//! CBP质押赎回机制
//! 
//! 实现CBP节点的质押赎回条件、流程、计算和记录功能

use crate::{CbpNode, CbpStatus, CbppL1Error};
use nac_udm::primitives::Address;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;

/// 赎回状态
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RedemptionStatus {
    /// 待处理
    Pending,
    /// 处理中
    Processing,
    /// 已完成
    Completed,
    /// 已取消
    Cancelled,
    /// 失败
    Failed,
}

/// 赎回类型
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RedemptionType {
    /// 全额赎回
    Full,
    /// 部分赎回
    Partial,
    /// 紧急赎回
    Emergency,
}

/// 赎回请求
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RedemptionRequest {
    /// CBP地址
    pub address: Address,
    /// 赎回类型
    pub redemption_type: RedemptionType,
    /// 请求赎回金额
    pub requested_amount: u64,
    /// 实际赎回金额
    pub actual_amount: Option<u64>,
    /// 处罚金额
    pub penalty_amount: Option<u64>,
    /// 请求时间
    pub requested_at: u64,
    /// 赎回状态
    pub status: RedemptionStatus,
    /// 完成时间
    pub completed_at: Option<u64>,
    /// 失败原因
    pub failure_reason: Option<String>,
}

impl RedemptionRequest {
    pub fn new(
        address: Address,
        redemption_type: RedemptionType,
        requested_amount: u64,
        timestamp: u64,
    ) -> Self {
        Self {
            address,
            redemption_type,
            requested_amount,
            actual_amount: None,
            penalty_amount: None,
            requested_at: timestamp,
            status: RedemptionStatus::Pending,
            completed_at: None,
            failure_reason: None,
        }
    }
}

/// 赎回记录
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RedemptionRecord {
    /// CBP地址
    pub address: Address,
    /// 赎回类型
    pub redemption_type: RedemptionType,
    /// 原始质押金额
    pub original_stake: u64,
    /// 赎回金额
    pub redeemed_amount: u64,
    /// 处罚金额
    pub penalty_amount: u64,
    /// 请求时间
    pub requested_at: u64,
    /// 完成时间
    pub completed_at: u64,
    /// 声誉分数
    pub reputation_at_redemption: f64,
}

/// 赎回条件
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RedemptionConditions {
    /// 最小锁定期（秒）
    pub min_lock_period: u64,
    /// 部分赎回最小保留金额
    pub min_remaining_stake: u64,
    /// 紧急赎回处罚率（百分比）
    pub emergency_penalty_rate: u8,
    /// 声誉处罚阈值
    pub reputation_penalty_threshold: f64,
    /// 低声誉处罚率（百分比）
    pub low_reputation_penalty_rate: u8,
}

impl Default for RedemptionConditions {
    fn default() -> Self {
        Self {
            min_lock_period: 30 * 24 * 3600, // 30天
            min_remaining_stake: 50_000_000_000, // 50 XIC
            emergency_penalty_rate: 20, // 20%
            reputation_penalty_threshold: 0.5,
            low_reputation_penalty_rate: 10, // 10%
        }
    }
}

/// 赎回管理器
pub struct RedemptionManager {
    /// 赎回请求
    requests: HashMap<Address, RedemptionRequest>,
    /// 赎回记录
    records: Vec<RedemptionRecord>,
    /// 赎回条件
    conditions: RedemptionConditions,
}

impl RedemptionManager {
    pub fn new() -> Self {
        Self {
            requests: HashMap::new(),
            records: Vec::new(),
            conditions: RedemptionConditions::default(),
        }
    }

    pub fn with_conditions(conditions: RedemptionConditions) -> Self {
        Self {
            requests: HashMap::new(),
            records: Vec::new(),
            conditions,
        }
    }

    /// 提交赎回请求
    pub fn submit_redemption_request(
        &mut self,
        node: &CbpNode,
        redemption_type: RedemptionType,
        requested_amount: u64,
        timestamp: u64,
    ) -> Result<(), CbppL1Error> {
        // 检查节点状态
        if node.status == CbpStatus::Exited {
            return Err(CbppL1Error::InvalidStatus("Node already exited".to_string()));
        }

        // 检查是否已有待处理的请求
        if let Some(existing) = self.requests.get(&node.address) {
            if existing.status == RedemptionStatus::Pending 
                || existing.status == RedemptionStatus::Processing {
                return Err(CbppL1Error::RedemptionRequestExists);
            }
        }

        // 检查锁定期
        if timestamp < node.registered_at + self.conditions.min_lock_period {
            return Err(CbppL1Error::LockPeriodNotMet);
        }

        // 检查赎回金额
        if requested_amount > node.stake_amount {
            return Err(CbppL1Error::InvalidRedemptionAmount);
        }

        // 检查部分赎回的最小保留金额
        if redemption_type == RedemptionType::Partial {
            let remaining = node.stake_amount - requested_amount;
            if remaining < self.conditions.min_remaining_stake {
                return Err(CbppL1Error::InsufficientRemainingStake);
            }
        }

