br-web-server 0.5.19

use crate::request::Request;
use crate::websocket::{CloseCode, ErrorCode, Message, MessageMode, MessageType};
use crate::{HttpError, Method, Uri};
use hpack::Decoder;
use log::{info, warn};
use rustls::{ClientConnection, ServerConnection, StreamOwned};
use std::io::{ErrorKind, Read, Write};
use std::net::TcpStream;
use std::sync::{Arc, Mutex};
use std::thread;
use std::time::Duration;

const IO_BUF_SIZE: usize = 1024 * 1024;
const IO_SMALL_BUF_SIZE: usize = 1024 * 64;
const WS_READ_TIMEOUT_MS: u64 = 100;

#[derive(Debug, Clone)]
pub enum Scheme {
    Http(Arc<Mutex<TcpStream>>),
    Https(Arc<Mutex<StreamOwned<ServerConnection, TcpStream>>>),
}

/// WebSocket 读取端 - 独立拥有读取半连接，无锁竞争
pub struct SchemeReader {
    inner: SchemeReaderInner,
    pending: Vec<u8>,
}

#[allow(dead_code)]
enum SchemeReaderInner {
    Http(TcpStream),
    Https(Box<rustls::StreamOwned<ServerConnection, TcpStream>>),
}

/// WebSocket 写入端 - 独立拥有写入半连接，无锁竞争
pub struct SchemeWriter {
    inner: SchemeWriterInner,
}

#[allow(dead_code)]
enum SchemeWriterInner {
    Http(TcpStream),
    Https(Box<rustls::StreamOwned<ServerConnection, TcpStream>>),
}

impl Scheme {
    pub fn split_for_websocket(
        scheme: &Arc<Mutex<Scheme>>,
    ) -> Result<(SchemeReader, SchemeWriter), HttpError> {
        let guard = scheme
            .lock()
            .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?;
        match &*guard {
            Scheme::Http(stream) => {
                let inner_guard = stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?;
                let read_stream = inner_guard.try_clone().map_err(|e| {
                    HttpError::new(500, &format!("clone read stream failed: {}", e))
                })?;
                let write_stream = inner_guard.try_clone().map_err(|e| {
                    HttpError::new(500, &format!("clone write stream failed: {}", e))
                })?;
                Ok((
                    SchemeReader {
                        inner: SchemeReaderInner::Http(read_stream),
                        pending: vec![],
                    },
                    SchemeWriter {
                        inner: SchemeWriterInner::Http(write_stream),
                    },
                ))
            }
            Scheme::Https(_) => Err(HttpError::new(
                500,
                "HTTPS split not supported, use shared mode",
            )),
        }
    }
}

impl SchemeReader {
    pub fn read_ws_data(
        &mut self,
        deflate: &crate::websocket::DeflateConfig,
    ) -> Result<Message, HttpError> {
        // 先检查 pending 缓冲区是否有完整帧
        if !self.pending.is_empty() {
            let message = Message::parse_message(&mut self.pending, deflate);
            match message.message_type {
                MessageType::TimeOut => {} // 数据不完整，继续读取
                _ => return Ok(message),
            }
        }

        let mut buffer = vec![0u8; IO_BUF_SIZE];

        let res = match &mut self.inner {
            SchemeReaderInner::Http(stream) => {
                stream
                    .set_read_timeout(Some(Duration::from_millis(WS_READ_TIMEOUT_MS)))
                    .ok();
                let result = stream.read(&mut buffer);
                stream.set_read_timeout(None).ok();
                result
            }
            SchemeReaderInner::Https(stream) => {
                stream
                    .get_mut()
                    .set_read_timeout(Some(Duration::from_millis(WS_READ_TIMEOUT_MS)))
                    .ok();
                let result = stream.read(&mut buffer);
                stream.get_mut().set_read_timeout(None).ok();
                result
            }
        };

