mod config;
mod filter;
mod model;
mod protocol;
mod tokenizers;
mod vocabs;

use crate::config::{Config, SocketConfig};
use crate::model::OnnxModel;
use crate::tokenizers::HFTokenizer;
use crate::vocabs::Dictionary;
use crate::filter::filter_candidates;
use crate::protocol::{Request, Response, Candidate};
use std::error::Error;
use std::io::{Read, Write};
use std::sync::{Arc, Mutex};
use std::thread;

#[cfg(unix)]
use std::os::unix::net::{UnixListener, UnixStream};
#[cfg(unix)]
use std::os::unix::fs::PermissionsExt; // 用于设置文件权限
#[cfg(unix)]
use std::fs::set_permissions;

#[cfg(windows)]
use std::net::{TcpListener, TcpStream};

// 添加 ctrlc 依赖，用于捕获退出信号（仅在 Unix 下需要）
#[cfg(unix)]
use ctrlc;

fn handle_client(mut stream: impl Read + Write, model: Arc<Mutex<OnnxModel>>, tokenizer: Arc<Mutex<HFTokenizer>>, dict: Arc<Dictionary>) -> Result<(), Box<dyn Error>> {
    loop {
        // 读取4字节长度头
        let mut len_buf = [0u8; 4];
        if let Err(e) = stream.read_exact(&mut len_buf) {
            // 如果读取失败，可能是连接关闭，正常退出循环
            if e.kind() == std::io::ErrorKind::UnexpectedEof {
                println!("客户端关闭连接");
                break;
            }
            return Err(Box::new(e)); // 其他错误上报
        }
        let payload_len = u32::from_be_bytes(len_buf) as usize;

        // 读取MessagePack载荷
        let mut payload = vec![0u8; payload_len];
        stream.read_exact(&mut payload)?;

        // 反序列化请求
        let request: Request = rmp_serde::from_slice(&payload)?;
        println!("接收请求: {:?}", request);

        // 准备模型输入
        let model_input = {
            let tokenizer = tokenizer.lock().unwrap();
            tokenizer.gen_predict_sample(&request.context, &request.pinyin)?
        };

        // 进行预测
        let predicted_pairs = {
            let mut model = model.lock().unwrap();
            model.predict_to_sorted_pairs_simple(model_input, true)?
        };

        // 筛选候选词
        let filtered = filter_candidates(&request.pinyin, predicted_pairs, &dict);

        // 转换为Response
        let candidates: Vec<Candidate> = filtered
        .into_iter()
        .map(|fc| Candidate {
            id: fc.id as u32,
            text: fc.text,
            weight: fc.weight,
        })
        .collect();
        let response = Response {
            candidates,
            offset: 0,
            limit: 10,
        };

        // 序列化响应
        let response_payload = rmp_serde::to_vec(&response)?;
        let response_len = response_payload.len() as u32;
        let response_len_bytes = response_len.to_be_bytes();

        // 发送响应
        stream.write_all(&response_len_bytes)?;
        stream.write_all(&response_payload)?;
        // 确保数据发送完成（flush 在 Write 实现中通常自动处理，但可显式调用）
        stream.flush()?;
    }
    Ok(())
}


fn main() -> Result<(), Box<dyn Error>> {
    // 加载配置
    let config = Config::load()?;
    println!("配置加载成功: {:?}", config);

    // 初始化组件
    let model = OnnxModel::new(&config.model_path, 1)?;
    let tokenizer = HFTokenizer::new(&config.tokenizer_path)?;
    let dict = Dictionary::from_json_file(&config.vocabs_path)?;

    let model = Arc::new(Mutex::new(model));
    let tokenizer = Arc::new(Mutex::new(tokenizer));
    let dict = Arc::new(dict);

    // 创建监听器
    match config.socket {
        SocketConfig::UnixDomainSocket(path) => {
            #[cfg(unix)]
            {
                // 尝试删除可能残留的socket文件
                if let Err(e) = std::fs::remove_file(&path) {
                    // 如果文件不存在，忽略错误；否则打印警告
                    if e.kind() != std::io::ErrorKind::NotFound {
                        eprintln!("警告：无法删除socket文件 {}: {}", path, e);
                    }
                }
                let listener = UnixListener::bind(&path)?;
                println!("监听Unix Domain Socket在: {}", path);

                // 设置socket文件权限为600（仅所有者可读写），减少被其他进程误操作的风险
                let mut perms = std::fs::metadata(&path)?.permissions();
                perms.set_mode(0o600); // 只允许所有者读写
                set_permissions(&path, perms)?;

                // 注册信号处理，确保程序退出时清理socket文件
                let socket_path = path.clone();
                ctrlc::set_handler(move || {
                    println!("收到退出信号，清理socket文件: {}", socket_path);
                    let _ = std::fs::remove_file(&socket_path);
                    std::process::exit(0);
                })?;

                for stream in listener.incoming() {
                    match stream {
                        Ok(stream) => {
                            println!("受理连接");
                            let model = Arc::clone(&model);
                            let tokenizer = Arc::clone(&tokenizer);
                            let dict = Arc::clone(&dict);
                            thread::spawn(move || {
                                if let Err(e) = handle_client(stream, model, tokenizer, dict) {
                                    eprintln!("处理连接错误: {}", e);
                                }
                            });
                        }
                        Err(e) => eprintln!("接受连接错误: {}", e),
                    }
                }
            }
            #[cfg(not(unix))]
            {
                return Err("Unix Domain Socket仅在Unix系统上支持".into());
            }
        }
        SocketConfig::TcpSocket(addr) => {
            #[cfg(windows)]
            {
                let listener = TcpListener::bind(&addr)?;
                println!("监听TCP Socket在: {}", addr);
                for stream in listener.incoming() {
                    match stream {
                        Ok(stream) => {
                            let model = Arc::clone(&model);
                            let tokenizer = Arc::clone(&tokenizer);
                            let dict = Arc::clone(&dict);
                            thread::spawn(move || {
                                if let Err(e) = handle_client(stream, model, tokenizer, dict) {
                                    eprintln!("处理连接错误: {}", e);
                                }
                            });
                        }
                        Err(e) => eprintln!("接受连接错误: {}", e),
                    }
                }
            }
            #[cfg(not(windows))]
            {
                return Err("TCP Socket仅在Windows系统上支持".into());
            }
        }
    }

    Ok(())
}