//! L2 文明层: 文明特征向量、灵魂签名
//!
//! 文明特征向量定义了一个区块链文明的核心属性:
//! - 宪法哈希
//! - 数学基础 (经典数学、直觉主义、量子逻辑等)
//! - 物理常数哈希
//! - 支持的协议
//! - 文明公钥 (灵魂签名用)
//!
//! 灵魂签名是文明级的集体签名:
//! - 通过分布式密钥生成(DKG)协议生成集体私钥
//! - 私钥以门限形式分片存储
//! - 签名大小固定，与文明成员数无关
//! - 抗量子 (可基于格密码实现)

use crate::types::{CivilizationId, CivilizationVector, Hash, SoulSignature};
use crate::error::{Nrpc4Error, Result};
use sha2::{Sha256, Digest};
use tracing::{debug, info};

/// 文明管理器
pub struct CivilizationManager {
    /// 本地文明向量
    civilization: CivilizationVector,
    /// 私钥分片 (门限签名的一部分)
    private_key_share: Option<Vec<u8>>,
}

impl CivilizationManager {
    /// 创建新的文明管理器
    pub fn new(civilization: CivilizationVector) -> Self {
        info!("Creating civilization manager for: {}", civilization.civilization_id);
        Self {
            civilization,
            private_key_share: None,
        }
    }

    /// 获取文明ID
    pub fn get_civilization_id(&self) -> &CivilizationId {
        &self.civilization.civilization_id
    }

    /// 获取文明向量
    pub fn get_civilization_vector(&self) -> &CivilizationVector {
        &self.civilization
    }

    /// 更新宪法哈希
    pub fn update_constitution_hash(&mut self, new_hash: Hash) {
        info!(
            "Updating constitution hash for civilization: {}",
            self.civilization.civilization_id
        );
        self.civilization.constitution_hash = new_hash;
    }

    /// 添加支持的协议
    pub fn add_supported_protocol(&mut self, protocol: String) {
        debug!(
            "Adding protocol {} to civilization: {}",
            protocol, self.civilization.civilization_id
        );
        self.civilization.add_protocol(protocol);
    }

    /// 设置私钥分片
    pub fn set_private_key_share(&mut self, share: Vec<u8>) {
        info!("Setting private key share for civilization");
        self.private_key_share = Some(share);
    }

    /// 检查是否有私钥分片
    pub fn has_private_key_share(&self) -> bool {
        self.private_key_share.is_some()
    }
}

/// 灵魂签名器
pub struct SoulSigner {
    /// 文明ID
    civilization_id: CivilizationId,
    /// 私钥分片
    private_key_share: Vec<u8>,
    /// 门限值
    threshold: u32,
    /// 总节点数
    total_nodes: u32,
}

impl SoulSigner {
    /// 创建新的灵魂签名器
    pub fn new(
        civilization_id: CivilizationId,
        private_key_share: Vec<u8>,
        threshold: u32,
        total_nodes: u32,
    ) -> Self {
        info!(
            "Creating soul signer for civilization: {} (threshold: {}/{})",
            civilization_id, threshold, total_nodes
        );
        Self {
            civilization_id,
            private_key_share,
            threshold,
            total_nodes,
        }
    }

    /// 生成部分签名
    ///
    /// 实际实现应该使用门限签名算法 (如BLS门限签名或Dilithium门限版本)
    /// 这里使用简化实现
    pub fn sign_partial(&self, message: &[u8]) -> Result<Vec<u8>> {
        debug!(
            "Generating partial signature for civilization: {}",
            self.civilization_id
        );

        // 简化实现: 使用SHA256哈希模拟部分签名
        let mut hasher = Sha256::new();
        hasher.update(message);
        hasher.update(&self.private_key_share);
        let signature = hasher.finalize().to_vec();

        Ok(signature)
    }

    /// 聚合部分签名
    ///
    /// 实际实现应该使用门限签名聚合算法
    /// 这里使用简化实现
    pub fn aggregate_signatures(
        &self,
        partial_signatures: Vec<Vec<u8>>,
    ) -> Result<SoulSignature> {
        if partial_signatures.len() < self.threshold as usize {
            return Err(Nrpc4Error::SoulSignatureError(format!(
                "Not enough signatures: got {}, need {}",
                partial_signatures.len(),
                self.threshold
            )));
        }

        info!(
            "Aggregating {} partial signatures for civilization: {}",
            partial_signatures.len(),
            self.civilization_id
        );

        // 简化实现: 连接所有部分签名
        let mut aggregated = Vec::new();
        for sig in &partial_signatures {
            aggregated.extend_from_slice(sig);
        }

        Ok(SoulSignature {
            signature: aggregated,
            participant_count: partial_signatures.len() as u32,
            threshold: self.threshold,
        })
    }

    /// 验证灵魂签名
    ///
    /// 实际实现应该使用门限签名验证算法
    /// 这里使用简化实现
    pub fn verify_soul_signature(
        &self,
        _message: &[u8],
        signature: &SoulSignature,
    ) -> Result<bool> {
        debug!(
            "Verifying soul signature for civilization: {}",
            self.civilization_id
        );

        // 检查参与者数量是否满足门限
        if signature.participant_count < signature.threshold {
            return Ok(false);
        }

        // 简化实现: 总是返回true
        // 实际实现应该验证签名的密码学正确性
        Ok(true)
    }
}

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

    #[test]
    fn test_civilization_manager() {
        let civ_id = "nac-mainnet-001".to_string();
        let vector = CivilizationVector::new(civ_id.clone(), [0u8; 32], [1u8; 32]);
        let mut manager = CivilizationManager::new(vector);

        assert_eq!(manager.get_civilization_id(), &civ_id);
        assert!(!manager.has_private_key_share());

        manager.set_private_key_share(vec![1, 2, 3, 4]);
        assert!(manager.has_private_key_share());

        manager.add_supported_protocol("XTZH".to_string());
        assert_eq!(manager.get_civilization_vector().supported_protocols.len(), 1);
    }

    #[test]
    fn test_soul_signer() {
        let civ_id = "nac-mainnet-001".to_string();
        let signer = SoulSigner::new(civ_id, vec![1, 2, 3, 4], 2, 3);

        let message = b"test message";
        let partial_sig = signer.sign_partial(message).unwrap();
        assert!(!partial_sig.is_empty());

        // 测试聚合签名
        let partial_sigs = vec![partial_sig.clone(), partial_sig.clone()];
        let soul_sig = signer.aggregate_signatures(partial_sigs).unwrap();
        assert_eq!(soul_sig.participant_count, 2);
        assert_eq!(soul_sig.threshold, 2);

        // 测试验证签名
        let is_valid = signer.verify_soul_signature(message, &soul_sig).unwrap();
        assert!(is_valid);
    }

    #[test]
    fn test_insufficient_signatures() {
        let civ_id = "nac-mainnet-001".to_string();
        let signer = SoulSigner::new(civ_id, vec![1, 2, 3, 4], 3, 5);

        let message = b"test message";
        let partial_sig = signer.sign_partial(message).unwrap();

        // 只有2个签名，但需要3个
        let partial_sigs = vec![partial_sig.clone(), partial_sig];
        let result = signer.aggregate_signatures(partial_sigs);
        assert!(result.is_err());
    }
}