//! 资产锁定/解锁模块

use crate::error::{BridgeError, BridgeResult};
use serde::{Deserialize, Serialize};
use std::collections::HashMap;

/// 锁定记录
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LockRecord {
    /// 锁定ID
    pub lock_id: String,
    /// 以太坊交易哈希
    pub eth_tx_hash: String,
    /// 锁定金额
    pub amount: u128,
    /// Token地址（None表示ETH）
    pub token_address: Option<String>,
    /// NAC目标地址
    pub nac_target_address: [u8; 32],
    /// 锁定时间戳
    pub locked_at: u64,
    /// 状态
    pub status: LockStatus,
    /// 签名列表（多签）
    pub signatures: Vec<Signature>,
}

/// 锁定状态
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum LockStatus {
    /// 待确认
    Pending,
    /// 已确认
    Confirmed,
    /// 已解锁
    Unlocked,
    /// 已取消
    Cancelled,
}

/// 签名
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Signature {
    /// 签名者地址
    pub signer: String,
    /// 签名数据
    pub signature: Vec<u8>,
    /// 签名时间
    pub signed_at: u64,
}

/// 解锁请求
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct UnlockRequest {
    /// 解锁ID
    pub unlock_id: String,
    /// NAC交易哈希
    pub nac_tx_hash: String,
    /// 解锁金额
    pub amount: u128,
    /// Token地址（None表示ETH）
    pub token_address: Option<String>,
    /// 以太坊目标地址
    pub eth_target_address: String,
    /// 请求时间戳
    pub requested_at: u64,
    /// 状态
    pub status: UnlockStatus,
    /// 签名列表（多签）
    pub signatures: Vec<Signature>,
}

/// 解锁状态
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum UnlockStatus {
    /// 待审批
    PendingApproval,
    /// 已批准
    Approved,
    /// 已执行
    Executed,
    /// 已拒绝
    Rejected,
}

/// 锁定/解锁管理器
pub struct LockUnlockManager {
    /// 锁定记录
    locks: HashMap<String, LockRecord>,
    /// 解锁请求
    unlocks: HashMap<String, UnlockRequest>,
    /// 多签阈值
    multisig_threshold: usize,
    /// 授权签名者列表
    authorized_signers: Vec<String>,
}

impl LockUnlockManager {
    /// 创建新的管理器
    pub fn new(multisig_threshold: usize, authorized_signers: Vec<String>) -> Self {
        Self {
            locks: HashMap::new(),
            unlocks: HashMap::new(),
            multisig_threshold,
            authorized_signers,
        }
    }

    /// 记录锁定
    pub fn record_lock(&mut self, lock: LockRecord) -> BridgeResult<()> {
        if self.locks.contains_key(&lock.lock_id) {
            return Err(BridgeError::ValidationError(
                "Lock ID already exists".to_string()
            ));
        }
        
        self.locks.insert(lock.lock_id.clone(), lock);
        Ok(())
    }

    /// 获取锁定记录
    pub fn get_lock(&self, lock_id: &str) -> Option<&LockRecord> {
        self.locks.get(lock_id)
    }

    /// 添加锁定签名
    pub fn add_lock_signature(
        &mut self,
        lock_id: &str,
        signature: Signature,
    ) -> BridgeResult<()> {
        // 验证签名者
        if !self.authorized_signers.contains(&signature.signer) {
            return Err(BridgeError::SecurityError(
                "Unauthorized signer".to_string()
            ));
        }

        let lock = self.locks.get_mut(lock_id)
            .ok_or_else(|| BridgeError::ValidationError("Lock not found".to_string()))?;

        // 检查是否已签名
        if lock.signatures.iter().any(|s| s.signer == signature.signer) {
            return Err(BridgeError::ValidationError(
                "Signer already signed".to_string()
            ));
        }

        lock.signatures.push(signature);

        // 检查是否达到阈值
        if lock.signatures.len() >= self.multisig_threshold {
            lock.status = LockStatus::Confirmed;
        }

        Ok(())
    }

    /// 记录解锁请求
    pub fn record_unlock(&mut self, unlock: UnlockRequest) -> BridgeResult<()> {
        if self.unlocks.contains_key(&unlock.unlock_id) {
            return Err(BridgeError::ValidationError(
                "Unlock ID already exists".to_string()
            ));
        }
        
        self.unlocks.insert(unlock.unlock_id.clone(), unlock);
        Ok(())
    }

    /// 获取解锁请求
    pub fn get_unlock(&self, unlock_id: &str) -> Option<&UnlockRequest> {
        self.unlocks.get(unlock_id)
    }