        match res {
            Ok(0) => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::Close,
                payload: vec![],
                text: CloseCode::GoingAway.str(),
                close: CloseCode::GoingAway,
                error: ErrorCode::None,
            }),
            Ok(n) => {
                self.pending.extend_from_slice(&buffer[..n]);
                let start = std::time::Instant::now();
                let total_timeout = Duration::from_secs(30);

                loop {
                    if start.elapsed() > total_timeout {
                        log::warn!("等待 WebSocket 完整帧超时 (30s)，关闭连接");
                        return Ok(Message {
                            mode: MessageMode::Client,
                            message_type: MessageType::Close,
                            payload: vec![],
                            text: "等待完整帧超时".to_string(),
                            close: CloseCode::ProtocolError,
                            error: ErrorCode::TimeOut,
                        });
                    }

                    let message = Message::parse_message(&mut self.pending, deflate);

                    match message.message_type {
                        MessageType::TimeOut => {
                            let mut more_buffer = vec![0u8; IO_SMALL_BUF_SIZE];
                            let more_res = match &mut self.inner {
                                SchemeReaderInner::Http(stream) => {
                                    stream
                                        .set_read_timeout(Some(Duration::from_millis(
                                            WS_READ_TIMEOUT_MS,
                                        )))
                                        .ok();
                                    let result = stream.read(&mut more_buffer);
                                    stream.set_read_timeout(None).ok();
                                    result
                                }
                                SchemeReaderInner::Https(stream) => {
                                    stream
                                        .get_mut()
                                        .set_read_timeout(Some(Duration::from_millis(
                                            WS_READ_TIMEOUT_MS,
                                        )))
                                        .ok();
                                    let result = stream.read(&mut more_buffer);
                                    stream.get_mut().set_read_timeout(None).ok();
                                    result
                                }
                            };
                            match more_res {
                                Ok(0) => {
                                    return Ok(Message {
                                        mode: MessageMode::Client,
                                        message_type: MessageType::Close,
                                        payload: vec![],
                                        text: CloseCode::GoingAway.str(),
                                        close: CloseCode::GoingAway,
                                        error: ErrorCode::None,
                                    });
                                }
                                Ok(m) => {
                                    self.pending.extend_from_slice(&more_buffer[..m]);
                                    continue;
                                }
                                Err(ref e)
                                    if e.kind() == ErrorKind::WouldBlock
                                        || e.kind() == ErrorKind::TimedOut =>
                                {
                                    continue;
                                }
                                Err(_) => {
                                    continue;
                                }
                            }
                        }
                        _ => return Ok(message),
                    }
                }
            }
            Err(ref e) if e.kind() == ErrorKind::WouldBlock => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::TimeOut,
                payload: vec![],
                text: String::new(),
                close: CloseCode::NormalClosure,
                error: ErrorCode::TimeOut,
            }),
            Err(e) => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::Error,
                payload: vec![],
                text: e.to_string(),
                close: CloseCode::Other(1011),
                error: ErrorCode::Unknown,
            }),
        }
    }
}

impl SchemeWriter {
    /// 写入数据
    pub fn write_all(&mut self, data: &[u8]) -> Result<(), HttpError> {
        let result = match &mut self.inner {
            SchemeWriterInner::Http(stream) => stream.write_all(data),
            SchemeWriterInner::Https(stream) => stream.write_all(data),
        };
        match result {
            Ok(()) => {
                self.flush()?;
                Ok(())
            }
            Err(e) => Err(HttpError::new(500, format!("write: {}", e).as_str())),
        }
    }

