//! CBP声誉更新机制
//! 
//! 实现CBP节点的声誉计算、衰减、恢复和查询功能

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

/// 声誉事件类型
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum ReputationEvent {
    /// 成功出块
    BlockProduced,
    /// 错过出块
    BlockMissed,
    /// 双签
    DoubleSign,
    /// 违规行为
    Violation,
    /// 长时间在线
    LongUptime,
    /// 宪法测试通过
    ConstitutionTestPassed,
    /// 社区贡献
    CommunityContribution,
}

/// 声誉变化记录
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReputationChange {
    /// CBP地址
    pub address: Address,
    /// 事件类型
    pub event: ReputationEvent,
    /// 变化前声誉
    pub old_reputation: f64,
    /// 变化后声誉
    pub new_reputation: f64,
    /// 变化量
    pub delta: f64,
    /// 时间戳
    pub timestamp: u64,
    /// 备注
    pub note: Option<String>,
}

/// 声誉配置
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReputationConfig {
    /// 初始声誉
    pub initial_reputation: f64,
    /// 最小声誉
    pub min_reputation: f64,
    /// 最大声誉
    pub max_reputation: f64,
    /// 衰减率（每天）
    pub decay_rate: f64,
    /// 衰减间隔（秒）
    pub decay_interval: u64,
    /// 恢复率（每次成功出块）
    pub recovery_rate: f64,
    /// 事件影响权重
    pub event_weights: HashMap<ReputationEvent, f64>,
}

impl Default for ReputationConfig {
    fn default() -> Self {
        let mut event_weights = HashMap::new();
        event_weights.insert(ReputationEvent::BlockProduced, 0.001);
        event_weights.insert(ReputationEvent::BlockMissed, -0.01);
        event_weights.insert(ReputationEvent::DoubleSign, -0.5);
        event_weights.insert(ReputationEvent::Violation, -0.3);
        event_weights.insert(ReputationEvent::LongUptime, 0.05);
        event_weights.insert(ReputationEvent::ConstitutionTestPassed, 0.02);
        event_weights.insert(ReputationEvent::CommunityContribution, 0.03);

        Self {
            initial_reputation: 0.5,
            min_reputation: 0.0,
            max_reputation: 1.0,
            decay_rate: 0.001, // 每天衰减0.1%
            decay_interval: 24 * 3600, // 1天
            recovery_rate: 0.002, // 每次成功出块恢复0.2%
            event_weights,
        }
    }
}

/// 声誉管理器
pub struct ReputationManager {
    /// 声誉配置
    config: ReputationConfig,
    /// 声誉变化记录
    changes: Vec<ReputationChange>,
    /// 上次衰减时间
    last_decay: HashMap<Address, u64>,
}

impl ReputationManager {
    pub fn new() -> Self {
        Self {
            config: ReputationConfig::default(),
            changes: Vec::new(),
            last_decay: HashMap::new(),
        }
    }

    pub fn with_config(config: ReputationConfig) -> Self {
        Self {
            config,
            changes: Vec::new(),
            last_decay: HashMap::new(),
        }
    }

    /// 记录声誉事件
    pub fn record_event(
        &mut self,
        node: &mut CbpNode,
        event: ReputationEvent,
        timestamp: u64,
        note: Option<String>,
    ) -> Result<f64, CbppL1Error> {
        let old_reputation = node.reputation;

        // 获取事件权重
        let weight = self.config.event_weights.get(&event)
            .copied()
            .unwrap_or(0.0);

        // 计算新声誉
        let mut new_reputation = old_reputation + weight;
        new_reputation = new_reputation.max(self.config.min_reputation);
        new_reputation = new_reputation.min(self.config.max_reputation);

        // 更新节点声誉
        node.reputation = new_reputation;

        // 记录变化
        let change = ReputationChange {
            address: node.address,
            event,
            old_reputation,
            new_reputation,
            delta: new_reputation - old_reputation,
            timestamp,
            note,
        };
        self.changes.push(change);

        Ok(new_reputation)
    }

    /// 应用声誉衰减
    pub fn apply_decay(
        &mut self,
        node: &mut CbpNode,
        timestamp: u64,
    ) -> Result<f64, CbppL1Error> {
        // 获取上次衰减时间
        let last_decay = self.last_decay.get(&node.address).copied().unwrap_or(node.registered_at);

        // 检查是否需要衰减
        if timestamp < last_decay + self.config.decay_interval {
            return Ok(node.reputation);
        }

        // 计算衰减次数
        let decay_count = (timestamp - last_decay) / self.config.decay_interval;
        
        let old_reputation = node.reputation;
        let mut new_reputation = old_reputation;

        // 应用衰减
        for _ in 0..decay_count {
            new_reputation *= 1.0 - self.config.decay_rate;
            new_reputation = new_reputation.max(self.config.min_reputation);
        }