    /// 添加解锁签名
    pub fn add_unlock_signature(
        &mut self,
        unlock_id: &str,
        signature: Signature,
    ) -> BridgeResult<()> {
        // 验证签名者
        if !self.authorized_signers.contains(&signature.signer) {
            return Err(BridgeError::SecurityError(
                "Unauthorized signer".to_string()
            ));
        }

        let unlock = self.unlocks.get_mut(unlock_id)
            .ok_or_else(|| BridgeError::ValidationError("Unlock not found".to_string()))?;

        // 检查是否已签名
        if unlock.signatures.iter().any(|s| s.signer == signature.signer) {
            return Err(BridgeError::ValidationError(
                "Signer already signed".to_string()
            ));
        }

        unlock.signatures.push(signature);

        // 检查是否达到阈值
        if unlock.signatures.len() >= self.multisig_threshold {
            unlock.status = UnlockStatus::Approved;
        }

        Ok(())
    }

    /// 执行解锁
    pub fn execute_unlock(&mut self, unlock_id: &str) -> BridgeResult<()> {
        let unlock = self.unlocks.get_mut(unlock_id)
            .ok_or_else(|| BridgeError::ValidationError("Unlock not found".to_string()))?;

        if unlock.status != UnlockStatus::Approved {
            return Err(BridgeError::ValidationError(
                "Unlock not approved".to_string()
            ));
        }

        unlock.status = UnlockStatus::Executed;
        Ok(())
    }

    /// 获取所有待确认的锁定
    pub fn get_pending_locks(&self) -> Vec<&LockRecord> {
        self.locks.values()
            .filter(|lock| lock.status == LockStatus::Pending)
            .collect()
    }

    /// 获取所有待审批的解锁
    pub fn get_pending_unlocks(&self) -> Vec<&UnlockRequest> {
        self.unlocks.values()
            .filter(|unlock| unlock.status == UnlockStatus::PendingApproval)
            .collect()
    }
}

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

    #[test]
    fn test_lock_unlock_manager() {
        let signers = vec!["signer1".to_string(), "signer2".to_string()];
        let mut manager = LockUnlockManager::new(2, signers);

        // 测试锁定
        let lock = LockRecord {
            lock_id: "lock1".to_string(),
            eth_tx_hash: "0x123".to_string(),
            amount: 1000,
            token_address: None,
            nac_target_address: [0u8; 32],
            locked_at: 1234567890,
            status: LockStatus::Pending,
            signatures: vec![],
        };

        assert!(manager.record_lock(lock).is_ok());
        assert!(manager.get_lock("lock1").is_some());

        // 测试签名
        let sig1 = Signature {
            signer: "signer1".to_string(),
            signature: vec![1, 2, 3],
            signed_at: 1234567891,
        };

        assert!(manager.add_lock_signature("lock1", sig1).is_ok());
        assert_eq!(manager.get_lock("lock1").unwrap().signatures.len(), 1);

        let sig2 = Signature {
            signer: "signer2".to_string(),
            signature: vec![4, 5, 6],
            signed_at: 1234567892,
        };

        assert!(manager.add_lock_signature("lock1", sig2).is_ok());
        assert_eq!(manager.get_lock("lock1").unwrap().status, LockStatus::Confirmed);
    }

    #[test]
    fn test_unauthorized_signer() {
        let signers = vec!["signer1".to_string()];
        let mut manager = LockUnlockManager::new(1, signers);

        let lock = LockRecord {
            lock_id: "lock1".to_string(),
            eth_tx_hash: "0x123".to_string(),
            amount: 1000,
            token_address: None,
            nac_target_address: [0u8; 32],
            locked_at: 1234567890,
            status: LockStatus::Pending,
            signatures: vec![],
        };

        manager.record_lock(lock).unwrap();

        let sig = Signature {
            signer: "unauthorized".to_string(),
            signature: vec![1, 2, 3],
            signed_at: 1234567891,
        };

        assert!(manager.add_lock_signature("lock1", sig).is_err());
    }
}