    /// 刷新缓冲区
    pub fn flush(&mut self) -> Result<(), HttpError> {
        let result = match &mut self.inner {
            SchemeWriterInner::Http(stream) => stream.flush(),
            SchemeWriterInner::Https(stream) => stream.flush(),
        };
        match result {
            Ok(()) => Ok(()),
            Err(e) => Err(HttpError::new(500, format!("flush: {}", e).as_str())),
        }
    }
}

impl Scheme {
    /// 读取
    pub fn read(&mut self, data: &mut Vec<u8>) -> Result<(), HttpError> {
        let mut buf = vec![0u8; IO_BUF_SIZE];

        let mut index = 2;
        loop {
            let result = match self {
                Self::Http(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .read(&mut buf),
                Self::Https(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .read(&mut buf),
            };
            return match result {
                Ok(0) => Err(HttpError::new(500, "read: 客户端主动关闭")),
                Ok(n) => {
                    data.extend(&buf[..n]);
                    return Ok(());
                }
                Err(ref e) if e.kind() == ErrorKind::Interrupted => {
                    if !data.is_empty() {
                        return Ok(());
                    }
                    if index > 0 {
                        index -= 1;
                        continue;
                    }
                    Err(HttpError::new(
                        500,
                        format!("read现在没数据可读: {}", e.to_string().as_str()).as_str(),
                    ))
                }
                Err(e) => Err(HttpError::new(
                    500,
                    format!("read: {}", e.to_string().as_str()).as_str(),
                )),
            };
        }
    }
    /// 指定长度
    fn read_data(&self, init_data: &mut Vec<u8>, length: usize) -> Result<(), HttpError> {
        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(30);
        loop {
            if init_data.len() >= length {
                return Ok(());
            }
            let mut buf = vec![0u8; IO_BUF_SIZE];
            let result = match self {
                Self::Http(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .read(&mut buf),
                Self::Https(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .read(&mut buf),
            };
            return match result {
                Ok(0) => Err(HttpError::new(500, "read_data: 客户端主动关闭")),
                Ok(n) => {
                    init_data.extend(&buf[..n]);
                    Ok(())
                }
                Err(ref e) if e.kind() == ErrorKind::WouldBlock => {
                    // ⚠️ 当前无数据可读，稍后再试
                    if std::time::Instant::now() > deadline {
                        return Err(HttpError::new(408, "read_data: timeout"));
                    }
                    thread::sleep(Duration::from_millis(100));
                    continue;
                }
                Err(e) => Err(HttpError::new(
                    500,
                    format!("read_data: {}", e.to_string().as_str()).as_str(),
                )),
            };
        }
    }

    /// 写入
    pub fn write(&mut self, data: &[u8]) -> Result<(), HttpError> {
        let mut off = 0;
        loop {
            let result = match self {
                Self::Http(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .write(&data[off..]),
                Self::Https(stream) => stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                    .get_mut()
                    .write(&data[off..]),
            };
            match result {
                Ok(0) => return Err(HttpError::new(500, "write: 客户端主动关闭")),
                Ok(e) => {
                    if e != data.len() {
                        off = e;
                        continue;
                    }
                    self.flush()?;
                    return Ok(());
                }
                Err(ref e)
                    if e.kind() == ErrorKind::WouldBlock || e.kind() == ErrorKind::Interrupted => {}
                Err(e) => {
                    return Err(HttpError::new(
                        500,
                        format!("write: {}", e.to_string().as_str()).as_str(),
                    ))
                }
            };
        }
    }
    pub fn write_all(&mut self, data: &[u8]) -> Result<(), HttpError> {
        let result = match self {
            Self::Http(stream) => stream
                .lock()
                .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                .write_all(data),
            Self::Https(stream) => stream
                .lock()
                .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                .write_all(data),
        };
        match result {
            Ok(()) => {
                self.flush()?;
                Ok(())
            }
            Err(e) => Err(HttpError::new(
                500,
                format!("write: {}", e.to_string().as_str()).as_str(),
            )),
        }
    }

