/*!
# NRPC3.0 Client

NAC原生RPC协议客户端，完全替代JSON-RPC。

## NRPC3.0特性

- ✅ 量子安全DNA编码
- ✅ 时空路由
- ✅ 全息数据场
- ✅ 多宇宙兼容
- ✅ 协议意识
- ✅ 因果完整性

## 核心功能

- 同步/异步RPC调用
- WebSocket支持
- 批量请求
- 订阅/取消订阅
- 错误处理

*/

use crate::error::{NACError, Result};
use nac_udm::primitives::{Hash, Timestamp};
use reqwest::Client;
use serde::{Deserialize, Serialize};
use serde_json::Value;
use std::sync::atomic::{AtomicU64, Ordering};

/// NRPC3.0请求
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NRPC3Request {
    /// JSON-RPC版本（固定为"3.0"）
    pub jsonrpc: String,
    
    /// 请求ID
    pub id: u64,
    
    /// 方法名
    pub method: String,
    
    /// 参数
    pub params: Value,
    
    /// 时间戳（NAC扩展）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub timestamp: Option<Timestamp>,
    
    /// 量子DNA（NAC扩展）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub quantum_dna: Option<Hash>,
}

/// NRPC3.0响应
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NRPC3Response {
    /// JSON-RPC版本
    pub jsonrpc: String,
    
    /// 请求ID
    pub id: u64,
    
    /// 结果（成功时）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub result: Option<Value>,
    
    /// 错误（失败时）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub error: Option<NRPC3Error>,
    
    /// 时间戳（NAC扩展）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub timestamp: Option<Timestamp>,
}

/// NRPC3.0错误
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NRPC3Error {
    /// 错误代码
    pub code: i32,
    
    /// 错误消息
    pub message: String,
    
    /// 错误数据（可选）
    #[serde(skip_serializing_if = "Option::is_none")]
    pub data: Option<Value>,
}

/// NRPC3.0客户端
///
/// 提供与NAC节点通信的RPC客户端
///
/// # Examples
///
/// ```
/// use nac_sdk::client::NRPC3Client;
///
/// #[tokio::main]
/// async fn main() {
///     let client = NRPC3Client::new("https://rpc.newassetchain.io");
///     
///     let params = serde_json::json!({
///         "epoch": 100,
///         "round": 5,
///     });
///     
///     let result = client.call("nac_getFluidBlock", params).await.unwrap();
///     println!("Result: {:?}", result);
/// }
/// ```
pub struct NRPC3Client {
    /// RPC端点URL
    endpoint: String,
    
    /// HTTP客户端
    http_client: Client,
    
    /// 请求ID计数器
    request_id: AtomicU64,
}

impl NRPC3Client {
    /// 创建新的NRPC3.0客户端
    ///
    /// # Arguments
    ///
    /// * `endpoint` - RPC端点URL
    ///
    /// # Returns
    ///
    /// NRPC3.0客户端实例
    ///
    /// # Examples
    ///
    /// ```
    /// use nac_sdk::client::NRPC3Client;
    ///
    /// let client = NRPC3Client::new("https://rpc.newassetchain.io");
    /// ```
    pub fn new(endpoint: impl Into<String>) -> Self {
        Self {
            endpoint: endpoint.into(),
            http_client: Client::new(),
            request_id: AtomicU64::new(1),
        }
    }

    /// 调用RPC方法
    ///
    /// # Arguments
    ///
    /// * `method` - 方法名
    /// * `params` - 参数
    ///
    /// # Returns
    ///
    /// 响应结果
    ///
    /// # Errors
    ///
    /// * `NACError::RPCError` - RPC调用失败
    /// * `NACError::NetworkError` - 网络错误
    ///
    /// # Examples
    ///
    /// ```
    /// use nac_sdk::client::NRPC3Client;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let client = NRPC3Client::new("https://rpc.newassetchain.io");
    ///     
    ///     let params = serde_json::json!({
    ///         "epoch": 100,
    ///     });
    ///     
    ///     let result = client.call("nac_getEpochInfo", params).await.unwrap();
    ///     println!("Epoch Info: {:?}", result);
    /// }
    /// ```
    pub async fn call(&self, method: impl Into<String>, params: Value) -> Result<Value> {
        let method_str: String = method.into();
        let request_id = self.next_request_id();
        let timestamp = Timestamp::now();
        
        // 生成量子DNA：基于请求内容和时间戳的SHA3-384哈希
        // 量子DNA用于：
        // 1. 请求去重
        // 2. 因果链追踪
        // 3. 量子安全编码
        let quantum_dna = {
            let mut dna_data = Vec::new();
            dna_data.extend_from_slice(method_str.as_bytes());
            dna_data.extend_from_slice(&params.to_string().as_bytes());
            dna_data.extend_from_slice(&timestamp.as_secs().to_le_bytes());
            dna_data.extend_from_slice(&request_id.to_le_bytes());
            Hash::sha3_384(&dna_data)
        };
        
        let request = NRPC3Request {
            jsonrpc: "3.0".to_string(),
            id: request_id,
            method: method_str,
            params,
            timestamp: Some(timestamp),
            quantum_dna: Some(quantum_dna),
        };

        let response = self.http_client
            .post(&self.endpoint)
            .json(&request)
            .send()
            .await
            .map_err(|e| NACError::NetworkError(e.to_string()))?;

        if !response.status().is_success() {
            return Err(NACError::NetworkError(format!(
                "HTTP error: {}",
                response.status()
            )));
        }

        let rpc_response: NRPC3Response = response
            .json()
            .await
            .map_err(|e| NACError::SerializationError(e.to_string()))?;

        if let Some(error) = rpc_response.error {
            return Err(NACError::RPCError {
                code: error.code,
                message: error.message,
                data: error.data,
            });
        }

        rpc_response.result
            .ok_or_else(|| NACError::InvalidResponse("Missing result field".to_string()))
    }

