lynn_tcp 1.1.3

mod common_api;
mod lynn_server_config;
mod lynn_server_user;
mod server_thread_pool;

use std::{
    collections::HashMap,
    net::SocketAddr,
    ops::{Deref, DerefMut},
    sync::Arc,
    time::SystemTime,
};

use bytes::Bytes;
use common_api::{spawn_check_heart, spawn_socket_server};
use lynn_server_config::{LynnServerConfig, LynnServerConfigBuilder};
use lynn_server_user::LynnUser;
use server_thread_pool::LynnServerThreadPool;
use tokio::{
    io::AsyncWriteExt,
    net::TcpListener,
    sync::{mpsc, RwLock, Semaphore},
    task::JoinHandle,
};
use tracing::{error, info, warn, Level};
use tracing_subscriber::fmt;

use crate::{
    const_config::{SERVER_MESSAGE_HEADER_MARK, SERVER_MESSAGE_TAIL_MARK},
    handler::{HandlerContext, IHandler, IntoSystem},
};

pub mod lynn_config_api {
    pub use super::lynn_server_config::LynnServerConfig;
    pub use super::lynn_server_config::LynnServerConfigBuilder;
}

/// Represents a server for the Lynn application.
///
/// The `LynnServer` struct holds information about the server, including its configuration,
/// client list, router map, and thread pool.
///
/// # Example
/// Use default config
/// ```rust
/// use lynn_tcp::{lynn_server::*, lynn_tcp_dependents::*};
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let _ = LynnServer::new()
///         .await
///         .add_router(1, my_service)
///         .add_router(2, my_service_with_buf)
///         .add_router(3, my_service_with_clients)
///         .start()
///         .await;
///     Ok(())
/// }
///
/// pub async fn my_service() -> HandlerResult {
///     HandlerResult::new_without_send()
/// }
/// pub async fn my_service_with_buf(input_buf_vo: InputBufVO) -> HandlerResult {
///     println!(
///         "service read from :{}",
///         input_buf_vo.get_input_addr().unwrap()
///     );
///     HandlerResult::new_without_send()
/// }
/// pub async fn my_service_with_clients(clients_context: ClientsContext) -> HandlerResult {
///     HandlerResult::new_with_send(1, "hello lynn".into(), clients_context.get_all_clients_addrs().await)
/// }
/// ```
/// # Example
/// Use customized config
/// ```rust
/// use lynn_tcp::{lynn_server::*, lynn_tcp_dependents::*};
///
/// #[tokio::main]
/// async fn main() -> Result<(), Box<dyn std::error::Error>> {
///     let _ = LynnServer::new_with_config(
///         LynnServerConfigBuilder::new()
///             .with_server_ipv4("0.0.0.0:9177")
///             .with_server_max_connections(Some(&200))
///             .with_server_max_threadpool_size(&10)
///             // ...more
///             .build(),
///         )
///         .await
///         .add_router(1, my_service)
///         .add_router(2, my_service_with_buf)
///         .add_router(3, my_service_with_clients)
///         .start()
///         .await;
///     Ok(())
/// }
///
/// pub async fn my_service() -> HandlerResult {
///     HandlerResult::new_without_send()
/// }
/// pub async fn my_service_with_buf(input_buf_vo: InputBufVO) -> HandlerResult {
///     println!(
///         "service read from :{}",
///         input_buf_vo.get_input_addr().unwrap()
///     );
///     HandlerResult::new_without_send()
/// }
/// pub async fn my_service_with_clients(clients_context: ClientsContext) -> HandlerResult {
///     HandlerResult::new_with_send(1, "hello lynn".into(), clients_context.get_all_clients_addrs().await)
/// }
/// ```
#[cfg(feature = "server")]
pub struct LynnServer<'a> {
    /// A map of connected clients, where the key is the client's address and the value is a `LynnUser` instance.
    clients: ClientsStruct,
    /// A map of routes, where the key is a method ID and the value is a service handler.
    router_map_async: RouterMapAsyncStruct,
    router_maps: RouterMapsStruct,
    /// The configuration for the server.
    lynn_config: LynnServerConfig<'a>,
    /// The thread pool for the server.
    lynn_thread_pool: LynnServerThreadPool,
}

pub(crate) type ClientsStructType = Arc<RwLock<HashMap<SocketAddr, LynnUser>>>;
#[derive(Clone)]
pub(crate) struct ClientsStruct(pub(crate) ClientsStructType);
struct RouterMapAsyncStruct(Arc<Option<HashMap<u16, Arc<AsyncFunc>>>>);
struct RouterMapsStruct(Option<HashMap<u16, Arc<AsyncFunc>>>);

pub(crate) type AsyncFunc = Box<dyn IHandler>;
pub(crate) type TaskBody = mpsc::Sender<(Arc<AsyncFunc>, HandlerContext, ClientsStructType)>;

