use core::future::Future;

use crate::buffer::ByteBuffer;
use alloc::sync::Arc;
use alloc::vec::Vec;
use mammoth::cap::Capability;
use mammoth::syscall;
use mammoth::task::Spawner;
use mammoth::task::Task;
use mammoth::thread;
use mammoth::thread::JoinHandle;
use mammoth::zion::z_cap_t;
use mammoth::zion::ZError;

pub trait YunqServer {
    fn server_loop(&mut self) {
        loop {
            let mut byte_buffer = ByteBuffer::<1024>::new();
            let mut cap_buffer = vec![0; 10];
            let (_, _, reply_port_cap) = syscall::endpoint_recv(
                self.endpoint_cap(),
                byte_buffer.mut_slice(),
                &mut cap_buffer,
            )
            .expect("Failed to call endpoint recv");

            let method = byte_buffer
                .at::<u64>(8)
                .expect("Failed to access request length.");
            let resp = self.handle_request(method, &mut byte_buffer, &mut cap_buffer);
            match resp {
                Ok(resp_len) => syscall::reply_port_send(
                    reply_port_cap,
                    byte_buffer.slice(resp_len),
                    &cap_buffer,
                )
                .expect("Failed to reply"),
                Err(err) => {
                    crate::message::serialize_error(&mut byte_buffer, err);
                    syscall::reply_port_send(reply_port_cap, byte_buffer.slice(0x10), &[])
                        .expect("Failed to reply w/ error")
                }
            }
        }
    }

    fn endpoint_cap(&self) -> &Capability;

    fn create_client_cap(&self) -> Result<Capability, ZError> {
        self.endpoint_cap()
            .duplicate(!mammoth::zion::kZionPerm_Read)
    }
    fn handle_request(
        &mut self,
        method_number: u64,
        byte_buffer: &mut ByteBuffer<1024>,
        cap_buffer: &mut Vec<z_cap_t>,
    ) -> Result<usize, ZError>;
}

pub fn spawn_server_thread<T>(mut server: T) -> JoinHandle
where
    T: YunqServer + Send + 'static,
{
    thread::spawn(move || server.server_loop())
}

pub trait AsyncYunqServer
where
    Self: Send + Sync + 'static,
{
    fn server_loop(self: Arc<Self>, spawner: Spawner) {
        loop {
            let mut byte_buffer = ByteBuffer::<1024>::new();
            let mut cap_buffer = vec![0; 10];
            let (_, _, reply_port_cap) = syscall::endpoint_recv(
                self.endpoint_cap(),
                byte_buffer.mut_slice(),
                &mut cap_buffer,
            )
            .expect("Failed to call endpoint recv");

            let method = byte_buffer
                .at::<u64>(8)
                .expect("Failed to access request length.");
            let self_clone = self.clone();
            spawner.spawn(Task::new(async move {
                self_clone
                    .handle_request_and_response(method, byte_buffer, cap_buffer, reply_port_cap)
                    .await
            }));
        }
    }

    fn handle_request_and_response(
        &self,
        method: u64,
        mut byte_buffer: ByteBuffer<1024>,
        mut cap_buffer: Vec<u64>,
        reply_port_cap: Capability,
    ) -> impl Future<Output = ()> + Sync + Send {
        async move {
            let resp = self
                .handle_request(method, &mut byte_buffer, &mut cap_buffer)
                .await;

            match resp {
                Ok(resp_len) => syscall::reply_port_send(
                    reply_port_cap,
                    byte_buffer.slice(resp_len),
                    &cap_buffer,
                )
                .expect("Failed to reply"),
                Err(err) => {
                    crate::message::serialize_error(&mut byte_buffer, err);
                    syscall::reply_port_send(reply_port_cap, byte_buffer.slice(0x10), &[])
                        .expect("Failed to reply w/ error")
                }
            }
        }
    }

    fn endpoint_cap(&self) -> &Capability;

    fn create_client_cap(&self) -> Result<Capability, ZError> {
        self.endpoint_cap()
            .duplicate(!mammoth::zion::kZionPerm_Read)
    }
    fn handle_request(
        &self,
        method_number: u64,
        byte_buffer: &mut ByteBuffer<1024>,
        cap_buffer: &mut Vec<z_cap_t>,
    ) -> impl Future<Output = Result<usize, ZError>> + Sync + Send;
}

pub fn spawn_async_server_thread<T>(server: Arc<T>, spawner: Spawner) -> JoinHandle
where
    T: AsyncYunqServer + Send + Sync + 'static,
{
    thread::spawn(move || {
        server.server_loop(spawner);
    })
}