        // 创建赎回请求
        let request = RedemptionRequest::new(
            node.address,
            redemption_type,
            requested_amount,
            timestamp,
        );
        self.requests.insert(node.address, request);

        Ok(())
    }

    /// 处理赎回请求
    pub fn process_redemption(
        &mut self,
        address: &Address,
        node: &CbpNode,
        timestamp: u64,
    ) -> Result<(u64, u64), CbppL1Error> {
        // 检查请求状态并保存信息
        let (redemption_type, requested_amount, requested_at) = {
            let request = self.requests.get_mut(address)
                .ok_or(CbppL1Error::RedemptionRequestNotFound)?;

            // 检查请求状态
            if request.status != RedemptionStatus::Pending {
                return Err(CbppL1Error::InvalidStatus(
                    format!("Request status is {:?}, expected Pending", request.status)
                ));
            }

            // 更新状态为处理中
            request.status = RedemptionStatus::Processing;

            (request.redemption_type, request.requested_amount, request.requested_at)
        };

        // 计算赎回金额和处罚
        let (actual_amount, penalty) = self.calculate_redemption(
            redemption_type,
            requested_amount,
            node.reputation,
        );

        // 更新请求
        let request = self.requests.get_mut(address).unwrap();
        request.actual_amount = Some(actual_amount);
        request.penalty_amount = Some(penalty);
        request.status = RedemptionStatus::Completed;
        request.completed_at = Some(timestamp);

        // 创建赎回记录
        let record = RedemptionRecord {
            address: *address,
            redemption_type,
            original_stake: node.stake_amount,
            redeemed_amount: actual_amount,
            penalty_amount: penalty,
            requested_at,
            completed_at: timestamp,
            reputation_at_redemption: node.reputation,
        };
        self.records.push(record);

        Ok((actual_amount, penalty))
    }

    /// 计算赎回金额
    fn calculate_redemption(
        &self,
        redemption_type: RedemptionType,
        requested_amount: u64,
        reputation: f64,
    ) -> (u64, u64) {
        let mut penalty = 0u64;

        // 紧急赎回处罚
        if redemption_type == RedemptionType::Emergency {
            penalty += (requested_amount as f64 * self.conditions.emergency_penalty_rate as f64 / 100.0) as u64;
        }

        // 低声誉处罚
        if reputation < self.conditions.reputation_penalty_threshold {
            penalty += (requested_amount as f64 * self.conditions.low_reputation_penalty_rate as f64 / 100.0) as u64;
        }

        let actual_amount = requested_amount.saturating_sub(penalty);
        (actual_amount, penalty)
    }

    /// 取消赎回请求
    pub fn cancel_redemption_request(&mut self, address: &Address) -> Result<(), CbppL1Error> {
        let request = self.requests.get_mut(address)
            .ok_or(CbppL1Error::RedemptionRequestNotFound)?;

        // 只能取消待处理的请求
        if request.status != RedemptionStatus::Pending {
            return Err(CbppL1Error::InvalidStatus(
                format!("Cannot cancel request with status {:?}", request.status)
            ));
        }

        request.status = RedemptionStatus::Cancelled;
        Ok(())
    }

    /// 获取赎回请求
    pub fn get_redemption_request(&self, address: &Address) -> Option<&RedemptionRequest> {
        self.requests.get(address)
    }

    /// 获取所有待处理的请求
    pub fn get_pending_requests(&self) -> Vec<&RedemptionRequest> {
        self.requests.values()
            .filter(|r| r.status == RedemptionStatus::Pending)
            .collect()
    }

    /// 获取赎回记录
    pub fn get_redemption_records(&self, address: Option<&Address>) -> Vec<&RedemptionRecord> {
        if let Some(addr) = address {
            self.records.iter()
                .filter(|r| &r.address == addr)
                .collect()
        } else {
            self.records.iter().collect()
        }
    }

    /// 获取赎回统计
    pub fn get_redemption_statistics(&self) -> RedemptionStatistics {
        let total_redemptions = self.records.len();
        let full_redemptions = self.records.iter()
            .filter(|r| r.redemption_type == RedemptionType::Full)
            .count();
        let partial_redemptions = self.records.iter()
            .filter(|r| r.redemption_type == RedemptionType::Partial)
            .count();
        let emergency_redemptions = self.records.iter()
            .filter(|r| r.redemption_type == RedemptionType::Emergency)
            .count();
        let total_redeemed = self.records.iter()
            .map(|r| r.redeemed_amount)
            .sum();
        let total_penalties = self.records.iter()
            .map(|r| r.penalty_amount)
            .sum();

        RedemptionStatistics {
            total_redemptions,
            full_redemptions,
            partial_redemptions,
            emergency_redemptions,
            total_redeemed,
            total_penalties,
        }
    }

    /// 更新赎回条件
    pub fn update_conditions(&mut self, conditions: RedemptionConditions) {
        self.conditions = conditions;
    }

    /// 获取赎回条件
    pub fn get_conditions(&self) -> &RedemptionConditions {
        &self.conditions
    }
}

impl Default for RedemptionManager {
    fn default() -> Self {
        Self::new()
    }
}

