal_system: LegalSystem::CommonLaw,
                accounting_standard: AccountingStandard::IFRS,
                corporate_tax_rate: 0.25,
                capital_gains_tax_rate: 0.20,
                vat_rate: 0.20,
                regulatory_cost_rate: 0.02,
                base_liquidity_discount: 0.125,
            },
            Jurisdiction::JP => JurisdictionInfo {
                code: Jurisdiction::JP,
                legal_system: LegalSystem::MixedLaw,
                accounting_standard: AccountingStandard::JGAAP,
                corporate_tax_rate: 0.232,
                capital_gains_tax_rate: 0.20,
                vat_rate: 0.10,
                regulatory_cost_rate: 0.03,
                base_liquidity_discount: 0.175,
            },
            Jurisdiction::ME => JurisdictionInfo {
                code: Jurisdiction::ME,
                legal_system: LegalSystem::ShariaLaw,
                accounting_standard: AccountingStandard::AAOIFI,
                corporate_tax_rate: 0.025, // Zakat
                capital_gains_tax_rate: 0.0,
                vat_rate: 0.05,
                regulatory_cost_rate: 0.02,
                base_liquidity_discount: 0.25,
            },
        }
    }
    
    /// 计算辖区调整系数
    pub fn adjustment_factor(self) -> f64 {
        let info = self.info();
        (1.0 - info.corporate_tax_rate) * (1.0 - info.regulatory_cost_rate)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_jurisdiction_info() {
        let us_info = Jurisdiction::US.info();
        assert_eq!(us_info.accounting_standard, AccountingStandard::USGAAP);
        assert_eq!(us_info.legal_system, LegalSystem::CommonLaw);
        
        let me_info = Jurisdiction::ME.info();
        assert_eq!(me_info.accounting_standard, AccountingStandard::AAOIFI);
        assert_eq!(me_info.legal_system, LegalSystem::ShariaLaw);
    }

    #[test]
    fn test_adjustment_factor() {
        let us_factor = Jurisdiction::US.adjustment_factor();
        assert!(us_factor > 0.7 && us_factor < 0.8);
        
        let hk_factor = Jurisdiction::HK.adjustment_factor();
        assert!(hk_factor > 0.8 && hk_factor < 0.9);
    }
}