    pub fn flush(&mut self) -> Result<(), HttpError> {
        let result = match self {
            Self::Http(stream) => stream
                .lock()
                .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                .flush(),
            Self::Https(stream) => stream
                .lock()
                .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?
                .flush(),
        };
        match result {
            Ok(()) => Ok(()),
            Err(e) => Err(HttpError::new(
                500,
                format!("flush: {}", e.to_string().as_str()).as_str(),
            )),
        }
    }

    pub fn read_ws_data(
        &mut self,
        deflate: &crate::websocket::DeflateConfig,
    ) -> Result<Message, HttpError> {
        let mut response = vec![];
        let mut buffer = vec![0u8; IO_BUF_SIZE];
        let res = match self {
            Self::Http(stream) => {
                let mut guard = stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?;
                guard
                    .set_read_timeout(Some(std::time::Duration::from_millis(WS_READ_TIMEOUT_MS)))
                    .ok();
                let result = guard.read(&mut buffer);
                guard.set_read_timeout(None).ok();
                result
            }
            Self::Https(ref mut stream) => {
                let mut guard = stream
                    .lock()
                    .map_err(|e| HttpError::new(500, &format!("lock poisoned: {}", e)))?;
                guard
                    .get_mut()
                    .set_read_timeout(Some(std::time::Duration::from_millis(WS_READ_TIMEOUT_MS)))
                    .ok();
                let result = guard.read(&mut buffer);
                guard.get_mut().set_read_timeout(None).ok();
                result
            }
        };
        match res {
            Ok(0) => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::Close,
                payload: vec![],
                text: CloseCode::GoingAway.str(),
                close: CloseCode::GoingAway,
                error: ErrorCode::None,
            }),
            Ok(n) => {
                response.extend(buffer[..n].to_vec());
                let start = std::time::Instant::now();
                let total_timeout = std::time::Duration::from_secs(30);

                loop {
                    if start.elapsed() > total_timeout {
                        log::warn!("等待 WebSocket 完整帧超时 (30s)，关闭连接");
                        return Ok(Message {
                            mode: MessageMode::Client,
                            message_type: MessageType::Close,
                            payload: vec![],
                            text: "等待完整帧超时".to_string(),
                            close: CloseCode::ProtocolError,
                            error: ErrorCode::TimeOut,
                        });
                    }

                    let message = Message::parse_message(&mut response, deflate);

                    match message.message_type {
                        MessageType::TimeOut => {
                            let mut more_buffer = vec![0u8; IO_SMALL_BUF_SIZE];
                            let more_res = match self {
                                Self::Http(stream) => {
                                    let mut guard = stream.lock().map_err(|e| {
                                        HttpError::new(500, &format!("lock poisoned: {}", e))
                                    })?;
                                    guard
                                        .set_read_timeout(Some(std::time::Duration::from_millis(
                                            WS_READ_TIMEOUT_MS,
                                        )))
                                        .ok();
                                    let result = guard.read(&mut more_buffer);
                                    guard.set_read_timeout(None).ok();
                                    result
                                }
                                Self::Https(ref mut stream) => {
                                    let mut guard = stream.lock().map_err(|e| {
                                        HttpError::new(500, &format!("lock poisoned: {}", e))
                                    })?;
                                    guard
                                        .get_mut()
                                        .set_read_timeout(Some(std::time::Duration::from_millis(
                                            WS_READ_TIMEOUT_MS,
                                        )))
                                        .ok();
                                    let result = guard.read(&mut more_buffer);
                                    guard.get_mut().set_read_timeout(None).ok();
                                    result
                                }
                            };
                            match more_res {
                                Ok(0) => {
                                    return Ok(Message {
                                        mode: MessageMode::Client,
                                        message_type: MessageType::Close,
                                        payload: vec![],
                                        text: CloseCode::GoingAway.str(),
                                        close: CloseCode::GoingAway,
                                        error: ErrorCode::None,
                                    });
                                }
                                Ok(m) => {
                                    response.extend(more_buffer[..m].to_vec());
                                    continue;
                                }
                                Err(ref e)
                                    if e.kind() == ErrorKind::WouldBlock
                                        || e.kind() == ErrorKind::TimedOut =>
                                {
                                    continue;
                                }
                                Err(_) => {
                                    continue;
                                }
                            }
                        }
                        _ => return Ok(message),
                    }
                }
            }
            Err(ref e) if e.kind() == ErrorKind::WouldBlock => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::TimeOut,
                payload: vec![],
                text: String::new(),
                close: CloseCode::NormalClosure,
                error: ErrorCode::TimeOut,
            }),
            Err(e) => Ok(Message {
                mode: MessageMode::Client,
                message_type: MessageType::Error,
                payload: vec![],
                text: e.to_string(),
                close: CloseCode::Other(1011),
                error: ErrorCode::Unknown,
            }),
        }
    }