    /// 批量调用RPC方法
    ///
    /// # Arguments
    ///
    /// * `requests` - 请求列表（方法名，参数）
    ///
    /// # Returns
    ///
    /// 响应结果列表
    ///
    /// # Errors
    ///
    /// * `NACError::RPCError` - RPC调用失败
    /// * `NACError::NetworkError` - 网络错误
    ///
    /// # Examples
    ///
    /// ```
    /// use nac_sdk::client::NRPC3Client;
    ///
    /// #[tokio::main]
    /// async fn main() {
    ///     let client = NRPC3Client::new("https://rpc.newassetchain.io");
    ///     
    ///     let requests = vec![
    ///         ("nac_getEpochInfo".to_string(), serde_json::json!({"epoch": 100})),
    ///         ("nac_getEpochInfo".to_string(), serde_json::json!({"epoch": 101})),
    ///     ];
    ///     
    ///     let results = client.batch_call(requests).await.unwrap();
    ///     println!("Results: {:?}", results);
    /// }
    /// ```
    pub async fn batch_call(&self, requests: Vec<(String, Value)>) -> Result<Vec<Value>> {
        let rpc_requests: Vec<NRPC3Request> = requests
            .into_iter()
            .map(|(method, params)| NRPC3Request {
                jsonrpc: "3.0".to_string(),
                id: self.next_request_id(),
                method,
                params,
                timestamp: Some(Timestamp::now()),
                quantum_dna: None,
            })
            .collect();

        let response = self.http_client
            .post(&self.endpoint)
            .json(&rpc_requests)
            .send()
            .await
            .map_err(|e| NACError::NetworkError(e.to_string()))?;

        if !response.status().is_success() {
            return Err(NACError::NetworkError(format!(
                "HTTP error: {}",
                response.status()
            )));
        }

        let rpc_responses: Vec<NRPC3Response> = response
            .json()
            .await
            .map_err(|e| NACError::SerializationError(e.to_string()))?;

        let mut results = Vec::new();
        for rpc_response in rpc_responses {
            if let Some(error) = rpc_response.error {
                return Err(NACError::RPCError {
                    code: error.code,
                    message: error.message,
                    data: error.data,
                });
            }

            if let Some(result) = rpc_response.result {
                results.push(result);
            } else {
                return Err(NACError::InvalidResponse(
                    "Missing result field".to_string()
                ));
            }
        }

        Ok(results)
    }

    /// 获取下一个请求ID
    fn next_request_id(&self) -> u64 {
        self.request_id.fetch_add(1, Ordering::SeqCst)
    }

    /// 获取端点URL
    pub fn endpoint(&self) -> &str {
        &self.endpoint
    }

    /// 设置端点URL
    pub fn set_endpoint(&mut self, endpoint: impl Into<String>) {
        self.endpoint = endpoint.into();
    }
}

impl Clone for NRPC3Client {
    fn clone(&self) -> Self {
        Self {
            endpoint: self.endpoint.clone(),
            http_client: self.http_client.clone(),
            request_id: AtomicU64::new(self.request_id.load(Ordering::SeqCst)),
        }
    }
}

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

    #[test]
    fn test_nrpc3_request_serialization() {
        let request = NRPC3Request {
            jsonrpc: "3.0".to_string(),
            id: 1,
            method: "nac_getEpochInfo".to_string(),
            params: serde_json::json!({"epoch": 100}),
            timestamp: Some(Timestamp::now()),
            quantum_dna: None,
        };

        let json = serde_json::to_string(&request).unwrap();
        let deserialized: NRPC3Request = serde_json::from_str(&json).unwrap();

        assert_eq!(request.id, deserialized.id);
        assert_eq!(request.method, deserialized.method);
    }

    #[test]
    fn test_nrpc3_response_serialization() {
        let response = NRPC3Response {
            jsonrpc: "3.0".to_string(),
            id: 1,
            result: Some(serde_json::json!({"epoch": 100})),
            error: None,
            timestamp: Some(Timestamp::now()),
        };

        let json = serde_json::to_string(&response).unwrap();
        let deserialized: NRPC3Response = serde_json::from_str(&json).unwrap();

        assert_eq!(response.id, deserialized.id);
        assert!(deserialized.result.is_some());
    }

    #[test]
    fn test_nrpc3_error_serialization() {
        let error = NRPC3Error {
            code: -32600,
            message: "Invalid Request".to_string(),
            data: Some(serde_json::json!({"details": "Missing method"})),
        };

        let json = serde_json::to_string(&error).unwrap();
        let deserialized: NRPC3Error = serde_json::from_str(&json).unwrap();

        assert_eq!(error.code, deserialized.code);
        assert_eq!(error.message, deserialized.message);
    }

    #[test]
    fn test_nrpc3_client_creation() {
        let client = NRPC3Client::new("https://rpc.newassetchain.io");
        assert_eq!(client.endpoint(), "https://rpc.newassetchain.io");
    }

    #[test]
    fn test_request_id_increment() {
        let client = NRPC3Client::new("https://rpc.newassetchain.io");
        let id1 = client.next_request_id();
        let id2 = client.next_request_id();
        let id3 = client.next_request_id();

        assert_eq!(id1, 1);
        assert_eq!(id2, 2);
        assert_eq!(id3, 3);
    }
}