/// 赎回统计
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RedemptionStatistics {
    /// 总赎回数
    pub total_redemptions: usize,
    /// 全额赎回数
    pub full_redemptions: usize,
    /// 部分赎回数
    pub partial_redemptions: usize,
    /// 紧急赎回数
    pub emergency_redemptions: usize,
    /// 总赎回金额
    pub total_redeemed: u64,
    /// 总处罚金额
    pub total_penalties: u64,
}

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

    fn create_test_node() -> CbpNode {
        CbpNode {
            address: Address::new([1u8; 32]),
            did: "did:nac:test".to_string(),
            stake_amount: 100_000_000_000,
            kyc_level: 2,
            hardware_score: 8000,
            constitution_score: 80,
            status: CbpStatus::Active,
            registered_at: 1000,
            last_active_at: 2000,
            blocks_produced: 100,
            reputation: 0.8,
        }
    }

    #[test]
    fn test_submit_redemption_request() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        // 满足锁定期
        let timestamp = node.registered_at + 31 * 24 * 3600;
        let result = manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        );
        assert!(result.is_ok());

        let request = manager.get_redemption_request(&node.address).unwrap();
        assert_eq!(request.status, RedemptionStatus::Pending);
    }

    #[test]
    fn test_lock_period_not_met() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        // 不满足锁定期
        let timestamp = node.registered_at + 10 * 24 * 3600;
        let result = manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        );
        assert!(result.is_err());
    }

    #[test]
    fn test_partial_redemption_insufficient_remaining() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        let timestamp = node.registered_at + 31 * 24 * 3600;
        // 赎回金额太多，剩余不足
        let result = manager.submit_redemption_request(
            &node,
            RedemptionType::Partial,
            60_000_000_000, // 剩余40XIC，小于最小保留50XIC
            timestamp,
        );
        assert!(result.is_err());
    }

    #[test]
    fn test_process_redemption_full() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        let timestamp = node.registered_at + 31 * 24 * 3600;
        manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        ).unwrap();

        let result = manager.process_redemption(&node.address, &node, timestamp + 100);
        assert!(result.is_ok());

        let (actual, penalty) = result.unwrap();
        assert_eq!(actual + penalty, node.stake_amount);
    }

    #[test]
    fn test_process_redemption_emergency() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        let timestamp = node.registered_at + 31 * 24 * 3600;
        manager.submit_redemption_request(
            &node,
            RedemptionType::Emergency,
            node.stake_amount,
            timestamp,
        ).unwrap();

        let result = manager.process_redemption(&node.address, &node, timestamp + 100);
        assert!(result.is_ok());

        let (actual, penalty) = result.unwrap();
        // 紧急赎回有20%处罚
        assert_eq!(penalty, node.stake_amount * 20 / 100);
        assert_eq!(actual, node.stake_amount - penalty);
    }

    #[test]
    fn test_process_redemption_low_reputation() {
        let mut manager = RedemptionManager::new();
        let mut node = create_test_node();
        node.reputation = 0.3; // 低于0.5阈值

        let timestamp = node.registered_at + 31 * 24 * 3600;
        manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        ).unwrap();

        let result = manager.process_redemption(&node.address, &node, timestamp + 100);
        assert!(result.is_ok());

        let (actual, penalty) = result.unwrap();
        // 低声誉有10%处罚
        assert_eq!(penalty, node.stake_amount * 10 / 100);
    }

    #[test]
    fn test_cancel_redemption_request() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        let timestamp = node.registered_at + 31 * 24 * 3600;
        manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        ).unwrap();

        let result = manager.cancel_redemption_request(&node.address);
        assert!(result.is_ok());

        let request = manager.get_redemption_request(&node.address).unwrap();
        assert_eq!(request.status, RedemptionStatus::Cancelled);
    }

    #[test]
    fn test_redemption_statistics() {
        let mut manager = RedemptionManager::new();
        let node = create_test_node();

        let timestamp = node.registered_at + 31 * 24 * 3600;
        manager.submit_redemption_request(
            &node,
            RedemptionType::Full,
            node.stake_amount,
            timestamp,
        ).unwrap();
        manager.process_redemption(&node.address, &node, timestamp + 100).unwrap();

        let stats = manager.get_redemption_statistics();
        assert_eq!(stats.total_redemptions, 1);
        assert_eq!(stats.full_redemptions, 1);
    }

    #[test]
    fn test_update_conditions() {
        let mut manager = RedemptionManager::new();
        
        let new_conditions = RedemptionConditions {
            min_lock_period: 60 * 24 * 3600, // 60天
            min_remaining_stake: 80_000_000_000,
            emergency_penalty_rate: 30,
            reputation_penalty_threshold: 0.6,
            low_reputation_penalty_rate: 15,
        };

        manager.update_conditions(new_conditions.clone());
        
        let conditions = manager.get_conditions();
        assert_eq!(conditions.min_lock_period, 60 * 24 * 3600);
        assert_eq!(conditions.emergency_penalty_rate, 30);
    }
}