    pub fn client_ip(&mut self) -> String {
        match self {
            Self::Http(stream) => match stream.lock() {
                Ok(guard) => match guard.peer_addr() {
                    Ok(e) => e.ip().to_string(),
                    Err(_) => "unknown".to_string(),
                },
                Err(_) => "unknown".to_string(),
            },
            Self::Https(stream) => stream
                .lock()
                .ok()
                .and_then(|mut guard| guard.get_mut().peer_addr().ok())
                .map(|a| a.ip().to_string())
                .unwrap_or_else(|| "unknown".to_string()),
        }
    }
    pub fn server_ip(&mut self) -> String {
        match self {
            Self::Http(stream) => stream
                .lock()
                .ok()
                .and_then(|guard| guard.local_addr().ok())
                .map(|a| a.ip().to_string())
                .unwrap_or_else(|| "unknown".to_string()),
            Self::Https(stream) => stream
                .lock()
                .ok()
                .and_then(|mut guard| guard.get_mut().local_addr().ok())
                .map(|a| a.ip().to_string())
                .unwrap_or_else(|| "unknown".to_string()),
        }
    }
    /// 读取HTTP2
    pub fn http2_packet(
        &mut self,
        init_data: &mut Vec<u8>,
    ) -> Result<(Vec<u8>, FrameType, u8, u32), HttpError> {
        let bytes = init_data;
        self.read_data(bytes, 9)?;
        let headers = bytes.drain(..9).collect::<Vec<u8>>();
        let length =
            ((headers[0] as u32) << 16) | (u32::from(headers[1]) << 8) | u32::from(headers[2]);
        let frame_type = headers[3];
        let flags = headers[4];
        let stream_id =
            u32::from_be_bytes([headers[5], headers[6], headers[7], headers[8]]) & 0x7FFF_FFFF;
        self.read_data(bytes, length as usize)?;
        let payload = bytes.drain(..length as usize).collect::<Vec<u8>>();
        Ok((payload, FrameType::from(frame_type), flags, stream_id))
    }
    /// 读取HTTP2消息头
    pub fn http2_handle_header(
        &mut self,
        data: &mut Vec<u8>,
        request: &mut Request,
    ) -> Result<(), HttpError> {
        loop {
            let (payload, frame_type, flags, stream_id) = self.http2_packet(data)?;
            if request.config.debug {
                info!("http2_handle_header: frame_type: {frame_type:?} flags: {flags} stream_id: {stream_id} payload: {}", payload.len());
            }
            match frame_type {
                FrameType::Settings => {
                    let is_ack = flags & 0x01 != 0;
                    if !is_ack {
                        self.http2_settings_ack()?;
                    }
                }
                FrameType::WindowUpdate => {
                    if payload.len() == 4 {
                        let raw =
                            u32::from_be_bytes(<[u8; 4]>::try_from(&payload[..4]).map_err(
                                |_| HttpError::new(400, "invalid WindowUpdate frame data"),
                            )?);
                        let increment = raw & 0x7FFF_FFFF; // 屏蔽最高位保留位
                        if request.config.debug {
                            info!("WindowUpdate: increment = {} {:?}", increment, payload);
                        }
                    } else {
                        return Err(HttpError::new(
                            400,
                            format!("Invalid WindowUpdate frame length: {}", payload.len())
                                .as_str(),
                        ));
                    }
                }
                FrameType::Headers => {
                    let mut decoder = Decoder::new();
                    let headers = decoder.decode(&payload).map_err(|e| {
                        HttpError::new(400, &format!("HPACK decode error: {:?}", e))
                    })?;