/// Implementation of methods for the LynnServer struct.
impl<'a> LynnServer<'a> {
    /// Creates a new instance of `LynnServer` with default configuration.
    ///
    /// # Returns
    ///
    /// A new instance of `LynnServer`.
    pub async fn new() -> Self {
        let lynn_config = LynnServerConfig::default();
        let server_max_threadpool_size = lynn_config.get_server_max_threadpool_size();
        let thread_pool = LynnServerThreadPool::new(server_max_threadpool_size).await;
        let app = Self {
            clients: ClientsStruct(Arc::new(RwLock::new(HashMap::new()))),
            router_map_async: RouterMapAsyncStruct(Arc::new(None)),
            router_maps: RouterMapsStruct(None),
            lynn_config,
            lynn_thread_pool: thread_pool,
        };
        app.log_server().await;
        app
    }

    /// Creates a new instance of `LynnServer` with a specified IPv4 address.
    ///
    /// # Parameters
    ///
    /// * `ipv4` - The IPv4 address to bind the server to.
    ///
    /// # Returns
    ///
    /// A new instance of `LynnServer`.
    pub async fn new_with_ipv4(ipv4: &'a str) -> Self {
        let lynn_config = LynnServerConfigBuilder::new()
            .with_server_ipv4(ipv4)
            .build();
        let server_max_threadpool_size = lynn_config.get_server_max_threadpool_size();
        let thread_pool = LynnServerThreadPool::new(server_max_threadpool_size).await;
        let app = Self {
            clients: ClientsStruct(Arc::new(RwLock::new(HashMap::new()))),
            router_map_async: RouterMapAsyncStruct(Arc::new(None)),
            router_maps: RouterMapsStruct(None),
            lynn_config,
            lynn_thread_pool: thread_pool,
        };
        app.log_server().await;
        app
    }

    /// Creates a new instance of `LynnServer` with a specified configuration.
    ///
    /// # Parameters
    ///
    /// * `lynn_config` - The configuration for the server.
    ///
    /// # Returns
    ///
    /// A new instance of `LynnServer`.
    pub async fn new_with_config(lynn_config: LynnServerConfig<'a>) -> Self {
        let server_max_threadpool_size = lynn_config.get_server_max_threadpool_size();
        let thread_pool = LynnServerThreadPool::new(server_max_threadpool_size).await;
        let app = Self {
            clients: ClientsStruct(Arc::new(RwLock::new(HashMap::new()))),
            router_map_async: RouterMapAsyncStruct(Arc::new(None)),
            router_maps: RouterMapsStruct(None),
            lynn_config,
            lynn_thread_pool: thread_pool,
        };
        app.log_server().await;
        app
    }

    /// Adds a route to the server.
    ///
    /// # Parameters
    ///
    /// * `method_id` - The ID of the method to route.
    /// * `handler` - The service handler for the method.
    ///
    /// # Returns
    ///
    /// The modified `LynnServer` instance.
    pub fn add_router<Param>(mut self, method_id: u16, handler: impl IntoSystem<Param>) -> Self {
        if let Some(ref mut map) = self.router_maps.0 {
            map.insert(method_id, Arc::new(Box::new(handler.to_system())));
        } else {
            let mut map: HashMap<u16, Arc<Box<dyn IHandler>>> = HashMap::new();
            map.insert(method_id, Arc::new(Box::new(handler.to_system())));
            self.router_maps.0 = Some(map);
        }
        self
    }

    async fn synchronous_router(&mut self) {
        self.router_map_async.0 = Arc::new(self.router_maps.0.clone());
        self.router_maps.0 = None;
    }

    /// Adds a new client to the server.
    ///
    /// # Parameters
    ///
    /// * `sender` - The sender channel for the client.
    /// * `addr` - The address of the client.
    /// * `process_permit` - The process permit for the client.
    /// * `join_handle` - The join handle for the client's task.
    /// * `last_communicate_time` - The last time the client communicated.
    async fn add_client(
        &self,
        sender: mpsc::Sender<Bytes>,
        addr: SocketAddr,
        process_permit: Arc<Semaphore>,
        join_handle: JoinHandle<()>,
        last_communicate_time: Arc<RwLock<SystemTime>>,
    ) {
        let mut clients = self.clients.0.write().await;
        let guard = clients.deref_mut();
        let lynn_user = LynnUser::new(sender, process_permit, join_handle, last_communicate_time);
        guard.insert(addr, lynn_user);
    }

