http-wasm-guest 0.3.0

//! library implementing the [Guest ABI](https://http-wasm.io/http-handler-abi/) for interfacing with
//! [http-wasm](https://github.com/http-wasm)
use std::{ops::BitOr, sync::OnceLock};

use host::{Request, Response};

pub mod feature;
pub mod host;

struct Handler {
    guest: Box<dyn Guest>,
}
unsafe impl Send for Handler {}
unsafe impl Sync for Handler {}

static GUEST: OnceLock<Handler> = OnceLock::new();

#[derive(Debug)]
pub struct Feature(pub i32);
impl BitOr for Feature {
    type Output = Feature;

    fn bitor(self, rhs: Self) -> Feature {
        Feature(self.0 | rhs.0)
    }
}
impl PartialEq for Feature {
    fn eq(&self, other: &Self) -> bool {
        self.0 == other.0
    }
}

pub trait Guest {
    fn handle_request(&self, _request: Request, _response: Response) -> (bool, i32) {
        (true, 0)
    }
    fn handle_response(&self, _request: Request, _response: Response) {}
}

pub fn register<T: Guest + 'static>(guest: T) {
    GUEST.get_or_init(|| Handler {
        guest: Box::new(guest),
    });
}

#[unsafe(export_name = "handle_request")]
fn http_request() -> i64 {
    let (next, ctx_next) = match GUEST.get() {
        Some(handler) => handler.guest.handle_request(Request {}, Response {}),
        None => (true, 0),
    };

    if next { (ctx_next as i64) << 32 | 1 } else { 0 }
}

#[unsafe(export_name = "handle_response")]
fn http_response(_req_ctx: i32, _is_error: i32) {
    if let Some(handler) = GUEST.get() {
        handler.guest.handle_response(Request {}, Response {})
    };
}

#[macro_export]
macro_rules! debug {
    ($($arg:tt)+) => ($crate::log!($crate::host::log::Level::Debug, $($arg)+))
}
#[macro_export]
macro_rules! info {
    ($($arg:tt)+) => ($crate::log!($crate::host::log::Level::Info, $($arg)+))
}
#[macro_export]
macro_rules! warn {
    ($($arg:tt)+) => ($crate::log!($crate::host::log::Level::Warn, $($arg)+))
}
#[macro_export]
macro_rules! log {
    // log!(Level::Info, "a log event {}", param1)
    ($lvl:expr, $($arg:tt)+) => { $crate::host::log::write($lvl, format!($($arg)+).as_str()); };
}