        // 更新节点声誉
        node.reputation = new_reputation;

        // 更新上次衰减时间
        self.last_decay.insert(node.address, timestamp);

        // 记录变化
        if (new_reputation - old_reputation).abs() > 0.0001 {
            let change = ReputationChange {
                address: node.address,
                event: ReputationEvent::BlockMissed, // 使用BlockMissed表示衰减
                old_reputation,
                new_reputation,
                delta: new_reputation - old_reputation,
                timestamp,
                note: Some(format!("Decay applied ({} intervals)", decay_count)),
            };
            self.changes.push(change);
        }

        Ok(new_reputation)
    }

    /// 恢复声誉
    pub fn recover_reputation(
        &mut self,
        node: &mut CbpNode,
        amount: f64,
        timestamp: u64,
        reason: String,
    ) -> Result<f64, CbppL1Error> {
        let old_reputation = node.reputation;
        let mut new_reputation = old_reputation + amount;
        new_reputation = new_reputation.min(self.config.max_reputation);

        // 更新节点声誉
        node.reputation = new_reputation;

        // 记录变化
        let change = ReputationChange {
            address: node.address,
            event: ReputationEvent::CommunityContribution,
            old_reputation,
            new_reputation,
            delta: new_reputation - old_reputation,
            timestamp,
            note: Some(reason),
        };
        self.changes.push(change);

        Ok(new_reputation)
    }

    /// 批量更新声誉（用于出块奖励）
    pub fn batch_update_for_blocks(
        &mut self,
        nodes: &mut [CbpNode],
        timestamp: u64,
    ) -> Result<usize, CbppL1Error> {
        let mut updated = 0;

        for node in nodes.iter_mut() {
            if node.blocks_produced > 0 {
                self.record_event(
                    node,
                    ReputationEvent::BlockProduced,
                    timestamp,
                    Some(format!("Block production reward")),
                )?;
                updated += 1;
            }
        }

        Ok(updated)
    }

    /// 查询声誉历史
    pub fn get_reputation_history(
        &self,
        address: &Address,
        limit: Option<usize>,
    ) -> Vec<&ReputationChange> {
        let mut history: Vec<&ReputationChange> = self.changes.iter()
            .filter(|c| &c.address == address)
            .collect();

        // 按时间倒序
        history.sort_by(|a, b| b.timestamp.cmp(&a.timestamp));

        if let Some(limit) = limit {
            history.truncate(limit);
        }

        history
    }

    /// 查询声誉统计
    pub fn get_reputation_statistics(&self, address: &Address) -> ReputationStatistics {
        let history: Vec<&ReputationChange> = self.changes.iter()
            .filter(|c| &c.address == address)
            .collect();

        if history.is_empty() {
            return ReputationStatistics {
                total_changes: 0,
                positive_changes: 0,
                negative_changes: 0,
                total_gain: 0.0,
                total_loss: 0.0,
                current_reputation: self.config.initial_reputation,
            };
        }

        let total_changes = history.len();
        let positive_changes = history.iter().filter(|c| c.delta > 0.0).count();
        let negative_changes = history.iter().filter(|c| c.delta < 0.0).count();
        let total_gain: f64 = history.iter()
            .filter(|c| c.delta > 0.0)
            .map(|c| c.delta)
            .sum();
        let total_loss: f64 = history.iter()
            .filter(|c| c.delta < 0.0)
            .map(|c| c.delta.abs())
            .sum();
        let current_reputation = history.first().map(|c| c.new_reputation).unwrap_or(self.config.initial_reputation);

        ReputationStatistics {
            total_changes,
            positive_changes,
            negative_changes,
            total_gain,
            total_loss,
            current_reputation,
        }
    }

    /// 获取声誉排名
    pub fn get_reputation_ranking(&self, nodes: &[CbpNode]) -> Vec<(Address, f64)> {
        let mut ranking: Vec<(Address, f64)> = nodes.iter()
            .map(|n| (n.address, n.reputation))
            .collect();

        // 按声誉降序排序
        ranking.sort_by(|a, b| b.1.partial_cmp(&a.1).expect("FIX-006: unexpected None/Err"));

        ranking
    }

    /// 更新配置
    pub fn update_config(&mut self, config: ReputationConfig) {
        self.config = config;
    }

    /// 获取配置
    pub fn get_config(&self) -> &ReputationConfig {
        &self.config
    }
}

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

/// 声誉统计
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReputationStatistics {
    /// 总变化次数
    pub total_changes: usize,
    /// 正向变化次数
    pub positive_changes: usize,
    /// 负向变化次数
    pub negative_changes: usize,
    /// 总增长
    pub total_gain: f64,
    /// 总损失
    pub total_loss: f64,
    /// 当前声誉
    pub current_reputation: f64,
}

