use std::process::Stdio;

use tauri::{AppHandle, Emitter};
use tokio::io::{AsyncBufReadExt, BufReader};
use tokio::process::Command;

#[tauri::command]
pub async fn run_traceroute(app: AppHandle, ip: String) -> Result<(), String> {
    let _ = app.emit("traceroute:start", &ip);

    #[cfg(target_os = "linux")]
    let mut child = Command::new("tracepath")
        .arg("-b")
        .arg(&ip)
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .spawn()
        .map_err(|e| {
            format!(
                "Failed to start tracepath: {}. Is iputils-tracepath installed?",
                e
            )
        })?;

    #[cfg(target_os = "windows")]
    let mut child = {
        use std::os::windows::process::CommandExt;
        const CREATE_NO_WINDOW: u32 = 0x08000000;
        Command::new("tracert")
            .arg("-d")
            .arg(&ip)
            .stdout(Stdio::piped())
            .stderr(Stdio::piped())
            .creation_flags(CREATE_NO_WINDOW)
            .spawn()
            .map_err(|e| format!("Failed to start tracert: {}", e))?
    };

    let stdout = child
        .stdout
        .take()
        .ok_or_else(|| "Failed to capture stdout".to_string())?;

    let mut reader = BufReader::new(stdout).lines();

    while let Ok(Some(line)) = reader.next_line().await {
        let _ = app.emit("traceroute:hop", &line);
    }

    let status = child
        .wait()
        .await
        .map_err(|e| format!("tracepath failed: {}", e))?;

    if status.success() {
        let _ = app.emit("traceroute:complete", &ip);
    } else {
        let _ = app.emit("traceroute:error", "tracepath exited with an error");
    }

    Ok(())
}