camel-bridge 0.6.0

use std::path::PathBuf;
use thiserror::Error;

#[derive(Debug, Error)]
pub enum BridgeError {
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),
    #[error("Bridge timed out: {0}")]
    Timeout(String),
    #[error("Bridge stdout closed before ready message")]
    StdoutClosed,
    #[error("Bridge ready message malformed: {0}")]
    BadReadyMessage(String),
    #[error("Download failed: {0}")]
    Download(String),
    #[error("Checksum mismatch: expected {expected}, got {actual}")]
    ChecksumMismatch { expected: String, actual: String },
    #[error("URL not allowed: {0}")]
    UrlNotAllowed(String),
    #[error("Transport error: {0}")]
    Transport(String),
}

#[derive(Debug, Clone, PartialEq, serde::Deserialize)]
#[serde(rename_all = "lowercase")]
pub enum BrokerType {
    #[serde(alias = "active_mq")]
    ActiveMq,
    Artemis,
    Generic,
}

impl BrokerType {
    pub fn as_env_str(&self) -> &'static str {
        match self {
            BrokerType::ActiveMq => "activemq",
            BrokerType::Artemis => "artemis",
            BrokerType::Generic => "generic",
        }
    }
}

impl std::str::FromStr for BrokerType {
    type Err = std::convert::Infallible;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Ok(match s.to_lowercase().as_str() {
            "activemq" => BrokerType::ActiveMq,
            "artemis" => BrokerType::Artemis,
            _ => BrokerType::Generic,
        })
    }
}

pub struct BridgeProcessConfig {
    pub binary_path: PathBuf,
    pub broker_url: String,
    pub broker_type: BrokerType,
    pub username: Option<String>,
    pub password: Option<String>,
    pub start_timeout_ms: u64,
}

pub struct BridgeProcess {
    child: tokio::process::Child,
    grpc_port: u16,
}

impl BridgeProcess {
    pub fn grpc_port(&self) -> u16 {
        self.grpc_port
    }

    /// Spawn the bridge process. Reads the gRPC port from stdout JSON line:
    ///   {"status":"ready","port":PORT}
    ///
    /// Picks a free OS port and passes it to the bridge via `QUARKUS_GRPC_SERVER_PORT`
    /// so Quarkus binds exactly to that port and PortAnnouncer can echo it back.
    pub async fn start(config: &BridgeProcessConfig) -> Result<Self, BridgeError> {
        use tokio::io::AsyncBufReadExt;
        use tokio::process::Command;
        use tokio::time::{Duration, timeout};

        // Bind :0 to let the OS pick a free port, then release so the bridge can use it.
        let free_port = {
            let listener = std::net::TcpListener::bind("127.0.0.1:0")?;
            listener.local_addr()?.port()
        };

        // If CAMEL_BRIDGE_LOG_STDERR is set, redirect stderr to a file for debugging.
        // The file path is: /tmp/jms-bridge-<pid>.log
        let stderr_stdio: std::process::Stdio =
            if let Ok(log_dir) = std::env::var("CAMEL_BRIDGE_LOG_STDERR") {
                let log_path = if log_dir.is_empty() {
                    format!("/tmp/jms-bridge-{}.log", std::process::id())
                } else {
                    format!("{}/jms-bridge-{}.log", log_dir, std::process::id())
                };
                match std::fs::File::create(&log_path) {
                    Ok(f) => {
                        eprintln!("[camel-bridge] stderr → {}", log_path);
                        f.into()
                    }
                    Err(e) => {
                        eprintln!(
                            "[camel-bridge] failed to create log file {}: {}",
                            log_path, e
                        );
                        std::process::Stdio::inherit()
                    }
                }
            } else {
                std::process::Stdio::inherit()
            };

        let mut child = Command::new(&config.binary_path)
            .env("BRIDGE_BROKER_URL", &config.broker_url)
            .env("BRIDGE_BROKER_TYPE", config.broker_type.as_env_str())
            .env("QUARKUS_GRPC_SERVER_PORT", free_port.to_string())
            // Let the OS pick a random HTTP port — we only use gRPC.
            // Without this, Quarkus binds HTTP on 8080 and fails if occupied.
            .env("QUARKUS_HTTP_PORT", "0")
            .env_opt("BRIDGE_USERNAME", &config.username)
            .env_opt("BRIDGE_PASSWORD", &config.password)
            .stdout(std::process::Stdio::piped())
            .stderr(stderr_stdio)
            .spawn()?;

