package sausage:process@0.1.0;

/// Programs share one world. These resources provide lifecycle and bounded stdio transport.
interface host {
    use wasi:io/streams@0.2.12.{input-stream, output-stream};
    use wasi:io/poll@0.2.12.{pollable};
    enum change-kind { created, modified, removed, overflow }
    record change { path: string, kind: change-kind }
    resource watcher {
        constructor(paths: list<string>);
        subscribe: func() -> pollable;
        changes: func() -> list<change>;
    }
    enum stdio { pipe, inherit, null }
    record request {
        program: string,
        argv: list<string>,
        env: list<tuple<string, string>>,
        cwd: string,
        /// None inherits the parent's group. Zero creates a group. A nonzero ID joins a group.
        group: option<u32>,
        stdin: stdio,
        stdout: stdio,
        stderr: stdio,
    }
    resource child {
        pid: func() -> u32;
        group: func() -> u32;
        stdin: func() -> output-stream;
        stdout: func() -> input-stream;
        stderr: func() -> input-stream;
        subscribe: func() -> pollable;
        status: func() -> option<s32>;
        wait: func() -> s32;
        kill: func();
    }
    spawn: func(request: request) -> result<child, string>;
    kill: func(pid: u32) -> result<_, string>;
}
world program {
    import host;
}