    /// Removes a client from the server.
    ///
    /// # Parameters
    ///
    /// * `addr` - The address of the client to remove.
    async fn remove_client(&mut self, addr: SocketAddr) {
        let mut clients = self.clients.0.write().await;
        let guard = clients.deref_mut();
        if guard.contains_key(&addr) {
            guard.remove(&addr);
        }
    }

    /// Checks the heartbeat of connected clients and removes those that have not sent messages for a long time.
    async fn check_heart(&self) {
        let clients = self.clients.0.clone();
        let server_check_heart_interval =
            self.lynn_config.get_server_check_heart_interval().clone();
        let server_check_heart_timeout_time = self
            .lynn_config
            .get_server_check_heart_timeout_time()
            .clone();
        spawn_check_heart(
            server_check_heart_interval,
            server_check_heart_timeout_time,
            clients,
        );
    }

    pub async fn start(mut self: Self) {
        self.synchronous_router().await;
        self.init_marks().await;
        let server_arc = Arc::new(self);
        if let Err(e) = server_arc.run().await {
            error!("{}", e);
        }
    }

    /// Starts the server and begins listening for client connections.
    ///
    /// # Returns
    ///
    /// Returns `Ok(())` if the server starts successfully, otherwise returns an error.
    async fn run(self: Arc<Self>) -> Result<(), Box<dyn std::error::Error>> {
        // Binds a TCP listener to the local address.
        let listener = TcpListener::bind(self.lynn_config.get_server_ipv4()).await?;
        info!(
            "Server - [Main-LynnServer] start success!!! with [server_ipv4:{}]",
            self.lynn_config.get_server_ipv4()
        );

        self.check_heart().await;

        loop {
            // Waits for a client to connect.
            let clinet_result = listener.accept().await;
            if let Ok((mut socket, addr)) = clinet_result {
                let mut socket_permit = true;
                {
                    if let Some(max_connections) = self.lynn_config.get_server_max_connections() {
                        let clients = self.clients.0.write().await;
                        let guard = clients.deref();
                        if guard.len() < *max_connections {
                            socket_permit = true;
                        } else {
                            socket_permit = false;
                        }
                    }
                }
                if socket_permit {
                    info!("Accepted connection from: {}", addr);
                    let process_permit = Arc::new(Semaphore::new(
                        *self.lynn_config.get_server_single_processs_permit(),
                    ));
                    let clients = self.clients.0.clone();
                    let router_map_async = self.router_map_async.0.clone();
                    let thread_pool_task_body_sender =
                        self.lynn_thread_pool.task_body_sender.0.clone();
                    let message_header_mark = self.lynn_config.get_message_header_mark().clone();
                    let message_tail_mark = self.lynn_config.get_message_tail_mark().clone();
                    spawn_socket_server(
                        addr,
                        process_permit,
                        message_header_mark,
                        message_tail_mark,
                        socket,
                        router_map_async,
                        clients,
                        thread_pool_task_body_sender,
                    );
                } else {
                    let _ = socket.shutdown().await;
                    warn!("Server socket's count is more than MAX_CONNECTIONS ,can not accept new client:{}",addr);
                }
            } else {
                if let Err(e) = clinet_result {
                    warn!(
                        "Failed to accept connection , server run next, e :{}",
                        e.to_string()
                    );
                }
            }
        }
    }

    async fn init_marks(&self) {
        SERVER_MESSAGE_HEADER_MARK.get_or_init(|| *self.lynn_config.get_message_header_mark());
        SERVER_MESSAGE_TAIL_MARK.get_or_init(|| *self.lynn_config.get_message_tail_mark());
    }

    /// Logs server information.
    async fn log_server(&self) {
        let subscriber = fmt::Subscriber::builder()
            .with_max_level(Level::INFO)
            .finish();
        match tracing::subscriber::set_global_default(subscriber) {
            Ok(_) => {
                info!("Server - [log server] start sucess!!!")
            }
            Err(e) => {
                warn!("set_global_default failed - e: {:?}", e.to_string())
            }
        }
    }
}