//! Dev backend: socket-only daemon. No FSKit, no `mount(8)`.
//!
//! Listens on `127.0.0.1:$SUBTEXT_DEV_PORT` (default `8080`). A client
//! (e.g. FSKitBridge or a local test harness) connects and drives the
//! [`Filesystem`] over the wire.

use async_trait::async_trait;
use fskit_rs::dev_session::DevSession;
use fskit_rs::{Filesystem, MountOptions};

use super::{Backend, Result};

const DEFAULT_PORT: u16 = 8080;

#[derive(Debug)]
pub struct DevBackend {
    port: u16,
    // Held for its `Drop` impl, which stops the socket.
    _session: DevSession,
}

#[async_trait]
impl Backend for DevBackend {
    async fn start<FS>(fs: FS, _opts: MountOptions) -> Result<Self>
    where
        FS: Filesystem + Send + Sync + Clone + 'static,
    {
        let port = std::env::var("SUBTEXT_DEV_PORT")
            .ok()
            .and_then(|v| v.parse().ok())
            .unwrap_or(DEFAULT_PORT);
        let session = DevSession::new(fs, port).await?;
        Ok(Self { port, _session: session })
    }

    fn describe(&self) -> String {
        format!("dev socket on 127.0.0.1:{}", self.port)
    }
}