                    if request.config.debug {
                        println!(
                            "=================请求头 {:?}=================",
                            thread::current().id()
                        );
                    }
                    for (name, value) in headers {
                        let header_name = String::from_utf8_lossy(name.as_slice());
                        let header_value = String::from_utf8_lossy(value.as_slice());
                        if request.config.debug {
                            println!("{header_name}: {header_value}");
                        }
                        match header_name.as_ref() {
                            ":method" => request.method = Method::from(header_value.as_ref()),
                            ":path" => request.uri = Uri::from(header_value.as_ref()),
                            ":scheme" => request.set_header("scheme", header_value.as_ref())?,
                            ":authority" => request.set_header("host", header_value.as_ref())?,
                            _ => request.set_header(&header_name, &header_value)?,
                        }
                    }
                    if request.config.debug {
                        println!("====================================================");
                    }
                    return Ok(());
                }
                _ => {
                    return Err(HttpError::new(
                        400,
                        format!("Invalid {frame_type:?}").as_str(),
                    ))
                }
            }
        }
    }
    /// 读取HTTP2消息体
    pub fn http2_handle_body(
        &mut self,
        data: &mut Vec<u8>,
        request: Request,
    ) -> Result<Vec<u8>, HttpError> {
        let mut body = vec![];
        loop {
            let (payload, frame_type, flags, stream_id) = self.http2_packet(data)?;
            if request.config.debug {
                info!("http2_handle_body: frame_type: {frame_type:?} flags: {flags} stream_id: {stream_id} data: {}",payload.len());
            }
            match frame_type {
                FrameType::Data => {
                    body.extend(payload);
                    if body.len() > request.config.max_body_size {
                        return Err(HttpError::new(413, "Request body too large"));
                    }
                    if flags == 1 {
                        return Ok(body);
                    }
                }
                FrameType::Headers => {}
                FrameType::RstStream => {}
                FrameType::Settings => {
                    if !payload.is_empty() {
                        self.http2_send_server_settings()?;
                    } else {
                        self.http2_settings_ack()?;
                    }
                }
                FrameType::Ping => {}
                FrameType::Goaway => {
                    let text = String::from_utf8_lossy(&payload);
                    if request.config.debug {
                        warn!("Goaway: {text}");
                    }
                    return Ok(vec![]);
                }
                FrameType::WindowUpdate => {
                    if payload.len() == 4 {
                        let raw =
                            u32::from_be_bytes(<[u8; 4]>::try_from(&payload[..4]).map_err(
                                |_| HttpError::new(400, "invalid WindowUpdate frame data"),
                            )?);
                        let increment = raw & 0x7FFF_FFFF; // 屏蔽最高位保留位
                        if request.config.debug {
                            info!("WindowUpdate: increment = {} {:?}", increment, payload);
                        }
                    } else {
                        return Err(HttpError::new(
                            400,