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

    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: 0.5,
        }
    }

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

        let result = manager.record_event(
            &mut node,
            ReputationEvent::BlockProduced,
            3000,
            None,
        );
        assert!(result.is_ok());
        assert!(node.reputation > 0.5);
    }

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

        let result = manager.record_event(
            &mut node,
            ReputationEvent::BlockMissed,
            3000,
            None,
        );
        assert!(result.is_ok());
        assert!(node.reputation < 0.5);
    }

    #[test]
    fn test_reputation_bounds() {
        let mut manager = ReputationManager::new();
        let mut node = create_test_node();
        node.reputation = 0.99;

        // 测试最大值
        manager.record_event(&mut node, ReputationEvent::LongUptime, 3000, None).expect("FIX-006: unexpected None/Err");
        assert!(node.reputation <= 1.0);

        // 测试最小值
        node.reputation = 0.01;
        manager.record_event(&mut node, ReputationEvent::DoubleSign, 3000, None).expect("FIX-006: unexpected None/Err");
        assert!(node.reputation >= 0.0);
    }

    #[test]
    fn test_apply_decay() {
        let mut manager = ReputationManager::new();
        let mut node = create_test_node();
        node.reputation = 0.8;

        // 1天后衰减
        let timestamp = node.registered_at + 24 * 3600;
        let result = manager.apply_decay(&mut node, timestamp);
        assert!(result.is_ok());
        assert!(node.reputation < 0.8);
    }

    #[test]
    fn test_no_decay_before_interval() {
        let mut manager = ReputationManager::new();
        let mut node = create_test_node();
        node.reputation = 0.8;

        // 不足1天，不应该衰减
        let timestamp = node.registered_at + 3600;
        let result = manager.apply_decay(&mut node, timestamp);
        assert!(result.is_ok());
        assert_eq!(node.reputation, 0.8);
    }

    #[test]
    fn test_recover_reputation() {
        let mut manager = ReputationManager::new();
        let mut node = create_test_node();
        node.reputation = 0.5;

        let result = manager.recover_reputation(
            &mut node,
            0.1,
            3000,
            "Community contribution".to_string(),
        );
        assert!(result.is_ok());
        assert_eq!(node.reputation, 0.6);
    }

    #[test]
    fn test_batch_update_for_blocks() {
        let mut manager = ReputationManager::new();
        let mut nodes = vec![
            create_test_node(),
            create_test_node(),
        ];
        nodes[0].blocks_produced = 10;
        nodes[1].blocks_produced = 5;

        let result = manager.batch_update_for_blocks(&mut nodes, 3000);
        assert!(result.is_ok());
        assert_eq!(result.expect("mainnet: handle error"), 2);
    }

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

        manager.record_event(&mut node, ReputationEvent::BlockProduced, 1000, None).expect("FIX-006: unexpected None/Err");
        manager.record_event(&mut node, ReputationEvent::BlockProduced, 2000, None).expect("FIX-006: unexpected None/Err");
        manager.record_event(&mut node, ReputationEvent::BlockMissed, 3000, None).expect("FIX-006: unexpected None/Err");

        let history = manager.get_reputation_history(&node.address, None);
        assert_eq!(history.len(), 3);

        // 限制数量
        let limited = manager.get_reputation_history(&node.address, Some(2));
        assert_eq!(limited.len(), 2);
    }

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

        manager.record_event(&mut node, ReputationEvent::BlockProduced, 1000, None).expect("FIX-006: unexpected None/Err");
        manager.record_event(&mut node, ReputationEvent::BlockProduced, 2000, None).expect("FIX-006: unexpected None/Err");
        manager.record_event(&mut node, ReputationEvent::BlockMissed, 3000, None).expect("FIX-006: unexpected None/Err");

        let stats = manager.get_reputation_statistics(&node.address);
        assert_eq!(stats.total_changes, 3);
        assert_eq!(stats.positive_changes, 2);
        assert_eq!(stats.negative_changes, 1);
    }

    #[test]
    fn test_get_reputation_ranking() {
        let manager = ReputationManager::new();
        let mut nodes = vec![
            create_test_node(),
            create_test_node(),
            create_test_node(),
        ];
        nodes[0].reputation = 0.8;
        nodes[1].reputation = 0.6;
        nodes[2].reputation = 0.9;

        let ranking = manager.get_reputation_ranking(&nodes);
        assert_eq!(ranking.len(), 3);
        assert_eq!(ranking[0].1, 0.9);
        assert_eq!(ranking[1].1, 0.8);
        assert_eq!(ranking[2].1, 0.6);
    }

    #[test]
    fn test_update_config() {
        let mut manager = ReputationManager::new();
        
        let mut new_config = ReputationConfig::default();
        new_config.decay_rate = 0.002;
        new_config.recovery_rate = 0.003;

        manager.update_config(new_config);

        let config = manager.get_config();
        assert_eq!(config.decay_rate, 0.002);
        assert_eq!(config.recovery_rate, 0.003);
    }
}