        let stdout = child.stdout.take().ok_or(BridgeError::StdoutClosed)?;
        let mut reader = tokio::io::BufReader::new(stdout).lines();

        let port = timeout(Duration::from_millis(config.start_timeout_ms), async {
            while let Some(line) = reader.next_line().await? {
                if let Ok(v) = serde_json::from_str::<serde_json::Value>(&line)
                    && v.get("status").and_then(|s| s.as_str()) == Some("ready")
                {
                    if let Some(p) = v.get("port").and_then(|p| p.as_u64()) {
                        return Ok(p as u16);
                    }
                    return Err(BridgeError::BadReadyMessage(line));
                }
            }
            Err(BridgeError::StdoutClosed)
        })
        .await
        .map_err(|_| {
            BridgeError::Timeout(format!(
                "JMS bridge failed to start: health check timeout after {}ms",
                config.start_timeout_ms
            ))
        })??;

        // Keep draining the bridge's stdout in the background so the pipe
        // buffer never fills up.  If the pipe blocks, the bridge's JMS
        // MessageListener thread blocks on its next log write and silently
        // stops delivering messages after the first one.
        tokio::spawn(async move {
            while let Ok(Some(line)) = reader.next_line().await {
                tracing::debug!(target: "camel_bridge::child", "{}", line);
            }
        });

        Ok(BridgeProcess {
            child,
            grpc_port: port,
        })
    }

    /// Gracefully stop: SIGTERM + wait for exit.
    pub async fn stop(mut self) -> Result<(), BridgeError> {
        use tokio::time::{Duration, sleep};

        // Send SIGTERM first (graceful shutdown)
        #[cfg(unix)]
        {
            let pid = self.child.id().unwrap_or(0);
            if pid > 0 {
                // SAFETY: libc::kill is called with the child process PID obtained from tokio.
                unsafe {
                    libc::kill(pid as i32, libc::SIGTERM);
                }
            }
        }

        // On non-Unix (Windows), fall through to kill immediately
        #[cfg(not(unix))]
        let _ = self.child.start_kill();

        // Wait up to 5 seconds for graceful exit, then SIGKILL
        tokio::select! {
            result = self.child.wait() => {
                result?;
            }
            _ = sleep(Duration::from_secs(5)) => {
                let _ = self.child.start_kill();
                self.child.wait().await?;
            }
        }
        Ok(())
    }
}

impl Drop for BridgeProcess {
    fn drop(&mut self) {
        // Best-effort only. Does NOT wait — cannot block in Drop.
        let _ = self.child.start_kill();
    }
}

// Helper trait for optional env vars
trait CommandExt {
    fn env_opt(&mut self, key: &str, val: &Option<String>) -> &mut Self;
}
impl CommandExt for tokio::process::Command {
    fn env_opt(&mut self, key: &str, val: &Option<String>) -> &mut Self {
        if let Some(v) = val {
            self.env(key, v);
        }
        self
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn broker_type_from_str_activemq() {
        assert_eq!(
            "activemq".parse::<BrokerType>().unwrap(),
            BrokerType::ActiveMq
        );
        assert_eq!(
            "ACTIVEMQ".parse::<BrokerType>().unwrap(),
            BrokerType::ActiveMq
        );
    }

    #[test]
    fn broker_type_from_str_artemis() {
        assert_eq!(
            "artemis".parse::<BrokerType>().unwrap(),
            BrokerType::Artemis
        );
    }

    #[test]
    fn broker_type_from_str_unknown_is_generic() {
        assert_eq!("ibmmq".parse::<BrokerType>().unwrap(), BrokerType::Generic);
    }

    #[test]
    fn broker_type_env_str() {
        assert_eq!(BrokerType::ActiveMq.as_env_str(), "activemq");
        assert_eq!(BrokerType::Artemis.as_env_str(), "artemis");
        assert_eq!(BrokerType::Generic.as_env_str(), "generic");
    }
}