                            format!("Invalid WindowUpdate frame length: {}", payload.len())
                                .as_str(),
                        ));
                    }
                }
                FrameType::Continuation => {}
                FrameType::None => {}
            }
        }
    }
    /// 发送HTTP2认证参数
    pub fn http2_send_server_settings(&mut self) -> Result<(), HttpError> {
        let payload = {
            let mut p = Vec::new();
            // SETTINGS_ENABLE_PUSH = 0  （对浏览器禁用推送）
            p.extend_from_slice(&2u16.to_be_bytes());
            p.extend_from_slice(&0u32.to_be_bytes());
            // SETTINGS_INITIAL_WINDOW_SIZE = 65535
            p.extend_from_slice(&4u16.to_be_bytes());
            p.extend_from_slice(&65_535u32.to_be_bytes());
            // SETTINGS_MAX_FRAME_SIZE = 16384
            p.extend_from_slice(&5u16.to_be_bytes());
            p.extend_from_slice(&16_384u32.to_be_bytes());
            // 可按需再加 MAX_CONCURRENT_STREAMS 等
            p
        };
        let len = payload.len();
        let mut f = Vec::with_capacity(9 + len);
        f.extend_from_slice(&[(len >> 16) as u8, (len >> 8) as u8, len as u8]); // ✅ 正确长度
        f.push(0x04); // type = SETTINGS
        f.push(0x00); // flags = none
        f.extend_from_slice(&0u32.to_be_bytes()); // sid=0
        f.extend_from_slice(&payload);
        self.write_all(&f)?;
        Ok(())
    }
    /// 发送对“对端 SETTINGS”的 ACK（len=0, flags=ACK）
    pub fn http2_settings_ack(&mut self) -> Result<(), HttpError> {
        let f = [0x00, 0x00, 0x00, 0x04, 0x01, 0x00, 0x00, 0x00, 0x00];
        self.write_all(&f)?;
        Ok(())
    }
    pub fn http2_goaway(&mut self, last_stream_id: u32, error_code: u32) -> Result<(), HttpError> {
        // 构造帧头
        let mut frame = Vec::new();
        frame.extend_from_slice(&[0x00, 0x00, 0x08]); // length
        frame.push(0x07); // type = GOAWAY
        frame.push(0x00); // flags = none
        frame.extend_from_slice(&[0x00, 0x00, 0x00, 0x00]); // stream id = 0
        frame.extend_from_slice(&last_stream_id.to_be_bytes());
        frame.extend_from_slice(&error_code.to_be_bytes());
        self.write_all(frame.as_slice())?;
        Ok(())
    }
}
#[derive(Debug)]
pub enum FrameType {
    Data,
    Headers,
    RstStream,
    Settings,
    Ping,
    Goaway,
    WindowUpdate,
    Continuation,
    None,
}
impl FrameType {
    pub fn from(code: u8) -> Self {
        match code {
            0x00 => Self::Data,
            0x01 => Self::Headers,
            0x03 => Self::RstStream,
            0x04 => Self::Settings,
            0x06 => Self::Ping,
            0x07 => Self::Goaway,
            0x08 => Self::WindowUpdate,
            0x09 => Self::Continuation,
            _ => Self::None,
        }
    }
}

pub enum ClientStream {
    Http(TcpStream),
    Https(Box<StreamOwned<ClientConnection, TcpStream>>),
}
impl ClientStream {
    pub fn write_all(&mut self, data: &[u8]) -> std::io::Result<()> {
        match self {
            ClientStream::Http(e) => e.write_all(data),
            ClientStream::Https(e) => e.write_all(data),
        }
    }
    pub fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
        match self {
            ClientStream::Http(e) => e.read(buf),
            ClientStream::Https(e) => e.read(buf),
        }
    }
    pub fn read_data(&mut self, buffer: &mut Vec<u8>) -> Result<(), String> {
        let mut tmp = [0u8; 1024];
        let n = self.read(&mut tmp).map_err(|e| e.to_string())?;
        if n == 0 {
            return Err("unexpected EOF while reading chunk data".to_string());
        }
        buffer.extend_from_slice(&tmp[..n]);
        Ok(())
    }
    /// 强制输出
    pub fn flush(&mut self) -> std::io::Result<()> {
        match self {
            ClientStream::Http(e) => e.flush(),
            ClientStream::Https(e) => e.flush(),
        }
    }
}